root/drivers/hwmon/sch5627.c
// SPDX-License-Identifier: GPL-2.0-or-later
/***************************************************************************
 *   Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com>           *
 *                                                                         *
 ***************************************************************************/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/bits.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/pm.h>
#include <linux/init.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include "sch56xx-common.h"

#define DRVNAME "sch5627"
#define DEVNAME DRVNAME /* We only support one model */

#define SCH5627_HWMON_ID                0xa5
#define SCH5627_COMPANY_ID              0x5c
#define SCH5627_PRIMARY_ID              0xa0

#define SCH5627_REG_BUILD_CODE          0x39
#define SCH5627_REG_BUILD_ID            0x3a
#define SCH5627_REG_HWMON_ID            0x3c
#define SCH5627_REG_HWMON_REV           0x3d
#define SCH5627_REG_COMPANY_ID          0x3e
#define SCH5627_REG_PRIMARY_ID          0x3f
#define SCH5627_REG_CTRL                0x40

#define SCH5627_CTRL_START              BIT(0)
#define SCH5627_CTRL_LOCK               BIT(1)
#define SCH5627_CTRL_VBAT               BIT(4)

#define SCH5627_NO_TEMPS                8
#define SCH5627_NO_FANS                 4
#define SCH5627_NO_IN                   5

static const u16 SCH5627_REG_TEMP_MSB[SCH5627_NO_TEMPS] = {
        0x2B, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x180, 0x181 };
static const u16 SCH5627_REG_TEMP_LSN[SCH5627_NO_TEMPS] = {
        0xE2, 0xE1, 0xE1, 0xE5, 0xE5, 0xE6, 0x182, 0x182 };
static const u16 SCH5627_REG_TEMP_HIGH_NIBBLE[SCH5627_NO_TEMPS] = {
        0, 0, 1, 1, 0, 0, 0, 1 };
static const u16 SCH5627_REG_TEMP_HIGH[SCH5627_NO_TEMPS] = {
        0x61, 0x57, 0x59, 0x5B, 0x5D, 0x5F, 0x184, 0x186 };
static const u16 SCH5627_REG_TEMP_ABS[SCH5627_NO_TEMPS] = {
        0x9B, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x1A8, 0x1A9 };

static const u16 SCH5627_REG_FAN[SCH5627_NO_FANS] = {
        0x2C, 0x2E, 0x30, 0x32 };
static const u16 SCH5627_REG_FAN_MIN[SCH5627_NO_FANS] = {
        0x62, 0x64, 0x66, 0x68 };

static const u16 SCH5627_REG_PWM_MAP[SCH5627_NO_FANS] = {
        0xA0, 0xA1, 0xA2, 0xA3 };

static const u16 SCH5627_REG_IN_MSB[SCH5627_NO_IN] = {
        0x22, 0x23, 0x24, 0x25, 0x189 };
static const u16 SCH5627_REG_IN_LSN[SCH5627_NO_IN] = {
        0xE4, 0xE4, 0xE3, 0xE3, 0x18A };
static const u16 SCH5627_REG_IN_HIGH_NIBBLE[SCH5627_NO_IN] = {
        1, 0, 1, 0, 1 };
static const u16 SCH5627_REG_IN_FACTOR[SCH5627_NO_IN] = {
        10745, 3660, 9765, 10745, 3660 };
static const char * const SCH5627_IN_LABELS[SCH5627_NO_IN] = {
        "VCC", "VTT", "VBAT", "VTR", "V_IN" };

struct sch5627_data {
        struct regmap *regmap;
        unsigned short addr;
        u8 control;

        struct mutex update_lock;
        unsigned long last_battery;     /* In jiffies */
        char temp_valid;                /* !=0 if following fields are valid */
        char fan_valid;
        char in_valid;
        unsigned long temp_last_updated;        /* In jiffies */
        unsigned long fan_last_updated;
        unsigned long in_last_updated;
        u16 temp[SCH5627_NO_TEMPS];
        u16 fan[SCH5627_NO_FANS];
        u16 in[SCH5627_NO_IN];
};

