root/drivers/hwmon/adt7470.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * A hwmon driver for the Analog Devices ADT7470
 * Copyright (C) 2007 IBM
 *
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/log2.h>
#include <linux/kthread.h>
#include <linux/regmap.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/util_macros.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x2C, 0x2E, 0x2F, I2C_CLIENT_END };

/* ADT7470 registers */
#define ADT7470_REG_BASE_ADDR                   0x20
#define ADT7470_REG_TEMP_BASE_ADDR              0x20
#define ADT7470_REG_TEMP_MAX_ADDR               0x29
#define ADT7470_REG_FAN_BASE_ADDR               0x2A
#define ADT7470_REG_FAN_MAX_ADDR                0x31
#define ADT7470_REG_PWM_BASE_ADDR               0x32
#define ADT7470_REG_PWM_MAX_ADDR                0x35
#define ADT7470_REG_PWM_MAX_BASE_ADDR           0x38
#define ADT7470_REG_PWM_MAX_MAX_ADDR            0x3B
#define ADT7470_REG_CFG                         0x40
#define         ADT7470_STRT_MASK               0x01
#define         ADT7470_TEST_MASK               0x02
#define         ADT7470_FSPD_MASK               0x04
#define         ADT7470_T05_STB_MASK            0x80
#define ADT7470_REG_ALARM1                      0x41
#define         ADT7470_R1T_ALARM               0x01
#define         ADT7470_R2T_ALARM               0x02
#define         ADT7470_R3T_ALARM               0x04
#define         ADT7470_R4T_ALARM               0x08
#define         ADT7470_R5T_ALARM               0x10
#define         ADT7470_R6T_ALARM               0x20
#define         ADT7470_R7T_ALARM               0x40
#define         ADT7470_OOL_ALARM               0x80
#define ADT7470_REG_ALARM2                      0x42
#define         ADT7470_R8T_ALARM               0x01
#define         ADT7470_R9T_ALARM               0x02
#define         ADT7470_R10T_ALARM              0x04
#define         ADT7470_FAN1_ALARM              0x10
#define         ADT7470_FAN2_ALARM              0x20
#define         ADT7470_FAN3_ALARM              0x40
#define         ADT7470_FAN4_ALARM              0x80
#define ADT7470_REG_TEMP_LIMITS_BASE_ADDR       0x44
#define ADT7470_REG_TEMP_LIMITS_MAX_ADDR        0x57
#define ADT7470_REG_FAN_MIN_BASE_ADDR           0x58
#define ADT7470_REG_FAN_MIN_MAX_ADDR            0x5F
#define ADT7470_REG_FAN_MAX_BASE_ADDR           0x60
#define ADT7470_REG_FAN_MAX_MAX_ADDR            0x67
#define ADT7470_REG_PWM_CFG_BASE_ADDR           0x68
#define ADT7470_REG_PWM12_CFG                   0x68
#define         ADT7470_PWM2_AUTO_MASK          0x40
#define         ADT7470_PWM1_AUTO_MASK          0x80
#define         ADT7470_PWM_AUTO_MASK           0xC0
#define ADT7470_REG_PWM34_CFG                   0x69
#define         ADT7470_PWM3_AUTO_MASK          0x40
#define         ADT7470_PWM4_AUTO_MASK          0x80
#define ADT7470_REG_PWM_MIN_BASE_ADDR           0x6A
#define ADT7470_REG_PWM_MIN_MAX_ADDR            0x6D
#define ADT7470_REG_PWM_TEMP_MIN_BASE_ADDR      0x6E
#define ADT7470_REG_PWM_TEMP_MIN_MAX_ADDR       0x71
#define ADT7470_REG_CFG_2                       0x74
#define ADT7470_REG_ACOUSTICS12                 0x75
#define ADT7470_REG_ACOUSTICS34                 0x76
#define ADT7470_REG_DEVICE                      0x3D
#define ADT7470_REG_VENDOR                      0x3E
#define ADT7470_REG_REVISION                    0x3F
#define ADT7470_REG_ALARM1_MASK                 0x72
#define ADT7470_REG_ALARM2_MASK                 0x73
#define ADT7470_REG_PWM_AUTO_TEMP_BASE_ADDR     0x7C
#define ADT7470_REG_PWM_AUTO_TEMP_MAX_ADDR      0x7D
#define ADT7470_REG_MAX_ADDR                    0x81

#define ADT7470_TEMP_COUNT      10
#define ADT7470_TEMP_REG(x)     (ADT7470_REG_TEMP_BASE_ADDR + (x))
#define ADT7470_TEMP_MIN_REG(x) (ADT7470_REG_TEMP_LIMITS_BASE_ADDR + ((x) * 2))
#define ADT7470_TEMP_MAX_REG(x) (ADT7470_REG_TEMP_LIMITS_BASE_ADDR + \
                                ((x) * 2) + 1)

