kernel-ark/drivers/macintosh/therm_adt746x.c
Rafael J. Wysocki 8314418629 Freezer: make kernel threads nonfreezable by default
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00

662 lines
17 KiB
C

/*
* 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 <colin@colino.net>");
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 */
}
}
static int monitor_task(void *arg)
{
struct thermostat* th = arg;
set_freezable();
while(!kthread_should_stop()) {
try_to_freeze();
msleep_interruptible(2000);
#ifndef DEBUG
if (fan_speed != -1)
read_sensors(th);
#else
read_sensors(th);
#endif
if (fan_speed != -1)
update_fans_speed(th);
#ifdef DEBUG
display_stats(th);
#endif
}
return 0;
}
static void set_limit(struct thermostat *th, int i)
{
/* Set sensor1 limit higher to avoid powerdowns */
th->limits[i] = default_limits_chip[i] + limit_adjust;
write_reg(th, LIMIT_REG[i], th->limits[i]);
/* set our limits to normal */
th->limits[i] = default_limits_local[i] + limit_adjust;
}
static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
int busno)
{
struct thermostat* th;
int rc;
int i;
if (thermostat)
return 0;
th = (struct thermostat *)
kmalloc(sizeof(struct thermostat), GFP_KERNEL);
if (!th)
return -ENOMEM;
memset(th, 0, sizeof(*th));
th->clt.addr = addr;
th->clt.adapter = adapter;
th->clt.driver = &thermostat_driver;
strcpy(th->clt.name, "thermostat");
rc = read_reg(th, 0);
if (rc < 0) {
printk(KERN_ERR "adt746x: Thermostat failed to read config "
"from bus %d !\n",
busno);
kfree(th);
return -ENODEV;
}
/* force manual control to start the fan quieter */
if (fan_speed == -1)
fan_speed = 64;
if(therm_type == ADT7460) {
printk(KERN_INFO "adt746x: ADT7460 initializing\n");
/* The 7460 needs to be started explicitly */
write_reg(th, CONFIG_REG, 1);
} else
printk(KERN_INFO "adt746x: ADT7467 initializing\n");
for (i = 0; i < 3; i++) {
th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
set_limit(th, i);
}
printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
" to %d, %d, %d\n",
th->initial_limits[0], th->initial_limits[1],
th->initial_limits[2], th->limits[0], th->limits[1],
th->limits[2]);
thermostat = th;
if (i2c_attach_client(&th->clt)) {
printk(KERN_INFO "adt746x: Thermostat failed to attach "
"client !\n");
thermostat = NULL;
kfree(th);
return -ENODEV;
}
/* be sure to really write fan speed the first time */
th->last_speed[0] = -2;
th->last_speed[1] = -2;
th->last_var[0] = -80;
th->last_var[1] = -80;
if (fan_speed != -1) {
/* manual mode, stop fans */
write_both_fan_speed(th, 0);
} else {
/* automatic mode */
write_both_fan_speed(th, -1);
}
thread_therm = kthread_run(monitor_task, th, "kfand");
if (thread_therm == ERR_PTR(-ENOMEM)) {
printk(KERN_INFO "adt746x: Kthread creation failed\n");
thread_therm = NULL;
return -ENOMEM;
}
return 0;
}
/*
* Now, unfortunately, sysfs doesn't give us a nice void * we could
* pass around to the attribute functions, so we don't really have
* choice but implement a bunch of them...
*
* FIXME, it does now...