static const struct regmap_range sch5627_tunables_ranges[] = {
        regmap_reg_range(0x57, 0x57),
        regmap_reg_range(0x59, 0x59),
        regmap_reg_range(0x5B, 0x5B),
        regmap_reg_range(0x5D, 0x5D),
        regmap_reg_range(0x5F, 0x5F),
        regmap_reg_range(0x61, 0x69),
        regmap_reg_range(0x96, 0x9B),
        regmap_reg_range(0xA0, 0xA3),
        regmap_reg_range(0x184, 0x184),
        regmap_reg_range(0x186, 0x186),
        regmap_reg_range(0x1A8, 0x1A9),
};

static const struct regmap_access_table sch5627_tunables_table = {
        .yes_ranges = sch5627_tunables_ranges,
        .n_yes_ranges = ARRAY_SIZE(sch5627_tunables_ranges),
};

static const struct regmap_config sch5627_regmap_config = {
        .reg_bits = 16,
        .val_bits = 8,
        .wr_table = &sch5627_tunables_table,
        .rd_table = &sch5627_tunables_table,
        .cache_type = REGCACHE_MAPLE,
        .use_single_read = true,
        .use_single_write = true,
        .can_sleep = true,
};

static int sch5627_update_temp(struct sch5627_data *data)
{
        int ret = 0;
        int i, val;

        mutex_lock(&data->update_lock);

        /* Cache the values for 1 second */
        if (time_after(jiffies, data->temp_last_updated + HZ) || !data->temp_valid) {
                for (i = 0; i < SCH5627_NO_TEMPS; i++) {
                        val = sch56xx_read_virtual_reg12(data->addr, SCH5627_REG_TEMP_MSB[i],
                                                         SCH5627_REG_TEMP_LSN[i],
                                                         SCH5627_REG_TEMP_HIGH_NIBBLE[i]);
                        if (unlikely(val < 0)) {
                                ret = val;
                                goto abort;
                        }
                        data->temp[i] = val;
                }
                data->temp_last_updated = jiffies;
                data->temp_valid = 1;
        }
abort:
        mutex_unlock(&data->update_lock);
        return ret;
}

static int sch5627_update_fan(struct sch5627_data *data)
{
        int ret = 0;
        int i, val;

        mutex_lock(&data->update_lock);

        /* Cache the values for 1 second */
        if (time_after(jiffies, data->fan_last_updated + HZ) || !data->fan_valid) {
                for (i = 0; i < SCH5627_NO_FANS; i++) {
                        val = sch56xx_read_virtual_reg16(data->addr, SCH5627_REG_FAN[i]);
                        if (unlikely(val < 0)) {
                                ret = val;
                                goto abort;
                        }
                        data->fan[i] = val;
                }
                data->fan_last_updated = jiffies;
                data->fan_valid = 1;
        }
abort:
        mutex_unlock(&data->update_lock);
        return ret;
}

static int sch5627_update_in(struct sch5627_data *data)
{
        int ret = 0;
        int i, val;

        mutex_lock(&data->update_lock);

        /* Trigger a Vbat voltage measurement every 5 minutes */
        if (time_after(jiffies, data->last_battery + 300 * HZ)) {
                sch56xx_write_virtual_reg(data->addr, SCH5627_REG_CTRL,
                                          data->control | SCH5627_CTRL_VBAT);
                data->last_battery = jiffies;
        }

        /* Cache the values for 1 second */
        if (time_after(jiffies, data->in_last_updated + HZ) || !data->in_valid) {
                for (i = 0; i < SCH5627_NO_IN; i++) {
                        val = sch56xx_read_virtual_reg12(data->addr, SCH5627_REG_IN_MSB[i],
                                                         SCH5627_REG_IN_LSN[i],
                                                         SCH5627_REG_IN_HIGH_NIBBLE[i]);
                        if (unlikely(val < 0)) {
                                ret = val;
                                goto abort;
                        }
                        data->in[i] = val;
                }
                data->in_last_updated = jiffies;
                data->in_valid = 1;
        }
abort:
        mutex_unlock(&data->update_lock);
        return ret;
}

