// 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 }; /* 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[4] = { 0x00, 0x01, 0x02, 0x03 }; static const u8 TMP421_TEMP_LSB[4] = { 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_data { struct i2c_client *client; struct mutex update_lock; u32 temp_config[5]; struct hwmon_channel_info temp_info; const struct hwmon_channel_info *info[2]; struct hwmon_chip_info chip; char valid; unsigned long last_updated; unsigned long channels; u8 config; s16 temp[4]; }; static int temp_from_s16(s16 reg) { /* Mask out status bits */ int temp = reg & ~0xf; return (temp * 1000 + 128) / 256; } static int temp_from_u16(u16 reg) { /* Mask out status bits */ int temp = reg & ~0xf; /* Add offset for extended temperature range. */ temp -= 64 * 256; return (temp * 1000 + 128) / 256; } static struct tmp421_data *tmp421_update_device(struct device *dev) { struct tmp421_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int i; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + (HZ / 2)) || !data->valid) { data->config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1); for (i = 0; i < data->channels; i++) { data->temp[i] = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]) << 8; data->temp[i] |= i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]); } data->last_updated = jiffies; data->valid = 1; } mutex_unlock(&data->update_lock); return data; } static int tmp421_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { struct tmp421_data *tmp421 = tmp421_update_device(dev); switch (attr) { case hwmon_temp_input: if (tmp421->config & TMP421_CONFIG_RANGE) *val = temp_from_u16(tmp421->temp[channel]); else *val = temp_from_s16(tmp421->temp[channel]); return 0; case hwmon_temp_fault: /* * The OPEN bit signals a fault. This is bit 0 of the temperature * register (low byte). */ *val = tmp421->temp[channel] & 0x01; return 0; default: return -EOPNOTSUPP; } } static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { switch (attr) { case hwmon_temp_fault: if (channel == 0) return 0; return 0444; case hwmon_temp_input: 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 const struct hwmon_ops tmp421_ops = { .is_visible = tmp421_is_visible, .read = tmp421_read, }; static int tmp421_probe(struct i2c_client *client, const struct i2c_device_id *id) { 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 = id->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; 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");