diff options
Diffstat (limited to 'drivers/hwmon/w83773g.c')
| -rw-r--r-- | drivers/hwmon/w83773g.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/drivers/hwmon/w83773g.c b/drivers/hwmon/w83773g.c new file mode 100644 index 000000000000..e858093ac806 --- /dev/null +++ b/drivers/hwmon/w83773g.c @@ -0,0 +1,329 @@ +/* + * Copyright (C) 2017 IBM Corp. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * Driver for the Nuvoton W83773G SMBus temperature sensor IC. + * Supported models: W83773G + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/i2c.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/err.h> +#include <linux/of_device.h> +#include <linux/regmap.h> + +/* W83773 has 3 channels */ +#define W83773_CHANNELS 3 + +/* The W83773 registers */ +#define W83773_CONVERSION_RATE_REG_READ 0x04 +#define W83773_CONVERSION_RATE_REG_WRITE 0x0A +#define W83773_MANUFACTURER_ID_REG 0xFE +#define W83773_LOCAL_TEMP 0x00 + +static const u8 W83773_STATUS[2] = { 0x02, 0x17 }; + +static const u8 W83773_TEMP_LSB[2] = { 0x10, 0x25 }; +static const u8 W83773_TEMP_MSB[2] = { 0x01, 0x24 }; + +static const u8 W83773_OFFSET_LSB[2] = { 0x12, 0x16 }; +static const u8 W83773_OFFSET_MSB[2] = { 0x11, 0x15 }; + +/* this is the number of sensors in the device */ +static const struct i2c_device_id w83773_id[] = { + { "w83773g" }, + { } +}; + +MODULE_DEVICE_TABLE(i2c, w83773_id); + +static const struct of_device_id w83773_of_match[] = { + { + .compatible = "nuvoton,w83773g" + }, + { }, +}; +MODULE_DEVICE_TABLE(of, w83773_of_match); + +static inline long temp_of_local(s8 reg) +{ + return reg * 1000; +} + +static inline long temp_of_remote(s8 hb, u8 lb) +{ + return (hb << 3 | lb >> 5) * 125; +} + +static int get_local_temp(struct regmap *regmap, long *val) +{ + unsigned int regval; + int ret; + + ret = regmap_read(regmap, W83773_LOCAL_TEMP, ®val); + if (ret < 0) + return ret; + + *val = temp_of_local(regval); + return 0; +} + +static int get_remote_temp(struct regmap *regmap, int index, long *val) +{ + unsigned int regval_high; + unsigned int regval_low; + int ret; + + ret = regmap_read(regmap, W83773_TEMP_MSB[index], ®val_high); + if (ret < 0) + return ret; + + ret = regmap_read(regmap, W83773_TEMP_LSB[index], ®val_low); + if (ret < 0) + return ret; + + *val = temp_of_remote(regval_high, regval_low); + return 0; +} + +static int get_fault(struct regmap *regmap, int index, long *val) +{ + unsigned int regval; + int ret; + + ret = regmap_read(regmap, W83773_STATUS[index], ®val); + if (ret < 0) + return ret; + + *val = (regval & 0x04) >> 2; + return 0; +} + +static int get_offset(struct regmap *regmap, int index, long *val) +{ + unsigned int regval_high; + unsigned int regval_low; + int ret; + + ret = regmap_read(regmap, W83773_OFFSET_MSB[index], ®val_high); + if (ret < 0) + return ret; + + ret = regmap_read(regmap, W83773_OFFSET_LSB[index], ®val_low); + if (ret < 0) + return ret; + + *val = temp_of_remote(regval_high, regval_low); + return 0; +} + +static int set_offset(struct regmap *regmap, int index, long val) +{ + int ret; + u8 high_byte; + u8 low_byte; + + val = clamp_val(val, -127825, 127825); + /* offset value equals to (high_byte << 3 | low_byte >> 5) * 125 */ + val /= 125; + high_byte = val >> 3; + low_byte = (val & 0x07) << 5; + + ret = regmap_write(regmap, W83773_OFFSET_MSB[index], high_byte); + if (ret < 0) + return ret; + + return regmap_write(regmap, W83773_OFFSET_LSB[index], low_byte); +} + +static int get_update_interval(struct regmap *regmap, long *val) +{ + unsigned int regval; + int ret; + + ret = regmap_read(regmap, W83773_CONVERSION_RATE_REG_READ, ®val); + if (ret < 0) + return ret; + + *val = 16000 >> regval; + return 0; +} + +static int set_update_interval(struct regmap *regmap, long val) +{ + int