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linux_dsm_epyc7002/drivers/hwmon/lm75.c
Alban Bedel 707d151bd1 hwmon: (lm75) Add regulator support 
Add regulator support for boards where the sensor first need to be
powered up before it can be used.

Signed-off-by: Alban Bedel <alban.bedel@aerq.com>
Link: https://lore.kernel.org/r/20201001145738.17326-4-alban.bedel@aerq.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2020-10-04 08:40:10 -07:00

932 lines
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// 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 <frodol@dds.nl>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.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/of.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>
#include <linux/regulator/consumer.h>
#include "lm75.h"
/*
* This driver handles the LM75 and compatible digital temperature sensors.
*/
enum lm75_type { /* keep sorted in alphabetical order */
adt75,
ds1775,
ds75,
ds7505,
g751,
lm75,
lm75a,
lm75b,
max6625,
max6626,
max31725,
mcp980x,
pct2075,
stds75,
stlm75,
tcn75,
tmp100,
tmp101,
tmp105,
tmp112,
tmp175,
tmp275,
tmp75,
tmp75b,
tmp75c,
};
/**
* 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,
},
[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,
}
};
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, &regval);
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, &reg);
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 *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_RBTREE,
.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 = (enum lm75_type)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, },
{ "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, },
{ /* 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 = "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
},
{ },
};
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;
}
strlcpy(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_new = lm75_probe,
.id_table = lm75_ids,
.detect = lm75_detect,
.address_list = normal_i2c,
};
module_i2c_driver(lm75_driver);
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
MODULE_DESCRIPTION("LM75 driver");
MODULE_LICENSE("GPL");
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