lm90.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

/*
 * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 * Copyright (C) 2003-2004  Jean Delvare <[e-mail]>
 *
 * Based on the lm83 driver. The LM90 is a sensor chip made by National
 * Semiconductor. It reports up to two temperatures (its own plus up to
 * one external one) with a 0.125 deg resolution (1 deg for local
 * temperature) and a 3-4 deg accuracy. Complete datasheet can be
 * obtained from National's website at:
 *   http://www.national.com/pf/LM/LM90.html
 *
 * This driver also supports the LM89 and LM99, two other sensor chips
 * made by National Semiconductor. Both have an increased remote
 * temperature measurement accuracy (1 degree), and the LM99
 * additionally shifts remote temperatures (measured and limits) by 16
 * degrees, which allows for higher temperatures measurement. The
 * driver doesn't handle it since it can be done easily in user-space.
 * Complete datasheets can be obtained from National's website at:
 *   http://www.national.com/pf/LM/LM89.html
 *   http://www.national.com/pf/LM/LM99.html
 * Note that there is no way to differenciate between both chips.
 *
 * This driver also supports the LM86, another sensor chip made by
 * National Semiconductor. It is exactly similar to the LM90 except it
 * has a higher accuracy.
 * Complete datasheet can be obtained from National's website at:
 *   http://www.national.com/pf/LM/LM86.html
 *
 * This driver also supports the ADM1032, a sensor chip made by Analog
 * Devices. That chip is similar to the LM90, with a few differences
 * that are not handled by this driver. Complete datasheet can be
 * obtained from Analog's website at:
 *   http://products.analog.com/products/info.asp?product=ADM1032
 * Among others, it has a higher accuracy than the LM90, much like the
 * LM86 does.
 *
 * This driver also supports the MAX6657 and MAX6658, sensor chips made
 * by Maxim. These chips are similar to the LM86. Complete datasheet
 * can be obtained at Maxim's website at:
 *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
 * Note that there is no way to differenciate between both chips (but
 * no need either).
 *
 * Since the LM90 was the first chipset supported by this driver, most
 * comments will refer to this chipset, but are actually general and
 * concern all supported chipsets, unless mentioned otherwise.
 *
 * 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
 * Address is fully defined internally and cannot be changed.
 * LM86, LM89, LM90, LM99, ADM1032, MAX6657 and MAX6658 have address 0x4c.
 * LM89-1, and LM99-1 have address 0x4d.
 */

static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
static unsigned short normal_i2c_range[] = { 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_5(lm90, adm1032, lm99, lm86, max6657);

/*
 * The LM90 registers
 */

#define LM90_REG_R_MAN_ID		0xFE
#define LM90_REG_R_CHIP_ID		0xFF
#define LM90_REG_R_CONFIG1		0x03
#define LM90_REG_W_CONFIG1		0x09
#define LM90_REG_R_CONFIG2		0xBF
#define LM90_REG_W_CONFIG2		0xBF
#define LM90_REG_R_CONVRATE		0x04
#define LM90_REG_W_CONVRATE		0x0A
#define LM90_REG_R_STATUS		0x02
#define LM90_REG_R_LOCAL_TEMP		0x00
#define LM90_REG_R_LOCAL_HIGH		0x05
#define LM90_REG_W_LOCAL_HIGH		0x0B
#define LM90_REG_R_LOCAL_LOW		0x06
#define LM90_REG_W_LOCAL_LOW		0x0C
#define LM90_REG_R_LOCAL_CRIT		0x20
#define LM90_REG_W_LOCAL_CRIT		0x20
#define LM90_REG_R_REMOTE_TEMPH		0x01
#define LM90_REG_R_REMOTE_TEMPL		0x10
#define LM90_REG_R_REMOTE_OFFSH		0x11
#define LM90_REG_W_REMOTE_OFFSH		0x11
#define LM90_REG_R_REMOTE_OFFSL		0x12
#define LM90_REG_W_REMOTE_OFFSL		0x12
#define LM90_REG_R_REMOTE_HIGHH		0x07
#define LM90_REG_W_REMOTE_HIGHH		0x0D
#define LM90_REG_R_REMOTE_HIGHL		0x13
#define LM90_REG_W_REMOTE_HIGHL		0x13
#define LM90_REG_R_REMOTE_LOWH		0x08
#define LM90_REG_W_REMOTE_LOWH		0x0E
#define LM90_REG_R_REMOTE_LOWL		0x14
#define LM90_REG_W_REMOTE_LOWL		0x14
#define LM90_REG_R_REMOTE_CRIT		0x19
#define LM90_REG_W_REMOTE_CRIT		0x19
#define LM90_REG_R_TCRIT_HYST		0x21
#define LM90_REG_W_TCRIT_HYST		0x21

/*
 * Conversions and various macros
 * The LM90 uses signed 8-bit values for the local temperatures,
 * and signed 11-bit values for the remote temperatures (except
 * T_CRIT). Note that TEMP2_TO_REG does not round values, but
 * stick to the nearest lower value instead. Fixing it is just
 * not worth it.
 */

