#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.h>
#include <linux/sysfs.h>
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
#define TMP421_STATUS_REG 0x08
#define TMP421_CONFIG_REG_1 0x09
#define TMP421_CONFIG_REG_2 0x0A
#define TMP421_CONFIG_REG_REN(x) (BIT(3 + (x)))
#define TMP421_CONFIG_REG_REN_MASK GENMASK(6, 3)
#define TMP421_CONVERSION_RATE_REG 0x0B
#define TMP421_N_FACTOR_REG_1 0x21
#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 };
#define TMP421_CONFIG_SHUTDOWN 0x40
#define TMP421_CONFIG_RANGE 0x04
#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;
bool enabled;
s16 temp;
};
struct tmp421_data {
struct i2c_client *client;
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)
{
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;
if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
!data->valid) {
data->valid = false;
ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
if (ret < 0)
return ret;
data->config = ret;
for (i = 0; i < data->channels; i++) {
ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
if (ret < 0)
return ret;
data->channel[i].temp = ret << 8;
ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
if (ret < 0)
return ret;
data->channel[i].temp |= ret;
}
data->last_updated = jiffies;
data->valid = true;
}
return 0;
}
static int tmp421_enable_channels(struct tmp421_data *data)
{
int err;
struct i2c_client *client = data->client;
struct device *dev = &client->dev;
int old = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);
int new, i;
if (old < 0) {
dev_err(dev, "error reading register, can't disable channels\n");
return old;
}
new = old & ~TMP421_CONFIG_REG_REN_MASK;
for (i = 0; i < data->channels; i++)
if (data->channel[i].enabled)
new |= TMP421_CONFIG_REG_REN(i);
if (new == old)
return 0;
err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, new);
if (err < 0)
dev_err(dev, "error writing register, can't disable channels\n");
return err;
}
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:
if (!tmp421->channel[channel].enabled)
return -ENODATA;
*val = temp_from_raw(tmp421->channel[channel].temp,
tmp421->config & TMP421_CONFIG_RANGE);
return 0;
case hwmon_temp_fault:
if (!tmp421->channel[channel].enabled)
return -ENODATA;
*val = !!(tmp421->channel[channel].temp & 0x03);
return 0;
case hwmon_temp_enable:
*val = tmp421->channel[channel].enabled;
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 int tmp421_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
struct tmp421_data *data = dev_get_drvdata(dev);
int ret;
switch (attr) {
case hwmon_temp_enable:
data->channel[channel].enabled = val;
ret = tmp421_enable_channels(data);
break;
default:
ret = -EOPNOTSUPP;
}
return ret;
}
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:
case hwmon_temp_label:
return 0444;
case hwmon_temp_enable:
return 0644;
default:
return 0;
}
}
static int tmp421_init_client(struct tmp421_data *data)
{
int config, config_orig;
struct i2c_client *client = data->client;
i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
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 tmp421_enable_channels(data);
}
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;
}
strscpy(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;
s32 val;
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;
}
err = of_property_read_string(child, "label", &data->channel[i].label);
if (err == -ENODATA || err == -EILSEQ) {
dev_err(dev, "invalid label property in %pOFn\n", child);
return err;
}
if (data->channel[i].label)
data->temp_config[i] |= HWMON_T_LABEL;
data->channel[i].enabled = of_device_is_available(child);
err = of_property_read_s32(child, "ti,n-factor", &val);
if (!err) {
if (i == 0) {
dev_err(dev, "n-factor can't be set for internal channel\n");
return -EINVAL;
}
if (val > 127 || val < -128) {
dev_err(dev, "n-factor for channel %d invalid (%d)\n",
i, val);
return -EINVAL;
}
i2c_smbus_write_byte_data(client, TMP421_N_FACTOR_REG_1 + i - 1,
val);
}
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;
int err;
for_each_child_of_node_scoped(np, child) {
if (strcmp(child->name, "channel"))
continue;
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,
.write = tmp421_write,
};
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;
data->channels = (unsigned long)i2c_get_match_data(client);
data->client = client;
for (i = 0; i < data->channels; i++) {
data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_ENABLE;
data->channel[i].enabled = true;
}
err = tmp421_probe_from_dt(client, data);
if (err)
return err;
err = tmp421_init_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 = 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");
