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- // SPDX-License-Identifier: GPL-2.0-or-later
- /* tmp421.c
- *
- * Copyright (C) 2009 Andre Prendel <[email protected]>
- * 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_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[] = {
- { "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;
- 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_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:
- return 0444;
- 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;
- }
- of_property_read_string(child, "label", &data->channel[i].label);
- 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;
- struct device_node *child;
- int err;
- for_each_child_of_node(np, child) {
- if (strcmp(child->name, "channel"))
- continue;
- err = tmp421_probe_child_from_dt(client, child, data);
- if (err) {
- of_node_put(child);
- 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;
- 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;
- 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_new = tmp421_probe,
- .id_table = tmp421_id,
- .detect = tmp421_detect,
- .address_list = normal_i2c,
- };
- module_i2c_driver(tmp421_driver);
- MODULE_AUTHOR("Andre Prendel <[email protected]>");
- MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
- MODULE_LICENSE("GPL");
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