#define ADT7470_FAN_COUNT       4
#define ADT7470_REG_FAN(x)      (ADT7470_REG_FAN_BASE_ADDR + ((x) * 2))
#define ADT7470_REG_FAN_MIN(x)  (ADT7470_REG_FAN_MIN_BASE_ADDR + ((x) * 2))
#define ADT7470_REG_FAN_MAX(x)  (ADT7470_REG_FAN_MAX_BASE_ADDR + ((x) * 2))

#define ADT7470_PWM_COUNT       4
#define ADT7470_REG_PWM(x)      (ADT7470_REG_PWM_BASE_ADDR + (x))
#define ADT7470_REG_PWM_MAX(x)  (ADT7470_REG_PWM_MAX_BASE_ADDR + (x))
#define ADT7470_REG_PWM_MIN(x)  (ADT7470_REG_PWM_MIN_BASE_ADDR + (x))
#define ADT7470_REG_PWM_TMIN(x) (ADT7470_REG_PWM_TEMP_MIN_BASE_ADDR + (x))
#define ADT7470_REG_PWM_CFG(x)  (ADT7470_REG_PWM_CFG_BASE_ADDR + ((x) / 2))
#define ADT7470_REG_PWM_AUTO_TEMP(x)    (ADT7470_REG_PWM_AUTO_TEMP_BASE_ADDR + \
                                        ((x) / 2))

#define ALARM2(x)               ((x) << 8)

#define ADT7470_VENDOR          0x41
#define ADT7470_DEVICE          0x70
/* datasheet only mentions a revision 2 */
#define ADT7470_REVISION        0x02

/* "all temps" according to hwmon sysfs interface spec */
#define ADT7470_PWM_ALL_TEMPS   0x3FF

/* How often do we reread sensors values? (In jiffies) */
#define SENSOR_REFRESH_INTERVAL (5 * HZ)

/* How often do we reread sensor limit values? (In jiffies) */
#define LIMIT_REFRESH_INTERVAL  (60 * HZ)

/* Wait at least 200ms per sensor for 10 sensors */
#define TEMP_COLLECTION_TIME    2000

/* auto update thing won't fire more than every 2s */
#define AUTO_UPDATE_INTERVAL    2000

/* datasheet says to divide this number by the fan reading to get fan rpm */
#define FAN_PERIOD_TO_RPM(x)    ((90000 * 60) / (x))
#define FAN_RPM_TO_PERIOD       FAN_PERIOD_TO_RPM
#define FAN_PERIOD_INVALID      65535
#define FAN_DATA_VALID(x)       ((x) && (x) != FAN_PERIOD_INVALID)

/* Config registers 1 and 2 include fields for selecting the PWM frequency */
#define ADT7470_CFG_LF          0x40
#define ADT7470_FREQ_MASK       0x70
#define ADT7470_FREQ_SHIFT      4

struct adt7470_data {
        struct regmap           *regmap;
        struct mutex            lock;
        char                    sensors_valid;
        char                    limits_valid;
        unsigned long           sensors_last_updated;   /* In jiffies */
        unsigned long           limits_last_updated;    /* In jiffies */

        int                     num_temp_sensors;       /* -1 = probe */
        int                     temperatures_probed;

        s8                      temp[ADT7470_TEMP_COUNT];
        s8                      temp_min[ADT7470_TEMP_COUNT];
        s8                      temp_max[ADT7470_TEMP_COUNT];
        u16                     fan[ADT7470_FAN_COUNT];
        u16                     fan_min[ADT7470_FAN_COUNT];
        u16                     fan_max[ADT7470_FAN_COUNT];
        u16                     alarm;
        u16                     alarms_mask;
        u8                      force_pwm_max;
        u8                      pwm[ADT7470_PWM_COUNT];
        u8                      pwm_max[ADT7470_PWM_COUNT];
        u8                      pwm_automatic[ADT7470_PWM_COUNT];
        u8                      pwm_min[ADT7470_PWM_COUNT];
        s8                      pwm_tmin[ADT7470_PWM_COUNT];
        u8                      pwm_auto_temp[ADT7470_PWM_COUNT];

        struct task_struct      *auto_update;
        unsigned int            auto_update_interval;
};

/*
 * 16-bit registers on the ADT7470 are low-byte first.  The data sheet says
 * that the low byte must be read before the high byte.
 */
static inline int adt7470_read_word_data(struct adt7470_data *data, unsigned int reg,
                                         unsigned int *val)
{
        u8 regval[2];
        int err;

        err = regmap_bulk_read(data->regmap, reg, &regval, 2);
        if (err < 0)
                return err;

        *val = regval[0] | (regval[1] << 8);

        return 0;
}

static inline int adt7470_write_word_data(struct adt7470_data *data, unsigned int reg,
                                          unsigned int val)
{
        u8 regval[2];

        regval[0] = val & 0xFF;
        regval[1] = val >> 8;

        return regmap_bulk_write(data->regmap, reg, &regval, 2);
}

/* Probe for temperature sensors.  Assumes lock is held */
static int adt7470_read_temperatures(struct adt7470_data *data)
{
        unsigned long res;
        unsigned int pwm_cfg[2];
        int err;
        int i;
        u8 pwm[ADT7470_FAN_COUNT];