static int reg_to_temp(u16 reg)
{
        return (reg * 625) / 10 - 64000;
}

static int reg_to_temp_limit(u8 reg)
{
        return (reg - 64) * 1000;
}

static int reg_to_rpm(u16 reg)
{
        if (reg == 0)
                return -EIO;
        if (reg == 0xffff)
                return 0;

        return 5400540 / reg;
}

static u8 sch5627_temp_limit_to_reg(long value)
{
        long limit = (value / 1000) + 64;

        return clamp_val(limit, 0, U8_MAX);
}

static u16 sch5627_rpm_to_reg(long value)
{
        long pulses;

        if (value <= 0)
                return U16_MAX - 1;

        pulses = 5400540 / value;

        return clamp_val(pulses, 1, U16_MAX - 1);
}

static umode_t sch5627_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
                                  int channel)
{
        const struct sch5627_data *data = drvdata;

        /* Once the lock bit is set, the virtual registers become read-only
         * until the next power cycle.
         */
        if (data->control & SCH5627_CTRL_LOCK)
                return 0444;

        switch (type) {
        case hwmon_temp:
                switch (attr) {
                case hwmon_temp_max:
                case hwmon_temp_crit:
                        return 0644;
                default:
                        break;
                }
                break;
        case hwmon_fan:
                switch (attr) {
                case hwmon_fan_min:
                        return 0644;
                default:
                        break;
                }
                break;
        case hwmon_pwm:
                switch (attr) {
                case hwmon_pwm_auto_channels_temp:
                        return 0644;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        return 0444;
}

static int sch5627_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
                        long *val)
{
        struct sch5627_data *data = dev_get_drvdata(dev);
        int ret, value;

        switch (type) {
        case hwmon_temp:
                switch (attr) {
                case hwmon_temp_input:
                        ret = sch5627_update_temp(data);
                        if (ret < 0)
                                return ret;

                        *val = reg_to_temp(data->temp[channel]);
                        return 0;
                case hwmon_temp_max:
                        ret = regmap_read(data->regmap, SCH5627_REG_TEMP_ABS[channel], &value);
                        if (ret < 0)
                                return ret;

                        *val = reg_to_temp_limit((u8)value);
                        return 0;
                case hwmon_temp_crit:
                        ret = regmap_read(data->regmap, SCH5627_REG_TEMP_HIGH[channel], &value);
                        if (ret < 0)
                                return ret;

                        *val = reg_to_temp_limit((u8)value);
                        return 0;
                case hwmon_temp_fault:
                        ret = sch5627_update_temp(data);
                        if (ret < 0)
                                return ret;

                        *val = (data->temp[channel] == 0);
                        return 0;
                default:
                        break;
                }
                break;
        case hwmon_fan:
                switch (attr) {
                case hwmon_fan_input:
                        ret = sch5627_update_fan(data);
                        if (ret < 0)
                                return ret;

                        ret = reg_to_rpm(data->fan[channel]);
                        if (ret < 0)
                                return ret;

                        *val = ret;
                        return 0;
                case hwmon_fan_min:
                        ret = sch56xx_regmap_read16(data->regmap, SCH5627_REG_FAN_MIN[channel],
                                                    &value);
                        if (ret < 0)
                                return ret;

                        ret = reg_to_rpm((u16)value);
                        if (ret < 0)
                                return ret;

                        *val = ret;
                        return 0;
                case hwmon_fan_fault:
                        ret = sch5627_update_fan(data);
                        if (ret < 0)
                                return ret;

                        *val = (data->fan[channel] == 0xffff);
                        return 0;
                default:
                        break;
                }
                break;
        case hwmon_pwm:
                switch (attr) {
                case hwmon_pwm_auto_channels_temp:
                        ret = regmap_read(data->regmap, SCH5627_REG_PWM_MAP[channel], &value);
                        if (ret < 0)
                                return ret;

