// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 * Copyright (C) 2003-2010  Jean Delvare <jdelvare@suse.de>
 *
 * Based on the lm83 driver. The LM90 is a sensor chip made by National
 * Semiconductor. It reports up to two temperatures (its own plus up to
 * one external one) with a 0.125 deg resolution (1 deg for local
 * temperature) and a 3-4 deg accuracy.
 *
 * This driver also supports the LM89 and LM99, two other sensor chips
 * made by National Semiconductor. Both have an increased remote
 * temperature measurement accuracy (1 degree), and the LM99
 * additionally shifts remote temperatures (measured and limits) by 16
 * degrees, which allows for higher temperatures measurement.
 * Note that there is no way to differentiate between both chips.
 * When device is auto-detected, the driver will assume an LM99.
 *
 * This driver also supports the LM86, another sensor chip made by
 * National Semiconductor. It is exactly similar to the LM90 except it
 * has a higher accuracy.
 *
 * This driver also supports the ADM1032, a sensor chip made by Analog
 * Devices. That chip is similar to the LM90, with a few differences
 * that are not handled by this driver. Among others, it has a higher
 * accuracy than the LM90, much like the LM86 does.
 *
 * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
 * chips made by Maxim. These chips are similar to the LM86.
 * Note that there is no easy way to differentiate between the three
 * variants. We use the device address to detect MAX6659, which will result
 * in a detection as max6657 if it is on address 0x4c. The extra address
 * and features of the MAX6659 are only supported if the chip is configured
 * explicitly as max6659, or if its address is not 0x4c.
 * These chips lack the remote temperature offset feature.
 *
 * This driver also supports the MAX6654 chip made by Maxim. This chip can be
 * at 9 different addresses, similar to MAX6680/MAX6681. The MAX6654 is similar
 * to MAX6657/MAX6658/MAX6659, but does not support critical temperature
 * limits. Extended range is available by setting the configuration register
 * accordingly, and is done during initialization. Extended precision is only
 * available at conversion rates of 1 Hz and slower. Note that extended
 * precision is not enabled by default, as this driver initializes all chips
 * to 2 Hz by design. The driver also supports MAX6690, which is practically
 * identical to MAX6654.
 *
 * This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
 * MAX6692 chips made by Maxim.  These are again similar to the LM86,
 * but they use unsigned temperature values and can report temperatures
 * from 0 to 145 degrees.
 *
 * This driver also supports the MAX6680 and MAX6681, two other sensor
 * chips made by Maxim. These are quite similar to the other Maxim
 * chips. The MAX6680 and MAX6681 only differ in the pinout so they can
 * be treated identically.
 *
 * This driver also supports the MAX6695 and MAX6696, two other sensor
 * chips made by Maxim. These are also quite similar to other Maxim
 * chips, but support three temperature sensors instead of two. MAX6695
 * and MAX6696 only differ in the pinout so they can be treated identically.
 *
 * This driver also supports ADT7461 and ADT7461A from Analog Devices as well as
 * NCT1008 from ON Semiconductor. The chips are supported in both compatibility
 * and extended mode. They are mostly compatible with LM90 except for a data
 * format difference for the temperature value registers.
 *
 * This driver also supports ADT7481, ADT7482, and ADT7483 from Analog Devices
 * / ON Semiconductor. The chips are similar to ADT7461 but support two external
 * temperature sensors.
 *
 * This driver also supports NCT72, NCT214, and NCT218 from ON Semiconductor.
 * The chips are similar to ADT7461/ADT7461A but have full PEC support
 * (undocumented).
 *
 * This driver also supports the SA56004 from Philips. This device is
 * pin-compatible with the LM86, the ED/EDP parts are also address-compatible.
 *
 * This driver also supports the G781 from GMT. This device is compatible
 * with the ADM1032.
 *
 * This driver also supports TMP451 and TMP461 from Texas Instruments.
 * Those devices are supported in both compatibility and extended mode.
 * They are mostly compatible with ADT7461 except for local temperature
 * low byte register and max conversion rate.
 *
 * This driver also supports MAX1617 and various clones such as G767
 * and NE1617. Such clones will be detected as MAX1617.
 *
 * This driver also supports NE1618 from Philips. It is similar to NE1617
 * but supports 11 bit external temperature values.
 *
 * This driver also supports NCT7716, NCT7717 and NCT7718 from Nuvoton.
 * The NCT7716 is similar to NCT7717 but has one more address support.
 *
 * Since the LM90 was the first chipset supported by this driver, most
 * comments will refer to this chipset, but are actually general and
 * concern all supported chipsets, unless mentioned otherwise.
 */

#include <linux/bits.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/hwmon.h>
#include <linux/kstrtox.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

/* The maximum number of channels currently supported */
#define MAX_CHANNELS    3

/*
 * Addresses to scan
 * Address is fully defined internally and cannot be changed except for
 * MAX6659, MAX6680 and MAX6681.
 * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
 * MAX6657, MAX6658, NCT1008, NCT7718 and W83L771 have address 0x4c.
 * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
 * have address 0x4d.
 * MAX6647 has address 0x4e.
 * MAX6659 can have address 0x4c, 0x4d or 0x4e.
 * MAX6654, MAX6680, and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29,
 * 0x2a, 0x2b, 0x4c, 0x4d or 0x4e.
 * NCT7716 can have address 0x48 or 0x49.
 * NCT7717 has address 0x48.
 * SA56004 can have address 0x48 through 0x4F.
 */

static const unsigned short normal_i2c[] = {
        0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
        0x4d, 0x4e, 0x4f, I2C_CLIENT_END };

enum chips { adm1023, adm1032, adt7461, adt7461a, adt7481,
        g781, lm84, lm90, lm99,
        max1617, max6642, max6646, max6648, max6654, max6657, max6659, max6680, max6696,
        nct210, nct72, nct7716, nct7717, nct7718, ne1618, sa56004, tmp451, tmp461, w83l771,
};

/*
 * The LM90 registers
 */

#define LM90_REG_MAN_ID                 0xFE
#define LM90_REG_CHIP_ID                0xFF
#define LM90_REG_CONFIG1                0x03
#define LM90_REG_CONFIG2                0xBF
#define LM90_REG_CONVRATE               0x04
#define LM90_REG_STATUS                 0x02
#define LM90_REG_LOCAL_TEMP             0x00
#define LM90_REG_LOCAL_HIGH             0x05
#define LM90_REG_LOCAL_LOW              0x06
#define LM90_REG_LOCAL_CRIT             0x20
#define LM90_REG_REMOTE_TEMPH           0x01
#define LM90_REG_REMOTE_TEMPL           0x10
#define LM90_REG_REMOTE_OFFSH           0x11
#define LM90_REG_REMOTE_OFFSL           0x12
#define LM90_REG_REMOTE_HIGHH           0x07
#define LM90_REG_REMOTE_HIGHL           0x13
#define LM90_REG_REMOTE_LOWH            0x08
#define LM90_REG_REMOTE_LOWL            0x14
#define LM90_REG_REMOTE_CRIT            0x19
#define LM90_REG_TCRIT_HYST             0x21

/* MAX6646/6647/6649/6654/6657/6658/6659/6695/6696 registers */

#define MAX6657_REG_LOCAL_TEMPL         0x11
#define MAX6696_REG_STATUS2             0x12
#define MAX6659_REG_REMOTE_EMERG        0x16
#define MAX6659_REG_LOCAL_EMERG         0x17

/*  SA56004 registers */

#define SA56004_REG_LOCAL_TEMPL         0x22

#define LM90_MAX_CONVRATE_MS    16000   /* Maximum conversion rate in ms */

/* TMP451/TMP461 registers */
#define TMP451_REG_LOCAL_TEMPL          0x15
#define TMP451_REG_CONALERT             0x22

#define TMP461_REG_CHEN                 0x16
#define TMP461_REG_DFC                  0x24

/* ADT7481 registers */
#define ADT7481_REG_STATUS2             0x23
#define ADT7481_REG_CONFIG2             0x24

#define ADT7481_REG_MAN_ID              0x3e
#define ADT7481_REG_CHIP_ID             0x3d

/* NCT7716/7717/7718 registers */
#define NCT7716_REG_CHIP_ID             0xFD

/* Device features */
#define LM90_HAVE_EXTENDED_TEMP BIT(0)  /* extended temperature support */
#define LM90_HAVE_OFFSET        BIT(1)  /* temperature offset register  */
#define LM90_HAVE_UNSIGNED_TEMP BIT(2)  /* temperatures are unsigned    */
#define LM90_HAVE_REM_LIMIT_EXT BIT(3)  /* extended remote limit        */
#define LM90_HAVE_EMERGENCY     BIT(4)  /* 3rd upper (emergency) limit  */
#define LM90_HAVE_EMERGENCY_ALARM BIT(5)/* emergency alarm              */
#define LM90_HAVE_TEMP3         BIT(6)  /* 3rd temperature sensor       */
#define LM90_HAVE_BROKEN_ALERT  BIT(7)  /* Broken alert                 */
#define LM90_PAUSE_FOR_CONFIG   BIT(8)  /* Pause conversion for config  */
#define LM90_HAVE_CRIT          BIT(9)  /* Chip supports CRIT/OVERT register    */
#define LM90_HAVE_CRIT_ALRM_SWP BIT(10) /* critical alarm bits swapped  */
#define LM90_HAVE_PEC           BIT(11) /* Chip supports PEC            */
#define LM90_HAVE_PARTIAL_PEC   BIT(12) /* Partial PEC support (adm1032)*/
#define LM90_HAVE_ALARMS        BIT(13) /* Create 'alarms' attribute    */
#define LM90_HAVE_EXT_UNSIGNED  BIT(14) /* extended unsigned temperature*/
#define LM90_HAVE_LOW           BIT(15) /* low limits                   */
#define LM90_HAVE_CONVRATE      BIT(16) /* conversion rate              */
#define LM90_HAVE_REMOTE_EXT    BIT(17) /* extended remote temperature  */
#define LM90_HAVE_FAULTQUEUE    BIT(18) /* configurable samples count   */

/* LM90 status */
#define LM90_STATUS_LTHRM       BIT(0)  /* local THERM limit tripped */
#define LM90_STATUS_RTHRM       BIT(1)  /* remote THERM limit tripped */
#define LM90_STATUS_ROPEN       BIT(2)  /* remote is an open circuit */
#define LM90_STATUS_RLOW        BIT(3)  /* remote low temp limit tripped */
#define LM90_STATUS_RHIGH       BIT(4)  /* remote high temp limit tripped */
#define LM90_STATUS_LLOW        BIT(5)  /* local low temp limit tripped */
#define LM90_STATUS_LHIGH       BIT(6)  /* local high temp limit tripped */
#define LM90_STATUS_BUSY        BIT(7)  /* conversion is ongoing */

/* MAX6695/6696 and ADT7481 2nd status register */
#define MAX6696_STATUS2_R2THRM  BIT(1)  /* remote2 THERM limit tripped */
#define MAX6696_STATUS2_R2OPEN  BIT(2)  /* remote2 is an open circuit */
#define MAX6696_STATUS2_R2LOW   BIT(3)  /* remote2 low temp limit tripped */
#define MAX6696_STATUS2_R2HIGH  BIT(4)  /* remote2 high temp limit tripped */
#define MAX6696_STATUS2_ROT2    BIT(5)  /* remote emergency limit tripped */
#define MAX6696_STATUS2_R2OT2   BIT(6)  /* remote2 emergency limit tripped */
#define MAX6696_STATUS2_LOT2    BIT(7)  /* local emergency limit tripped */

