path: root/drivers/hwmon/asc7621.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * asc7621.c - Part of lm_sensors, Linux kernel modules for hardware monitoring
 * Copyright (c) 2007, 2010 George Joseph  <george.joseph@fairview5.com>
 */

#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>

/* Addresses to scan */
static const unsigned short normal_i2c[] = {
	0x2c, 0x2d, 0x2e, I2C_CLIENT_END
};

enum asc7621_type {
	asc7621,
	asc7621a
};

#define INTERVAL_HIGH   (HZ + HZ / 2)
#define INTERVAL_LOW    (1 * 60 * HZ)
#define PRI_NONE        0
#define PRI_LOW         1
#define PRI_HIGH        2
#define FIRST_CHIP      asc7621
#define LAST_CHIP       asc7621a

struct asc7621_chip {
	char *name;
	enum asc7621_type chip_type;
	u8 company_reg;
	u8 company_id;
	u8 verstep_reg;
	u8 verstep_id;
	const unsigned short *addresses;
};

static struct asc7621_chip asc7621_chips[] = {
	{
		.name = "asc7621",
		.chip_type = asc7621,
		.company_reg = 0x3e,
		.company_id = 0x61,
		.verstep_reg = 0x3f,
		.verstep_id = 0x6c,
		.addresses = normal_i2c,
	 },
	{
		.name = "asc7621a",
		.chip_type = asc7621a,
		.company_reg = 0x3e,
		.company_id = 0x61,
		.verstep_reg = 0x3f,
		.verstep_id = 0x6d,
		.addresses = normal_i2c,
	 },
};

/*
 * Defines the highest register to be used, not the count.
 * The actual count will probably be smaller because of gaps
 * in the implementation (unused register locations).
 * This define will safely set the array size of both the parameter
 * and data arrays.
 * This comes from the data sheet register description table.
 */
#define LAST_REGISTER 0xff

struct asc7621_data {
	struct i2c_client client;
	struct device *class_dev;
	struct mutex update_lock;
	bool valid;		/* true if following fields are valid */
	unsigned long last_high_reading;	/* In jiffies */
	unsigned long last_low_reading;		/* In jiffies */
	/*
	 * Registers we care about occupy the corresponding index
	 * in the array.  Registers we don't care about are left
	 * at 0.
	 */
	u8 reg[LAST_REGISTER + 1];
};

/*
 * Macro to get the parent asc7621_param structure
 * from a sensor_device_attribute passed into the
 * show/store functions.
 */
#define to_asc7621_param(_sda) \
	container_of(_sda, struct asc7621_param, sda)

/*
 * Each parameter to be retrieved needs an asc7621_param structure
 * allocated.  It contains the sensor_device_attribute structure
 * and the control info needed to retrieve the value from the register map.
 */
struct asc7621_param {
	struct sensor_device_attribute sda;
	u8 priority;
	u8 msb[3];
	u8 lsb[3];
	u8 mask[3];
	u8 shift[3];
};

/*
 * This is the map that ultimately indicates whether we'll be
 * retrieving a register value or not, and at what frequency.
 */
static u8 asc7621_register_priorities[255];

static struct asc7621_data *asc7621_update_device(struct device *dev);

static inline u8 read_byte(struct i2c_client *client, u8 reg)
{
	int res = i2c_smbus_read_byte_data(client, reg);
	if (res < 0) {
		dev_err(&client->dev,
			"Unable to read from register 0x%02x.\n", reg);
		return 0;
	}
	return res & 0xff;
}

static inline int write_byte(struct i2c_client *client, u8 reg, u8 data)
{
	int res = i2c_smbus_write_byte_data(client, reg, data);
	if (res < 0) {
		dev_err(&client->dev,
			"Unable to write value 0x%02x to register 0x%02x.\n",
			data, reg);
	}
	return res;
}

/*
 * Data Handlers
 * Each function handles the formatting, storage
 * and retrieval of like parameters.
 */

#define SETUP_SHOW_DATA_PARAM(d, a) \
	struct sensor_device_attribute *sda = to_sensor_dev_attr(a); \
	struct asc7621_data *data = asc7621_update_device(d); \
	struct asc7621_param *param = to_asc7621_param(sda)

#define SETUP_STORE_DATA_PARAM(d, a) \
	struct sensor_device_attribute *sda = to_sensor_dev_attr(a); \
	struct i2c_client *client = to_i2c_client(d); \
	struct asc7621_data *data = i2c_get_clientdata(client); \
	struct asc7621_param *param = to_asc7621_param(sda)

/*
 * u8 is just what it sounds like...an unsigned byte with no
 * special formatting.
 */
static ssize_t show_u8(struct device *<