501 lines
11 KiB
C
501 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* tmp421.c
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*
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* Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
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* Preliminary support by:
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* Melvin Rook, Raymond Ng
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*/
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/*
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* Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
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* Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/jiffies.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/of_device.h>
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#include <linux/sysfs.h>
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/* Addresses to scan */
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static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
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I2C_CLIENT_END };
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enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
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#define MAX_CHANNELS 4
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/* The TMP421 registers */
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#define TMP421_STATUS_REG 0x08
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#define TMP421_CONFIG_REG_1 0x09
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#define TMP421_CONFIG_REG_2 0x0A
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#define TMP421_CONFIG_REG_REN(x) (BIT(3 + (x)))
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#define TMP421_CONFIG_REG_REN_MASK GENMASK(6, 3)
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#define TMP421_CONVERSION_RATE_REG 0x0B
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#define TMP421_N_FACTOR_REG_1 0x21
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#define TMP421_MANUFACTURER_ID_REG 0xFE
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#define TMP421_DEVICE_ID_REG 0xFF
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static const u8 TMP421_TEMP_MSB[MAX_CHANNELS] = { 0x00, 0x01, 0x02, 0x03 };
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static const u8 TMP421_TEMP_LSB[MAX_CHANNELS] = { 0x10, 0x11, 0x12, 0x13 };
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/* Flags */
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#define TMP421_CONFIG_SHUTDOWN 0x40
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#define TMP421_CONFIG_RANGE 0x04
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/* Manufacturer / Device ID's */
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#define TMP421_MANUFACTURER_ID 0x55
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#define TMP421_DEVICE_ID 0x21
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#define TMP422_DEVICE_ID 0x22
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#define TMP423_DEVICE_ID 0x23
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#define TMP441_DEVICE_ID 0x41
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#define TMP442_DEVICE_ID 0x42
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static const struct i2c_device_id tmp421_id[] = {
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{ "tmp421", 2 },
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{ "tmp422", 3 },
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{ "tmp423", 4 },
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{ "tmp441", 2 },
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{ "tmp442", 3 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, tmp421_id);
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static const struct of_device_id __maybe_unused tmp421_of_match[] = {
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{
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.compatible = "ti,tmp421",
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.data = (void *)2
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},
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{
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.compatible = "ti,tmp422",
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.data = (void *)3
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},
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{
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.compatible = "ti,tmp423",
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.data = (void *)4
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},
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{
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.compatible = "ti,tmp441",
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.data = (void *)2
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},
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{
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.compatible = "ti,tmp442",
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.data = (void *)3
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},
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{ },
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};
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MODULE_DEVICE_TABLE(of, tmp421_of_match);
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struct tmp421_channel {
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const char *label;
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bool enabled;
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s16 temp;
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};
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struct tmp421_data {
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struct i2c_client *client;
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struct mutex update_lock;
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u32 temp_config[MAX_CHANNELS + 1];
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struct hwmon_channel_info temp_info;
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const struct hwmon_channel_info *info[2];
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struct hwmon_chip_info chip;
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bool valid;
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unsigned long last_updated;
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unsigned long channels;
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u8 config;
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struct tmp421_channel channel[MAX_CHANNELS];
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};
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static int temp_from_raw(u16 reg, bool extended)
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{
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/* Mask out status bits */
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int temp = reg & ~0xf;
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if (extended)
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temp = temp - 64 * 256;
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else
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temp = (s16)temp;
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return DIV_ROUND_CLOSEST(temp * 1000, 256);
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}
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static int tmp421_update_device(struct tmp421_data *data)
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{
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struct i2c_client *client = data->client;
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int ret = 0;
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int i;
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mutex_lock(&data->update_lock);
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if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
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!data->valid) {
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ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
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if (ret < 0)
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goto exit;
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data->config = ret;
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for (i = 0; i < data->channels; i++) {
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ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
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if (ret < 0)
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goto exit;
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data->channel[i].temp = ret << 8;
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ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
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if (ret < 0)
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goto exit;
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data->channel[i].temp |= ret;
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}
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data->last_updated = jiffies;
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data->valid = true;
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}
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exit:
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mutex_unlock(&data->update_lock);
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if (ret < 0) {
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data->valid = false;
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return ret;
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}
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return 0;
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}
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static int tmp421_enable_channels(struct tmp421_data *data)
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{
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int err;
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struct i2c_client *client = data->client;
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struct device *dev = &client->dev;