        /* save pwm[1-4] config register */
        err = regmap_read(data->regmap, ADT7470_REG_PWM_CFG(0), &pwm_cfg[0]);
        if (err < 0)
                return err;
        err = regmap_read(data->regmap, ADT7470_REG_PWM_CFG(2), &pwm_cfg[1]);
        if (err < 0)
                return err;

        /* set manual pwm to whatever it is set to now */
        err = regmap_bulk_read(data->regmap, ADT7470_REG_PWM(0), &pwm[0],
                               ADT7470_PWM_COUNT);
        if (err < 0)
                return err;

        /* put pwm in manual mode */
        err = regmap_update_bits(data->regmap, ADT7470_REG_PWM_CFG(0),
                                 ADT7470_PWM_AUTO_MASK, 0);
        if (err < 0)
                return err;
        err = regmap_update_bits(data->regmap, ADT7470_REG_PWM_CFG(2),
                                 ADT7470_PWM_AUTO_MASK, 0);
        if (err < 0)
                return err;

        /* write pwm control to whatever it was */
        err = regmap_bulk_write(data->regmap, ADT7470_REG_PWM(0), &pwm[0],
                                ADT7470_PWM_COUNT);
        if (err < 0)
                return err;

        /* start reading temperature sensors */
        err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
                                 ADT7470_T05_STB_MASK, ADT7470_T05_STB_MASK);
        if (err < 0)
                return err;

        /* Delay is 200ms * number of temp sensors. */
        res = msleep_interruptible((data->num_temp_sensors >= 0 ?
                                    data->num_temp_sensors * 200 :
                                    TEMP_COLLECTION_TIME));

        /* done reading temperature sensors */
        err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
                                 ADT7470_T05_STB_MASK, 0);
        if (err < 0)
                return err;

        /* restore pwm[1-4] config registers */
        err = regmap_write(data->regmap, ADT7470_REG_PWM_CFG(0), pwm_cfg[0]);
        if (err < 0)
                return err;
        err = regmap_write(data->regmap, ADT7470_REG_PWM_CFG(2), pwm_cfg[1]);
        if (err < 0)
                return err;

        if (res)
                return -EAGAIN;

        /* Only count fans if we have to */
        if (data->num_temp_sensors >= 0)
                return 0;

        err = regmap_bulk_read(data->regmap, ADT7470_TEMP_REG(0), &data->temp[0],
                               ADT7470_TEMP_COUNT);
        if (err < 0)
                return err;
        for (i = 0; i < ADT7470_TEMP_COUNT; i++) {
                if (data->temp[i])
                        data->num_temp_sensors = i + 1;
        }
        data->temperatures_probed = 1;
        return 0;
}

static int adt7470_update_thread(void *p)
{
        struct i2c_client *client = p;
        struct adt7470_data *data = i2c_get_clientdata(client);

        while (!kthread_should_stop()) {
                mutex_lock(&data->lock);
                adt7470_read_temperatures(data);
                mutex_unlock(&data->lock);

                if (kthread_should_stop())
                        break;

                schedule_timeout_interruptible(msecs_to_jiffies(data->auto_update_interval));
        }

        return 0;
}

static int adt7470_update_sensors(struct adt7470_data *data)
{
        unsigned int val;
        int err;
        int i;

        if (!data->temperatures_probed)
                err = adt7470_read_temperatures(data);
        else
                err = regmap_bulk_read(data->regmap, ADT7470_TEMP_REG(0), &data->temp[0],
                                       ADT7470_TEMP_COUNT);
        if (err < 0)
                return err;

        for (i = 0; i < ADT7470_FAN_COUNT; i++) {
                err = adt7470_read_word_data(data, ADT7470_REG_FAN(i), &val);
                if (err < 0)
                        return err;
                data->fan[i] =  val;
        }

        err = regmap_bulk_read(data->regmap, ADT7470_REG_PWM(0), &data->pwm[0], ADT7470_PWM_COUNT);
        if (err < 0)
                return err;

        for (i = 0; i < ADT7470_PWM_COUNT; i++) {
                unsigned int mask;

                if (i % 2)
                        mask = ADT7470_PWM2_AUTO_MASK;
                else
                        mask = ADT7470_PWM1_AUTO_MASK;

                err = regmap_read(data->regmap, ADT7470_REG_PWM_CFG(i), &val);
                if (err < 0)
                        return err;
                data->pwm_automatic[i] = !!(val & mask);

                err = regmap_read(data->regmap, ADT7470_REG_PWM_AUTO_TEMP(i), &val);
                if (err < 0)
                        return err;
                if (!(i % 2))
                        data->pwm_auto_temp[i] = val >> 4;
                else
                        data->pwm_auto_temp[i] = val & 0xF;
        }

        err = regmap_read(data->regmap, ADT7470_REG_CFG, &val);
        if (err < 0)
                return err;
        data->force_pwm_max = !!(val & ADT7470_FSPD_MASK);

