From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/hwmon/lm75.c | 957 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 957 insertions(+) create mode 100644 drivers/hwmon/lm75.c (limited to 'drivers/hwmon/lm75.c') diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c new file mode 100644 index 0000000000..5b2ea05c95 --- /dev/null +++ b/drivers/hwmon/lm75.c @@ -0,0 +1,957 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * lm75.c - Part of lm_sensors, Linux kernel modules for hardware + * monitoring + * Copyright (c) 1998, 1999 Frodo Looijaard + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "lm75.h" + +/* + * This driver handles the LM75 and compatible digital temperature sensors. + */ + +enum lm75_type { /* keep sorted in alphabetical order */ + adt75, + at30ts74, + ds1775, + ds75, + ds7505, + g751, + lm75, + lm75a, + lm75b, + max6625, + max6626, + max31725, + mcp980x, + pct2075, + stds75, + stlm75, + tcn75, + tmp100, + tmp101, + tmp105, + tmp112, + tmp175, + tmp275, + tmp75, + tmp75b, + tmp75c, + tmp1075, +}; + +/** + * struct lm75_params - lm75 configuration parameters. + * @set_mask: Bits to set in configuration register when configuring + * the chip. + * @clr_mask: Bits to clear in configuration register when configuring + * the chip. + * @default_resolution: Default number of bits to represent the temperature + * value. + * @resolution_limits: Limit register resolution. Optional. Should be set if + * the resolution of limit registers does not match the + * resolution of the temperature register. + * @resolutions: List of resolutions associated with sample times. + * Optional. Should be set if num_sample_times is larger + * than 1, and if the resolution changes with sample times. + * If set, number of entries must match num_sample_times. + * @default_sample_time:Sample time to be set by default. + * @num_sample_times: Number of possible sample times to be set. Optional. + * Should be set if the number of sample times is larger + * than one. + * @sample_times: All the possible sample times to be set. Mandatory if + * num_sample_times is larger than 1. If set, number of + * entries must match num_sample_times. + */ + +struct lm75_params { + u8 set_mask; + u8 clr_mask; + u8 default_resolution; + u8 resolution_limits; + const u8 *resolutions; + unsigned int default_sample_time; + u8 num_sample_times; + const unsigned int *sample_times; +}; + +/* Addresses scanned */ +static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, + 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; + +/* The LM75 registers */ +#define LM75_REG_TEMP 0x00 +#define LM75_REG_CONF 0x01 +#define LM75_REG_HYST 0x02 +#define LM75_REG_MAX 0x03 +#define PCT2075_REG_IDLE 0x04 + +/* Each client has this additional data */ +struct lm75_data { + struct i2c_client *client; + struct regmap *regmap; + struct regulator *vs; + u8 orig_conf; + u8 current_conf; + u8 resolution; /* In bits, 9 to 16 */ + unsigned int sample_time; /* In ms */ + enum lm75_type kind; + const struct lm75_params *params; +}; + +/*-----------------------------------------------------------------------*/ + +static const u8 lm75_sample_set_masks[] = { 0 << 5, 1 << 5, 2 << 5, 3 << 5 }; + +#define LM75_SAMPLE_CLEAR_MASK (3 << 5) + +/* The structure below stores the configuration values of the supported devices. + * In case of being supported multiple configurations, the default one must + * always be the first element of the array + */ +static const struct lm75_params device_params[] = { + [adt75] = { + .clr_mask = 1 << 5, /* not one-shot mode */ + .default_resolution = 12, + .default_sample_time = MSEC_PER_SEC / 10, + }, + [at30ts74] = { + .set_mask = 3 << 5, /* 12-bit mode*/ + .default_resolution = 12, + .default_sample_time = 200, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 25, 50, 100, 200 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [ds1775] = { + .clr_mask = 3 << 5, + .set_mask = 2 << 5, /* 11-bit mode */ + .default_resolution = 11, + .default_sample_time = 500, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 125, 250, 500, 1000 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [ds75] = { + .clr_mask = 3 << 5, + .set_mask = 2 << 5, /* 11-bit mode */ + .default_resolution = 11, + .default_sample_time = 600, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 150, 300, 600, 1200 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [stds75] = { + .clr_mask = 3 << 5, + .set_mask = 2 << 5, /* 11-bit mode */ + .default_resolution = 11, + .default_sample_time = 600, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 150, 300, 600, 1200 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [stlm75] = { + .default_resolution = 9, + .default_sample_time = MSEC_PER_SEC / 6, + }, + [ds7505] = { + .set_mask = 3 << 5, /* 12-bit mode*/ + .default_resolution = 12, + .default_sample_time = 200, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 25, 50, 100, 200 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [g751] = { + .default_resolution = 9, + .default_sample_time = MSEC_PER_SEC / 10, + }, + [lm75] = { + .default_resolution = 9, + .default_sample_time = MSEC_PER_SEC / 10, + }, + [lm75a] = { + .default_resolution = 9, + .default_sample_time = MSEC_PER_SEC / 10, + }, + [lm75b] = { + .default_resolution = 11, + .default_sample_time = MSEC_PER_SEC / 10, + }, + [max6625] = { + .default_resolution = 9, + .default_sample_time = MSEC_PER_SEC / 7, + }, + [max6626] = { + .default_resolution = 12, + .default_sample_time = MSEC_PER_SEC / 7, + .resolution_limits = 9, + }, + [max31725] = { + .default_resolution = 16, + .default_sample_time = MSEC_PER_SEC / 20, + }, + [tcn75] = { + .default_resolution = 9, + .default_sample_time = MSEC_PER_SEC / 18, + }, + [pct2075] = { + .default_resolution = 11, + .default_sample_time = MSEC_PER_SEC / 10, + .num_sample_times = 31, + .sample_times = (unsigned int []){ 100, 200, 300, 400, 500, 600, + 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, + 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, + 2800, 2900, 3000, 3100 }, + }, + [mcp980x] = { + .set_mask = 3 << 5, /* 12-bit mode */ + .clr_mask = 1 << 7, /* not one-shot mode */ + .default_resolution = 12, + .resolution_limits = 9, + .default_sample_time = 240, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 30, 60, 120, 240 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [tmp100] = { + .set_mask = 3 << 5, /* 12-bit mode */ + .clr_mask = 1 << 7, /* not one-shot mode */ + .default_resolution = 12, + .default_sample_time = 320, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 40, 80, 160, 320 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [tmp101] = { + .set_mask = 3 << 5, /* 12-bit mode */ + .clr_mask = 1 << 7, /* not one-shot mode */ + .default_resolution = 12, + .default_sample_time = 320, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 40, 80, 160, 320 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [tmp105] = { + .set_mask = 3 << 5, /* 12-bit mode */ + .clr_mask = 1 << 7, /* not one-shot mode*/ + .default_resolution = 12, + .default_sample_time = 220, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 28, 55, 110, 220 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [tmp112] = { + .set_mask = 3 << 5, /* 8 samples / second */ + .clr_mask = 1 << 7, /* no one-shot mode*/ + .default_resolution = 12, + .default_sample_time = 125, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 125, 250, 1000, 4000 }, + }, + [tmp175] = { + .set_mask = 3 << 5, /* 12-bit mode */ + .clr_mask = 1 << 7, /* not one-shot mode*/ + .default_resolution = 12, + .default_sample_time = 220, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 28, 55, 110, 220 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [tmp275] = { + .set_mask = 3 << 5, /* 12-bit mode */ + .clr_mask = 1 << 7, /* not one-shot mode*/ + .default_resolution = 12, + .default_sample_time = 220, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 28, 55, 110, 220 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [tmp75] = { + .set_mask = 3 << 5, /* 12-bit mode */ + .clr_mask = 1 << 7, /* not one-shot mode*/ + .default_resolution = 12, + .default_sample_time = 220, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 28, 55, 110, 220 }, + .resolutions = (u8 []) {9, 10, 11, 12 }, + }, + [tmp75b] = { /* not one-shot mode, Conversion rate 37Hz */ + .clr_mask = 1 << 7 | 3 << 5, + .default_resolution = 12, + .default_sample_time = MSEC_PER_SEC / 37, + .sample_times = (unsigned int []){ MSEC_PER_SEC / 37, + MSEC_PER_SEC / 18, + MSEC_PER_SEC / 9, MSEC_PER_SEC / 4 }, + .num_sample_times = 4, + }, + [tmp75c] = { + .clr_mask = 1 << 5, /*not one-shot mode*/ + .default_resolution = 12, + .default_sample_time = MSEC_PER_SEC / 12, + }, + [tmp1075] = { /* not one-shot mode, 27.5 ms sample rate */ + .clr_mask = 1 << 5 | 1 << 6 | 1 << 7, + .default_resolution = 12, + .default_sample_time = 28, + .num_sample_times = 4, + .sample_times = (unsigned int []){ 28, 55, 110, 220 }, + } +}; + +static inline long lm75_reg_to_mc(s16 temp, u8 resolution) +{ + return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8); +} + +static int lm75_write_config(struct lm75_data *data, u8 set_mask, + u8 clr_mask) +{ + u8 value; + + clr_mask |= LM75_SHUTDOWN; + value = data->current_conf & ~clr_mask; + value |= set_mask; + + if (data->current_conf != value) { + s32 err; + + err = i2c_smbus_write_byte_data(data->client, LM75_REG_CONF, + value); + if (err) + return err; + data->current_conf = value; + } + return 0; +} + +static int lm75_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct lm75_data *data = dev_get_drvdata(dev); + unsigned int regval; + int err, reg; + + switch (type) { + case hwmon_chip: + switch (attr) { + case hwmon_chip_update_interval: + *val = data->sample_time; + break; + default: + return -EINVAL; + } + break; + case hwmon_temp: + switch (attr) { + case hwmon_temp_input: + reg = LM75_REG_TEMP; + break; + case hwmon_temp_max: + reg = LM75_REG_MAX; + break; + case hwmon_temp_max_hyst: + reg = LM75_REG_HYST; + break; + default: + return -EINVAL; + } + err = regmap_read(data->regmap, reg, ®val); + if (err < 0) + return err; + + *val = lm75_reg_to_mc(regval, data->resolution); + break; + default: + return -EINVAL; + } + return 0; +} + +static int lm75_write_temp(struct device *dev, u32 attr, long temp) +{ + struct lm75_data *data = dev_get_drvdata(dev); + u8 resolution; + int reg; + + switch (attr) { + case hwmon_temp_max: + reg = LM75_REG_MAX; + break; + case hwmon_temp_max_hyst: + reg = LM75_REG_HYST; + break; + default: + return -EINVAL; + } + + /* + * Resolution of limit registers is assumed to be the same as the + * temperature input register resolution unless given explicitly. + */ + if (data->params->resolution_limits) + resolution = data->params->resolution_limits; + else + resolution = data->resolution; + + temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX); + temp = DIV_ROUND_CLOSEST(temp << (resolution - 8), + 1000) << (16 - resolution); + + return regmap_write(data->regmap, reg, (u16)temp); +} + +static int lm75_update_interval(struct device *dev, long val) +{ + struct lm75_data *data = dev_get_drvdata(dev); + unsigned int reg; + u8 index; + s32 err; + + index = find_closest(val, data->params->sample_times, + (int)data->params->num_sample_times); + + switch (data->kind) { + default: + err = lm75_write_config(data, lm75_sample_set_masks[index], + LM75_SAMPLE_CLEAR_MASK); + if (err) + return err; + + data->sample_time = data->params->sample_times[index]; + if (data->params->resolutions) + data->resolution = data->params->resolutions[index]; + break; + case tmp112: + err = regmap_read(data->regmap, LM75_REG_CONF, ®); + if (err < 0) + return err; + reg &= ~0x00c0; + reg |= (3 - index) << 6; + err = regmap_write(data->regmap, LM75_REG_CONF, reg); + if (err < 0) + return err; + data->sample_time = data->params->sample_times[index]; + break; + case pct2075: + err = i2c_smbus_write_byte_data(data->client, PCT2075_REG_IDLE, + index + 1); + if (err) + return