therm_adt746x.c

linux 内核源代码

/*
 * Device driver for the i2c thermostat found on the iBook G4, Albook G4
 *
 * Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
 *
 * Documentation from
 * http://www.analog.com/UploadedFiles/Data_Sheets/115254175ADT7467_pra.pdf
 * http://www.analog.com/UploadedFiles/Data_Sheets/3686221171167ADT7460_b.pdf
 *
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/suspend.h>
#include <linux/kthread.h>
#include <linux/moduleparam.h>
#include <linux/freezer.h>

#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/sections.h>
#include <asm/of_platform.h>

#undef DEBUG

#define CONFIG_REG   0x40
#define MANUAL_MASK  0xe0
#define AUTO_MASK    0x20

static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
static u8 MANUAL_MODE[2] = {0x5c, 0x5d};       
static u8 REM_CONTROL[2] = {0x00, 0x40};
static u8 FAN_SPEED[2]   = {0x28, 0x2a};
static u8 FAN_SPD_SET[2] = {0x30, 0x31};

static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
static const char *sensor_location[3];

static int limit_adjust;
static int fan_speed = -1;
static int verbose;

MODULE_AUTHOR("Colin Leroy <[e-mail]>");
MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
		   "Powerbook G4 Alu");
MODULE_LICENSE("GPL");

module_param(limit_adjust, int, 0644);
MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
		 "by N degrees.");

module_param(fan_speed, int, 0644);
MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
		 "(default 64)");

module_param(verbose, bool, 0);
MODULE_PARM_DESC(verbose,"Verbose log operations "
		 "(default 0)");

struct thermostat {
	struct i2c_client	clt;
	u8			temps[3];
	u8			cached_temp[3];
	u8			initial_limits[3];
	u8			limits[3];
	int			last_speed[2];
	int			last_var[2];
};

static enum {ADT7460, ADT7467} therm_type;
static int therm_bus, therm_address;
static struct of_device * of_dev;
static struct thermostat* thermostat;
static struct task_struct *thread_therm = NULL;

static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
				 int busno);

static void write_both_fan_speed(struct thermostat *th, int speed);
static void write_fan_speed(struct thermostat *th, int speed, int fan);

static int
write_reg(struct thermostat* th, int reg, u8 data)
{
	u8 tmp[2];
	int rc;
	
	tmp[0] = reg;
	tmp[1] = data;
	rc = i2c_master_send(&th->clt, (const char *)tmp, 2);
	if (rc < 0)
		return rc;
	if (rc != 2)
		return -ENODEV;
	return 0;
}

static int
read_reg(struct thermostat* th, int reg)
{
	u8 reg_addr, data;
	int rc;

	reg_addr = (u8)reg;
	rc = i2c_master_send(&th->clt, &reg_addr, 1);
	if (rc < 0)
		return rc;
	if (rc != 1)
		return -ENODEV;
	rc = i2c_master_recv(&th->clt, (char *)&data, 1);
	if (rc < 0)
		return rc;
	return data;
}

static int
attach_thermostat(struct i2c_adapter *adapter)
{
	unsigned long bus_no;

	if (strncmp(adapter->name, "uni-n", 5))
		return -ENODEV;
	bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
	if (bus_no != therm_bus)
		return -ENODEV;
	return attach_one_thermostat(adapter, therm_address, bus_no);
}

static int
detach_thermostat(struct i2c_adapter *adapter)
{
	struct thermostat* th;
	int i;
	
	if (thermostat == NULL)
		return 0;

	th = thermostat;

	if (thread_therm != NULL) {
		kthread_stop(thread_therm);
	}

	printk(KERN_INFO "adt746x: Putting max temperatures back from "
			 "%d, %d, %d to %d, %d, %d\n",
		th->limits[0], th->limits[1], th->limits[2],
		th->initial_limits[0], th->initial_limits[1],
		th->initial_limits[2]);

	for (i = 0; i < 3; i++)
		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);

	write_both_fan_speed(th, -1);

	i2c_detach_client(&th->clt);

	thermostat = NULL;

	kfree(th);

	return 0;
}

static struct i2c_driver thermostat_driver = {  
	.driver = {
		.name	= "therm_adt746x",
	},
	.attach_adapter	= attach_thermostat,
	.detach_adapter	= detach_thermostat,
};

static int read_fan_speed(struct thermostat *th, u8 addr)
{
	u8 tmp[2];
	u16 res;
	