        err = regmap_read(data->regmap, ADT7470_REG_ALARM1, &val);
        if (err < 0)
                return err;
        data->alarm = val;
        if (data->alarm & ADT7470_OOL_ALARM) {
                err = regmap_read(data->regmap, ADT7470_REG_ALARM2, &val);
                if (err < 0)
                        return err;
                data->alarm |= ALARM2(val);
        }

        err = adt7470_read_word_data(data, ADT7470_REG_ALARM1_MASK, &val);
        if (err < 0)
                return err;
        data->alarms_mask = val;

        return 0;
}

static int adt7470_update_limits(struct adt7470_data *data)
{
        unsigned int val;
        int err;
        int i;

        for (i = 0; i < ADT7470_TEMP_COUNT; i++) {
                err = regmap_read(data->regmap, ADT7470_TEMP_MIN_REG(i), &val);
                if (err < 0)
                        return err;
                data->temp_min[i] = (s8)val;
                err = regmap_read(data->regmap, ADT7470_TEMP_MAX_REG(i), &val);
                if (err < 0)
                        return err;
                data->temp_max[i] = (s8)val;
        }

        for (i = 0; i < ADT7470_FAN_COUNT; i++) {
                err = adt7470_read_word_data(data, ADT7470_REG_FAN_MIN(i), &val);
                if (err < 0)
                        return err;
                data->fan_min[i] = val;
                err = adt7470_read_word_data(data, ADT7470_REG_FAN_MAX(i), &val);
                if (err < 0)
                        return err;
                data->fan_max[i] = val;
        }

        for (i = 0; i < ADT7470_PWM_COUNT; i++) {
                err = regmap_read(data->regmap, ADT7470_REG_PWM_MAX(i), &val);
                if (err < 0)
                        return err;
                data->pwm_max[i] = val;
                err = regmap_read(data->regmap, ADT7470_REG_PWM_MIN(i), &val);
                if (err < 0)
                        return err;
                data->pwm_min[i] = val;
                err = regmap_read(data->regmap, ADT7470_REG_PWM_TMIN(i), &val);
                if (err < 0)
                        return err;
                data->pwm_tmin[i] = (s8)val;
        }

        return 0;
}

static struct adt7470_data *adt7470_update_device(struct device *dev)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        unsigned long local_jiffies = jiffies;
        int need_sensors = 1;
        int need_limits = 1;
        int err;

        /*
         * Figure out if we need to update the shadow registers.
         * Lockless means that we may occasionally report out of
         * date data.
         */
        if (time_before(local_jiffies, data->sensors_last_updated +
                        SENSOR_REFRESH_INTERVAL) &&
            data->sensors_valid)
                need_sensors = 0;

        if (time_before(local_jiffies, data->limits_last_updated +
                        LIMIT_REFRESH_INTERVAL) &&
            data->limits_valid)
                need_limits = 0;

        if (!need_sensors && !need_limits)
                return data;

        mutex_lock(&data->lock);
        if (need_sensors) {
                err = adt7470_update_sensors(data);
                if (err < 0)
                        goto out;
                data->sensors_last_updated = local_jiffies;
                data->sensors_valid = 1;
        }

        if (need_limits) {
                err = adt7470_update_limits(data);
                if (err < 0)
                        goto out;
                data->limits_last_updated = local_jiffies;
                data->limits_valid = 1;
        }
out:
        mutex_unlock(&data->lock);

        return err < 0 ? ERR_PTR(err) : data;
}

static ssize_t auto_update_interval_show(struct device *dev,
                                         struct device_attribute *devattr,
                                         char *buf)
{
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        return sprintf(buf, "%d\n", data->auto_update_interval);
}

static ssize_t auto_update_interval_store(struct device *dev,
                                          struct device_attribute *devattr,
                                          const char *buf, size_t count)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        long temp;

        if (kstrtol(buf, 10, &temp))
                return -EINVAL;

        temp = clamp_val(temp, 0, 60000);

        mutex_lock(&data->lock);
        data->auto_update_interval = temp;
        mutex_unlock(&data->lock);

        return count;
}

static ssize_t num_temp_sensors_show(struct device *dev,
                                     struct device_attribute *devattr,
                                     char *buf)
{
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        return sprintf(buf, "%d\n", data->num_temp_sensors);
}

static ssize_t num_temp_sensors_store(struct device *dev,
                                      struct device_attribute *devattr,
                                      const char *buf, size_t count)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        long temp;

        if (kstrtol(buf, 10, &temp))
                return -EINVAL;

        temp = clamp_val(temp, -1, 10);

        mutex_lock(&data->lock);
        data->num_temp_sensors = temp;
        if (temp < 0)
                data->temperatures_probed = 0;
        mutex_unlock(&data->lock);

        return count;
}

static int adt7470_temp_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        switch (attr) {
        case hwmon_temp_input:
                *val = 1000 * data->temp[channel];
                break;
        case hwmon_temp_min:
                *val = 1000 * data->temp_min[channel];
                break;
        case hwmon_temp_max:
                *val = 1000 * data->temp_max[channel];
                break;
        case hwmon_temp_alarm:
                *val = !!(data->alarm & channel);
                break;
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static int adt7470_temp_write(struct device *dev, u32 attr, int channel, long val)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        int err;

