linux/drivers/hwmon/pmbus/max31785.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2017 IBM Corp.
 */

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include "pmbus.h"

enum max31785_regs { … };

#define MAX31785 …
#define MAX31785A …
#define MAX31785B …

#define MFR_FAN_CONFIG_DUAL_TACH …

#define MAX31785_NR_PAGES …
#define MAX31785_NR_FAN_PAGES …
#define MAX31785_WAIT_DELAY_US …

struct max31785_data { … };

#define to_max31785_data(x) …

/*
 * MAX31785 Driver Workaround
 *
 * The MAX31785 fan controller occasionally exhibits communication issues.
 * These issues are not indicated by the device itself, except for occasional
 * NACK responses during master transactions. No error bits are set in STATUS_BYTE.
 *
 * To address this, we introduce a delay of 250us between consecutive accesses
 * to the fan controller. This delay helps mitigate communication problems by
 * allowing sufficient time between accesses.
 */
static inline void max31785_wait(const struct max31785_data *data)
{ … }

static int max31785_i2c_write_byte_data(struct i2c_client *client,
					struct max31785_data *driver_data,
					int command, u16 data)
{ … }

static int max31785_i2c_read_word_data(struct i2c_client *client,
				       struct max31785_data *driver_data,
				       int command)
{ … }

static int _max31785_read_byte_data(struct i2c_client *client,
				    struct max31785_data *driver_data,
				    int page, int command)
{ … }

static int _max31785_write_byte_data(struct i2c_client *client,
				     struct max31785_data *driver_data,
				     int page, int command, u16 data)
{ … }

static int _max31785_read_word_data(struct i2c_client *client,
				    struct max31785_data *driver_data,
				    int page, int phase, int command)
{ … }

static int _max31785_write_word_data(struct i2c_client *client,
				     struct max31785_data *driver_data,
				     int page, int command, u16 data)
{ … }

static int max31785_read_byte_data(struct i2c_client *client, int page, int reg)
{ … }

static int max31785_write_byte(struct i2c_client *client, int page, u8 value)
{ … }

static int max31785_read_long_data(struct i2c_client *client, int page,
				   int reg, u32 *data)
{ … }

static int max31785_get_pwm(struct i2c_client *client, int page)
{ … }

static int max31785_get_pwm_mode(struct i2c_client *client,
				 struct max31785_data *driver_data, int page)
{ … }

static int max31785_read_word_data(struct i2c_client *client, int page,
				   int phase, int reg)
{ … }

static inline u32 max31785_scale_pwm(u32 sensor_val)
{ … }

static int max31785_update_fan(struct i2c_client *client,
			       struct max31785_data *driver_data, int page,
			       u8 config, u8 mask, u16 command)
{ … }

static int max31785_pwm_enable(struct i2c_client *client,
			       struct max31785_data *driver_data, int page,
			       u16 word)
{ … }

static int max31785_write_word_data(struct i2c_client *client, int page,
				    int reg, u16 word)
{ … }

#define MAX31785_FAN_FUNCS …

#define MAX31785_TEMP_FUNCS …

#define MAX31785_VOUT_FUNCS …

static const struct pmbus_driver_info max31785_info = …;

static int max31785_configure_dual_tach(struct i2c_client *client,
					struct pmbus_driver_info *info)
{ … }

static int max31785_probe(struct i2c_client *client)
{ … }

static const struct i2c_device_id max31785_id[] = …;

MODULE_DEVICE_TABLE(i2c, max31785_id);

static const struct of_device_id max31785_of_match[] = …;

MODULE_DEVICE_TABLE(of, max31785_of_match);

static struct i2c_driver max31785_driver = …;

module_i2c_driver(…) …;

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;
MODULE_IMPORT_NS(…);