441 lines
11 KiB
C
441 lines
11 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Driver for MAX31730 3-Channel Remote Temperature Sensor
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*
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* Copyright (c) 2019 Guenter Roeck <linux@roeck-us.net>
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*/
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#include <linux/bits.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/hwmon.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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/* Addresses scanned */
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static const unsigned short normal_i2c[] = { 0x1c, 0x1d, 0x1e, 0x1f, 0x4c,
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0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
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/* The MAX31730 registers */
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#define MAX31730_REG_TEMP 0x00
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#define MAX31730_REG_CONF 0x13
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#define MAX31730_STOP BIT(7)
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#define MAX31730_EXTRANGE BIT(1)
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#define MAX31730_REG_TEMP_OFFSET 0x16
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#define MAX31730_TEMP_OFFSET_BASELINE 0x77
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#define MAX31730_REG_OFFSET_ENABLE 0x17
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#define MAX31730_REG_TEMP_MAX 0x20
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#define MAX31730_REG_TEMP_MIN 0x30
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#define MAX31730_REG_STATUS_HIGH 0x32
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#define MAX31730_REG_STATUS_LOW 0x33
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#define MAX31730_REG_CHANNEL_ENABLE 0x35
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#define MAX31730_REG_TEMP_FAULT 0x36
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#define MAX31730_REG_MFG_ID 0x50
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#define MAX31730_MFG_ID 0x4d
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#define MAX31730_REG_MFG_REV 0x51
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#define MAX31730_MFG_REV 0x01
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#define MAX31730_TEMP_MIN (-128000)
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#define MAX31730_TEMP_MAX 127937
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/* Each client has this additional data */
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struct max31730_data {
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struct i2c_client *client;
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u8 orig_conf;
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u8 current_conf;
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u8 offset_enable;
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u8 channel_enable;
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};
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/*-----------------------------------------------------------------------*/
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static inline long max31730_reg_to_mc(s16 temp)
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{
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return DIV_ROUND_CLOSEST((temp >> 4) * 1000, 16);
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}
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static int max31730_write_config(struct max31730_data *data, u8 set_mask,
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u8 clr_mask)
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{
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u8 value;
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clr_mask |= MAX31730_EXTRANGE;
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value = data->current_conf & ~clr_mask;
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value |= set_mask;
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if (data->current_conf != value) {
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s32 err;
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err = i2c_smbus_write_byte_data(data->client, MAX31730_REG_CONF,
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value);
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if (err)
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return err;
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data->current_conf = value;
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}
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return 0;
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}
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static int max31730_set_enable(struct i2c_client *client, int reg,
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u8 *confdata, int channel, bool enable)
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{
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u8 regval = *confdata;
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int err;
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if (enable)
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regval |= BIT(channel);
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else
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regval &= ~BIT(channel);
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if (regval != *confdata) {
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err = i2c_smbus_write_byte_data(client, reg, regval);
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if (err)
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return err;
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*confdata = regval;
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}
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return 0;
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}
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static int max31730_set_offset_enable(struct max31730_data *data, int channel,
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bool enable)
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{
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return max31730_set_enable(data->client, MAX31730_REG_OFFSET_ENABLE,
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&data->offset_enable, channel, enable);
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}
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static int max31730_set_channel_enable(struct max31730_data *data, int channel,
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bool enable)
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{
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return max31730_set_enable(data->client, MAX31730_REG_CHANNEL_ENABLE,
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&data->channel_enable, channel, enable);
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}
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static int max31730_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 max31730_data *data = dev_get_drvdata(dev);
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int regval, reg, offset;
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if (type != hwmon_temp)
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return -EINVAL;
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switch (attr) {
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case hwmon_temp_input:
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if (!(data->channel_enable & BIT(channel)))
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return -ENODATA;
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reg = MAX31730_REG_TEMP + (channel * 2);
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break;
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case hwmon_temp_max:
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reg = MAX31730_REG_TEMP_MAX + (channel * 2);
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break;
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case hwmon_temp_min:
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reg = MAX31730_REG_TEMP_MIN;
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break;
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case hwmon_temp_enable:
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*val = !!(data->channel_enable & BIT(channel));