        val = clamp_val(val, -128000, 127000);
        val = DIV_ROUND_CLOSEST(val, 1000);

        switch (attr) {
        case hwmon_temp_min:
                mutex_lock(&data->lock);
                data->temp_min[channel] = val;
                err = regmap_write(data->regmap, ADT7470_TEMP_MIN_REG(channel), val);
                mutex_unlock(&data->lock);
                break;
        case hwmon_temp_max:
                mutex_lock(&data->lock);
                data->temp_max[channel] = val;
                err = regmap_write(data->regmap, ADT7470_TEMP_MAX_REG(channel), val);
                mutex_unlock(&data->lock);
                break;
        default:
                return -EOPNOTSUPP;
        }

        return err;
}

static ssize_t alarm_mask_show(struct device *dev,
                               struct device_attribute *devattr, char *buf)
{
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        return sprintf(buf, "%x\n", data->alarms_mask);
}

static ssize_t alarm_mask_store(struct device *dev,
                                struct device_attribute *devattr,
                                const char *buf, size_t count)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        long mask;
        int err;

        if (kstrtoul(buf, 0, &mask))
                return -EINVAL;

        if (mask & ~0xffff)
                return -EINVAL;

        mutex_lock(&data->lock);
        data->alarms_mask = mask;
        err = adt7470_write_word_data(data, ADT7470_REG_ALARM1_MASK, mask);
        mutex_unlock(&data->lock);

        return err < 0 ? err : count;
}

static int adt7470_fan_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        switch (attr) {
        case hwmon_fan_input:
                if (FAN_DATA_VALID(data->fan[channel]))
                        *val = FAN_PERIOD_TO_RPM(data->fan[channel]);
                else
                        *val = 0;
                break;
        case hwmon_fan_min:
                if (FAN_DATA_VALID(data->fan_min[channel]))
                        *val = FAN_PERIOD_TO_RPM(data->fan_min[channel]);
                else
                        *val = 0;
                break;
        case hwmon_fan_max:
                if (FAN_DATA_VALID(data->fan_max[channel]))
                        *val = FAN_PERIOD_TO_RPM(data->fan_max[channel]);
                else
                        *val = 0;
                break;
        case hwmon_fan_alarm:
                *val = !!(data->alarm & (1 << (12 + channel)));
                break;
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static int adt7470_fan_write(struct device *dev, u32 attr, int channel, long val)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        int err;

        if (val <= 0)
                return -EINVAL;

        val = FAN_RPM_TO_PERIOD(val);
        val = clamp_val(val, 1, 65534);

        switch (attr) {
        case hwmon_fan_min:
                mutex_lock(&data->lock);
                data->fan_min[channel] = val;
                err = adt7470_write_word_data(data, ADT7470_REG_FAN_MIN(channel), val);
                mutex_unlock(&data->lock);
                break;
        case hwmon_fan_max:
                mutex_lock(&data->lock);
                data->fan_max[channel] = val;
                err = adt7470_write_word_data(data, ADT7470_REG_FAN_MAX(channel), val);
                mutex_unlock(&data->lock);
                break;
        default:
                return -EOPNOTSUPP;
        }

        return err;
}

static ssize_t force_pwm_max_show(struct device *dev,
                                  struct device_attribute *devattr, char *buf)
{
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        return sprintf(buf, "%d\n", data->force_pwm_max);
}

static ssize_t force_pwm_max_store(struct device *dev,
                                   struct device_attribute *devattr,
                                   const char *buf, size_t count)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        long temp;
        int err;

        if (kstrtol(buf, 10, &temp))
                return -EINVAL;

        mutex_lock(&data->lock);
        data->force_pwm_max = temp;
        err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
                                 ADT7470_FSPD_MASK,
                                 temp ? ADT7470_FSPD_MASK : 0);
        mutex_unlock(&data->lock);

        return err < 0 ? err : count;
}

/* These are the valid PWM frequencies to the nearest Hz */
static const int adt7470_freq_map[] = {
        11, 15, 22, 29, 35, 44, 59, 88, 1400, 22500
};

static int pwm1_freq_get(struct device *dev)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        unsigned int regs[2] = {ADT7470_REG_CFG, ADT7470_REG_CFG_2};
        u8 cfg_reg[2];
        int index;
        int err;

        err = regmap_multi_reg_read(data->regmap, regs, cfg_reg, 2);
        if (err)
                return err;

        index = (cfg_reg[1] & ADT7470_FREQ_MASK) >> ADT7470_FREQ_SHIFT;
        if (!(cfg_reg[0] & ADT7470_CFG_LF))
                index += 8;
        if (index >= ARRAY_SIZE(adt7470_freq_map))
                index = ARRAY_SIZE(adt7470_freq_map) - 1;

        return adt7470_freq_map[index];
}

static int adt7470_pwm_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        switch (attr) {
        case hwmon_pwm_input:
                *val = data->pwm[channel];
                break;
        case hwmon_pwm_enable:
                *val = 1 + data->pwm_automatic[channel];
                break;
        case hwmon_pwm_freq:
                *val = pwm1_freq_get(dev);
                break;
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static int pwm1_freq_set(struct device *dev, long freq)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        unsigned int low_freq = ADT7470_CFG_LF;
        int index;
        int err;