/*
 * Driver data (common to all clients)
 */

static const struct i2c_device_id lm90_id[] = {
        { .name = "adm1020", .driver_data = max1617 },
        { .name = "adm1021", .driver_data = max1617 },
        { .name = "adm1023", .driver_data = adm1023 },
        { .name = "adm1032", .driver_data = adm1032 },
        { .name = "adt7421", .driver_data = adt7461a },
        { .name = "adt7461", .driver_data = adt7461 },
        { .name = "adt7461a", .driver_data = adt7461a },
        { .name = "adt7481", .driver_data = adt7481 },
        { .name = "adt7482", .driver_data = adt7481 },
        { .name = "adt7483a", .driver_data = adt7481 },
        { .name = "g781", .driver_data = g781 },
        { .name = "gl523sm", .driver_data = max1617 },
        { .name = "lm84", .driver_data = lm84 },
        { .name = "lm86", .driver_data = lm90 },
        { .name = "lm89", .driver_data = lm90 },
        { .name = "lm90", .driver_data = lm90 },
        { .name = "lm99", .driver_data = lm99 },
        { .name = "max1617", .driver_data = max1617 },
        { .name = "max6642", .driver_data = max6642 },
        { .name = "max6646", .driver_data = max6646 },
        { .name = "max6647", .driver_data = max6646 },
        { .name = "max6648", .driver_data = max6648 },
        { .name = "max6649", .driver_data = max6646 },
        { .name = "max6654", .driver_data = max6654 },
        { .name = "max6657", .driver_data = max6657 },
        { .name = "max6658", .driver_data = max6657 },
        { .name = "max6659", .driver_data = max6659 },
        { .name = "max6680", .driver_data = max6680 },
        { .name = "max6681", .driver_data = max6680 },
        { .name = "max6690", .driver_data = max6654 },
        { .name = "max6692", .driver_data = max6648 },
        { .name = "max6695", .driver_data = max6696 },
        { .name = "max6696", .driver_data = max6696 },
        { .name = "mc1066", .driver_data = max1617 },
        { .name = "nct1008", .driver_data = adt7461a },
        { .name = "nct210", .driver_data = nct210 },
        { .name = "nct214", .driver_data = nct72 },
        { .name = "nct218", .driver_data = nct72 },
        { .name = "nct72", .driver_data = nct72 },
        { .name = "nct7716", .driver_data = nct7716 },
        { .name = "nct7717", .driver_data = nct7717 },
        { .name = "nct7718", .driver_data = nct7718 },
        { .name = "ne1618", .driver_data = ne1618 },
        { .name = "w83l771", .driver_data = w83l771 },
        { .name = "sa56004", .driver_data = sa56004 },
        { .name = "thmc10", .driver_data = max1617 },
        { .name = "tmp451", .driver_data = tmp451 },
        { .name = "tmp461", .driver_data = tmp461 },
        { }
};
MODULE_DEVICE_TABLE(i2c, lm90_id);

static const struct of_device_id __maybe_unused lm90_of_match[] = {
        {
                .compatible = "adi,adm1032",
                .data = (void *)adm1032
        },
        {
                .compatible = "adi,adt7461",
                .data = (void *)adt7461
        },
        {
                .compatible = "adi,adt7461a",
                .data = (void *)adt7461a
        },
        {
                .compatible = "adi,adt7481",
                .data = (void *)adt7481
        },
        {
                .compatible = "gmt,g781",
                .data = (void *)g781
        },
        {
                .compatible = "national,lm90",
                .data = (void *)lm90
        },
        {
                .compatible = "national,lm86",
                .data = (void *)lm90
        },
        {
                .compatible = "national,lm89",
                .data = (void *)lm90
        },
        {
                .compatible = "national,lm99",
                .data = (void *)lm99
        },
        {
                .compatible = "dallas,max6646",
                .data = (void *)max6646
        },
        {
                .compatible = "dallas,max6647",
                .data = (void *)max6646
        },
        {
                .compatible = "dallas,max6649",
                .data = (void *)max6646
        },
        {
                .compatible = "dallas,max6654",
                .data = (void *)max6654
        },
        {
                .compatible = "dallas,max6657",
                .data = (void *)max6657
        },
        {
                .compatible = "dallas,max6658",
                .data = (void *)max6657
        },
        {
                .compatible = "dallas,max6659",
                .data = (void *)max6659
        },
        {
                .compatible = "dallas,max6680",
                .data = (void *)max6680
        },
        {
                .compatible = "dallas,max6681",
                .data = (void *)max6680
        },
        {
                .compatible = "dallas,max6695",
                .data = (void *)max6696
        },
        {
                .compatible = "dallas,max6696",
                .data = (void *)max6696
        },
        {
                .compatible = "onnn,nct1008",
                .data = (void *)adt7461a
        },
        {
                .compatible = "onnn,nct214",
                .data = (void *)nct72
        },
        {
                .compatible = "onnn,nct218",
                .data = (void *)nct72
        },
        {
                .compatible = "onnn,nct72",
                .data = (void *)nct72
        },
        {
                .compatible = "nuvoton,nct7716",
                .data = (void *)nct7716
        },
        {
                .compatible = "nuvoton,nct7717",
                .data = (void *)nct7717
        },
        {
                .compatible = "nuvoton,nct7718",
                .data = (void *)nct7718
        },
        {
                .compatible = "winbond,w83l771",
                .data = (void *)w83l771
        },
        {
                .compatible = "nxp,sa56004",
                .data = (void *)sa56004
        },
        {
                .compatible = "ti,tmp451",
                .data = (void *)tmp451
        },
        {
                .compatible = "ti,tmp461",
                .data = (void *)tmp461
        },
        { },
};
MODULE_DEVICE_TABLE(of, lm90_of_match);

/*
 * chip type specific parameters
 */
struct lm90_params {
        u32 flags;              /* Capabilities */
        u16 alert_alarms;       /* Which alarm bits trigger ALERT# */
                                /* Upper 8 bits for max6695/96 */
        u8 max_convrate;        /* Maximum conversion rate register value */
        u8 resolution;          /* 16-bit resolution (default 11 bit) */
        u8 reg_status2;         /* 2nd status register (optional) */
        u8 reg_local_ext;       /* Extended local temp register (optional) */
        u8 faultqueue_mask;     /* fault queue bit mask */
        u8 faultqueue_depth;    /* fault queue depth if mask is used */
};

static const struct lm90_params lm90_params[] = {
        [adm1023] = {
                .flags = LM90_HAVE_ALARMS | LM90_HAVE_OFFSET | LM90_HAVE_BROKEN_ALERT
                  | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .resolution = 8,
                .max_convrate = 7,
        },
        [adm1032] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_CRIT
                  | LM90_HAVE_PARTIAL_PEC | LM90_HAVE_ALARMS
                  | LM90_HAVE_LOW | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT
                  | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7c,
                .max_convrate = 10,
        },
        [adt7461] = {
                /*
                 * Standard temperature range is supposed to be unsigned,
                 * but that does not match reality. Negative temperatures
                 * are always reported.
                 */
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP
                  | LM90_HAVE_CRIT | LM90_HAVE_PARTIAL_PEC
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7c,
                .max_convrate = 10,
                .resolution = 10,
        },
        [adt7461a] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP
                  | LM90_HAVE_CRIT | LM90_HAVE_PEC | LM90_HAVE_ALARMS
                  | LM90_HAVE_LOW | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT
                  | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7c,
                .max_convrate = 10,
        },
        [adt7481] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP
                  | LM90_HAVE_UNSIGNED_TEMP | LM90_HAVE_PEC
                  | LM90_HAVE_TEMP3 | LM90_HAVE_CRIT | LM90_HAVE_LOW
                  | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT
                  | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x1c7c,
                .max_convrate = 11,
                .resolution = 10,
                .reg_status2 = ADT7481_REG_STATUS2,
        },
        [g781] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7c,
                .max_convrate = 7,
        },
        [lm84] = {
                .flags = LM90_HAVE_ALARMS,
                .resolution = 8,
        },
        [lm90] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_CRIT | LM90_HAVE_ALARMS | LM90_HAVE_LOW
                  | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT
                  | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7b,
                .max_convrate = 9,
                .faultqueue_mask = BIT(0),
                .faultqueue_depth = 3,
        },
        [lm99] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_CRIT | LM90_HAVE_ALARMS | LM90_HAVE_LOW
                  | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT
                  | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7b,
                .max_convrate = 9,
                .faultqueue_mask = BIT(0),
                .faultqueue_depth = 3,
        },
        [max1617] = {
                .flags = LM90_HAVE_CONVRATE | LM90_HAVE_BROKEN_ALERT |
                  LM90_HAVE_LOW | LM90_HAVE_ALARMS,
                .alert_alarms = 0x78,
                .resolution = 8,
                .max_convrate = 7,
        },
        [max6642] = {
                .flags = LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXT_UNSIGNED
                  | LM90_HAVE_REMOTE_EXT | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x50,
                .resolution = 10,
                .reg_local_ext = MAX6657_REG_LOCAL_TEMPL,
                .faultqueue_mask = BIT(4),
                .faultqueue_depth = 2,
        },
        [max6646] = {
                .flags = LM90_HAVE_CRIT | LM90_HAVE_BROKEN_ALERT
                  | LM90_HAVE_EXT_UNSIGNED | LM90_HAVE_ALARMS | LM90_HAVE_LOW
                  | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .max_convrate = 6,
                .reg_local_ext = MAX6657_REG_LOCAL_TEMPL,
        },
        [max6648] = {
                .flags = LM90_HAVE_UNSIGNED_TEMP | LM90_HAVE_CRIT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_LOW
                  | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .max_convrate = 6,
                .reg_local_ext = MAX6657_REG_LOCAL_TEMPL,
        },
        [max6654] = {
                .flags = LM90_HAVE_BROKEN_ALERT | LM90_HAVE_ALARMS | LM90_HAVE_LOW
                  | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .max_convrate = 7,
                .reg_local_ext = MAX6657_REG_LOCAL_TEMPL,
        },
        [max6657] = {
                .flags = LM90_PAUSE_FOR_CONFIG | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .max_convrate = 8,
                .reg_local_ext = MAX6657_REG_LOCAL_TEMPL,
        },
        [max6659] = {
                .flags = LM90_HAVE_EMERGENCY | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .max_convrate = 8,
                .reg_local_ext = MAX6657_REG_LOCAL_TEMPL,
        },
        [max6680] = {
                /*
                 * Apparent temperatures of 128 degrees C or higher are reported
                 * and treated as negative temperatures (meaning min_alarm will
                 * be set).
                 */
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_CRIT
                  | LM90_HAVE_CRIT_ALRM_SWP | LM90_HAVE_BROKEN_ALERT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .max_convrate = 7,
        },
        [max6696] = {
                .flags = LM90_HAVE_EMERGENCY
                  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3 | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x1c7c,
                .max_convrate = 6,
                .reg_status2 = MAX6696_REG_STATUS2,
                .reg_local_ext = MAX6657_REG_LOCAL_TEMPL,
                .faultqueue_mask = BIT(5),
                .faultqueue_depth = 4,
        },
        [nct72] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP
                  | LM90_HAVE_CRIT | LM90_HAVE_PEC | LM90_HAVE_UNSIGNED_TEMP
                  | LM90_HAVE_LOW | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT
                  | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7c,
                .max_convrate = 10,
                .resolution = 10,
        },
        [nct210] = {
                .flags = LM90_HAVE_ALARMS | LM90_HAVE_BROKEN_ALERT
                  | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .resolution = 11,
                .max_convrate = 7,
        },
        [nct7716] = {
                .flags = LM90_HAVE_ALARMS | LM90_HAVE_CONVRATE,
                .alert_alarms = 0x40,
                .resolution = 8,
                .max_convrate = 8,
        },
        [nct7717] = {
                .flags = LM90_HAVE_ALARMS | LM90_HAVE_CONVRATE,
                .alert_alarms = 0x40,
                .resolution = 8,
                .max_convrate = 8,
        },
        [nct7718] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .resolution = 11,
                .max_convrate = 8,
        },
        [ne1618] = {
                .flags = LM90_PAUSE_FOR_CONFIG | LM90_HAVE_BROKEN_ALERT
                  | LM90_HAVE_LOW | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .resolution = 11,
                .max_convrate = 7,
        },
        [w83l771] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT,
                .alert_alarms = 0x7c,
                .max_convrate = 8,
        },
        [sa56004] = {
                /*
                 * Apparent temperatures of 128 degrees C or higher are reported
                 * and treated as negative temperatures (meaning min_alarm will
                 * be set).
                 */
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7b,
                .max_convrate = 9,
                .reg_local_ext = SA56004_REG_LOCAL_TEMPL,
                .faultqueue_mask = BIT(0),
                .faultqueue_depth = 3,
        },
        [tmp451] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP | LM90_HAVE_CRIT
                  | LM90_HAVE_UNSIGNED_TEMP | LM90_HAVE_ALARMS | LM90_HAVE_LOW
                  | LM90_HAVE_CONVRATE | LM90_HAVE_REMOTE_EXT | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7c,
                .max_convrate = 9,
                .resolution = 12,
                .reg_local_ext = TMP451_REG_LOCAL_TEMPL,
        },
        [tmp461] = {
                .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
                  | LM90_HAVE_BROKEN_ALERT | LM90_HAVE_EXTENDED_TEMP | LM90_HAVE_CRIT
                  | LM90_HAVE_ALARMS | LM90_HAVE_LOW | LM90_HAVE_CONVRATE
                  | LM90_HAVE_REMOTE_EXT | LM90_HAVE_FAULTQUEUE,
                .alert_alarms = 0x7c,
                .max_convrate = 9,
                .resolution = 12,
                .reg_local_ext = TMP451_REG_LOCAL_TEMPL,
        },
};

/*
 * temperature register index
 */
enum lm90_temp_reg_index {
        LOCAL_LOW = 0,
        LOCAL_HIGH,
        LOCAL_CRIT,
        REMOTE_CRIT,
        LOCAL_EMERG,    /* max6659 and max6695/96 */
        REMOTE_EMERG,   /* max6659 and max6695/96 */
        REMOTE2_CRIT,   /* max6695/96 only */
        REMOTE2_EMERG,  /* max6695/96 only */