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int old = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);
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int new, i;
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if (old < 0) {
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dev_err(dev, "error reading register, can't disable channels\n");
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return old;
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}
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new = old & ~TMP421_CONFIG_REG_REN_MASK;
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for (i = 0; i < data->channels; i++)
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if (data->channel[i].enabled)
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new |= TMP421_CONFIG_REG_REN(i);
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if (new == old)
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return 0;
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err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, new);
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if (err < 0)
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dev_err(dev, "error writing register, can't disable channels\n");
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return err;
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}
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static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
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u32 attr, int channel, long *val)
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{
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struct tmp421_data *tmp421 = dev_get_drvdata(dev);
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int ret = 0;
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ret = tmp421_update_device(tmp421);
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if (ret)
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return ret;
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switch (attr) {
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case hwmon_temp_input:
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if (!tmp421->channel[channel].enabled)
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return -ENODATA;
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*val = temp_from_raw(tmp421->channel[channel].temp,
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tmp421->config & TMP421_CONFIG_RANGE);
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return 0;
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case hwmon_temp_fault:
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if (!tmp421->channel[channel].enabled)
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return -ENODATA;
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/*
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* Any of OPEN or /PVLD bits indicate a hardware mulfunction
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* and the conversion result may be incorrect
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*/
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*val = !!(tmp421->channel[channel].temp & 0x03);
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return 0;
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case hwmon_temp_enable:
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*val = tmp421->channel[channel].enabled;
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return 0;
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default:
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return -EOPNOTSUPP;
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}
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}
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static int tmp421_read_string(struct device *dev, enum hwmon_sensor_types type,
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u32 attr, int channel, const char **str)
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{
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struct tmp421_data *data = dev_get_drvdata(dev);
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*str = data->channel[channel].label;
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return 0;
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}
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static int tmp421_write(struct device *dev, enum hwmon_sensor_types type,
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u32 attr, int channel, long val)
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{
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struct tmp421_data *data = dev_get_drvdata(dev);
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int ret;
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switch (attr) {
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case hwmon_temp_enable:
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data->channel[channel].enabled = val;
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ret = tmp421_enable_channels(data);
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break;
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default:
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ret = -EOPNOTSUPP;
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}
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return ret;
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}
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static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
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u32 attr, int channel)
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{
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switch (attr) {
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case hwmon_temp_fault:
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case hwmon_temp_input:
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return 0444;
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case hwmon_temp_label:
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return 0444;
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case hwmon_temp_enable:
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return 0644;
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default:
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return 0;
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}
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}
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static int tmp421_init_client(struct tmp421_data *data)
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{
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int config, config_orig;
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struct i2c_client *client = data->client;
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/* Set the conversion rate to 2 Hz */
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i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
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/* Start conversions (disable shutdown if necessary) */
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config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
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if (config < 0) {
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dev_err(&client->dev,
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"Could not read configuration register (%d)\n", config);
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return config;
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}
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config_orig = config;
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config &= ~TMP421_CONFIG_SHUTDOWN;
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if (config != config_orig) {
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dev_info(&client->dev, "Enable monitoring chip\n");
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i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
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}
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return tmp421_enable_channels(data);
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}
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static int tmp421_detect(struct i2c_client *client,
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struct i2c_board_info *info)
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{
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enum chips kind;
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struct i2c_adapter *adapter = client->adapter;
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static const char * const names[] = {
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"TMP421", "TMP422", "TMP423",
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"TMP441", "TMP442"
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};
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int addr = client->addr;
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u8 reg;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -ENODEV;
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reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
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if (reg != TMP421_MANUFACTURER_ID)
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return -ENODEV;
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reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
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if (reg & 0xf8)
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return -ENODEV;
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reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
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if (reg & 0x7f)
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return -ENODEV;
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reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
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switch (reg) {
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case TMP421_DEVICE_ID:
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kind = tmp421;
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break;
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case TMP422_DEVICE_ID:
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if (addr == 0x2a)