        /* Round the user value given to the closest available frequency */
        index = find_closest(freq, adt7470_freq_map,
                             ARRAY_SIZE(adt7470_freq_map));

        if (index >= 8) {
                index -= 8;
                low_freq = 0;
        }

        mutex_lock(&data->lock);
        /* Configuration Register 1 */
        err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
                                 ADT7470_CFG_LF, low_freq);
        if (err < 0)
                goto out;

        /* Configuration Register 2 */
        err = regmap_update_bits(data->regmap, ADT7470_REG_CFG_2,
                                 ADT7470_FREQ_MASK,
                                 index << ADT7470_FREQ_SHIFT);
out:
        mutex_unlock(&data->lock);

        return err;
}

static int adt7470_pwm_write(struct device *dev, u32 attr, int channel, long val)
{
        struct adt7470_data *data = dev_get_drvdata(dev);
        unsigned int pwm_auto_reg_mask;
        int err;

        switch (attr) {
        case hwmon_pwm_input:
                val = clamp_val(val, 0, 255);
                mutex_lock(&data->lock);
                data->pwm[channel] = val;
                err = regmap_write(data->regmap, ADT7470_REG_PWM(channel),
                                   data->pwm[channel]);
                mutex_unlock(&data->lock);
                break;
        case hwmon_pwm_enable:
                if (channel % 2)
                        pwm_auto_reg_mask = ADT7470_PWM2_AUTO_MASK;
                else
                        pwm_auto_reg_mask = ADT7470_PWM1_AUTO_MASK;

                if (val != 2 && val != 1)
                        return -EINVAL;
                val--;

                mutex_lock(&data->lock);
                data->pwm_automatic[channel] = val;
                err = regmap_update_bits(data->regmap, ADT7470_REG_PWM_CFG(channel),
                                         pwm_auto_reg_mask,
                                         val ? pwm_auto_reg_mask : 0);
                mutex_unlock(&data->lock);
                break;
        case hwmon_pwm_freq:
                err = pwm1_freq_set(dev, val);
                break;
        default:
                return -EOPNOTSUPP;
        }

        return err;
}

static ssize_t pwm_max_show(struct device *dev,
                            struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        return sprintf(buf, "%d\n", data->pwm_max[attr->index]);
}

static ssize_t pwm_max_store(struct device *dev,
                             struct device_attribute *devattr,
                             const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = dev_get_drvdata(dev);
        long temp;
        int err;

        if (kstrtol(buf, 10, &temp))
                return -EINVAL;

        temp = clamp_val(temp, 0, 255);

        mutex_lock(&data->lock);
        data->pwm_max[attr->index] = temp;
        err = regmap_write(data->regmap, ADT7470_REG_PWM_MAX(attr->index),
                           temp);
        mutex_unlock(&data->lock);

        return err < 0 ? err : count;
}

static ssize_t pwm_min_show(struct device *dev,
                            struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        return sprintf(buf, "%d\n", data->pwm_min[attr->index]);
}

static ssize_t pwm_min_store(struct device *dev,
                             struct device_attribute *devattr,
                             const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = dev_get_drvdata(dev);
        long temp;
        int err;

        if (kstrtol(buf, 10, &temp))
                return -EINVAL;

        temp = clamp_val(temp, 0, 255);

        mutex_lock(&data->lock);
        data->pwm_min[attr->index] = temp;
        err = regmap_write(data->regmap, ADT7470_REG_PWM_MIN(attr->index),
                           temp);
        mutex_unlock(&data->lock);

        return err < 0 ? err : count;
}

static ssize_t pwm_tmax_show(struct device *dev,
                             struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        /* the datasheet says that tmax = tmin + 20C */
        return sprintf(buf, "%d\n", 1000 * (20 + data->pwm_tmin[attr->index]));
}

static ssize_t pwm_tmin_show(struct device *dev,
                             struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);

        if (IS_ERR(data))
                return PTR_ERR(data);

        return sprintf(buf, "%d\n", 1000 * data->pwm_tmin[attr->index]);
}

static ssize_t pwm_tmin_store(struct device *dev,
                              struct device_attribute *devattr,
                              const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = dev_get_drvdata(dev);
        long temp;
        int err;

        if (kstrtol(buf, 10, &temp))
                return -EINVAL;

        temp = clamp_val(temp, -128000, 127000);
        temp = DIV_ROUND_CLOSEST(temp, 1000);

        mutex_lock(&data->lock);
        data->pwm_tmin[attr->index] = temp;
        err = regmap_write(data->regmap, ADT7470_REG_PWM_TMIN(attr->index),
                           temp);
        mutex_unlock(&data->lock);