        REMOTE_TEMP,
        REMOTE_LOW,
        REMOTE_HIGH,
        REMOTE_OFFSET,  /* except max6646, max6657/58/59, and max6695/96 */
        LOCAL_TEMP,
        REMOTE2_TEMP,   /* max6695/96 only */
        REMOTE2_LOW,    /* max6695/96 only */
        REMOTE2_HIGH,   /* max6695/96 only */
        REMOTE2_OFFSET,

        TEMP_REG_NUM
};

/*
 * Client data (each client gets its own)
 */

struct lm90_data {
        struct i2c_client *client;
        struct device *hwmon_dev;
        u32 chip_config[2];
        u32 channel_config[MAX_CHANNELS + 1];
        const char *channel_label[MAX_CHANNELS];
        struct hwmon_channel_info chip_info;
        struct hwmon_channel_info temp_info;
        const struct hwmon_channel_info *info[3];
        struct hwmon_chip_info chip;
        struct delayed_work alert_work;
        struct work_struct report_work;
        bool shutdown;          /* true if shutting down */
        bool valid;             /* true if register values are valid */
        bool alarms_valid;      /* true if status register values are valid */
        unsigned long last_updated; /* in jiffies */
        unsigned long alarms_updated; /* in jiffies */
        int kind;
        u32 flags;

        unsigned int update_interval; /* in milliseconds */

        u8 config;              /* Current configuration register value */
        u8 config_orig;         /* Original configuration register value */
        u8 convrate_orig;       /* Original conversion rate register value */
        u8 resolution;          /* temperature resolution in bit */
        u16 alert_alarms;       /* Which alarm bits trigger ALERT# */
                                /* Upper 8 bits for max6695/96 */
        u8 max_convrate;        /* Maximum conversion rate */
        u8 reg_status2;         /* 2nd status register (optional) */
        u8 reg_local_ext;       /* local extension register offset */
        u8 reg_remote_ext;      /* remote temperature low byte */
        u8 faultqueue_mask;     /* fault queue mask */
        u8 faultqueue_depth;    /* fault queue mask */

        /* registers values */
        u16 temp[TEMP_REG_NUM];
        u8 temp_hyst;
        u8 conalert;
        u16 reported_alarms;    /* alarms reported as sysfs/udev events */
        u16 current_alarms;     /* current alarms, reported by chip */
        u16 alarms;             /* alarms not yet reported to user */
};

/*
 * Support functions
 */

/*
 * If the chip supports PEC but not on write byte transactions, we need
 * to explicitly ask for a transaction without PEC.
 */
static inline s32 lm90_write_no_pec(struct i2c_client *client, u8 value)
{
        return i2c_smbus_xfer(client->adapter, client->addr,
                              client->flags & ~I2C_CLIENT_PEC,
                              I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
}

/*
 * It is assumed that client->update_lock is held (unless we are in
 * detection or initialization steps). This matters when PEC is enabled
 * for chips with partial PEC support, because we don't want the address
 * pointer to change between the write byte and the read byte transactions.
 */
static int lm90_read_reg(struct i2c_client *client, u8 reg)
{
        struct lm90_data *data = i2c_get_clientdata(client);
        bool partial_pec = (client->flags & I2C_CLIENT_PEC) &&
                        (data->flags & LM90_HAVE_PARTIAL_PEC);
        int err;

        if (partial_pec) {
                err = lm90_write_no_pec(client, reg);
                if (err)
                        return err;
                return i2c_smbus_read_byte(client);
        }
        return i2c_smbus_read_byte_data(client, reg);
}

/*
 * Return register write address
 *
 * The write address for registers 0x03 .. 0x08 is the read address plus 6.
 * For other registers the write address matches the read address.
 */
static u8 lm90_write_reg_addr(u8 reg)
{
        if (reg >= LM90_REG_CONFIG1 && reg <= LM90_REG_REMOTE_LOWH)
                return reg + 6;
        return reg;
}

/*
 * Write into LM90 register.
 * Convert register address to write address if needed, then execute the
 * operation.
 */
static int lm90_write_reg(struct i2c_client *client, u8 reg, u8 val)
{
        return i2c_smbus_write_byte_data(client, lm90_write_reg_addr(reg), val);
}

/*
 * Write into 16-bit LM90 register.
 * Convert register addresses to write address if needed, then execute the
 * operation.
 */
static int lm90_write16(struct i2c_client *client, u8 regh, u8 regl, u16 val)
{
        int ret;

        ret = lm90_write_reg(client, regh, val >> 8);
        if (ret < 0 || !regl)
                return ret;
        return lm90_write_reg(client, regl, val & 0xff);
}

static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl,
                       bool is_volatile)
{
        int oldh, newh, l;

        oldh = lm90_read_reg(client, regh);
        if (oldh < 0)
                return oldh;

        if (!regl)
                return oldh << 8;

        l = lm90_read_reg(client, regl);
        if (l < 0)
                return l;

        if (!is_volatile)
                return (oldh << 8) | l;

        /*
         * For volatile registers we have to use a trick.
         * We have to read two registers to have the sensor temperature,
         * but we have to beware a conversion could occur between the
         * readings. The datasheet says we should either use
         * the one-shot conversion register, which we don't want to do
         * (disables hardware monitoring) or monitor the busy bit, which is
         * impossible (we can't read the values and monitor that bit at the
         * exact same time). So the solution used here is to read the high
         * the high byte again. If the new high byte matches the old one,
         * then we have a valid reading. Otherwise we have to read the low
         * byte again, and now we believe we have a correct reading.
         */
        newh = lm90_read_reg(client, regh);
        if (newh < 0)
                return newh;
        if (oldh != newh) {
                l = lm90_read_reg(client, regl);
                if (l < 0)
                        return l;
        }
        return (newh << 8) | l;
}

static int lm90_update_confreg(struct lm90_data *data, u8 config)
{
        if (data->config != config) {
                int err;

                err = lm90_write_reg(data->client, LM90_REG_CONFIG1, config);
                if (err)
                        return err;
                data->config = config;
        }
        return 0;
}

/*
 * client->update_lock must be held when calling this function (unless we are
 * in detection or initialization steps), and while a remote channel other
 * than channel 0 is selected. Also, calling code must make sure to re-select
 * external channel 0 before releasing the lock. This is necessary because
 * various registers have different meanings as a result of selecting a
 * non-default remote channel.
 */
static int lm90_select_remote_channel(struct lm90_data *data, bool second)
{
        u8 config = data->config & ~0x08;

        if (second)
                config |= 0x08;

        return lm90_update_confreg(data, config);
}

static int lm90_write_convrate(struct lm90_data *data, int val)
{
        u8 config = data->config;
        int err;

        /* Save config and pause conversion */
        if (data->flags & LM90_PAUSE_FOR_CONFIG) {
                err = lm90_update_confreg(data, config | 0x40);
                if (err < 0)
                        return err;
        }

        /* Set conv rate */
        err = lm90_write_reg(data->client, LM90_REG_CONVRATE, val);

        /* Revert change to config */
        lm90_update_confreg(data, config);

        return err;
}

/*
 * Set conversion rate.
 * client->update_lock must be held when calling this function (unless we are
 * in detection or initialization steps).
 */
static int lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
                             unsigned int interval)
{
        unsigned int update_interval;
        int i, err;

        /* Shift calculations to avoid rounding errors */
        interval <<= 6;

        /* find the nearest update rate */
        for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
             i < data->max_convrate; i++, update_interval >>= 1)
                if (interval >= update_interval * 3 / 4)
                        break;

        err = lm90_write_convrate(data, i);
        data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
        return err;
}

static int lm90_set_faultqueue(struct i2c_client *client,
                               struct lm90_data *data, int val)
{
        int err;

        if (data->faultqueue_mask) {
                err = lm90_update_confreg(data, val <= data->faultqueue_depth / 2 ?
                                          data->config & ~data->faultqueue_mask :
                                          data->config | data->faultqueue_mask);
        } else {
                static const u8 values[4] = {0, 2, 6, 0x0e};

                data->conalert = (data->conalert & 0xf1) | values[val - 1];
                err = lm90_write_reg(data->client, TMP451_REG_CONALERT,
                                     data->conalert);
        }

        return err;
}

static int lm90_update_limits(struct device *dev)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        int val;

        if (data->flags & LM90_HAVE_CRIT) {
                val = lm90_read_reg(client, LM90_REG_LOCAL_CRIT);
                if (val < 0)
                        return val;
                data->temp[LOCAL_CRIT] = val << 8;

                val = lm90_read_reg(client, LM90_REG_REMOTE_CRIT);
                if (val < 0)
                        return val;
                data->temp[REMOTE_CRIT] = val << 8;

                val = lm90_read_reg(client, LM90_REG_TCRIT_HYST);
                if (val < 0)
                        return val;
                data->temp_hyst = val;
        }
        if ((data->flags & LM90_HAVE_FAULTQUEUE) && !data->faultqueue_mask) {
                val = lm90_read_reg(client, TMP451_REG_CONALERT);
                if (val < 0)
                        return val;
                data->conalert = val;
        }

        val = lm90_read16(client, LM90_REG_REMOTE_LOWH,
                          (data->flags & LM90_HAVE_REM_LIMIT_EXT) ? LM90_REG_REMOTE_LOWL : 0,
                          false);
        if (val < 0)
                return val;
        data->temp[REMOTE_LOW] = val;

        val = lm90_read16(client, LM90_REG_REMOTE_HIGHH,
                          (data->flags & LM90_HAVE_REM_LIMIT_EXT) ? LM90_REG_REMOTE_HIGHL : 0,
                          false);
        if (val < 0)
                return val;
        data->temp[REMOTE_HIGH] = val;

        if (data->flags & LM90_HAVE_OFFSET) {
                val = lm90_read16(client, LM90_REG_REMOTE_OFFSH,
                                  LM90_REG_REMOTE_OFFSL, false);
                if (val < 0)
                        return val;
                data->temp[REMOTE_OFFSET] = val;
        }

        if (data->flags & LM90_HAVE_EMERGENCY) {
                val = lm90_read_reg(client, MAX6659_REG_LOCAL_EMERG);
                if (val < 0)
                        return val;
                data->temp[LOCAL_EMERG] = val << 8;

                val = lm90_read_reg(client, MAX6659_REG_REMOTE_EMERG);
                if (val < 0)
                        return val;
                data->temp[REMOTE_EMERG] = val << 8;
        }

        if (data->flags & LM90_HAVE_TEMP3) {
                val = lm90_select_remote_channel(data, true);
                if (val < 0)
                        return val;

                val = lm90_read_reg(client, LM90_REG_REMOTE_CRIT);
                if (val < 0)
                        return val;
                data->temp[REMOTE2_CRIT] = val << 8;

                if (data->flags & LM90_HAVE_EMERGENCY) {
                        val = lm90_read_reg(client, MAX6659_REG_REMOTE_EMERG);
                        if (val < 0)
                                return val;
                        data->temp[REMOTE2_EMERG] = val << 8;
                }

                val = lm90_read_reg(client, LM90_REG_REMOTE_LOWH);
                if (val < 0)
                        return val;
                data->temp[REMOTE2_LOW] = val << 8;

                val = lm90_read_reg(client, LM90_REG_REMOTE_HIGHH);
                if (val < 0)
                        return val;
                data->temp[REMOTE2_HIGH] = val << 8;

                if (data->flags & LM90_HAVE_OFFSET) {
                        val = lm90_read16(client, LM90_REG_REMOTE_OFFSH,
                                          LM90_REG_REMOTE_OFFSL, false);
                        if (val < 0)
                                return val;
                        data->temp[REMOTE2_OFFSET] = val;
                }

                lm90_select_remote_channel(data, false);
        }

        return 0;
}

static void lm90_report_alarms(struct work_struct *work)
{
        struct lm90_data *data = container_of(work, struct lm90_data, report_work);
        u16 cleared_alarms, new_alarms, current_alarms;
        struct device *hwmon_dev = data->hwmon_dev;
        struct device *dev = &data->client->dev;
        int st, st2;

        current_alarms = data->current_alarms;
        cleared_alarms = data->reported_alarms & ~current_alarms;
        new_alarms = current_alarms & ~data->reported_alarms;

        if (!cleared_alarms && !new_alarms)
                return;

        st = new_alarms & 0xff;
        st2 = new_alarms >> 8;

        if ((st & (LM90_STATUS_LLOW | LM90_STATUS_LHIGH | LM90_STATUS_LTHRM)) ||
            (st2 & MAX6696_STATUS2_LOT2))
                dev_dbg(dev, "temp%d out of range, please check!\n", 1);
        if ((st & (LM90_STATUS_RLOW | LM90_STATUS_RHIGH | LM90_STATUS_RTHRM)) ||
            (st2 & MAX6696_STATUS2_ROT2))
                dev_dbg(dev, "temp%d out of range, please check!\n", 2);
        if (st & LM90_STATUS_ROPEN)
                dev_dbg(dev, "temp%d diode open, please check!\n", 2);
        if (st2 & (MAX6696_STATUS2_R2LOW | MAX6696_STATUS2_R2HIGH |
                   MAX6696_STATUS2_R2THRM | MAX6696_STATUS2_R2OT2))
                dev_dbg(dev, "temp%d out of range, please check!\n", 3);
        if (st2 & MAX6696_STATUS2_R2OPEN)
                dev_dbg(dev, "temp%d diode open, please check!\n", 3);

