iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
c1143d1bc5
linux/drivers/hwmon/tmp421.c
Krzysztof Adamski c1143d1bc5 hwmon: (tmp421) add support for defining labels from DT 
tmp42x is a multichannel temperature sensor with several external
channels. Since those channels can be used to connect diodes placed
anywhere in the system, their meaning will vary depending on the
project. For this case, the hwmon framework has an idea of labels which
allows us to assign the meaning to each channel.

The similar concept is already implemented in ina3221 - the label for
each channel can be defined via device tree. See commit a9e9dd9c6d
("hwmon: (ina3221) Read channel input source info from DT")

This patch adds support for similar feature to tmp421.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Link: https://lore.kernel.org/r/dab0fda6ac0e8d7f163c3762a7fb1e595a4d8159.1634206677.git.krzysztof.adamski@nokia.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2021-10-15 15:44:21 -07:00

413 lines
9.1 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-or-later
/* tmp421.c
*
* Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
* Preliminary support by:
* Melvin Rook, Raymond Ng
*/
/*
* Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
* Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
*/
#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/mutex.h>
#include <linux/of_device.h>
#include <linux/sysfs.h>
/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
I2C_CLIENT_END };
enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
#define MAX_CHANNELS 4
/* The TMP421 registers */
#define TMP421_STATUS_REG 0x08
#define TMP421_CONFIG_REG_1 0x09
#define TMP421_CONVERSION_RATE_REG 0x0B
#define TMP421_MANUFACTURER_ID_REG 0xFE
#define TMP421_DEVICE_ID_REG 0xFF
static const u8 TMP421_TEMP_MSB[MAX_CHANNELS] = { 0x00, 0x01, 0x02, 0x03 };
static const u8 TMP421_TEMP_LSB[MAX_CHANNELS] = { 0x10, 0x11, 0x12, 0x13 };
/* Flags */
#define TMP421_CONFIG_SHUTDOWN 0x40
#define TMP421_CONFIG_RANGE 0x04
/* Manufacturer / Device ID's */
#define TMP421_MANUFACTURER_ID 0x55
#define TMP421_DEVICE_ID 0x21
#define TMP422_DEVICE_ID 0x22
#define TMP423_DEVICE_ID 0x23
#define TMP441_DEVICE_ID 0x41
#define TMP442_DEVICE_ID 0x42
static const struct i2c_device_id tmp421_id[] = {
{ "tmp421", 2 },
{ "tmp422", 3 },
{ "tmp423", 4 },
{ "tmp441", 2 },
{ "tmp442", 3 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tmp421_id);
static const struct of_device_id __maybe_unused tmp421_of_match[] = {
{
.compatible = "ti,tmp421",
.data = (void *)2
},
{
.compatible = "ti,tmp422",
.data = (void *)3
},
{
.compatible = "ti,tmp423",
.data = (void *)4
},
{
.compatible = "ti,tmp441",
.data = (void *)2
},
{
.compatible = "ti,tmp442",
.data = (void *)3
},
{ },
};
MODULE_DEVICE_TABLE(of, tmp421_of_match);
struct tmp421_channel {
const char *label;
s16 temp;
};
struct tmp421_data {
struct i2c_client *client;
struct mutex update_lock;
u32 temp_config[MAX_CHANNELS + 1];
struct hwmon_channel_info temp_info;
const struct hwmon_channel_info *info[2];
struct hwmon_chip_info chip;
bool valid;
unsigned long last_updated;
unsigned long channels;
u8 config;
struct tmp421_channel channel[MAX_CHANNELS];
};
static int temp_from_raw(u16 reg, bool extended)
{
/* Mask out status bits */
int temp = reg & ~0xf;
if (extended)
temp = temp - 64 * 256;
else
temp = (s16)temp;
return DIV_ROUND_CLOSEST(temp * 1000, 256);
}
static int tmp421_update_device(struct tmp421_data *data)
{
struct i2c_client *client = data->client;
int ret = 0;
int i;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
!data->valid) {
ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
if (ret < 0)
goto exit;
data->config = ret;
for (i = 0; i < data->channels; i++) {
ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
if (ret < 0)
goto exit;
data->channel[i].temp = ret << 8;
ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
if (ret < 0)
goto exit;
data->channel[i].temp |= ret;
}
data->last_updated = jiffies;
data->valid = true;
}
exit:
mutex_unlock(&data->update_lock);
if (ret < 0) {
data->valid = false;
return ret;
}
return 0;
}
static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct tmp421_data *tmp421 = dev_get_drvdata(dev);
int ret = 0;
ret = tmp421_update_device(tmp421);
if (ret)
return ret;
switch (attr) {
case hwmon_temp_input:
*val = temp_from_raw(tmp421->channel[channel].temp,
tmp421->config & TMP421_CONFIG_RANGE);
return 0;
case hwmon_temp_fault:
/*
* Any of OPEN or /PVLD bits indicate a hardware mulfunction