        return err < 0 ? err : count;
}

static ssize_t pwm_auto_temp_show(struct device *dev,
                                  struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
        u8 ctrl;

        if (IS_ERR(data))
                return PTR_ERR(data);

        ctrl = data->pwm_auto_temp[attr->index];
        if (ctrl)
                return sprintf(buf, "%d\n", 1 << (ctrl - 1));
        else
                return sprintf(buf, "%d\n", ADT7470_PWM_ALL_TEMPS);
}

static int cvt_auto_temp(int input)
{
        if (input == ADT7470_PWM_ALL_TEMPS)
                return 0;
        if (input < 1 || !is_power_of_2(input))
                return -EINVAL;
        return ilog2(input) + 1;
}

static ssize_t pwm_auto_temp_store(struct device *dev,
                                   struct device_attribute *devattr,
                                   const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = dev_get_drvdata(dev);
        int pwm_auto_reg = ADT7470_REG_PWM_AUTO_TEMP(attr->index);
        unsigned int mask, val;
        long temp;
        int err;

        if (kstrtol(buf, 10, &temp))
                return -EINVAL;

        temp = cvt_auto_temp(temp);
        if (temp < 0)
                return temp;

        mutex_lock(&data->lock);
        data->pwm_automatic[attr->index] = temp;

        if (!(attr->index % 2)) {
                mask = 0xF0;
                val = (temp << 4) & 0xF0;
        } else {
                mask = 0x0F;
                val = temp & 0x0F;
        }

        err = regmap_update_bits(data->regmap, pwm_auto_reg, mask, val);
        mutex_unlock(&data->lock);

        return err < 0 ? err : count;
}

static DEVICE_ATTR_RW(alarm_mask);
static DEVICE_ATTR_RW(num_temp_sensors);
static DEVICE_ATTR_RW(auto_update_interval);

static SENSOR_DEVICE_ATTR_RW(force_pwm_max, force_pwm_max, 0);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_pwm, pwm_min, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point1_pwm, pwm_min, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point1_pwm, pwm_min, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_point1_pwm, pwm_min, 3);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_pwm, pwm_max, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point2_pwm, pwm_max, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point2_pwm, pwm_max, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_point2_pwm, pwm_max, 3);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point1_temp, pwm_tmin, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_point1_temp, pwm_tmin, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_point1_temp, pwm_tmin, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_point1_temp, pwm_tmin, 3);

static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point2_temp, pwm_tmax, 0);
static SENSOR_DEVICE_ATTR_RO(pwm2_auto_point2_temp, pwm_tmax, 1);
static SENSOR_DEVICE_ATTR_RO(pwm3_auto_point2_temp, pwm_tmax, 2);
static SENSOR_DEVICE_ATTR_RO(pwm4_auto_point2_temp, pwm_tmax, 3);

static SENSOR_DEVICE_ATTR_RW(pwm1_auto_channels_temp, pwm_auto_temp, 0);
static SENSOR_DEVICE_ATTR_RW(pwm2_auto_channels_temp, pwm_auto_temp, 1);
static SENSOR_DEVICE_ATTR_RW(pwm3_auto_channels_temp, pwm_auto_temp, 2);
static SENSOR_DEVICE_ATTR_RW(pwm4_auto_channels_temp, pwm_auto_temp, 3);

static struct attribute *adt7470_attrs[] = {
        &dev_attr_alarm_mask.attr,
        &dev_attr_num_temp_sensors.attr,
        &dev_attr_auto_update_interval.attr,
        &sensor_dev_attr_force_pwm_max.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm3_auto_point1_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm4_auto_point1_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm3_auto_point2_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm4_auto_point2_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
        &sensor_dev_attr_pwm2_auto_point1_temp.dev_attr.attr,
        &sensor_dev_attr_pwm3_auto_point1_temp.dev_attr.attr,
        &sensor_dev_attr_pwm4_auto_point1_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
        &sensor_dev_attr_pwm2_auto_point2_temp.dev_attr.attr,
        &sensor_dev_attr_pwm3_auto_point2_temp.dev_attr.attr,
        &sensor_dev_attr_pwm4_auto_point2_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
        &sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
        &sensor_dev_attr_pwm3_auto_channels_temp.dev_attr.attr,
        &sensor_dev_attr_pwm4_auto_channels_temp.dev_attr.attr,
        NULL
};