        st |= cleared_alarms & 0xff;
        st2 |= cleared_alarms >> 8;

        if (st & LM90_STATUS_LLOW)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_min_alarm, 0);
        if (st & LM90_STATUS_RLOW)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_min_alarm, 1);
        if (st2 & MAX6696_STATUS2_R2LOW)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_min_alarm, 2);

        if (st & LM90_STATUS_LHIGH)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_max_alarm, 0);
        if (st & LM90_STATUS_RHIGH)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_max_alarm, 1);
        if (st2 & MAX6696_STATUS2_R2HIGH)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_max_alarm, 2);

        if (st & LM90_STATUS_LTHRM)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_crit_alarm, 0);
        if (st & LM90_STATUS_RTHRM)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_crit_alarm, 1);
        if (st2 & MAX6696_STATUS2_R2THRM)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_crit_alarm, 2);

        if (st2 & MAX6696_STATUS2_LOT2)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_emergency_alarm, 0);
        if (st2 & MAX6696_STATUS2_ROT2)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_emergency_alarm, 1);
        if (st2 & MAX6696_STATUS2_R2OT2)
                hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_emergency_alarm, 2);

        data->reported_alarms = current_alarms;
}

static int lm90_update_alarms_locked(struct lm90_data *data, bool force)
{
        if (data->shutdown)
                return 0;

        if (force || !data->alarms_valid ||
            time_after(jiffies, data->alarms_updated + msecs_to_jiffies(data->update_interval))) {
                struct i2c_client *client = data->client;
                bool check_enable;
                u16 alarms;
                int val;

                data->alarms_valid = false;

                val = lm90_read_reg(client, LM90_REG_STATUS);
                if (val < 0)
                        return val;
                alarms = val & ~LM90_STATUS_BUSY;

                if (data->reg_status2) {
                        val = lm90_read_reg(client, data->reg_status2);
                        if (val < 0)
                                return val;
                        alarms |= val << 8;
                }
                /*
                 * If the update is forced (called from interrupt or alert
                 * handler) and alarm data is valid, the alarms may have been
                 * updated after the last update interval, and the status
                 * register may still be cleared. Only add additional alarms
                 * in this case. Alarms will be cleared later if appropriate.
                 */
                if (force && data->alarms_valid)
                        data->current_alarms |= alarms;
                else
                        data->current_alarms = alarms;
                data->alarms |= alarms;

                check_enable = (client->irq || !(data->config_orig & 0x80)) &&
                        (data->config & 0x80);

                if (data->hwmon_dev && (force || check_enable))
                        schedule_work(&data->report_work);

                /*
                 * Re-enable ALERT# output if it was originally enabled, relevant
                 * alarms are all clear, and alerts are currently disabled.
                 * Otherwise (re)schedule worker if needed.
                 */
                if (check_enable && data->hwmon_dev) {
                        if (!(data->current_alarms & data->alert_alarms)) {
                                dev_dbg(&client->dev, "Re-enabling ALERT#\n");
                                lm90_update_confreg(data, data->config & ~0x80);
                                /*
                                 * We may have been called from the update handler.
                                 * If so, the worker, if scheduled, is no longer
                                 * needed. Cancel it. Don't synchronize because
                                 * it may already be running.
                                 */
                                cancel_delayed_work(&data->alert_work);
                        } else {
                                schedule_delayed_work(&data->alert_work,
                                        max_t(int, HZ, msecs_to_jiffies(data->update_interval)));
                        }
                }
                data->alarms_updated = jiffies;
                data->alarms_valid = true;
        }
        return 0;
}

static int lm90_update_alarms(struct lm90_data *data, bool force)
{
        guard(hwmon_lock)(data->hwmon_dev);
        return lm90_update_alarms_locked(data, force);
}

static void lm90_alert_work(struct work_struct *__work)
{
        struct delayed_work *delayed_work = to_delayed_work(__work);
        struct lm90_data *data = container_of(delayed_work, struct lm90_data, alert_work);

        /* Nothing to do if alerts are enabled */
        if (!(data->config & 0x80))
                return;

        lm90_update_alarms(data, true);
}

static int lm90_update_device(struct device *dev)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        unsigned long next_update;
        int val;

        if (!data->valid) {
                val = lm90_update_limits(dev);
                if (val < 0)
                        return val;
        }

        next_update = data->last_updated +
                      msecs_to_jiffies(data->update_interval);
        if (time_after(jiffies, next_update) || !data->valid) {
                dev_dbg(&client->dev, "Updating lm90 data.\n");

                data->valid = false;

                val = lm90_read_reg(client, LM90_REG_LOCAL_LOW);
                if (val < 0)
                        return val;
                data->temp[LOCAL_LOW] = val << 8;

                val = lm90_read_reg(client, LM90_REG_LOCAL_HIGH);
                if (val < 0)
                        return val;
                data->temp[LOCAL_HIGH] = val << 8;

                val = lm90_read16(client, LM90_REG_LOCAL_TEMP,
                                  data->reg_local_ext, true);
                if (val < 0)
                        return val;
                data->temp[LOCAL_TEMP] = val;
                val = lm90_read16(client, LM90_REG_REMOTE_TEMPH,
                                  data->reg_remote_ext, true);
                if (val < 0)
                        return val;
                data->temp[REMOTE_TEMP] = val;

                if (data->flags & LM90_HAVE_TEMP3) {
                        val = lm90_select_remote_channel(data, true);
                        if (val < 0)
                                return val;

                        val = lm90_read16(client, LM90_REG_REMOTE_TEMPH,
                                          data->reg_remote_ext, true);
                        if (val < 0) {
                                lm90_select_remote_channel(data, false);
                                return val;
                        }
                        data->temp[REMOTE2_TEMP] = val;

                        lm90_select_remote_channel(data, false);
                }

                val = lm90_update_alarms_locked(data, false);
                if (val < 0)
                        return val;

                data->last_updated = jiffies;
                data->valid = true;
        }

        return 0;
}

static int lm90_temp_get_resolution(struct lm90_data *data, int index)
{
        switch (index) {
        case REMOTE_TEMP:
                if (data->reg_remote_ext)
                        return data->resolution;
                return 8;
        case REMOTE_OFFSET:
        case REMOTE2_OFFSET:
        case REMOTE2_TEMP:
                return data->resolution;
        case LOCAL_TEMP:
                if (data->reg_local_ext)
                        return data->resolution;
                return 8;
        case REMOTE_LOW:
        case REMOTE_HIGH:
        case REMOTE2_LOW:
        case REMOTE2_HIGH:
                if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
                        return data->resolution;
                return 8;
        default:
                return 8;
        }
}

static int lm90_temp_from_reg(u32 flags, u16 regval, u8 resolution)
{
        int val;

        if (flags & LM90_HAVE_EXTENDED_TEMP)
                val = regval - 0x4000;
        else if (flags & (LM90_HAVE_UNSIGNED_TEMP | LM90_HAVE_EXT_UNSIGNED))
                val = regval;
        else
                val = (s16)regval;

        return ((val >> (16 - resolution)) * 1000) >> (resolution - 8);
}

static int lm90_get_temp(struct lm90_data *data, int index, int channel)
{
        int temp = lm90_temp_from_reg(data->flags, data->temp[index],
                                      lm90_temp_get_resolution(data, index));

        /* +16 degrees offset for remote temperature on LM99 */
        if (data->kind == lm99 && channel)
                temp += 16000;

        return temp;
}

static u16 lm90_temp_to_reg(u32 flags, long val, u8 resolution)
{
        int fraction = resolution > 8 ?
                        1000 - DIV_ROUND_CLOSEST(1000, BIT(resolution - 8)) : 0;

        if (flags & LM90_HAVE_EXTENDED_TEMP) {
                val = clamp_val(val, -64000, 191000 + fraction);
                val += 64000;
        } else if (flags & LM90_HAVE_EXT_UNSIGNED) {
                val = clamp_val(val, 0, 255000 + fraction);
        } else if (flags & LM90_HAVE_UNSIGNED_TEMP) {
                val = clamp_val(val, 0, 127000 + fraction);
        } else {
                val = clamp_val(val, -128000, 127000 + fraction);
        }

        return DIV_ROUND_CLOSEST(val << (resolution - 8), 1000) << (16 - resolution);
}

static int lm90_set_temp(struct lm90_data *data, int index, int channel, long val)
{
        static const u8 regs[] = {
                [LOCAL_LOW] = LM90_REG_LOCAL_LOW,
                [LOCAL_HIGH] = LM90_REG_LOCAL_HIGH,
                [LOCAL_CRIT] = LM90_REG_LOCAL_CRIT,
                [REMOTE_CRIT] = LM90_REG_REMOTE_CRIT,
                [LOCAL_EMERG] = MAX6659_REG_LOCAL_EMERG,
                [REMOTE_EMERG] = MAX6659_REG_REMOTE_EMERG,
                [REMOTE2_CRIT] = LM90_REG_REMOTE_CRIT,
                [REMOTE2_EMERG] = MAX6659_REG_REMOTE_EMERG,
                [REMOTE_LOW] = LM90_REG_REMOTE_LOWH,
                [REMOTE_HIGH] = LM90_REG_REMOTE_HIGHH,
                [REMOTE2_LOW] = LM90_REG_REMOTE_LOWH,
                [REMOTE2_HIGH] = LM90_REG_REMOTE_HIGHH,
        };
        struct i2c_client *client = data->client;
        u8 regh = regs[index];
        u8 regl = 0;
        int err;

        if (channel && (data->flags & LM90_HAVE_REM_LIMIT_EXT)) {
                if (index == REMOTE_LOW || index == REMOTE2_LOW)
                        regl = LM90_REG_REMOTE_LOWL;
                else if (index == REMOTE_HIGH || index == REMOTE2_HIGH)
                        regl = LM90_REG_REMOTE_HIGHL;
        }

        /* +16 degrees offset for remote temperature on LM99 */
        if (data->kind == lm99 && channel) {
                /* prevent integer underflow */
                val = max(val, -128000l);
                val -= 16000;
        }

        data->temp[index] = lm90_temp_to_reg(data->flags, val,
                                             lm90_temp_get_resolution(data, index));

        if (channel > 1)
                lm90_select_remote_channel(data, true);

        err = lm90_write16(client, regh, regl, data->temp[index]);

        if (channel > 1)
                lm90_select_remote_channel(data, false);

        return err;
}

static int lm90_get_temphyst(struct lm90_data *data, int index, int channel)
{
        int temp = lm90_get_temp(data, index, channel);

        return temp - data->temp_hyst * 1000;
}

static int lm90_set_temphyst(struct lm90_data *data, long val)
{
        int temp = lm90_get_temp(data, LOCAL_CRIT, 0);

        /* prevent integer overflow/underflow */
        val = clamp_val(val, -128000l, 255000l);
        data->temp_hyst = clamp_val(DIV_ROUND_CLOSEST(temp - val, 1000), 0, 31);

        return lm90_write_reg(data->client, LM90_REG_TCRIT_HYST, data->temp_hyst);
}

static int lm90_get_temp_offset(struct lm90_data *data, int index)
{
        int res = lm90_temp_get_resolution(data, index);

        return lm90_temp_from_reg(0, data->temp[index], res);
}

static int lm90_set_temp_offset(struct lm90_data *data, int index, int channel, long val)
{
        int err;

        val = lm90_temp_to_reg(0, val, lm90_temp_get_resolution(data, index));