rate; + + /* + * For valid rates, interval can be calculated as + * interval = (1 << (8 - rate)) * 62.5; + * Rounded rate is therefore + * rate = 8 - __fls(interval * 8 / (62.5 * 7)); + * Use clamp_val() to avoid overflows, and to ensure valid input + * for __fls. + */ + val = clamp_val(val, 62, 16000) * 10; + rate = 8 - __fls((val * 8 / (625 * 7))); + return regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, rate); +} + +static int w83773_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct regmap *regmap = dev_get_drvdata(dev); + + if (type == hwmon_chip) { + if (attr == hwmon_chip_update_interval) + return get_update_interval(regmap, val); + return -EOPNOTSUPP; + } + + switch (attr) { + case hwmon_temp_input: + if (channel == 0) + return get_local_temp(regmap, val); + return get_remote_temp(regmap, channel - 1, val); + case hwmon_temp_fault: + return get_fault(regmap, channel - 1, val); + case hwmon_temp_offset: + return get_offset(regmap, channel - 1, val); + default: + return -EOPNOTSUPP; + } +} + +static int w83773_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct regmap *regmap = dev_get_drvdata(dev); + + if (type == hwmon_chip && attr == hwmon_chip_update_interval) + return set_update_interval(regmap, val); + + if (type == hwmon_temp && attr == hwmon_temp_offset) + return set_offset(regmap, channel - 1, val); + + return -EOPNOTSUPP; +} + +static umode_t w83773_is_visible(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_chip: + switch (attr) { + case hwmon_chip_update_interval: + return 0644; + } + break; + case hwmon_temp: + switch (attr) { + case hwmon_temp_input: + case hwmon_temp_fault: + return 0444; + case hwmon_temp_offset: + return 0644; + } + break; + default: + break; + } + return 0; +} + +static const u32 w83773_chip_config[] = { + HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL, + 0 +}; + +static const struct hwmon_channel_info w83773_chip = { + .type = hwmon_chip, + .config = w83773_chip_config, +}; + +static const u32 w83773_temp_config[] = { + HWMON_T_INPUT, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET, + 0 +}; + +static const struct hwmon_channel_info w83773_temp = { + .type = hwmon_temp, + .config = w83773_temp_config, +}; + +static const struct hwmon_channel_info *w83773_info[] = { + &w83773_chip, + &w83773_temp, + NULL +}; + +static const struct hwmon_ops w83773_ops = { + .is_visible = w83773_is_visible, + .read = w83773_read, + .write = w83773_write, +}; + +static const struct hwmon_chip_info w83773_chip_info = { + .ops = &w83773_ops, + .info = w83773_info, +}; + +static const struct regmap_config w83773_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int w83773_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct device *hwmon_dev; + struct regmap *regmap; + int ret; + + regmap = devm_regmap_init_i2c(client, &w83773_regmap_config); + if (IS_ERR(regmap)) { + dev_err(dev, "failed to allocate register map\n"); + return PTR_ERR(regmap); + } + + /* Set the conversion rate to 2 Hz */ + ret = regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, 0x05); + if (ret < 0) { + dev_err(&client->dev, "error writing config rate register\n"); + return ret; + } + + i2c_set_clientdata(client, regmap); + + hwmon_dev = devm_hwmon_device_register_with_info(dev, + client->name, + regmap, + &w83773_chip_info, + NULL); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static struct i2c_driver w83773_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "w83773g", + .of_match_table = of_match_ptr(w83773_of_match), + }, + .probe = w83773_probe, + .id_table = w83773_id, +}; + +module_i2c_driver(w83773_driver); + +MODULE_AUTHOR("Lei YU <mine260309@gmail.com>"); +MODULE_DESCRIPTION("W83773G temperature sensor driver"); +MODULE_LICENSE("GPL"); |