#define TEMP1_FROM_REG(val)	((val & 0x80 ? val-0x100 : val) * 1000)
#define TEMP1_TO_REG(val)	((val < 0 ? val+0x100*1000 : val) / 1000)
#define TEMP2_FROM_REG(val)	(((val & 0x8000 ? val-0x10000 : val) >> 5) * 125)
#define TEMP2_TO_REG(val)	((((val / 125) << 5) + (val < 0 ? 0x10000 : 0)) & 0xFFE0)
#define HYST_FROM_REG(val)	(val * 1000)
#define HYST_TO_REG(val)	(val <= 0 ? 0 : val >= 31000 ? 31 : val / 1000)

/*
 * Functions declaration
 */

static int lm90_attach_adapter(struct i2c_adapter *adapter);
static int lm90_detect(struct i2c_adapter *adapter, int address,
	int kind);
static void lm90_init_client(struct i2c_client *client);
static int lm90_detach_client(struct i2c_client *client);
static struct lm90_data *lm90_update_device(struct device *dev);

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

static struct i2c_driver lm90_driver = {
	.owner		= THIS_MODULE,
	.name		= "lm90",
	.id		= I2C_DRIVERID_LM90,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= lm90_attach_adapter,
	.detach_client	= lm90_detach_client,
};

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

struct lm90_data {
	struct i2c_client client;
	struct semaphore update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	u8 temp_input1, temp_low1, temp_high1; /* local */
	u16 temp_input2, temp_low2, temp_high2; /* remote, combined */
	u8 temp_crit1, temp_crit2;
	u8 temp_hyst;
	u16 alarms; /* bitvector, combined */
};

/*
 * Internal variables
 */

static int lm90_id = 0;

/*
 * Sysfs stuff
 */

#define show_temp(value, converter) \
static ssize_t show_##value(struct device *dev, char *buf) \
{ \
	struct lm90_data *data = lm90_update_device(dev); \
	return sprintf(buf, "%d\n", converter(data->value)); \
}
show_temp(temp_input1, TEMP1_FROM_REG);
show_temp(temp_input2, TEMP2_FROM_REG);
show_temp(temp_low1, TEMP1_FROM_REG);
show_temp(temp_low2, TEMP2_FROM_REG);
show_temp(temp_high1, TEMP1_FROM_REG);
show_temp(temp_high2, TEMP2_FROM_REG);
show_temp(temp_crit1, TEMP1_FROM_REG);
show_temp(temp_crit2, TEMP1_FROM_REG);

#define set_temp1(value, reg) \
static ssize_t set_##value(struct device *dev, const char *buf, \
	size_t count) \
{ \
	struct i2c_client *client = to_i2c_client(dev); \
	struct lm90_data *data = i2c_get_clientdata(client); \
	data->value = TEMP1_TO_REG(simple_strtol(buf, NULL, 10)); \
	i2c_smbus_write_byte_data(client, reg, data->value); \
	return count; \
}
#define set_temp2(value, regh, regl) \
static ssize_t set_##value(struct device *dev, const char *buf, \
	size_t count) \
{ \
	struct i2c_client *client = to_i2c_client(dev); \
	struct lm90_data *data = i2c_get_clientdata(client); \
	data->value = TEMP2_TO_REG(simple_strtol(buf, NULL, 10)); \
	i2c_smbus_write_byte_data(client, regh, data->value >> 8); \
	i2c_smbus_write_byte_data(client, regl, data->value & 0xff); \
	return count; \
}
set_temp1(temp_low1, LM90_REG_W_LOCAL_LOW);
set_temp2(temp_low2, LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL);
set_temp1(temp_high1, LM90_REG_W_LOCAL_HIGH);
set_temp2(temp_high2, LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL);
set_temp1(temp_crit1, LM90_REG_W_LOCAL_CRIT);
set_temp1(temp_crit2, LM90_REG_W_REMOTE_CRIT);

#define show_temp_hyst(value, basereg) \
static ssize_t show_##value(struct device *dev, char *buf) \
{ \
	struct lm90_data *data = lm90_update_device(dev); \
	return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->basereg) \
		       - HYST_FROM_REG(data->temp_hyst)); \
}
show_temp_hyst(temp_hyst1, temp_crit1);
show_temp_hyst(temp_hyst2, temp_crit2);

static ssize_t set_temp_hyst1(struct device *dev, const char *buf,
	size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm90_data *data = i2c_get_clientdata(client);
	int hyst = TEMP1_FROM_REG(data->temp_crit1) -
		   simple_strtol(buf, NULL, 10);
	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
				  HYST_TO_REG(hyst));
	return count;
}

static ssize_t show_alarms(struct device *dev, char *buf)
{
	struct lm90_data *data = lm90_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
}

static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp_low1,
	set_temp_low1);
static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
	set_temp_low2);
static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_high1,
	set_temp_high1);
static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
	set_temp_high2);
static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_crit1,
	set_temp_crit1);
static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
	set_temp_crit2);
static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst1,
	set_temp_hyst1);
static DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temp_hyst2, NULL);
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);