        /* For ADT7481 we can use the same registers for remote channel 1 and 2 */
        if (channel > 1)
                lm90_select_remote_channel(data, true);

        err = lm90_write16(data->client, LM90_REG_REMOTE_OFFSH, LM90_REG_REMOTE_OFFSL, val);

        if (channel > 1)
                lm90_select_remote_channel(data, false);

        if (err)
                return err;

        data->temp[index] = val;

        return 0;
}

static const u8 lm90_temp_index[MAX_CHANNELS] = {
        LOCAL_TEMP, REMOTE_TEMP, REMOTE2_TEMP
};

static const u8 lm90_temp_min_index[MAX_CHANNELS] = {
        LOCAL_LOW, REMOTE_LOW, REMOTE2_LOW
};

static const u8 lm90_temp_max_index[MAX_CHANNELS] = {
        LOCAL_HIGH, REMOTE_HIGH, REMOTE2_HIGH
};

static const u8 lm90_temp_crit_index[MAX_CHANNELS] = {
        LOCAL_CRIT, REMOTE_CRIT, REMOTE2_CRIT
};

static const u8 lm90_temp_emerg_index[MAX_CHANNELS] = {
        LOCAL_EMERG, REMOTE_EMERG, REMOTE2_EMERG
};

static const s8 lm90_temp_offset_index[MAX_CHANNELS] = {
        -1, REMOTE_OFFSET, REMOTE2_OFFSET
};

static const u16 lm90_min_alarm_bits[MAX_CHANNELS] = { BIT(5), BIT(3), BIT(11) };
static const u16 lm90_max_alarm_bits[MAX_CHANNELS] = { BIT(6), BIT(4), BIT(12) };
static const u16 lm90_crit_alarm_bits[MAX_CHANNELS] = { BIT(0), BIT(1), BIT(9) };
static const u16 lm90_crit_alarm_bits_swapped[MAX_CHANNELS] = { BIT(1), BIT(0), BIT(9) };
static const u16 lm90_emergency_alarm_bits[MAX_CHANNELS] = { BIT(15), BIT(13), BIT(14) };
static const u16 lm90_fault_bits[MAX_CHANNELS] = { BIT(0), BIT(2), BIT(10) };

static int lm90_temp_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        int err;
        u16 bit;

        err = lm90_update_device(dev);
        if (err)
                return err;

        switch (attr) {
        case hwmon_temp_input:
                *val = lm90_get_temp(data, lm90_temp_index[channel], channel);
                break;
        case hwmon_temp_min_alarm:
        case hwmon_temp_max_alarm:
        case hwmon_temp_crit_alarm:
        case hwmon_temp_emergency_alarm:
        case hwmon_temp_fault:
                switch (attr) {
                case hwmon_temp_min_alarm:
                        bit = lm90_min_alarm_bits[channel];
                        break;
                case hwmon_temp_max_alarm:
                        bit = lm90_max_alarm_bits[channel];
                        break;
                case hwmon_temp_crit_alarm:
                        if (data->flags & LM90_HAVE_CRIT_ALRM_SWP)
                                bit = lm90_crit_alarm_bits_swapped[channel];
                        else
                                bit = lm90_crit_alarm_bits[channel];
                        break;
                case hwmon_temp_emergency_alarm:
                        bit = lm90_emergency_alarm_bits[channel];
                        break;
                case hwmon_temp_fault:
                        bit = lm90_fault_bits[channel];
                        break;
                }
                *val = !!(data->alarms & bit);
                data->alarms &= ~bit;
                data->alarms |= data->current_alarms;
                break;
        case hwmon_temp_min:
                *val = lm90_get_temp(data, lm90_temp_min_index[channel], channel);
                break;
        case hwmon_temp_max:
                *val = lm90_get_temp(data, lm90_temp_max_index[channel], channel);
                break;
        case hwmon_temp_crit:
                *val = lm90_get_temp(data, lm90_temp_crit_index[channel], channel);
                break;
        case hwmon_temp_crit_hyst:
                *val = lm90_get_temphyst(data, lm90_temp_crit_index[channel], channel);
                break;
        case hwmon_temp_emergency:
                *val = lm90_get_temp(data, lm90_temp_emerg_index[channel], channel);
                break;
        case hwmon_temp_emergency_hyst:
                *val = lm90_get_temphyst(data, lm90_temp_emerg_index[channel], channel);
                break;
        case hwmon_temp_offset:
                *val = lm90_get_temp_offset(data, lm90_temp_offset_index[channel]);
                break;
        default:
                return -EOPNOTSUPP;
        }
        return 0;
}

static int lm90_temp_write(struct device *dev, u32 attr, int channel, long val)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        int err;

        err = lm90_update_device(dev);
        if (err)
                return err;

        switch (attr) {
        case hwmon_temp_min:
                err = lm90_set_temp(data, lm90_temp_min_index[channel],
                                    channel, val);
                break;
        case hwmon_temp_max:
                err = lm90_set_temp(data, lm90_temp_max_index[channel],
                                    channel, val);
                break;
        case hwmon_temp_crit:
                err = lm90_set_temp(data, lm90_temp_crit_index[channel],
                                    channel, val);
                break;
        case hwmon_temp_crit_hyst:
                err = lm90_set_temphyst(data, val);
                break;
        case hwmon_temp_emergency:
                err = lm90_set_temp(data, lm90_temp_emerg_index[channel],
                                    channel, val);
                break;
        case hwmon_temp_offset:
                err = lm90_set_temp_offset(data, lm90_temp_offset_index[channel],
                                           channel, val);
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }
        return err;
}

static umode_t lm90_temp_is_visible(const void *data, u32 attr, int channel)
{
        switch (attr) {
        case hwmon_temp_input:
        case hwmon_temp_min_alarm:
        case hwmon_temp_max_alarm:
        case hwmon_temp_crit_alarm:
        case hwmon_temp_emergency_alarm:
        case hwmon_temp_emergency_hyst:
        case hwmon_temp_fault:
        case hwmon_temp_label:
                return 0444;
        case hwmon_temp_min:
        case hwmon_temp_max:
        case hwmon_temp_crit:
        case hwmon_temp_emergency:
        case hwmon_temp_offset:
                return 0644;
        case hwmon_temp_crit_hyst:
                if (channel == 0)
                        return 0644;
                return 0444;
        default:
                return 0;
        }
}

static int lm90_chip_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        int err;

        err = lm90_update_device(dev);
        if (err)
                return err;

        switch (attr) {
        case hwmon_chip_update_interval:
                *val = data->update_interval;
                break;
        case hwmon_chip_alarms:
                *val = data->alarms;
                break;
        case hwmon_chip_temp_samples:
                if (data->faultqueue_mask) {
                        *val = (data->config & data->faultqueue_mask) ?
                                data->faultqueue_depth : 1;
                } else {
                        switch (data->conalert & 0x0e) {
                        case 0x0:
                        default:
                                *val = 1;
                                break;
                        case 0x2:
                                *val = 2;
                                break;
                        case 0x6:
                                *val = 3;
                                break;
                        case 0xe:
                                *val = 4;
                                break;
                        }
                }
                break;
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static int lm90_chip_write(struct device *dev, u32 attr, int channel, long val)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        int err;

        err = lm90_update_device(dev);
        if (err)
                return err;

        switch (attr) {
        case hwmon_chip_update_interval:
                err = lm90_set_convrate(client, data,
                                        clamp_val(val, 0, 100000));
                break;
        case hwmon_chip_temp_samples:
                err = lm90_set_faultqueue(client, data, clamp_val(val, 1, 4));
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }
        return err;
}

static umode_t lm90_chip_is_visible(const void *data, u32 attr, int channel)
{
        switch (attr) {
        case hwmon_chip_update_interval:
        case hwmon_chip_temp_samples:
                return 0644;
        case hwmon_chip_alarms:
                return 0444;
        default:
                return 0;
        }
}

static int lm90_read(struct device *dev, enum hwmon_sensor_types type,
                     u32 attr, int channel, long *val)
{
        switch (type) {
        case hwmon_chip:
                return lm90_chip_read(dev, attr, channel, val);
        case hwmon_temp:
                return lm90_temp_read(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static int lm90_read_string(struct device *dev, enum hwmon_sensor_types type,
                            u32 attr, int channel, const char **str)
{
        struct lm90_data *data = dev_get_drvdata(dev);

        *str = data->channel_label[channel];

        return 0;
}

static int lm90_write(struct device *dev, enum hwmon_sensor_types type,
                      u32 attr, int channel, long val)
{
        switch (type) {
        case hwmon_chip:
                return lm90_chip_write(dev, attr, channel, val);
        case hwmon_temp:
                return lm90_temp_write(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static umode_t lm90_is_visible(const void *data, enum hwmon_sensor_types type,
                               u32 attr, int channel)
{
        switch (type) {
        case hwmon_chip:
                return lm90_chip_is_visible(data, attr, channel);
        case hwmon_temp:
                return lm90_temp_is_visible(data, attr, channel);
        default:
                return 0;
        }
}

static const char *lm90_detect_lm84(struct i2c_client *client)
{
        static const u8 regs[] = {
                LM90_REG_STATUS, LM90_REG_LOCAL_TEMP, LM90_REG_LOCAL_HIGH,
                LM90_REG_REMOTE_TEMPH, LM90_REG_REMOTE_HIGHH
        };
        int status = i2c_smbus_read_byte_data(client, LM90_REG_STATUS);
        int reg1, reg2, reg3, reg4;
        bool nonzero = false;
        u8 ff = 0xff;
        int i;

        if (status < 0 || (status & 0xab))
                return NULL;

        /*
         * For LM84, undefined registers return the most recent value.
         * Repeat several times, each time checking against a different
         * (presumably) existing register.
         */
        for (i = 0; i < ARRAY_SIZE(regs); i++) {
                reg1 = i2c_smbus_read_byte_data(client, regs[i]);
                reg2 = i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_TEMPL);
                reg3 = i2c_smbus_read_byte_data(client, LM90_REG_LOCAL_LOW);
                reg4 = i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_LOWH);

                if (reg1 < 0)
                        return NULL;

                /* If any register has a different value, this is not an LM84 */
                if (reg2 != reg1 || reg3 != reg1 || reg4 != reg1)
                        return NULL;

                nonzero |= reg1 || reg2 || reg3 || reg4;
                ff &= reg1;
        }
        /*
         * If all registers always returned 0 or 0xff, all bets are off,
         * and we can not make any predictions about the chip type.
         */
        return nonzero && ff != 0xff ? "lm84" : NULL;
}

static const char *lm90_detect_max1617(struct i2c_client *client, int config1)
{
        int status = i2c_smbus_read_byte_data(client, LM90_REG_STATUS);
        int llo, rlo, lhi, rhi;

        if (status < 0 || (status & 0x03))
                return NULL;

        if (config1 & 0x3f)
                return NULL;

        /*
         * Fail if unsupported registers return anything but 0xff.
         * The calling code already checked man_id and chip_id.
         * A byte read operation repeats the most recent read operation
         * and should also return 0xff.
         */
        if (i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_TEMPL) != 0xff ||
            i2c_smbus_read_byte_data(client, MAX6657_REG_LOCAL_TEMPL) != 0xff ||
            i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_LOWL) != 0xff ||
            i2c_smbus_read_byte(client) != 0xff)
                return NULL;

        llo = i2c_smbus_read_byte_data(client, LM90_REG_LOCAL_LOW);
        rlo = i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_LOWH);

        lhi = i2c_smbus_read_byte_data(client, LM90_REG_LOCAL_HIGH);
        rhi = i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_HIGHH);

        if (llo < 0 || rlo < 0)
                return NULL;

        /*
         * A byte read operation repeats the most recent read and should
         * return the same value.
         */
        if (i2c_smbus_read_byte(client) != rhi)
                return NULL;

        /*
         * The following two checks are marginal since the checked values
         * are strictly speaking valid.
         */

        /* fail for negative high limits; this also catches read errors */
        if ((s8)lhi < 0 || (s8)rhi < 0)
                return NULL;

        /* fail if low limits are larger than or equal to high limits */
        if ((s8)llo >= lhi || (s8)rlo >= rhi)
                return NULL;

        if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
                /*
                 * Word read operations return 0xff in second byte
                 */
                if (i2c_smbus_read_word_data(client, LM90_REG_REMOTE_TEMPL) !=
                                                0xffff)
                        return NULL;
                if (i2c_smbus_read_word_data(client, LM90_REG_CONFIG1) !=
                                                (config1 | 0xff00))
                        return NULL;
                if (i2c_smbus_read_word_data(client, LM90_REG_LOCAL_HIGH) !=
                                                (lhi | 0xff00))
                        return NULL;
        }

        return "max1617";
}

static const char *lm90_detect_national(struct i2c_client *client, int chip_id,
                                        int config1, int convrate)
{
        int config2 = i2c_smbus_read_byte_data(client, LM90_REG_CONFIG2);
        int address = client->addr;
        const char *name = NULL;

        if (config2 < 0)
                return NULL;

        if ((config1 & 0x2a) || (config2 & 0xf8) || convrate > 0x09)
                return NULL;

        if (address != 0x4c && address != 0x4d)
                return NULL;

        switch (chip_id & 0xf0) {
        case 0x10:      /* LM86 */
                if (address == 0x4c)
                        name = "lm86";
                break;
        case 0x20:      /* LM90 */
                if (address == 0x4c)
                        name = "lm90";
                break;
        case 0x30:      /* LM89/LM99 */
                name = "lm99";  /* detect LM89 as LM99 */
                break;
        default:
                break;
        }

        return name;
}

static const char *lm90_detect_on(struct i2c_client *client, int chip_id, int config1,
                                  int convrate)
{
        int address = client->addr;
        const char *name = NULL;

        switch (chip_id) {
        case 0xca:              /* NCT218 */
                if ((address == 0x4c || address == 0x4d) && !(config1 & 0x1b) &&
                    convrate <= 0x0a)
                        name = "nct218";
                break;
        default:
                break;
        }
        return name;
}

static const char *lm90_detect_analog(struct i2c_client *client, bool common_address,
                                      int chip_id, int config1, int convrate)
{
        int status = i2c_smbus_read_byte_data(client, LM90_REG_STATUS);
        int config2 = i2c_smbus_read_byte_data(client, ADT7481_REG_CONFIG2);
        int man_id2 = i2c_smbus_read_byte_data(client, ADT7481_REG_MAN_ID);
        int chip_id2 = i2c_smbus_read_byte_data(client, ADT7481_REG_CHIP_ID);
        int address = client->addr;
        const char *name = NULL;

        if (status < 0 || config2 < 0 || man_id2 < 0 || chip_id2 < 0)
                return NULL;

