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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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/* * 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/of.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_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 };
/* 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[] = { { .name = "tmp421", .driver_data = 2 }, { .name = "tmp422", .driver_data = 3 }, { .name = "tmp423", .driver_data = 4 }, { .name = "tmp441", .driver_data = 2 }, { .name = "tmp442", .driver_data = 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){ /* 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;
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; /* * 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; 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;
/* 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 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");