* and the conversion result may be incorrect
*/
*val = !!(tmp421->channel[channel].temp & 0x03);
return 0;
default:
return -EOPNOTSUPP;
}
}
static int tmp421_read_string(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, const char **str)
{
struct tmp421_data *data = dev_get_drvdata(dev);
*str = data->channel[channel].label;
return 0;
}
static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
switch (attr) {
case hwmon_temp_fault:
case hwmon_temp_input:
return 0444;
case hwmon_temp_label:
return 0444;
default:
return 0;
}
}
static int tmp421_init_client(struct i2c_client *client)
{
int config, config_orig;
/* Set the conversion rate to 2 Hz */
i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
/* Start conversions (disable shutdown if necessary) */
config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
if (config < 0) {
dev_err(&client->dev,
"Could not read configuration register (%d)\n", config);
return config;
}
config_orig = config;
config &= ~TMP421_CONFIG_SHUTDOWN;
if (config != config_orig) {
dev_info(&client->dev, "Enable monitoring chip\n");
i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
}
return 0;
}
static int tmp421_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
enum chips kind;
struct i2c_adapter *adapter = client->adapter;
static const char * const names[] = {
"TMP421", "TMP422", "TMP423",
"TMP441", "TMP442"
};
int addr = client->addr;
u8 reg;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
if (reg != TMP421_MANUFACTURER_ID)
return -ENODEV;
reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
if (reg & 0xf8)
return -ENODEV;
reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
if (reg & 0x7f)
return -ENODEV;
reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
switch (reg) {
case TMP421_DEVICE_ID:
kind = tmp421;
break;
case TMP422_DEVICE_ID:
if (addr == 0x2a)
return -ENODEV;
kind = tmp422;
break;
case TMP423_DEVICE_ID:
if (addr != 0x4c && addr != 0x4d)
return -ENODEV;
kind = tmp423;
break;
case TMP441_DEVICE_ID:
kind = tmp441;
break;
case TMP442_DEVICE_ID:
if (addr != 0x4c && addr != 0x4d)
return -ENODEV;
kind = tmp442;
break;
default:
return -ENODEV;
}
strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
names[kind], client->addr);
return 0;
}
static int tmp421_probe_child_from_dt(struct i2c_client *client,
struct device_node *child,
struct tmp421_data *data)
{
struct device *dev = &client->dev;
u32 i;
int err;
err = of_property_read_u32(child, "reg", &i);
if (err) {
dev_err(dev, "missing reg property of %pOFn\n", child);
return err;
}
if (i >= data->channels) {
dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
return -EINVAL;
}
of_property_read_string(child, "label", &data->channel[i].label);
if (data->channel[i].label)
data->temp_config[i] |= HWMON_T_LABEL;
return 0;
}
static int tmp421_probe_from_dt(struct i2c_client *client, struct tmp421_data *data)
{
struct device *dev = &client->dev;
const struct device_node *np = dev->of_node;
struct device_node *child;
int err;
for_each_child_of_node(np, child) {
err = tmp421_probe_child_from_dt(client, child, data);
if (err)
return err;
}
return 0;
}
static const struct hwmon_ops tmp421_ops = {
.is_visible = tmp421_is_visible,
.read = tmp421_read,
.read_string = tmp421_read_string,
};
static int tmp421_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct tmp421_data *data;
int i, err;
data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
mutex_init(&data->update_lock);
if (client->dev.of_node)
data->channels = (unsigned long)
of_device_get_match_data(&client->dev);
else
data->channels = i2c_match_id(tmp421_id, client)->driver_data;
data->client = client;
err = tmp421_init_client(client);
if (err)
return err;
for (i = 0; i < data->channels; i++)
data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
err = tmp421_probe_from_dt(client, data);
if (err)
return err;
data->chip.ops = &tmp421_ops;
data->chip.info = data->info;
data->info[0] = &data->temp_info;
data->temp_info.type = hwmon_temp;
data->temp_info.config = data->temp_config;
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data,
&data->chip,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static struct i2c_driver tmp421_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "tmp421",
.of_match_table = of_match_ptr(tmp421_of_match),
},
.probe_new = tmp421_probe,
.id_table = tmp421_id,
.detect = tmp421_detect,
.address_list = normal_i2c,
};
module_i2c_driver(tmp421_driver);
MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
MODULE_LICENSE("GPL");
Reference in New Issue View Git Blame Copy Permalink