lm80.c

《linux驱动程序设计从入门到精通》一书中所有的程序代码含驱动和相应的应用程序

/*
 * lm80.c - From lm_sensors, Linux kernel modules for hardware
 * monitoring
 * Copyright (C) 1998, 1999  Frodo Looijaard <[e-mail]>
 * and Philip Edelbrock <[e-mail]>
 *
 * Ported to Linux 2.6 by Tiago Sousa <[e-mail]>
 *
 * 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/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/i2c-sensor.h>

/* Addresses to scan */
static unsigned short normal_i2c[] = { I2C_CLIENT_END };
static unsigned short normal_i2c_range[] = { 0x28, 0x2f, I2C_CLIENT_END };
static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
static unsigned int normal_isa_range[] = { I2C_CLIENT_ISA_END };

/* Insmod parameters */
SENSORS_INSMOD_1(lm80);

/* Many LM80 constants specified below */

/* The LM80 registers */
#define LM80_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
#define LM80_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
#define LM80_REG_IN(nr)			(0x20 + (nr))

#define LM80_REG_FAN1			0x28
#define LM80_REG_FAN2			0x29
#define LM80_REG_FAN_MIN(nr)		(0x3b + (nr))

#define LM80_REG_TEMP			0x27
#define LM80_REG_TEMP_HOT_MAX		0x38
#define LM80_REG_TEMP_HOT_HYST		0x39
#define LM80_REG_TEMP_OS_MAX		0x3a
#define LM80_REG_TEMP_OS_HYST		0x3b

#define LM80_REG_CONFIG			0x00
#define LM80_REG_ALARM1			0x01
#define LM80_REG_ALARM2			0x02
#define LM80_REG_MASK1			0x03
#define LM80_REG_MASK2			0x04
#define LM80_REG_FANDIV			0x05
#define LM80_REG_RES			0x06


/* Conversions. Rounding and limit checking is only done on the TO_REG
   variants. Note that you should be a bit careful with which arguments
   these macros are called: arguments may be evaluated more than once.
   Fixing this is just not worth it. */

#define IN_TO_REG(val)		(SENSORS_LIMIT(((val)+5)/10,0,255))
#define IN_FROM_REG(val)	((val)*10)

static inline unsigned char FAN_TO_REG(unsigned rpm, unsigned div)
{
	if (rpm == 0)
		return 255;
	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
	return SENSORS_LIMIT((1350000 + rpm*div / 2) / (rpm*div), 1, 254);
}

#define FAN_FROM_REG(val,div)	((val)==0?-1:\
				(val)==255?0:1350000/((div)*(val)))

static inline long TEMP_FROM_REG(u16 temp)
{
	long res;

	temp >>= 4;
	if (temp < 0x0800)
		res = 625 * (long) temp;
	else
		res = ((long) temp - 0x01000) * 625;

	return res / 10;
}

#define TEMP_LIMIT_FROM_REG(val)	(((val)>0x80?(val)-0x100:(val))*1000)

#define TEMP_LIMIT_TO_REG(val)		SENSORS_LIMIT((val)<0?\
					((val)-500)/1000:((val)+500)/1000,0,255)

#define ALARMS_FROM_REG(val)		(val)

#define DIV_FROM_REG(val)		(1 << (val))
#define DIV_TO_REG(val)			((val)==8?3:(val)==4?2:(val)==1?0:1)

/*
 * Client data (each client gets its own)
 */

struct lm80_data {
	struct i2c_client client;
	struct semaphore update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	u8 in[7];		/* Register value */
	u8 in_max[7];		/* Register value */
	u8 in_min[7];		/* Register value */
	u8 fan[2];		/* Register value */
	u8 fan_min[2];		/* Register value */
	u8 fan_div[2];		/* Register encoding, shifted right */
	u16 temp;		/* Register values, shifted right */
	u8 temp_hot_max;	/* Register value */
	u8 temp_hot_hyst;	/* Register value */
	u8 temp_os_max;		/* Register value */
	u8 temp_os_hyst;	/* Register value */
	u16 alarms;		/* Register encoding, combined */
};

/* 
 * Functions declaration
 */

static int lm80_attach_adapter(struct i2c_adapter *adapter);
static int lm80_detect(struct i2c_adapter *adapter, int address, int kind);
static void lm80_init_client(struct i2c_client *client);
static int lm80_detach_client(struct i2c_client *client);
static struct lm80_data *lm80_update_device(struct device *dev);
static int lm80_read_value(struct i2c_client *client, u8 reg);
static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value);

/*
 * Internal variables
 */

static int lm80_id = 0;

/*
 * Driver data (common to all clients)
 */

static struct i2c_driver lm80_driver = {
	.owner		= THIS_MODULE,
	.name		= "lm80",
	.id		= I2C_DRIVERID_LM80,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= lm80_attach_adapter,
	.detach_client	= lm80_detach_client,
};