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return 0;
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case hwmon_temp_offset:
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if (!channel)
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return -EINVAL;
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if (!(data->offset_enable & BIT(channel))) {
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*val = 0;
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return 0;
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}
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offset = i2c_smbus_read_byte_data(data->client,
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MAX31730_REG_TEMP_OFFSET);
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if (offset < 0)
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return offset;
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*val = (offset - MAX31730_TEMP_OFFSET_BASELINE) * 125;
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return 0;
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case hwmon_temp_fault:
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regval = i2c_smbus_read_byte_data(data->client,
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MAX31730_REG_TEMP_FAULT);
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if (regval < 0)
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return regval;
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*val = !!(regval & BIT(channel));
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return 0;
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case hwmon_temp_min_alarm:
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regval = i2c_smbus_read_byte_data(data->client,
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MAX31730_REG_STATUS_LOW);
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if (regval < 0)
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return regval;
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*val = !!(regval & BIT(channel));
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return 0;
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case hwmon_temp_max_alarm:
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regval = i2c_smbus_read_byte_data(data->client,
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MAX31730_REG_STATUS_HIGH);
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if (regval < 0)
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return regval;
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*val = !!(regval & BIT(channel));
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return 0;
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default:
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return -EINVAL;
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}
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regval = i2c_smbus_read_word_swapped(data->client, reg);
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if (regval < 0)
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return regval;
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*val = max31730_reg_to_mc(regval);
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return 0;
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}
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static int max31730_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 max31730_data *data = dev_get_drvdata(dev);
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int reg, err;
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if (type != hwmon_temp)
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return -EINVAL;
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switch (attr) {
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case hwmon_temp_max:
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reg = MAX31730_REG_TEMP_MAX + channel * 2;
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break;
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case hwmon_temp_min:
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reg = MAX31730_REG_TEMP_MIN;
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break;
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case hwmon_temp_enable:
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if (val != 0 && val != 1)
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return -EINVAL;
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return max31730_set_channel_enable(data, channel, val);
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case hwmon_temp_offset:
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val = clamp_val(val, -14875, 17000) + 14875;
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val = DIV_ROUND_CLOSEST(val, 125);
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err = max31730_set_offset_enable(data, channel,
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val != MAX31730_TEMP_OFFSET_BASELINE);
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if (err)
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return err;
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return i2c_smbus_write_byte_data(data->client,
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MAX31730_REG_TEMP_OFFSET, val);
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default:
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return -EINVAL;
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}
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val = clamp_val(val, MAX31730_TEMP_MIN, MAX31730_TEMP_MAX);
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val = DIV_ROUND_CLOSEST(val << 4, 1000) << 4;
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return i2c_smbus_write_word_swapped(data->client, reg, (u16)val);
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}
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static umode_t max31730_is_visible(const void *data,
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enum hwmon_sensor_types type,
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u32 attr, int channel)
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{
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switch (type) {
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case hwmon_temp:
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switch (attr) {
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case hwmon_temp_input:
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case hwmon_temp_min_alarm:
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case hwmon_temp_max_alarm:
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case hwmon_temp_fault:
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return 0444;
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case hwmon_temp_min:
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return channel ? 0444 : 0644;
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case hwmon_temp_offset:
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case hwmon_temp_enable:
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case hwmon_temp_max:
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return 0644;
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}
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break;
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default:
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break;
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}
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return 0;
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}
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static const struct hwmon_channel_info *max31730_info[] = {
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HWMON_CHANNEL_INFO(chip,
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HWMON_C_REGISTER_TZ),
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HWMON_CHANNEL_INFO(temp,
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HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
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HWMON_T_ENABLE |
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HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM,
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HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
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HWMON_T_OFFSET | HWMON_T_ENABLE |
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HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
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HWMON_T_FAULT,