                        *val = value;
                        return 0;
                default:
                        break;
                }
                break;
        case hwmon_in:
                ret = sch5627_update_in(data);
                if (ret < 0)
                        return ret;
                switch (attr) {
                case hwmon_in_input:
                        *val = DIV_ROUND_CLOSEST(data->in[channel] * SCH5627_REG_IN_FACTOR[channel],
                                                 10000);
                        return 0;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        return -EOPNOTSUPP;
}

static int sch5627_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
                               int channel, const char **str)
{
        switch (type) {
        case hwmon_in:
                switch (attr) {
                case hwmon_in_label:
                        *str = SCH5627_IN_LABELS[channel];
                        return 0;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        return -EOPNOTSUPP;
}

static int sch5627_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
                         long val)
{
        struct sch5627_data *data = dev_get_drvdata(dev);
        u16 fan;
        u8 temp;

        switch (type) {
        case hwmon_temp:
                temp = sch5627_temp_limit_to_reg(val);

                switch (attr) {
                case hwmon_temp_max:
                        return regmap_write(data->regmap, SCH5627_REG_TEMP_ABS[channel], temp);
                case hwmon_temp_crit:
                        return regmap_write(data->regmap, SCH5627_REG_TEMP_HIGH[channel], temp);
                default:
                        break;
                }
                break;
        case hwmon_fan:
                switch (attr) {
                case hwmon_fan_min:
                        fan = sch5627_rpm_to_reg(val);

                        return sch56xx_regmap_write16(data->regmap, SCH5627_REG_FAN_MIN[channel],
                                                      fan);
                default:
                        break;
                }
                break;
        case hwmon_pwm:
                switch (attr) {
                case hwmon_pwm_auto_channels_temp:
                        /* registers are 8 bit wide */
                        if (val > U8_MAX || val < 0)
                                return -EINVAL;

                        return regmap_write(data->regmap, SCH5627_REG_PWM_MAP[channel], val);
                default:
                        break;
                }
                break;
        default:
                break;
        }

        return -EOPNOTSUPP;
}

static const struct hwmon_ops sch5627_ops = {
        .is_visible = sch5627_is_visible,
        .read = sch5627_read,
        .read_string = sch5627_read_string,
        .write = sch5627_write,
};

static const struct hwmon_channel_info * const sch5627_info[] = {
        HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
        HWMON_CHANNEL_INFO(temp,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT
                           ),
        HWMON_CHANNEL_INFO(fan,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_FAULT,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_FAULT,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_FAULT,
                           HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_FAULT
                           ),
        HWMON_CHANNEL_INFO(pwm,
                           HWMON_PWM_AUTO_CHANNELS_TEMP,
                           HWMON_PWM_AUTO_CHANNELS_TEMP,
                           HWMON_PWM_AUTO_CHANNELS_TEMP,
                           HWMON_PWM_AUTO_CHANNELS_TEMP
                           ),
        HWMON_CHANNEL_INFO(in,
                           HWMON_I_INPUT | HWMON_I_LABEL,
                           HWMON_I_INPUT | HWMON_I_LABEL,
                           HWMON_I_INPUT | HWMON_I_LABEL,
                           HWMON_I_INPUT | HWMON_I_LABEL,
                           HWMON_I_INPUT
                           ),
        NULL
};

static const struct hwmon_chip_info sch5627_chip_info = {
        .ops = &sch5627_ops,
        .info = sch5627_info,
};

static int sch5627_probe(struct platform_device *pdev)
{
        struct sch5627_data *data;
        struct device *hwmon_dev;
        int build_code, build_id, hwmon_rev, val;

        data = devm_kzalloc(&pdev->dev, sizeof(struct sch5627_data),
                            GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->addr = platform_get_resource(pdev, IORESOURCE_IO, 0)->start;
        mutex_init(&data->update_lock);
        platform_set_drvdata(pdev, data);

        val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_HWMON_ID);
        if (val < 0)
                return val;

        if (val != SCH5627_HWMON_ID) {
                pr_err("invalid %s id: 0x%02X (expected 0x%02X)\n", "hwmon",
                       val, SCH5627_HWMON_ID);
                return -ENODEV;
        }