        /*
         * The following chips should be detected by this function. Known
         * register values are listed. Registers 0x3d .. 0x3e are undocumented
         * for most of the chips, yet appear to return a well defined value.
         * Register 0xff is undocumented for some of the chips. Register 0x3f
         * is undocumented for all chips, but also returns a well defined value.
         * Values are as reported from real chips unless mentioned otherwise.
         * The code below checks values for registers 0x3d, 0x3e, and 0xff,
         * but not for register 0x3f.
         *
         * Chip                 Register
         *              3d      3e      3f      fe      ff      Notes
         * ----------------------------------------------------------
         * adm1020      00      00      00      41      39
         * adm1021      00      00      00      41      03
         * adm1021a     00      00      00      41      3c
         * adm1023      00      00      00      41      3c      same as adm1021a
         * adm1032      00      00      00      41      42
         *
         * adt7421      21      41      04      41      04
         * adt7461      00      00      00      41      51
         * adt7461a     61      41      05      41      57
         * adt7481      81      41      02      41      62
         * adt7482      -       -       -       41      65      datasheet
         *              82      41      05      41      75      real chip
         * adt7483      83      41      04      41      94
         *
         * nct72        61      41      07      41      55
         * nct210       00      00      00      41      3f
         * nct214       61      41      08      41      5a
         * nct1008      -       -       -       41      57      datasheet rev. 3
         *              61      41      06      41      54      real chip
         *
         * nvt210       -       -       -       41      -       datasheet
         * nvt211       -       -       -       41      -       datasheet
         */
        switch (chip_id) {
        case 0x00 ... 0x03:     /* ADM1021 */
        case 0x05 ... 0x0f:
                if (man_id2 == 0x00 && chip_id2 == 0x00 && common_address &&
                    !(status & 0x03) && !(config1 & 0x3f) && !(convrate & 0xf8))
                        name = "adm1021";
                break;
        case 0x04:              /* ADT7421 (undocumented) */
                if (man_id2 == 0x41 && chip_id2 == 0x21 &&
                    (address == 0x4c || address == 0x4d) &&
                    (config1 & 0x0b) == 0x08 && convrate <= 0x0a)
                        name = "adt7421";
                break;
        case 0x30 ... 0x38:     /* ADM1021A, ADM1023 */
        case 0x3a ... 0x3e:
                /*
                 * ADM1021A and compatible chips will be mis-detected as
                 * ADM1023. Chips labeled 'ADM1021A' and 'ADM1023' were both
                 * found to have a Chip ID of 0x3c.
                 * ADM1021A does not officially support low byte registers
                 * (0x12 .. 0x14), but a chip labeled ADM1021A does support it.
                 * Official support for the temperature offset high byte
                 * register (0x11) was added to revision F of the ADM1021A
                 * datasheet.
                 * It is currently unknown if there is a means to distinguish
                 * ADM1021A from ADM1023, and/or if revisions of ADM1021A exist
                 * which differ in functionality from ADM1023.
                 */
                if (man_id2 == 0x00 && chip_id2 == 0x00 && common_address &&
                    !(status & 0x03) && !(config1 & 0x3f) && !(convrate & 0xf8))
                        name = "adm1023";
                break;
        case 0x39:              /* ADM1020 (undocumented) */
                if (man_id2 == 0x00 && chip_id2 == 0x00 &&
                    (address == 0x4c || address == 0x4d || address == 0x4e) &&
                    !(status & 0x03) && !(config1 & 0x3f) && !(convrate & 0xf8))
                        name = "adm1020";
                break;
        case 0x3f:              /* NCT210 */
                if (man_id2 == 0x00 && chip_id2 == 0x00 && common_address &&
                    !(status & 0x03) && !(config1 & 0x3f) && !(convrate & 0xf8))
                        name = "nct210";
                break;
        case 0x40 ... 0x4f:     /* ADM1032 */
                if (man_id2 == 0x00 && chip_id2 == 0x00 &&
                    (address == 0x4c || address == 0x4d) && !(config1 & 0x3f) &&
                    convrate <= 0x0a)
                        name = "adm1032";
                break;
        case 0x51:      /* ADT7461 */
                if (man_id2 == 0x00 && chip_id2 == 0x00 &&
                    (address == 0x4c || address == 0x4d) && !(config1 & 0x1b) &&
                    convrate <= 0x0a)
                        name = "adt7461";
                break;
        case 0x54:      /* NCT1008 */
                if (man_id2 == 0x41 && chip_id2 == 0x61 &&
                    (address == 0x4c || address == 0x4d) && !(config1 & 0x1b) &&
                    convrate <= 0x0a)
                        name = "nct1008";
                break;
        case 0x55:      /* NCT72 */
                if (man_id2 == 0x41 && chip_id2 == 0x61 &&
                    (address == 0x4c || address == 0x4d) && !(config1 & 0x1b) &&
                    convrate <= 0x0a)
                        name = "nct72";
                break;
        case 0x57:      /* ADT7461A, NCT1008 (datasheet rev. 3) */
                if (man_id2 == 0x41 && chip_id2 == 0x61 &&
                    (address == 0x4c || address == 0x4d) && !(config1 & 0x1b) &&
                    convrate <= 0x0a)
                        name = "adt7461a";
                break;
        case 0x5a:      /* NCT214 */
                if (man_id2 == 0x41 && chip_id2 == 0x61 &&
                    common_address && !(config1 & 0x1b) && convrate <= 0x0a)
                        name = "nct214";
                break;
        case 0x62:      /* ADT7481, undocumented */
                if (man_id2 == 0x41 && chip_id2 == 0x81 &&
                    (address == 0x4b || address == 0x4c) && !(config1 & 0x10) &&
                    !(config2 & 0x7f) && (convrate & 0x0f) <= 0x0b) {
                        name = "adt7481";
                }
                break;
        case 0x65:      /* ADT7482, datasheet */
        case 0x75:      /* ADT7482, real chip */
                if (man_id2 == 0x41 && chip_id2 == 0x82 &&
                    address == 0x4c && !(config1 & 0x10) && !(config2 & 0x7f) &&
                    convrate <= 0x0a)
                        name = "adt7482";
                break;
        case 0x94:      /* ADT7483 */
                if (man_id2 == 0x41 && chip_id2 == 0x83 &&
                    common_address &&
                    ((address >= 0x18 && address <= 0x1a) ||
                     (address >= 0x29 && address <= 0x2b) ||
                     (address >= 0x4c && address <= 0x4e)) &&
                    !(config1 & 0x10) && !(config2 & 0x7f) && convrate <= 0x0a)
                        name = "adt7483a";
                break;
        default:
                break;
        }

        return name;
}

static const char *lm90_detect_maxim(struct i2c_client *client, bool common_address,
                                     int chip_id, int config1, int convrate)
{
        int man_id, emerg, emerg2, status2;
        int address = client->addr;
        const char *name = NULL;

        switch (chip_id) {
        case 0x01:
                if (!common_address)
                        break;

                /*
                 * We read MAX6659_REG_REMOTE_EMERG twice, and re-read
                 * LM90_REG_MAN_ID in between. If MAX6659_REG_REMOTE_EMERG
                 * exists, both readings will reflect the same value. Otherwise,
                 * the readings will be different.
                 */
                emerg = i2c_smbus_read_byte_data(client,
                                                 MAX6659_REG_REMOTE_EMERG);
                man_id = i2c_smbus_read_byte_data(client,
                                                  LM90_REG_MAN_ID);
                emerg2 = i2c_smbus_read_byte_data(client,
                                                  MAX6659_REG_REMOTE_EMERG);
                status2 = i2c_smbus_read_byte_data(client,
                                                   MAX6696_REG_STATUS2);
                if (emerg < 0 || man_id < 0 || emerg2 < 0 || status2 < 0)
                        return NULL;

                /*
                 * Even though MAX6695 and MAX6696 do not have a chip ID
                 * register, reading it returns 0x01. Bit 4 of the config1
                 * register is unused and should return zero when read. Bit 0 of
                 * the status2 register is unused and should return zero when
                 * read.
                 *
                 * MAX6695 and MAX6696 have an additional set of temperature
                 * limit registers. We can detect those chips by checking if
                 * one of those registers exists.
                 */
                if (!(config1 & 0x10) && !(status2 & 0x01) && emerg == emerg2 &&
                    convrate <= 0x07)
                        name = "max6696";
                /*
                 * The chip_id register of the MAX6680 and MAX6681 holds the
                 * revision of the chip. The lowest bit of the config1 register
                 * is unused and should return zero when read, so should the
                 * second to last bit of config1 (software reset). Register
                 * address 0x12 (LM90_REG_REMOTE_OFFSL) exists for this chip and
                 * should differ from emerg2, and emerg2 should match man_id
                 * since it does not exist.
                 */
                else if (!(config1 & 0x03) && convrate <= 0x07 &&
                         emerg2 == man_id && emerg2 != status2)
                        name = "max6680";
                /*
                 * MAX1617A does not have any extended registers (register
                 * address 0x10 or higher) except for manufacturer and
                 * device ID registers. Unlike other chips of this series,
                 * unsupported registers were observed to return a fixed value
                 * of 0x01.
                 * Note: Multiple chips with different markings labeled as
                 * "MAX1617" (no "A") were observed to report manufacturer ID
                 * 0x4d and device ID 0x01. It is unknown if other variants of
                 * MAX1617/MAX617A with different behavior exist. The detection
                 * code below works for those chips.
                 */
                else if (!(config1 & 0x03f) && convrate <= 0x07 &&
                         emerg == 0x01 && emerg2 == 0x01 && status2 == 0x01)
                        name = "max1617";
                break;
        case 0x08:
                /*
                 * The chip_id of the MAX6654 holds the revision of the chip.
                 * The lowest 3 bits of the config1 register are unused and
                 * should return zero when read.
                 */
                if (common_address && !(config1 & 0x07) && convrate <= 0x07)
                        name = "max6654";
                break;
        case 0x09:
                /*
                 * The chip_id of the MAX6690 holds the revision of the chip.
                 * The lowest 3 bits of the config1 register are unused and
                 * should return zero when read.
                 * Note that MAX6654 and MAX6690 are practically the same chips.
                 * The only diference is the rated accuracy. Rev. 1 of the
                 * MAX6690 datasheet lists a chip ID of 0x08, and a chip labeled
                 * MAX6654 was observed to have a chip ID of 0x09.
                 */
                if (common_address && !(config1 & 0x07) && convrate <= 0x07)
                        name = "max6690";
                break;
        case 0x4d:
                /*
                 * MAX6642, MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
                 * register. Reading from that address will return the last
                 * read value, which in our case is those of the man_id
                 * register, or 0x4d.
                 * MAX6642 does not have a conversion rate register, nor low
                 * limit registers. Reading from those registers returns the
                 * last read value.
                 *
                 * For MAX6657, MAX6658 and MAX6659, the config1 register lacks
                 * a low nibble, so the value will be those of the previous
                 * read, so in our case again those of the man_id register.
                 * MAX6659 has a third set of upper temperature limit registers.
                 * Those registers also return values on MAX6657 and MAX6658,
                 * thus the only way to detect MAX6659 is by its address.
                 * For this reason it will be mis-detected as MAX6657 if its
                 * address is 0x4c.
                 */
                if (address >= 0x48 && address <= 0x4f && config1 == convrate &&
                    !(config1 & 0x0f)) {
                        int regval;

                        /*
                         * We know that this is not a MAX6657/58/59 because its
                         * configuration register has the wrong value and it does
                         * not appear to have a conversion rate register.
                         */

                        /* re-read manufacturer ID to have a good baseline */
                        if (i2c_smbus_read_byte_data(client, LM90_REG_MAN_ID) != 0x4d)
                                break;

                        /* check various non-existing registers */
                        if (i2c_smbus_read_byte_data(client, LM90_REG_CONVRATE) != 0x4d ||
                            i2c_smbus_read_byte_data(client, LM90_REG_LOCAL_LOW) != 0x4d ||
                            i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_LOWH) != 0x4d)
                                break;

                        /* check for unused status register bits */
                        regval = i2c_smbus_read_byte_data(client, LM90_REG_STATUS);
                        if (regval < 0 || (regval & 0x2b))
                                break;