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return -ENODEV;
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kind = tmp422;
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break;
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case TMP423_DEVICE_ID:
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if (addr != 0x4c && addr != 0x4d)
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return -ENODEV;
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kind = tmp423;
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break;
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case TMP441_DEVICE_ID:
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kind = tmp441;
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break;
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case TMP442_DEVICE_ID:
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if (addr != 0x4c && addr != 0x4d)
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return -ENODEV;
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kind = tmp442;
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break;
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default:
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return -ENODEV;
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}
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strscpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
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dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
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names[kind], client->addr);
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return 0;
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}
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static int tmp421_probe_child_from_dt(struct i2c_client *client,
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struct device_node *child,
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struct tmp421_data *data)
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{
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struct device *dev = &client->dev;
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u32 i;
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s32 val;
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int err;
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err = of_property_read_u32(child, "reg", &i);
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if (err) {
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dev_err(dev, "missing reg property of %pOFn\n", child);
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return err;
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}
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if (i >= data->channels) {
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dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
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return -EINVAL;
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}
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of_property_read_string(child, "label", &data->channel[i].label);
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if (data->channel[i].label)
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data->temp_config[i] |= HWMON_T_LABEL;
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data->channel[i].enabled = of_device_is_available(child);
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err = of_property_read_s32(child, "ti,n-factor", &val);
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if (!err) {
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if (i == 0) {
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dev_err(dev, "n-factor can't be set for internal channel\n");
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return -EINVAL;
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}
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if (val > 127 || val < -128) {
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dev_err(dev, "n-factor for channel %d invalid (%d)\n",
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i, val);
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return -EINVAL;
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}
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i2c_smbus_write_byte_data(client, TMP421_N_FACTOR_REG_1 + i - 1,
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val);
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}
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return 0;
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}
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static int tmp421_probe_from_dt(struct i2c_client *client, struct tmp421_data *data)
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{
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struct device *dev = &client->dev;
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const struct device_node *np = dev->of_node;
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struct device_node *child;
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int err;
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for_each_child_of_node(np, child) {
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if (strcmp(child->name, "channel"))
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continue;
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err = tmp421_probe_child_from_dt(client, child, data);
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if (err) {
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of_node_put(child);
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return err;
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}
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}
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return 0;
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}
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static const struct hwmon_ops tmp421_ops = {
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.is_visible = tmp421_is_visible,
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.read = tmp421_read,
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.read_string = tmp421_read_string,
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.write = tmp421_write,
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};
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static int tmp421_probe(struct i2c_client *client)
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{
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struct device *dev = &client->dev;
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struct device *hwmon_dev;
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struct tmp421_data *data;
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int i, err;
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data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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mutex_init(&data->update_lock);
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if (client->dev.of_node)
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data->channels = (unsigned long)
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of_device_get_match_data(&client->dev);
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else
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data->channels = i2c_match_id(tmp421_id, client)->driver_data;
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data->client = client;
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for (i = 0; i < data->channels; i++) {
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data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_ENABLE;
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data->channel[i].enabled = true;
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}
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err = tmp421_probe_from_dt(client, data);
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if (err)
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return err;
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err = tmp421_init_client(data);
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if (err)
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return err;
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data->chip.ops = &tmp421_ops;
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data->chip.info = data->info;
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data->info[0] = &data->temp_info;
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data->temp_info.type = hwmon_temp;
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data->temp_info.config = data->temp_config;
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hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
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data,
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&data->chip,
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NULL);
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return PTR_ERR_OR_ZERO(hwmon_dev);
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}
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static struct i2c_driver tmp421_driver = {
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.class = I2C_CLASS_HWMON,
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.driver = {
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.name = "tmp421",
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.of_match_table = of_match_ptr(tmp421_of_match),
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},
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.probe = tmp421_probe,
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.id_table = tmp421_id,
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.detect = tmp421_detect,
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.address_list = normal_i2c,
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};
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module_i2c_driver(tmp421_driver);
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MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
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MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
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MODULE_LICENSE("GPL");
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