/*
 * Sysfs stuff
 */

#define show_in(suffix, value) \
static ssize_t show_in_##suffix(struct device *dev, char *buf) \
{ \
	struct lm80_data *data = lm80_update_device(dev); \
	return sprintf(buf, "%d\n", IN_FROM_REG(data->value)); \
}
show_in(min0, in_min[0]);
show_in(min1, in_min[1]);
show_in(min2, in_min[2]);
show_in(min3, in_min[3]);
show_in(min4, in_min[4]);
show_in(min5, in_min[5]);
show_in(min6, in_min[6]);
show_in(max0, in_max[0]);
show_in(max1, in_max[1]);
show_in(max2, in_max[2]);
show_in(max3, in_max[3]);
show_in(max4, in_max[4]);
show_in(max5, in_max[5]);
show_in(max6, in_max[6]);
show_in(input0, in[0]);
show_in(input1, in[1]);
show_in(input2, in[2]);
show_in(input3, in[3]);
show_in(input4, in[4]);
show_in(input5, in[5]);
show_in(input6, in[6]);

#define set_in(suffix, value, reg) \
static ssize_t set_in_##suffix(struct device *dev, const char *buf, \
	size_t count) \
{ \
	struct i2c_client *client = to_i2c_client(dev); \
	struct lm80_data *data = i2c_get_clientdata(client); \
	long val = simple_strtol(buf, NULL, 10); \
	data->value = IN_TO_REG(val); \
	lm80_write_value(client, reg, data->value); \
	return count; \
}
set_in(min0, in_min[0], LM80_REG_IN_MIN(0));
set_in(min1, in_min[1], LM80_REG_IN_MIN(1));
set_in(min2, in_min[2], LM80_REG_IN_MIN(2));
set_in(min3, in_min[3], LM80_REG_IN_MIN(3));
set_in(min4, in_min[4], LM80_REG_IN_MIN(4));
set_in(min5, in_min[5], LM80_REG_IN_MIN(5));
set_in(min6, in_min[6], LM80_REG_IN_MIN(6));
set_in(max0, in_max[0], LM80_REG_IN_MAX(0));
set_in(max1, in_max[1], LM80_REG_IN_MAX(1));
set_in(max2, in_max[2], LM80_REG_IN_MAX(2));
set_in(max3, in_max[3], LM80_REG_IN_MAX(3));
set_in(max4, in_max[4], LM80_REG_IN_MAX(4));
set_in(max5, in_max[5], LM80_REG_IN_MAX(5));
set_in(max6, in_max[6], LM80_REG_IN_MAX(6));

#define show_fan(suffix, value, div) \
static ssize_t show_fan_##suffix(struct device *dev, char *buf) \
{ \
	struct lm80_data *data = lm80_update_device(dev); \
	return sprintf(buf, "%d\n", FAN_FROM_REG(data->value, \
		       DIV_FROM_REG(data->div))); \
}
show_fan(min1, fan_min[0], fan_div[0]);
show_fan(min2, fan_min[1], fan_div[1]);
show_fan(input1, fan[0], fan_div[0]);
show_fan(input2, fan[1], fan_div[1]);

#define show_fan_div(suffix, value) \
static ssize_t show_fan_div##suffix(struct device *dev, char *buf) \
{ \
	struct lm80_data *data = lm80_update_device(dev); \
	return sprintf(buf, "%d\n", DIV_FROM_REG(data->value)); \
}
show_fan_div(1, fan_div[0]);
show_fan_div(2, fan_div[1]);

#define set_fan(suffix, value, reg, div) \
static ssize_t set_fan_##suffix(struct device *dev, const char *buf, \
	size_t count) \
{ \
	struct i2c_client *client = to_i2c_client(dev); \
	struct lm80_data *data = i2c_get_clientdata(client); \
	long val = simple_strtoul(buf, NULL, 10); \
	data->value = FAN_TO_REG(val, DIV_FROM_REG(data->div)); \
	lm80_write_value(client, reg, data->value); \
	return count; \
}
set_fan(min1, fan_min[0], LM80_REG_FAN_MIN(1), fan_div[0]);
set_fan(min2, fan_min[1], LM80_REG_FAN_MIN(2), fan_div[1]);

/* Note: we save and restore the fan minimum here, because its value is
   determined in part by the fan divisor.  This follows the principle of
   least suprise; the user doesn't expect the fan minimum to change just
   because the divisor changed. */
static ssize_t set_fan_div(struct device *dev, const char *buf,
	size_t count, int nr)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm80_data *data = i2c_get_clientdata(client);
	unsigned long min;
	u8 reg;

	/* Save fan_min */
	min = FAN_FROM_REG(data->fan_min[nr],
			   DIV_FROM_REG(data->fan_div[nr]));

	data->fan_div[nr] = DIV_TO_REG(simple_strtoul(buf, NULL, 10));

	reg = (lm80_read_value(client, LM80_REG_FANDIV) & ~(3 << (2 * (nr + 1))))
	    | (data->fan_div[nr] << (2 * (nr + 1)));
	lm80_write_value(client, LM80_REG_FANDIV, reg);

	/* Restore fan_min */
	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);

	return count;
}

#define set_fan_div(number) \
static ssize_t set_fan_div##number(struct device *dev, const char *buf, \
	size_t count) \
{ \
	return set_fan_div(dev, buf, count, number - 1); \
}
set_fan_div(1);
set_fan_div(2);

static ssize_t show_temp_input1(struct device *dev, char *buf)
{
	struct lm80_data *data = lm80_update_device(dev);
	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp));
}