                        /* re-check unsupported registers */
                        if (i2c_smbus_read_byte_data(client, LM90_REG_CONVRATE) != regval ||
                            i2c_smbus_read_byte_data(client, LM90_REG_LOCAL_LOW) != regval ||
                            i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_LOWH) != regval)
                                break;

                        name = "max6642";
                } else if ((address == 0x4c || address == 0x4d || address == 0x4e) &&
                           (config1 & 0x1f) == 0x0d && convrate <= 0x09) {
                        if (address == 0x4c)
                                name = "max6657";
                        else
                                name = "max6659";
                }
                break;
        case 0x59:
                /*
                 * The chip_id register of the MAX6646/6647/6649 holds the
                 * revision of the chip. The lowest 6 bits of the config1
                 * register are unused and should return zero when read.
                 * The I2C address of MAX6648/6692 is fixed at 0x4c.
                 * MAX6646 is at address 0x4d, MAX6647 is at address 0x4e,
                 * and MAX6649 is at address 0x4c. A slight difference between
                 * the two sets of chips is that the remote temperature register
                 * reports different values if the DXP pin is open or shorted.
                 * We can use that information to help distinguish between the
                 * chips. MAX6648 will be mis-detected as MAX6649 if the remote
                 * diode is connected, but there isn't really anything we can
                 * do about that.
                 */
                if (!(config1 & 0x3f) && convrate <= 0x07) {
                        int temp;

                        switch (address) {
                        case 0x4c:
                                /*
                                 * MAX6649 reports an external temperature
                                 * value of 0xff if DXP is open or shorted.
                                 * MAX6648 reports 0x80 in that case.
                                 */
                                temp = i2c_smbus_read_byte_data(client,
                                                                LM90_REG_REMOTE_TEMPH);
                                if (temp == 0x80)
                                        name = "max6648";
                                else
                                        name = "max6649";
                                break;
                        case 0x4d:
                                name = "max6646";
                                break;
                        case 0x4e:
                                name = "max6647";
                                break;
                        default:
                                break;
                        }
                }
                break;
        default:
                break;
        }

        return name;
}

static const char *lm90_detect_nuvoton(struct i2c_client *client, int chip_id,
                                       int config1, int convrate)
{
        int config2 = i2c_smbus_read_byte_data(client, LM90_REG_CONFIG2);
        int address = client->addr;
        const char *name = NULL;

        if (config2 < 0)
                return NULL;

        if (address == 0x4c && !(config1 & 0x2a) && !(config2 & 0xf8)) {
                if (chip_id == 0x01 && convrate <= 0x09) {
                        /* W83L771W/G */
                        name = "w83l771";
                } else if ((chip_id & 0xfe) == 0x10 && convrate <= 0x08) {
                        /* W83L771AWG/ASG */
                        name = "w83l771";
                }
        }
        return name;
}

static const char *lm90_detect_nuvoton_50(struct i2c_client *client, int chip_id,
                                          int config1, int convrate)
{
        int chip_id2 = i2c_smbus_read_byte_data(client, NCT7716_REG_CHIP_ID);
        int config2 = i2c_smbus_read_byte_data(client, LM90_REG_CONFIG2);
        int address = client->addr;
        const char *name = NULL;

        if (chip_id2 < 0 || config2 < 0)
                return NULL;

        if (chip_id2 != 0x50 || convrate > 0x08)
                return NULL;

        switch (chip_id) {
        case 0x90:
                if (address == 0x48 && !(config1 & 0x3e) && !(config2 & 0xfe))
                        name = "nct7717";
                break;
        case 0x91:
                if ((address == 0x48 || address == 0x49) && !(config1 & 0x3e) &&
                    !(config2 & 0xfe))
                        name = "nct7716";
                else if (address == 0x4c && !(config1 & 0x38) && !(config2 & 0xf8))
                        name = "nct7718";
                break;
        default:
                break;
        }
        return name;
}

static const char *lm90_detect_nxp(struct i2c_client *client, bool common_address,
                                   int chip_id, int config1, int convrate)
{
        int address = client->addr;
        const char *name = NULL;
        int config2;

        switch (chip_id) {
        case 0x00:
                config2 = i2c_smbus_read_byte_data(client, LM90_REG_CONFIG2);
                if (config2 < 0)
                        return NULL;
                if (address >= 0x48 && address <= 0x4f &&
                    !(config1 & 0x2a) && !(config2 & 0xfe) && convrate <= 0x09)
                        name = "sa56004";
                break;
        case 0x80:
                if (common_address && !(config1 & 0x3f) && convrate <= 0x07)
                        name = "ne1618";
                break;
        default:
                break;
        }
        return name;
}

static const char *lm90_detect_gmt(struct i2c_client *client, int chip_id,
                                   int config1, int convrate)
{
        int address = client->addr;

        /*
         * According to the datasheet, G781 is supposed to be at I2C Address
         * 0x4c and have a chip ID of 0x01. G781-1 is supposed to be at I2C
         * address 0x4d and have a chip ID of 0x03. However, when support
         * for G781 was added, chips at 0x4c and 0x4d were found to have a
         * chip ID of 0x01. A G781-1 at I2C address 0x4d was now found with
         * chip ID 0x03.
         * To avoid detection failures, accept chip ID 0x01 and 0x03 at both
         * addresses.
         * G784 reports manufacturer ID 0x47 and chip ID 0x01. A public
         * datasheet is not available. Extensive testing suggests that
         * the chip appears to be fully compatible with G781.
         * Available register dumps show that G751 also reports manufacturer
         * ID 0x47 and chip ID 0x01 even though that chip does not officially
         * support those registers. This makes chip detection somewhat
         * vulnerable. To improve detection quality, read the offset low byte
         * and alert fault queue registers and verify that only expected bits
         * are set.
         */
        if ((chip_id == 0x01 || chip_id == 0x03) &&
            (address == 0x4c || address == 0x4d) &&
            !(config1 & 0x3f) && convrate <= 0x08) {
                int reg;

                reg = i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_OFFSL);
                if (reg < 0 || reg & 0x1f)
                        return NULL;
                reg = i2c_smbus_read_byte_data(client, TMP451_REG_CONALERT);
                if (reg < 0 || reg & 0xf1)
                        return NULL;

                return "g781";
        }

        return NULL;
}

static const char *lm90_detect_ti49(struct i2c_client *client, bool common_address,
                                    int chip_id, int config1, int convrate)
{
        if (common_address && chip_id == 0x00 && !(config1 & 0x3f) && !(convrate & 0xf8)) {
                /* THMC10: Unsupported registers return 0xff */
                if (i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_TEMPL) == 0xff &&
                    i2c_smbus_read_byte_data(client, LM90_REG_REMOTE_CRIT) == 0xff)
                        return "thmc10";
        }
        return NULL;
}

static const char *lm90_detect_ti(struct i2c_client *client, int chip_id,
                                  int config1, int convrate)
{
        int address = client->addr;
        const char *name = NULL;

        if (chip_id == 0x00 && !(config1 & 0x1b) && convrate <= 0x09) {
                int local_ext, conalert, chen, dfc;

                local_ext = i2c_smbus_read_byte_data(client,
                                                     TMP451_REG_LOCAL_TEMPL);
                conalert = i2c_smbus_read_byte_data(client,
                                                    TMP451_REG_CONALERT);
                chen = i2c_smbus_read_byte_data(client, TMP461_REG_CHEN);
                dfc = i2c_smbus_read_byte_data(client, TMP461_REG_DFC);

                if (!(local_ext & 0x0f) && (conalert & 0xf1) == 0x01 &&
                    (chen & 0xfc) == 0x00 && (dfc & 0xfc) == 0x00) {
                        if (address == 0x4c && !(chen & 0x03))
                                name = "tmp451";
                        else if (address >= 0x48 && address <= 0x4f)
                                name = "tmp461";
                }
        }

        return name;
}

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm90_detect(struct i2c_client *client, struct i2c_board_info *info)
{
        struct i2c_adapter *adapter = client->adapter;
        int man_id, chip_id, config1, convrate, lhigh;
        const char *name = NULL;
        int address = client->addr;
        bool common_address =
                        (address >= 0x18 && address <= 0x1a) ||
                        (address >= 0x29 && address <= 0x2b) ||
                        (address >= 0x4c && address <= 0x4e);

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        /*
         * Get well defined register value for chips with neither man_id nor
         * chip_id registers.
         */
        lhigh = i2c_smbus_read_byte_data(client, LM90_REG_LOCAL_HIGH);

        /* detection and identification */
        man_id = i2c_smbus_read_byte_data(client, LM90_REG_MAN_ID);
        chip_id = i2c_smbus_read_byte_data(client, LM90_REG_CHIP_ID);
        config1 = i2c_smbus_read_byte_data(client, LM90_REG_CONFIG1);
        convrate = i2c_smbus_read_byte_data(client, LM90_REG_CONVRATE);
        if (man_id < 0 || chip_id < 0 || config1 < 0 || convrate < 0 || lhigh < 0)
                return -ENODEV;

        /* Bail out immediately if all register report the same value */
        if (lhigh == man_id && lhigh == chip_id && lhigh == config1 && lhigh == convrate)
                return -ENODEV;

        /*
         * If reading man_id and chip_id both return the same value as lhigh,
         * the chip may not support those registers and return the most recent read
         * value. Check again with a different register and handle accordingly.
         */
        if (man_id == lhigh && chip_id == lhigh) {
                convrate = i2c_smbus_read_byte_data(client, LM90_REG_CONVRATE);
                man_id = i2c_smbus_read_byte_data(client, LM90_REG_MAN_ID);
                chip_id = i2c_smbus_read_byte_data(client, LM90_REG_CHIP_ID);
                if (convrate < 0 || man_id < 0 || chip_id < 0)
                        return -ENODEV;
                if (man_id == convrate && chip_id == convrate)
                        man_id = -1;
        }
        switch (man_id) {
        case -1:        /* Chip does not support man_id / chip_id */
                if (common_address && !convrate && !(config1 & 0x7f))
                        name = lm90_detect_lm84(client);
                break;
        case 0x01:      /* National Semiconductor */
                name = lm90_detect_national(client, chip_id, config1, convrate);
                break;
        case 0x1a:      /* ON */
                name = lm90_detect_on(client, chip_id, config1, convrate);
                break;
        case 0x23:      /* Genesys Logic */
                if (common_address && !(config1 & 0x3f) && !(convrate & 0xf8))
                        name = "gl523sm";
                break;
        case 0x41:      /* Analog Devices */
                name = lm90_detect_analog(client, common_address, chip_id, config1,
                                          convrate);
                break;
        case 0x47:      /* GMT */
                name = lm90_detect_gmt(client, chip_id, config1, convrate);
                break;
        case 0x49:      /* TI */
                name = lm90_detect_ti49(client, common_address, chip_id, config1, convrate);
                break;
        case 0x4d:      /* Maxim Integrated */
                name = lm90_detect_maxim(client, common_address, chip_id,
                                         config1, convrate);
                break;
        case 0x50:
                name = lm90_detect_nuvoton_50(client, chip_id, config1, convrate);
                break;
        case 0x54:      /* ON MC1066, Microchip TC1068, TCM1617 (originally TelCom) */
                if (common_address && !(config1 & 0x3f) && !(convrate & 0xf8))
                        name = "mc1066";
                break;
        case 0x55:      /* TI */
                name = lm90_detect_ti(client, chip_id, config1, convrate);
                break;
        case 0x5c:      /* Winbond/Nuvoton */
                name = lm90_detect_nuvoton(client, chip_id, config1, convrate);
                break;
        case 0xa1:      /*  NXP Semiconductor/Philips */
                name = lm90_detect_nxp(client, common_address, chip_id, config1, convrate);
                break;
        case 0xff:      /* MAX1617, G767, NE1617 */
                if (common_address && chip_id == 0xff && convrate < 8)
                        name = lm90_detect_max1617(client, config1);
                break;
        default:
                break;
        }

        if (!name) {    /* identification failed */
                dev_dbg(&adapter->dev,
                        "Unsupported chip at 0x%02x (man_id=0x%02X, chip_id=0x%02X)\n",
                        client->addr, man_id, chip_id);
                return -ENODEV;
        }

        strscpy(info->type, name, I2C_NAME_SIZE);

        return 0;
}

static void lm90_restore_conf(void *_data)
{
        struct lm90_data *data = _data;
        struct i2c_client *client = data->client;