ATTRIBUTE_GROUPS(adt7470);

static int adt7470_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
                        int channel, long *val)
{
        switch (type) {
        case hwmon_temp:
                return adt7470_temp_read(dev, attr, channel, val);
        case hwmon_fan:
                return adt7470_fan_read(dev, attr, channel, val);
        case hwmon_pwm:
                return adt7470_pwm_read(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static int adt7470_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
                         int channel, long val)
{
        switch (type) {
        case hwmon_temp:
                return adt7470_temp_write(dev, attr, channel, val);
        case hwmon_fan:
                return adt7470_fan_write(dev, attr, channel, val);
        case hwmon_pwm:
                return adt7470_pwm_write(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static umode_t adt7470_is_visible(const void *_data, enum hwmon_sensor_types type,
                                  u32 attr, int channel)
{
        umode_t mode = 0;

        switch (type) {
        case hwmon_temp:
                switch (attr) {
                case hwmon_temp:
                case hwmon_temp_alarm:
                        mode = 0444;
                        break;
                case hwmon_temp_min:
                case hwmon_temp_max:
                        mode = 0644;
                        break;
                default:
                        break;
                }
                break;
        case hwmon_fan:
                switch (attr) {
                case hwmon_fan_input:
                case hwmon_fan_alarm:
                        mode = 0444;
                        break;
                case hwmon_fan_min:
                case hwmon_fan_max:
                        mode = 0644;
                        break;
                default:
                        break;
                }
                break;
        case hwmon_pwm:
                switch (attr) {
                case hwmon_pwm_input:
                case hwmon_pwm_enable:
                        mode = 0644;
                        break;
                case hwmon_pwm_freq:
                        if (channel == 0)
                                mode = 0644;
                        else
                                mode = 0;
                        break;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        return mode;
}

static const struct hwmon_ops adt7470_hwmon_ops = {
        .is_visible = adt7470_is_visible,
        .read = adt7470_read,
        .write = adt7470_write,
};

static const struct hwmon_channel_info * const adt7470_info[] = {
        HWMON_CHANNEL_INFO(temp,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
                           HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM),
        HWMON_CHANNEL_INFO(fan,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX | HWMON_F_DIV | HWMON_F_ALARM),
        HWMON_CHANNEL_INFO(pwm,
                           HWMON_PWM_INPUT | HWMON_PWM_ENABLE | HWMON_PWM_FREQ,
                           HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
                           HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
                           HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
        NULL
};

static const struct hwmon_chip_info adt7470_chip_info = {
        .ops = &adt7470_hwmon_ops,
        .info = adt7470_info,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int adt7470_detect(struct i2c_client *client,
                          struct i2c_board_info *info)
{
        struct i2c_adapter *adapter = client->adapter;
        int vendor, device, revision;

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

        vendor = i2c_smbus_read_byte_data(client, ADT7470_REG_VENDOR);
        if (vendor != ADT7470_VENDOR)
                return -ENODEV;

        device = i2c_smbus_read_byte_data(client, ADT7470_REG_DEVICE);
        if (device != ADT7470_DEVICE)
                return -ENODEV;

        revision = i2c_smbus_read_byte_data(client, ADT7470_REG_REVISION);
        if (revision != ADT7470_REVISION)
                return -ENODEV;

        strscpy(info->type, "adt7470", I2C_NAME_SIZE);

        return 0;
}

static const struct regmap_config adt7470_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .use_single_read = true,
        .use_single_write = true,
};

static int adt7470_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct adt7470_data *data;
        struct device *hwmon_dev;
        int err;

        data = devm_kzalloc(dev, sizeof(struct adt7470_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->num_temp_sensors = -1;
        data->auto_update_interval = AUTO_UPDATE_INTERVAL;
        data->regmap = devm_regmap_init_i2c(client, &adt7470_regmap_config);
        if (IS_ERR(data->regmap))
                return PTR_ERR(data->regmap);

        i2c_set_clientdata(client, data);
        mutex_init(&data->lock);

        dev_info(&client->dev, "%s chip found\n", client->name);

        /* Initialize the ADT7470 chip */
        err = regmap_update_bits(data->regmap, ADT7470_REG_CFG,
                                 ADT7470_STRT_MASK | ADT7470_TEST_MASK,
                                 ADT7470_STRT_MASK | ADT7470_TEST_MASK);
        if (err < 0)
                return err;

        /* Register sysfs hooks */
        hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
                                                         &adt7470_chip_info,
                                                         adt7470_groups);

        if (IS_ERR(hwmon_dev))
                return PTR_ERR(hwmon_dev);

        data->auto_update = kthread_run(adt7470_update_thread, client, "%s",
                                        dev_name(hwmon_dev));
        if (IS_ERR(data->auto_update))
                return PTR_ERR(data->auto_update);

        return 0;
}

static void adt7470_remove(struct i2c_client *client)
{
        struct adt7470_data *data = i2c_get_clientdata(client);

        kthread_stop(data->auto_update);
}

static const struct i2c_device_id adt7470_id[] = {
        { "adt7470" },
        { }
};
MODULE_DEVICE_TABLE(i2c, adt7470_id);

static struct i2c_driver adt7470_driver = {
        .class          = I2C_CLASS_HWMON,
        .driver = {
                .name   = "adt7470",
        },
        .probe          = adt7470_probe,
        .remove         = adt7470_remove,
        .id_table       = adt7470_id,
        .detect         = adt7470_detect,
        .address_list   = normal_i2c,
};

module_i2c_driver(adt7470_driver);

MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
MODULE_DESCRIPTION("ADT7470 driver");
MODULE_LICENSE("GPL");