	/* should start with low byte */
	tmp[1] = read_reg(th, addr);
	tmp[0] = read_reg(th, addr + 1);
	
	res = tmp[1] + (tmp[0] << 8);
	/* "a value of 0xffff means that the fan has stopped" */
	return (res == 0xffff ? 0 : (90000*60)/res);
}

static void write_both_fan_speed(struct thermostat *th, int speed)
{
	write_fan_speed(th, speed, 0);
	if (therm_type == ADT7460)
		write_fan_speed(th, speed, 1);
}

static void write_fan_speed(struct thermostat *th, int speed, int fan)
{
	u8 manual;
	
	if (speed > 0xff) 
		speed = 0xff;
	else if (speed < -1) 
		speed = 0;
	
	if (therm_type == ADT7467 && fan == 1)
		return;
	
	if (th->last_speed[fan] != speed) {
		if (verbose) {
			if (speed == -1)
				printk(KERN_DEBUG "adt746x: Setting speed to automatic "
					"for %s fan.\n", sensor_location[fan+1]);
			else
				printk(KERN_DEBUG "adt746x: Setting speed to %d "
					"for %s fan.\n", speed, sensor_location[fan+1]);
		}
	} else
		return;
	
	if (speed >= 0) {
		manual = read_reg(th, MANUAL_MODE[fan]);
		write_reg(th, MANUAL_MODE[fan], manual|MANUAL_MASK);
		write_reg(th, FAN_SPD_SET[fan], speed);
	} else {
		/* back to automatic */
		if(therm_type == ADT7460) {
			manual = read_reg(th,
				MANUAL_MODE[fan]) & (~MANUAL_MASK);

			write_reg(th,
				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
		} else {
			manual = read_reg(th, MANUAL_MODE[fan]);
			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
		}
	}
	
	th->last_speed[fan] = speed;			
}

static void read_sensors(struct thermostat *th)
{
	int i = 0;

	for (i = 0; i < 3; i++)
		th->temps[i]  = read_reg(th, TEMP_REG[i]);
}

#ifdef DEBUG
static void display_stats(struct thermostat *th)
{
	if (th->temps[0] != th->cached_temp[0]
	||  th->temps[1] != th->cached_temp[1]
	||  th->temps[2] != th->cached_temp[2]) {
		printk(KERN_INFO "adt746x: Temperature infos:"
				 " thermostats: %d,%d,%d;"
				 " limits: %d,%d,%d;"
				 " fan speed: %d RPM\n",
				 th->temps[0], th->temps[1], th->temps[2],
				 th->limits[0],  th->limits[1],  th->limits[2],
				 read_fan_speed(th, FAN_SPEED[0]));
	}
	th->cached_temp[0] = th->temps[0];
	th->cached_temp[1] = th->temps[1];
	th->cached_temp[2] = th->temps[2];
}
#endif

static void update_fans_speed (struct thermostat *th)
{
	int lastvar = 0; /* last variation, for iBook */
	int i = 0;

	/* we don't care about local sensor, so we start at sensor 1 */
	for (i = 1; i < 3; i++) {
		int started = 0;
		int fan_number = (therm_type == ADT7460 && i == 2);
		int var = th->temps[i] - th->limits[i];

		if (var > -1) {
			int step = (255 - fan_speed) / 7;
			int new_speed = 0;

			/* hysteresis : change fan speed only if variation is
			 * more than two degrees */
			if (abs(var - th->last_var[fan_number]) < 2)
				continue;

			started = 1;
			new_speed = fan_speed + ((var-1)*step);

			if (new_speed < fan_speed)
				new_speed = fan_speed;
			if (new_speed > 255)
				new_speed = 255;

			if (verbose)
				printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
						 "(limit exceeded by %d on %s) \n",
						new_speed, var,
						sensor_location[fan_number+1]);
			write_both_fan_speed(th, new_speed);
			th->last_var[fan_number] = var;
		} else if (var < -2) {
			/* don't stop fan if sensor2 is cold and sensor1 is not
			 * so cold (lastvar >= -1) */
			if (i == 2 && lastvar < -1) {
				if (th->last_speed[fan_number] != 0)
					if (verbose)
						printk(KERN_DEBUG "adt746x: Stopping "
							"fans.\n");
				write_both_fan_speed(th, 0);
			}
		}

		lastvar = var;

		if (started)
			return; /* we don't want to re-stop the fan
				* if sensor1 is heating and sensor2 is not */