        /* Restore initial configuration */
        if (data->flags & LM90_HAVE_CONVRATE)
                lm90_write_convrate(data, data->convrate_orig);
        lm90_write_reg(client, LM90_REG_CONFIG1, data->config_orig);
}

static void lm90_stop_work(void *_data)
{
        struct lm90_data *data = _data;

        scoped_guard(hwmon_lock, data->hwmon_dev) {
                data->shutdown = true;
        }
        cancel_delayed_work_sync(&data->alert_work);
        cancel_work_sync(&data->report_work);
}

static int lm90_init_client(struct i2c_client *client, struct lm90_data *data)
{
        struct device_node *np = client->dev.of_node;
        int config, convrate;

        if (data->flags & LM90_HAVE_CONVRATE) {
                convrate = lm90_read_reg(client, LM90_REG_CONVRATE);
                if (convrate < 0)
                        return convrate;
                data->convrate_orig = convrate;
                lm90_set_convrate(client, data, 500); /* 500ms; 2Hz conversion rate */
        } else {
                data->update_interval = 500;
        }

        /*
         * Start the conversions.
         */
        config = lm90_read_reg(client, LM90_REG_CONFIG1);
        if (config < 0)
                return config;
        data->config_orig = config;
        data->config = config;

        /* Check Temperature Range Select */
        if (data->flags & LM90_HAVE_EXTENDED_TEMP) {
                if (of_property_read_bool(np, "ti,extended-range-enable"))
                        config |= 0x04;
                if (!(config & 0x04))
                        data->flags &= ~LM90_HAVE_EXTENDED_TEMP;
        }

        /*
         * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
         * 0.125 degree resolution) and range (0x08, extend range
         * to -64 degree) mode for the remote temperature sensor.
         * Note that expeciments with an actual chip do not show a difference
         * if bit 3 is set or not.
         */
        if (data->kind == max6680)
                config |= 0x18;

        /*
         * Put MAX6654 into extended range (0x20, extend minimum range from
         * 0 degrees to -64 degrees). Note that extended resolution is not
         * possible on the MAX6654 unless conversion rate is set to 1 Hz or
         * slower, which is intentionally not done by default.
         */
        if (data->kind == max6654)
                config |= 0x20;

        /*
         * Select external channel 0 for devices with three sensors
         */
        if (data->flags & LM90_HAVE_TEMP3)
                config &= ~0x08;

        /*
         * Interrupt is enabled by default on reset, but it may be disabled
         * by bootloader, unmask it.
         */
        if (client->irq)
                config &= ~0x80;

        config &= 0xBF; /* run */
        lm90_update_confreg(data, config);

        return devm_add_action_or_reset(&client->dev, lm90_restore_conf, data);
}

static bool lm90_is_tripped(struct i2c_client *client)
{
        struct lm90_data *data = i2c_get_clientdata(client);
        int ret;

        ret = lm90_update_alarms(data, true);
        if (ret < 0)
                return false;

        return !!data->current_alarms;
}

static irqreturn_t lm90_irq_thread(int irq, void *dev_id)
{
        struct i2c_client *client = dev_id;

        if (lm90_is_tripped(client))
                return IRQ_HANDLED;
        else
                return IRQ_NONE;
}

static int lm90_probe_channel_from_dt(struct i2c_client *client,
                                      struct device_node *child,
                                      struct lm90_data *data)
{
        u32 id;
        s32 val;
        int err;
        struct device *dev = &client->dev;

        err = of_property_read_u32(child, "reg", &id);
        if (err) {
                dev_err(dev, "missing reg property of %pOFn\n", child);
                return err;
        }

        if (id >= MAX_CHANNELS) {
                dev_err(dev, "invalid reg property value %d in %pOFn\n", id, child);
                return -EINVAL;
        }

        err = of_property_read_string(child, "label", &data->channel_label[id]);
        if (err == -ENODATA || err == -EILSEQ) {
                dev_err(dev, "invalid label property in %pOFn\n", child);
                return err;
        }

        if (data->channel_label[id])
                data->channel_config[id] |= HWMON_T_LABEL;

        err = of_property_read_s32(child, "temperature-offset-millicelsius", &val);
        if (!err) {
                if (id == 0) {
                        dev_err(dev, "temperature-offset-millicelsius can't be set for internal channel\n");
                        return -EINVAL;
                }

                err = lm90_set_temp_offset(data, lm90_temp_offset_index[id], id, val);
                if (err) {
                        dev_err(dev, "can't set temperature offset %d for channel %d (%d)\n",
                                val, id, err);
                        return err;
                }
        }

        return 0;
}

static int lm90_parse_dt_channel_info(struct i2c_client *client,
                                      struct lm90_data *data)
{
        int err;
        struct device *dev = &client->dev;
        const struct device_node *np = dev->of_node;

        for_each_child_of_node_scoped(np, child) {
                if (strcmp(child->name, "channel"))
                        continue;

                err = lm90_probe_channel_from_dt(client, child, data);
                if (err)
                        return err;
        }

        return 0;
}

static const struct hwmon_ops lm90_ops = {
        .is_visible = lm90_is_visible,
        .read = lm90_read,
        .read_string = lm90_read_string,
        .write = lm90_write,
};

static int lm90_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct i2c_adapter *adapter = client->adapter;
        struct hwmon_channel_info *info;
        struct device *hwmon_dev;
        struct lm90_data *data;
        int err;

        err = devm_regulator_get_enable(dev, "vcc");
        if (err)
                return dev_err_probe(dev, err, "Failed to enable regulator\n");

        data = devm_kzalloc(dev, sizeof(struct lm90_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->client = client;
        i2c_set_clientdata(client, data);
        INIT_DELAYED_WORK(&data->alert_work, lm90_alert_work);
        INIT_WORK(&data->report_work, lm90_report_alarms);

        /* Set the device type */
        data->kind = (uintptr_t)i2c_get_match_data(client);

        /*
         * Different devices have different alarm bits triggering the
         * ALERT# output
         */
        data->alert_alarms = lm90_params[data->kind].alert_alarms;
        data->resolution = lm90_params[data->kind].resolution ? : 11;

        /* Set chip capabilities */
        data->flags = lm90_params[data->kind].flags;

        if ((data->flags & (LM90_HAVE_PEC | LM90_HAVE_PARTIAL_PEC)) &&
            !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_PEC))
                data->flags &= ~(LM90_HAVE_PEC | LM90_HAVE_PARTIAL_PEC);

        if ((data->flags & LM90_HAVE_PARTIAL_PEC) &&
            !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
                data->flags &= ~LM90_HAVE_PARTIAL_PEC;

        data->chip.ops = &lm90_ops;
        data->chip.info = data->info;

        data->info[0] = &data->chip_info;
        info = &data->chip_info;
        info->type = hwmon_chip;
        info->config = data->chip_config;

        data->chip_config[0] = HWMON_C_REGISTER_TZ;
        if (data->flags & LM90_HAVE_ALARMS)
                data->chip_config[0] |= HWMON_C_ALARMS;
        if (data->flags & LM90_HAVE_CONVRATE)
                data->chip_config[0] |= HWMON_C_UPDATE_INTERVAL;
        if (data->flags & LM90_HAVE_FAULTQUEUE)
                data->chip_config[0] |= HWMON_C_TEMP_SAMPLES;
        if (data->flags & (LM90_HAVE_PEC | LM90_HAVE_PARTIAL_PEC))
                data->chip_config[0] |= HWMON_C_PEC;
        data->info[1] = &data->temp_info;

        info = &data->temp_info;
        info->type = hwmon_temp;
        info->config = data->channel_config;

        data->channel_config[0] = HWMON_T_INPUT | HWMON_T_MAX |
                HWMON_T_MAX_ALARM;
        data->channel_config[1] = HWMON_T_INPUT | HWMON_T_MAX |
                HWMON_T_MAX_ALARM | HWMON_T_FAULT;

        if (data->flags & LM90_HAVE_LOW) {
                data->channel_config[0] |= HWMON_T_MIN | HWMON_T_MIN_ALARM;
                data->channel_config[1] |= HWMON_T_MIN | HWMON_T_MIN_ALARM;
        }

        if (data->flags & LM90_HAVE_CRIT) {
                data->channel_config[0] |= HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_CRIT_HYST;
                data->channel_config[1] |= HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_CRIT_HYST;
        }

        if (data->flags & LM90_HAVE_OFFSET)
                data->channel_config[1] |= HWMON_T_OFFSET;

        if (data->flags & LM90_HAVE_EMERGENCY) {
                data->channel_config[0] |= HWMON_T_EMERGENCY |
                        HWMON_T_EMERGENCY_HYST;
                data->channel_config[1] |= HWMON_T_EMERGENCY |
                        HWMON_T_EMERGENCY_HYST;
        }

        if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
                data->channel_config[0] |= HWMON_T_EMERGENCY_ALARM;
                data->channel_config[1] |= HWMON_T_EMERGENCY_ALARM;
        }

        if (data->flags & LM90_HAVE_TEMP3) {
                data->channel_config[2] = HWMON_T_INPUT |
                        HWMON_T_MIN | HWMON_T_MAX |
                        HWMON_T_CRIT | HWMON_T_CRIT_HYST |
                        HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
                        HWMON_T_CRIT_ALARM | HWMON_T_FAULT;
                if (data->flags & LM90_HAVE_EMERGENCY) {
                        data->channel_config[2] |= HWMON_T_EMERGENCY |
                                HWMON_T_EMERGENCY_HYST;
                }
                if (data->flags & LM90_HAVE_EMERGENCY_ALARM)
                        data->channel_config[2] |= HWMON_T_EMERGENCY_ALARM;
                if (data->flags & LM90_HAVE_OFFSET)
                        data->channel_config[2] |= HWMON_T_OFFSET;
        }

        data->faultqueue_mask = lm90_params[data->kind].faultqueue_mask;
        data->faultqueue_depth = lm90_params[data->kind].faultqueue_depth;
        data->reg_local_ext = lm90_params[data->kind].reg_local_ext;
        if (data->flags & LM90_HAVE_REMOTE_EXT)
                data->reg_remote_ext = LM90_REG_REMOTE_TEMPL;
        data->reg_status2 = lm90_params[data->kind].reg_status2;

        /* Set maximum conversion rate */
        data->max_convrate = lm90_params[data->kind].max_convrate;

        /* Parse device-tree channel information */
        if (client->dev.of_node) {
                err = lm90_parse_dt_channel_info(client, data);
                if (err)
                        return err;
        }

        /* Initialize the LM90 chip */
        err = lm90_init_client(client, data);
        if (err < 0) {
                dev_err(dev, "Failed to initialize device\n");
                return err;
        }

        hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
                                                         data, &data->chip,
                                                         NULL);
        if (IS_ERR(hwmon_dev))
                return PTR_ERR(hwmon_dev);

        data->hwmon_dev = hwmon_dev;

        err = devm_add_action_or_reset(&client->dev, lm90_stop_work, data);
        if (err)
                return err;

        if (client->irq) {
                dev_dbg(dev, "IRQ: %d\n", client->irq);
                err = devm_request_threaded_irq(dev, client->irq,
                                                NULL, lm90_irq_thread,
                                                IRQF_ONESHOT, "lm90", client);
                if (err < 0) {
                        dev_err(dev, "cannot request IRQ %d\n", client->irq);
                        return err;
                }
        }

        return 0;
}

static void lm90_alert(struct i2c_client *client, enum i2c_alert_protocol type,
                       unsigned int flag)
{
        if (type != I2C_PROTOCOL_SMBUS_ALERT)
                return;

        if (lm90_is_tripped(client)) {
                /*
                 * Disable ALERT# output, because these chips don't implement
                 * SMBus alert correctly; they should only hold the alert line
                 * low briefly.
                 */
                struct lm90_data *data = i2c_get_clientdata(client);

                scoped_guard(hwmon_lock, data->hwmon_dev) {
                        if (!data->shutdown && (data->flags & LM90_HAVE_BROKEN_ALERT) &&
                            (data->current_alarms & data->alert_alarms)) {
                                if (!(data->config & 0x80)) {
                                        dev_dbg(&client->dev, "Disabling ALERT#\n");
                                        lm90_update_confreg(data, data->config | 0x80);
                                }
                                schedule_delayed_work(&data->alert_work,
                                        max_t(int, HZ, msecs_to_jiffies(data->update_interval)));
                        }
                }
        } else {
                dev_dbg(&client->dev, "Everything OK\n");
        }
}

static int lm90_suspend(struct device *dev)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;

        if (client->irq)
                disable_irq(client->irq);

        return 0;
}

static int lm90_resume(struct device *dev)
{
        struct lm90_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;

        if (client->irq)
                enable_irq(client->irq);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(lm90_pm_ops, lm90_suspend, lm90_resume);

static struct i2c_driver lm90_driver = {
        .class          = I2C_CLASS_HWMON,
        .driver = {
                .name   = "lm90",
                .of_match_table = of_match_ptr(lm90_of_match),
                .pm     = pm_sleep_ptr(&lm90_pm_ops),
        },
        .probe          = lm90_probe,
        .alert          = lm90_alert,
        .id_table       = lm90_id,
        .detect         = lm90_detect,
        .address_list   = normal_i2c,
};

module_i2c_driver(lm90_driver);

MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("LM90/ADM1032 driver");
MODULE_LICENSE("GPL");