max1668.c - Android社区 - https://www.androidos.net.cn/

Kernel | 3.3

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/*
    Copyright (c) 2011 David George <david.george@ska.ac.za>

based on adm1021.c
    some credit to Christoph Scheurer, but largely a rewrite

This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#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 unsigned short max1668_addr_list[] = {
	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

/* max1668 registers */

#define MAX1668_REG_TEMP(nr)	(nr)
#define MAX1668_REG_STAT1	0x05
#define MAX1668_REG_STAT2	0x06
#define MAX1668_REG_MAN_ID	0xfe
#define MAX1668_REG_DEV_ID	0xff

/* limits */

/* write high limits */
#define MAX1668_REG_LIMH_WR(nr)	(0x13 + 2 * (nr))
/* write low limits */
#define MAX1668_REG_LIML_WR(nr)	(0x14 + 2 * (nr))
/* read high limits */
#define MAX1668_REG_LIMH_RD(nr)	(0x08 + 2 * (nr))
/* read low limits */
#define MAX1668_REG_LIML_RD(nr)	(0x09 + 2 * (nr))

/* manufacturer and device ID Constants */
#define MAN_ID_MAXIM		0x4d
#define DEV_ID_MAX1668		0x3
#define DEV_ID_MAX1805		0x5
#define DEV_ID_MAX1989		0xb

/* read only mode module parameter */
static bool read_only;
module_param(read_only, bool, 0);
MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");

enum chips { max1668, max1805, max1989 };

struct max1668_data {
	struct device *hwmon_dev;
	enum chips type;

struct mutex update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

/* 1x local and 4x remote */
	s8 temp_max[5];
	s8 temp_min[5];
	s8 temp[5];
	u16 alarms;
};

static struct max1668_data *max1668_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct max1668_data *data = i2c_get_clientdata(client);
	struct max1668_data *ret = data;
	s32 val;
	int i;

mutex_lock(&data->update_lock);

if (data->valid && !time_after(jiffies,
			data->last_updated + HZ + HZ / 2))
		goto abort;

for (i = 0; i < 5; i++) {
		val = i2c_smbus_read_byte_data(client, MAX1668_REG_TEMP(i));
		if (unlikely(val < 0)) {
			ret = ERR_PTR(val);
			goto abort;
		}
		data->temp[i] = (s8) val;

val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIMH_RD(i));
		if (unlikely(val < 0)) {
			ret = ERR_PTR(val);
			goto abort;
		}
		data->temp_max[i] = (s8) val;

val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIML_RD(i));
		if (unlikely(val < 0)) {
			ret = ERR_PTR(val);
			goto abort;
		}
		data->temp_min[i] = (s8) val;
	}

val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT1);
	if (unlikely(val < 0)) {
		ret = ERR_PTR(val);
		goto abort;
	}
	data->alarms = val << 8;

val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT2);
	if (unlikely(val < 0)) {
		ret = ERR_PTR(val);
		goto abort;
	}
	data->alarms |= val;

data->last_updated = jiffies;
	data->valid = 1;
abort:
	mutex_unlock(&data->update_lock);

return ret;
}

static ssize_t show_temp(struct device *dev,
			 struct device_attribute *devattr, char *buf)
{
	int index = to_sensor_dev_attr(devattr)->index;
	struct max1668_data *data = max1668_update_device(dev);