err; + data->sample_time = data->params->sample_times[index]; + break; + } + return 0; +} + +static int lm75_write_chip(struct device *dev, u32 attr, long val) +{ + switch (attr) { + case hwmon_chip_update_interval: + return lm75_update_interval(dev, val); + default: + return -EINVAL; + } + return 0; +} + +static int lm75_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + switch (type) { + case hwmon_chip: + return lm75_write_chip(dev, attr, val); + case hwmon_temp: + return lm75_write_temp(dev, attr, val); + default: + return -EINVAL; + } + return 0; +} + +static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + const struct lm75_data *config_data = data; + + switch (type) { + case hwmon_chip: + switch (attr) { + case hwmon_chip_update_interval: + if (config_data->params->num_sample_times > 1) + return 0644; + return 0444; + } + break; + case hwmon_temp: + switch (attr) { + case hwmon_temp_input: + return 0444; + case hwmon_temp_max: + case hwmon_temp_max_hyst: + return 0644; + } + break; + default: + break; + } + return 0; +} + +static const struct hwmon_channel_info * const lm75_info[] = { + HWMON_CHANNEL_INFO(chip, + HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL), + HWMON_CHANNEL_INFO(temp, + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST), + NULL +}; + +static const struct hwmon_ops lm75_hwmon_ops = { + .is_visible = lm75_is_visible, + .read = lm75_read, + .write = lm75_write, +}; + +static const struct hwmon_chip_info lm75_chip_info = { + .ops = &lm75_hwmon_ops, + .info = lm75_info, +}; + +static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg) +{ + return reg != LM75_REG_TEMP; +} + +static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg) +{ + return reg == LM75_REG_TEMP || reg == LM75_REG_CONF; +} + +static const struct regmap_config lm75_regmap_config = { + .reg_bits = 8, + .val_bits = 16, + .max_register = PCT2075_REG_IDLE, + .writeable_reg = lm75_is_writeable_reg, + .volatile_reg = lm75_is_volatile_reg, + .val_format_endian = REGMAP_ENDIAN_BIG, + .cache_type = REGCACHE_MAPLE, + .use_single_read = true, + .use_single_write = true, +}; + +static void lm75_disable_regulator(void *data) +{ + struct lm75_data *lm75 = data; + + regulator_disable(lm75->vs); +} + +static void lm75_remove(void *data) +{ + struct lm75_data *lm75 = data; + struct i2c_client *client = lm75->client; + + i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf); +} + +static const struct i2c_device_id lm75_ids[]; + +static int lm75_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct device *hwmon_dev; + struct lm75_data *data; + int status, err; + enum lm75_type kind; + + if (client->dev.of_node) + kind = (uintptr_t)of_device_get_match_data(&client->dev); + else + kind = i2c_match_id(lm75_ids, client)->driver_data; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) + return -EIO; + + data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + data->kind = kind; + + data->vs = devm_regulator_get(dev, "vs"); + if (IS_ERR(data->vs)) + return PTR_ERR(data->vs); + + data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config); + if (IS_ERR(data->regmap)) + return PTR_ERR(data->regmap); + + /* Set to LM75 resolution (9 bits, 1/2 degree C) and range. + * Then tweak to be more precise when appropriate. + */ + + data->params = &device_params[data->kind]; + + /* Save default sample time and resolution*/ + data->sample_time = data->params->default_sample_time; + data->resolution = data->params->default_resolution; + + /* Enable the power */ + err = regulator_enable(data->vs); + if (err) { + dev_err(dev, "failed to enable regulator: %d\n", err); + return err; + } + + err = devm_add_action_or_reset(dev, lm75_disable_regulator, data); + if (err) + return err; + + /* Cache original configuration */ + status = i2c_smbus_read_byte_data(client, LM75_REG_CONF); + if (status < 0) { + dev_dbg(dev, "Can't read config? %d\n", status); + return status; + } + data->orig_conf = status; + data->current_conf = status; + + err = lm75_write_config(data, data->params->set_mask, + data->params->clr_mask); + if (err) + return err; + + err = devm_add_action_or_reset(dev, lm75_remove, data); + if (err) + return err; + + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, + data, &lm75_chip_info, + NULL); + if (IS_ERR(hwmon_dev)) + return PTR_ERR(hwmon_dev); + + dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name); + + return 0; +} + +static const struct i2c_device_id lm75_ids[] = { + { "adt75", adt75, }, + { "at30ts74", at30ts74, }, + { "ds1775", ds1775, }, + { "ds75", ds75, }, + { "ds7505", ds7505, }, + { "g751", g751, }, + { "lm75", lm75, }, + { "lm75a", lm75a, }, + { "lm75b", lm75b, }, + { "max6625", max6625, }, + { "max6626", max6626, }, + { "max31725", max31725, }, + { "max31726", max31725, }, + { "mcp980x", mcp980x, }, + { "pct2075", pct2075, }, + { "stds75", stds75, }, + { "stlm75", stlm75, }, + { "tcn75", tcn75, }, + { "tmp100", tmp100, }, + { "tmp101", tmp101, }, + { "tmp105", tmp105, }, + { "tmp112", tmp112, }, + { "tmp175", tmp175, }, + { "tmp275", tmp275, }, + { "tmp75", tmp75, }, + { "tmp75b", tmp75b, }, + { "tmp75c", tmp75c, }, + { "tmp1075", tmp1075, }, + { /* LIST END */ } +}; +MODULE_DEVICE_TABLE(i2c, lm75_ids); + +static const struct of_device_id __maybe_unused lm75_of_match[] = { + { + .compatible = "adi,adt75", + .data = (void *)adt75 + }, + { + .compatible = "atmel,at30ts74", + .data = (void *)at30ts74 + }, + { + .compatible = "dallas,ds1775", + .data = (void *)ds1775 + }, + { + .compatible = "dallas,ds75", + .data = (void *)ds75 + }, + { + .compatible = "dallas,ds7505", + .data = (void *)ds7505 + }, + { + .compatible = "gmt,g751", + .data = (void *)g751 + }, + { + .compatible = "national,lm75", + .data = (void *)lm75 + }, + { + .compatible = "national,lm75a", + .data = (void *)lm75a + }, + { + .compatible = "national,lm75b", + .data = (void *)lm75b + }, + { + .compatible = "maxim,max6625", + .data = (void *)max6625 + }, + { + .compatible = "maxim,max6626", + .data = (void *)max6626 + }, + { + .compatible = "maxim,max31725", + .data = (void *)max31725 + }, + { + .compatible = "maxim,max31726", + .data = (void *)max31725 + }, + { + .compatible = "maxim,mcp980x", + .data = (void *)mcp980x + }, + { + .compatible = "nxp,pct2075", + .data = (void *)pct2075 + }, + { + .compatible = "st,stds75", + .data = (void *)stds75 + }, + { + .compatible = "st,stlm75", + .data = (void *)stlm75 + }, + { + .compatible = "microchip,tcn75", + .data = (void *)tcn75 + }, + { + .compatible = "ti,tmp100", + .data = (void *)tmp100 + }, + { + .compatible = "ti,tmp101", + .data = (void *)tmp101 + }, + { + .compatible = "ti,tmp105", + .data = (void *)tmp105 + }, + { + .compatible = "ti,tmp112", + .data = (void *)tmp112 + }, + { + .compatible = "ti,tmp175", + .data = (void *)tmp175 + }, + { + .compatible = "ti,tmp275", + .data = (void *)tmp275 + }, + { + .compatible = "ti,tmp75", + .data = (void *)tmp75 + }, + { + .compatible = "ti,tmp75b", + .data = (void *)tmp75b + }, + { + .compatible = "ti,tmp75c", + .data = (void *)tmp75c + }, + { + .compatible = "ti,tmp1075", + .data = (void *)tmp1075 + }, + { }, +}; +MODULE_DEVICE_TABLE(of, lm75_of_match); + +#define LM75A_ID 0xA1 + +/* Return 0 if detection is successful, -ENODEV otherwise */ +static int lm75_detect(struct i2c_client *new_client, + struct i2c_board_info *info) +{ + struct i2c_adapter *adapter = new_client->adapter; + int i; + int conf, hyst, os; + bool is_lm75a = 0; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_WORD_DATA)) + return -ENODEV; + + /* + * Now, we do the remaining detection. There is no identification- + * dedicated register so we have to rely on several tricks: + * unused bits, registers cycling over 8-address boundaries, + * addresses 0x04-0x07 returning the last read value. + * The cycling+unused addresses combination is not tested, + * since it would significantly slow the detection down and would + * hardly add any value. + * + * The National Semiconductor LM75A is different than earlier + * LM75s. It