        val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_COMPANY_ID);
        if (val < 0)
                return val;

        if (val != SCH5627_COMPANY_ID) {
                pr_err("invalid %s id: 0x%02X (expected 0x%02X)\n", "company",
                       val, SCH5627_COMPANY_ID);
                return -ENODEV;
        }

        val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_PRIMARY_ID);
        if (val < 0)
                return val;

        if (val != SCH5627_PRIMARY_ID) {
                pr_err("invalid %s id: 0x%02X (expected 0x%02X)\n", "primary",
                       val, SCH5627_PRIMARY_ID);
                return -ENODEV;
        }

        build_code = sch56xx_read_virtual_reg(data->addr,
                                              SCH5627_REG_BUILD_CODE);
        if (build_code < 0)
                return build_code;

        build_id = sch56xx_read_virtual_reg16(data->addr,
                                              SCH5627_REG_BUILD_ID);
        if (build_id < 0)
                return build_id;

        hwmon_rev = sch56xx_read_virtual_reg(data->addr,
                                             SCH5627_REG_HWMON_REV);
        if (hwmon_rev < 0)
                return hwmon_rev;

        val = sch56xx_read_virtual_reg(data->addr, SCH5627_REG_CTRL);
        if (val < 0)
                return val;

        data->control = val;
        if (!(data->control & SCH5627_CTRL_START)) {
                pr_err("hardware monitoring not enabled\n");
                return -ENODEV;
        }

        data->regmap = devm_regmap_init_sch56xx(&pdev->dev, &data->update_lock, data->addr,
                                                &sch5627_regmap_config);
        if (IS_ERR(data->regmap))
                return PTR_ERR(data->regmap);

        /* Trigger a Vbat voltage measurement, so that we get a valid reading
           the first time we read Vbat */
        sch56xx_write_virtual_reg(data->addr, SCH5627_REG_CTRL, data->control | SCH5627_CTRL_VBAT);
        data->last_battery = jiffies;

        pr_info("found %s chip at %#hx\n", DEVNAME, data->addr);
        pr_info("firmware build: code 0x%02X, id 0x%04X, hwmon: rev 0x%02X\n",
                build_code, build_id, hwmon_rev);

        hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, DEVNAME, data,
                                                         &sch5627_chip_info, NULL);
        if (IS_ERR(hwmon_dev))
                return PTR_ERR(hwmon_dev);

        /* Note failing to register the watchdog is not a fatal error */
        sch56xx_watchdog_register(&pdev->dev, data->addr,
                                  (build_code << 24) | (build_id << 8) | hwmon_rev,
                                  &data->update_lock, 1);

        return 0;
}

static int sch5627_suspend(struct device *dev)
{
        struct sch5627_data *data = dev_get_drvdata(dev);

        regcache_cache_only(data->regmap, true);
        regcache_mark_dirty(data->regmap);

        return 0;
}

static int sch5627_resume(struct device *dev)
{
        struct sch5627_data *data = dev_get_drvdata(dev);

        regcache_cache_only(data->regmap, false);
        /* We must not access the virtual registers when the lock bit is set */
        if (data->control & SCH5627_CTRL_LOCK)
                return regcache_drop_region(data->regmap, 0, U16_MAX);

        return regcache_sync(data->regmap);
}

static DEFINE_SIMPLE_DEV_PM_OPS(sch5627_dev_pm_ops, sch5627_suspend, sch5627_resume);

static const struct platform_device_id sch5627_device_id[] = {
        {
                .name = "sch5627",
        },
        { }
};
MODULE_DEVICE_TABLE(platform, sch5627_device_id);

static struct platform_driver sch5627_driver = {
        .driver = {
                .name   = DRVNAME,
                .pm     = pm_sleep_ptr(&sch5627_dev_pm_ops),
        },
        .probe          = sch5627_probe,
        .id_table       = sch5627_device_id,
};

module_platform_driver(sch5627_driver);

MODULE_DESCRIPTION("SMSC SCH5627 Hardware Monitoring Driver");
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_LICENSE("GPL");