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HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
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HWMON_T_OFFSET | HWMON_T_ENABLE |
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HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
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HWMON_T_FAULT,
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HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
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HWMON_T_OFFSET | HWMON_T_ENABLE |
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HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
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HWMON_T_FAULT
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),
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NULL
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};
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static const struct hwmon_ops max31730_hwmon_ops = {
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.is_visible = max31730_is_visible,
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.read = max31730_read,
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.write = max31730_write,
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};
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static const struct hwmon_chip_info max31730_chip_info = {
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.ops = &max31730_hwmon_ops,
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.info = max31730_info,
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};
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static void max31730_remove(void *data)
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{
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struct max31730_data *max31730 = data;
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struct i2c_client *client = max31730->client;
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i2c_smbus_write_byte_data(client, MAX31730_REG_CONF,
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max31730->orig_conf);
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}
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static int
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max31730_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 max31730_data *data;
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int status, err;
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
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return -EIO;
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data = devm_kzalloc(dev, sizeof(struct max31730_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->client = client;
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/* Cache original configuration and enable status */
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status = i2c_smbus_read_byte_data(client, MAX31730_REG_CHANNEL_ENABLE);
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if (status < 0)
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return status;
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data->channel_enable = status;
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status = i2c_smbus_read_byte_data(client, MAX31730_REG_OFFSET_ENABLE);
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if (status < 0)
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return status;
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data->offset_enable = status;
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status = i2c_smbus_read_byte_data(client, MAX31730_REG_CONF);
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if (status < 0)
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return status;
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data->orig_conf = status;
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data->current_conf = status;
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err = max31730_write_config(data,
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data->channel_enable ? 0 : MAX31730_STOP,
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data->channel_enable ? MAX31730_STOP : 0);
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if (err)
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return err;
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dev_set_drvdata(dev, data);
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err = devm_add_action_or_reset(dev, max31730_remove, data);
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if (err)
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return err;
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hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
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data,
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&max31730_chip_info,
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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 const struct i2c_device_id max31730_ids[] = {
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{ "max31730", 0, },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, max31730_ids);
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static const struct of_device_id __maybe_unused max31730_of_match[] = {
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{
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.compatible = "maxim,max31730",
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},
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{ },
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};
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MODULE_DEVICE_TABLE(of, max31730_of_match);
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static bool max31730_check_reg_temp(struct i2c_client *client,
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int reg)
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{
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int regval;
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regval = i2c_smbus_read_byte_data(client, reg + 1);
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return regval < 0 || (regval & 0x0f);
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}
|
||
|
|
|
||
|
|
/* Return 0 if detection is successful, -ENODEV otherwise */
|
||
|
|
static int max31730_detect(struct i2c_client *client,
|
||
|
|
struct i2c_board_info *info)
|
||
|
|
{
|
||
|
|
struct i2c_adapter *adapter = client->adapter;
|
||
|
|
int regval;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
|
||
|
|
I2C_FUNC_SMBUS_WORD_DATA))
|
||
|
|
return -ENODEV;
|
||
|
|
|
||
|
|
regval = i2c_smbus_read_byte_data(client, MAX31730_REG_MFG_ID);
|
||
|
|
if (regval != MAX31730_MFG_ID)
|
||
|
|
return -ENODEV;
|
||
|
|
regval = i2c_smbus_read_byte_data(client, MAX31730_REG_MFG_REV);
|
||
|
|
if (regval != MAX31730_MFG_REV)
|
||
|
|
return -ENODEV;
|
||
|
|
|
||
|
|
/* lower 4 bit of temperature and limit registers must be 0 */
|
||
|
|
if (max31730_check_reg_temp(client, MAX31730_REG_TEMP_MIN))
|
||
|
|
return -ENODEV;
|
||
|
|
|
||
|
|
for (i = 0; i < 4; i++) {
|
||
|
|
if (max31730_check_reg_temp(client, MAX31730_REG_TEMP + i * 2))
|
||
|
|
return -ENODEV;
|
||
|
|
if (max31730_check_reg_temp(client,
|
||
|
|
MAX31730_REG_TEMP_MAX + i * 2))
|
||
|
|
return -ENODEV;
|
||
|
|
}
|
||
|
|
|
||
|
|
strscpy(info->type, "max31730", I2C_NAME_SIZE);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int max31730_suspend(struct device *dev)
|
||
|
|
{
|
||
|
|
struct max31730_data *data = dev_get_drvdata(dev);
|
||
|
|
|
||
|
|
return max31730_write_config(data, MAX31730_STOP, 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int max31730_resume(struct device *dev)
|
||
|
|
{
|
||
|
|
struct max31730_data *data = dev_get_drvdata(dev);
|
||
|
|
|
||
|
|
return max31730_write_config(data, 0, MAX31730_STOP);
|
||
|
|
}
|
||
|
|
|
||
|
|
static DEFINE_SIMPLE_DEV_PM_OPS(max31730_pm_ops, max31730_suspend, max31730_resume);
|
||
|
|
|
||
|
|
static struct i2c_driver max31730_driver = {
|
||
|
|
.class = I2C_CLASS_HWMON,
|
||
|
|
.driver = {
|
||
|
|
.name = "max31730",
|
||
|
|
.of_match_table = of_match_ptr(max31730_of_match),
|
||
|
|
.pm = pm_sleep_ptr(&max31730_pm_ops),
|
||
|
|
},
|
||
|
|
.probe_new = max31730_probe,
|
||
|
|
.id_table = max31730_ids,
|
||
|
|
.detect = max31730_detect,
|
||
|
|
.address_list = normal_i2c,
|
||
|
|
};
|
||
|
|
|
||
|
|
module_i2c_driver(max31730_driver);
|
||
|
|
|
||
|
|
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
|
||
|
|
MODULE_DESCRIPTION("MAX31730 driver");
|
||
|
|
MODULE_LICENSE("GPL");
|