has an ID byte of 0xaX (where X is the chip + * revision, with 1 being the only revision in existence) in + * register 7, and unused registers return 0xff rather than the + * last read value. + * + * Note that this function only detects the original National + * Semiconductor LM75 and the LM75A. Clones from other vendors + * aren't detected, on purpose, because they are typically never + * found on PC hardware. They are found on embedded designs where + * they can be instantiated explicitly so detection is not needed. + * The absence of identification registers on all these clones + * would make their exhaustive detection very difficult and weak, + * and odds are that the driver would bind to unsupported devices. + */ + + /* Unused bits */ + conf = i2c_smbus_read_byte_data(new_client, 1); + if (conf & 0xe0) + return -ENODEV; + + /* First check for LM75A */ + if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) { + /* + * LM75A returns 0xff on unused registers so + * just to be sure we check for that too. + */ + if (i2c_smbus_read_byte_data(new_client, 4) != 0xff + || i2c_smbus_read_byte_data(new_client, 5) != 0xff + || i2c_smbus_read_byte_data(new_client, 6) != 0xff) + return -ENODEV; + is_lm75a = 1; + hyst = i2c_smbus_read_byte_data(new_client, 2); + os = i2c_smbus_read_byte_data(new_client, 3); + } else { /* Traditional style LM75 detection */ + /* Unused addresses */ + hyst = i2c_smbus_read_byte_data(new_client, 2); + if (i2c_smbus_read_byte_data(new_client, 4) != hyst + || i2c_smbus_read_byte_data(new_client, 5) != hyst + || i2c_smbus_read_byte_data(new_client, 6) != hyst + || i2c_smbus_read_byte_data(new_client, 7) != hyst) + return -ENODEV; + os = i2c_smbus_read_byte_data(new_client, 3); + if (i2c_smbus_read_byte_data(new_client, 4) != os + || i2c_smbus_read_byte_data(new_client, 5) != os + || i2c_smbus_read_byte_data(new_client, 6) != os + || i2c_smbus_read_byte_data(new_client, 7) != os) + return -ENODEV; + } + /* + * It is very unlikely that this is a LM75 if both + * hysteresis and temperature limit registers are 0. + */ + if (hyst == 0 && os == 0) + return -ENODEV; + + /* Addresses cycling */ + for (i = 8; i <= 248; i += 40) { + if (i2c_smbus_read_byte_data(new_client, i + 1) != conf + || i2c_smbus_read_byte_data(new_client, i + 2) != hyst + || i2c_smbus_read_byte_data(new_client, i + 3) != os) + return -ENODEV; + if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7) + != LM75A_ID) + return -ENODEV; + } + + strscpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE); + + return 0; +} + +#ifdef CONFIG_PM +static int lm75_suspend(struct device *dev) +{ + int status; + struct i2c_client *client = to_i2c_client(dev); + + status = i2c_smbus_read_byte_data(client, LM75_REG_CONF); + if (status < 0) { + dev_dbg(&client->dev, "Can't read config? %d\n", status); + return status; + } + status = status | LM75_SHUTDOWN; + i2c_smbus_write_byte_data(client, LM75_REG_CONF, status); + return 0; +} + +static int lm75_resume(struct device *dev) +{ + int status; + struct i2c_client *client = to_i2c_client(dev); + + status = i2c_smbus_read_byte_data(client, LM75_REG_CONF); + if (status < 0) { + dev_dbg(&client->dev, "Can't read config? %d\n", status); + return status; + } + status = status & ~LM75_SHUTDOWN; + i2c_smbus_write_byte_data(client, LM75_REG_CONF, status); + return 0; +} + +static const struct dev_pm_ops lm75_dev_pm_ops = { + .suspend = lm75_suspend, + .resume = lm75_resume, +}; +#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops) +#else +#define LM75_DEV_PM_OPS NULL +#endif /* CONFIG_PM */ + +static struct i2c_driver lm75_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "lm75", + .of_match_table = of_match_ptr(lm75_of_match), + .pm = LM75_DEV_PM_OPS, + }, + .probe = lm75_probe, + .id_table = lm75_ids, + .detect = lm75_detect, + .address_list = normal_i2c, +}; + +module_i2c_driver(lm75_driver); + +MODULE_AUTHOR("Frodo Looijaard "); +MODULE_DESCRIPTION("LM75 driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3