*/
#define BUILD_SHOW_FUNC_INT(name, data) \
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%d\n", data); \
}
#define BUILD_SHOW_FUNC_STR(name, data) \
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%s\n", data); \
}
#define BUILD_SHOW_FUNC_FAN(name, data) \
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%d (%d rpm)\n", \
thermostat->last_speed[data], \
read_fan_speed(thermostat, FAN_SPEED[data]) \
); \
}
#define BUILD_STORE_FUNC_DEG(name, data) \
static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
{ \
int val; \
int i; \
val = simple_strtol(buf, NULL, 10); \
printk(KERN_INFO "Adjusting limits by %d degrees\n", val); \
limit_adjust = val; \
for (i=0; i < 3; i++) \
set_limit(thermostat, i); \
return n; \
}
#define BUILD_STORE_FUNC_INT(name, data) \
static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
{ \
u32 val; \
val = simple_strtoul(buf, NULL, 10); \
if (val < 0 || val > 255) \
return -EINVAL; \
printk(KERN_INFO "Setting specified fan speed to %d\n", val); \
data = val; \
return n; \
}
BUILD_SHOW_FUNC_INT(sensor1_temperature, (read_reg(thermostat, TEMP_REG[1])))
BUILD_SHOW_FUNC_INT(sensor2_temperature, (read_reg(thermostat, TEMP_REG[2])))
BUILD_SHOW_FUNC_INT(sensor1_limit, thermostat->limits[1])
BUILD_SHOW_FUNC_INT(sensor2_limit, thermostat->limits[2])
BUILD_SHOW_FUNC_STR(sensor1_location, sensor_location[1])
BUILD_SHOW_FUNC_STR(sensor2_location, sensor_location[2])
BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
BUILD_SHOW_FUNC_FAN(sensor1_fan_speed, 0)
BUILD_SHOW_FUNC_FAN(sensor2_fan_speed, 1)
BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
BUILD_SHOW_FUNC_INT(limit_adjust, limit_adjust)
BUILD_STORE_FUNC_DEG(limit_adjust, thermostat)
static DEVICE_ATTR(sensor1_temperature, S_IRUGO,
show_sensor1_temperature,NULL);
static DEVICE_ATTR(sensor2_temperature, S_IRUGO,
show_sensor2_temperature,NULL);
static DEVICE_ATTR(sensor1_limit, S_IRUGO,
show_sensor1_limit, NULL);
static DEVICE_ATTR(sensor2_limit, S_IRUGO,
show_sensor2_limit, NULL);
static DEVICE_ATTR(sensor1_location, S_IRUGO,
show_sensor1_location, NULL);
static DEVICE_ATTR(sensor2_location, S_IRUGO,
show_sensor2_location, NULL);
static DEVICE_ATTR(specified_fan_speed, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
show_specified_fan_speed,store_specified_fan_speed);
static DEVICE_ATTR(sensor1_fan_speed, S_IRUGO,
show_sensor1_fan_speed, NULL);
static DEVICE_ATTR(sensor2_fan_speed, S_IRUGO,
show_sensor2_fan_speed, NULL);
static DEVICE_ATTR(limit_adjust, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
show_limit_adjust, store_limit_adjust);
static int __init
thermostat_init(void)
{
struct device_node* np;
const u32 *prop;
int i = 0, offset = 0;
np = of_find_node_by_name(NULL, "fan");
if (!np)
return -ENODEV;
if (of_device_is_compatible(np, "adt7460"))
therm_type = ADT7460;
else if (of_device_is_compatible(np, "adt7467"))
therm_type = ADT7467;
else
return -ENODEV;
prop = of_get_property(np, "hwsensor-params-version", NULL);
printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
(*prop == 1)?"":"un");
if (*prop != 1)
return -ENODEV;
prop = of_get_property(np, "reg", NULL);
if (!prop)
return -ENODEV;
/* look for bus either by path or using "reg" */
if (strstr(np->full_name, "/i2c-bus@") != NULL) {
const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
therm_bus = tmp_bus[0]-'0';
} else {
therm_bus = ((*prop) >> 8) & 0x0f;
}
therm_address = ((*prop) & 0xff) >> 1;
printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
"limit_adjust: %d, fan_speed: %d\n",
therm_bus, therm_address, limit_adjust, fan_speed);
if (of_get_property(np, "hwsensor-location", NULL)) {
for (i = 0; i < 3; i++) {
sensor_location[i] = of_get_property(np,
"hwsensor-location", NULL) + offset;
if (sensor_location[i] == NULL)
sensor_location[i] = "";
printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
offset += strlen(sensor_location[i]) + 1;
}
} else {
sensor_location[0] = "?";
sensor_location[1] = "?";
sensor_location[2] = "?";
}
of_dev = of_platform_device_create(np, "temperatures", NULL);
if (of_dev == NULL) {
printk(KERN_ERR "Can't register temperatures device !\n");
return -ENODEV;
}
device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
if(therm_type == ADT7460)
device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
#ifndef CONFIG_I2C_POWERMAC
request_module("i2c-powermac");
#endif
return i2c_add_driver(&thermostat_driver);
}
static void __exit
thermostat_exit(void)
{
if (of_dev) {
device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
if(therm_type == ADT7460)
device_remove_file(&of_dev->dev,
&dev_attr_sensor2_fan_speed);
of_device_unregister(of_dev);
}
i2c_del_driver(&thermostat_driver);
}
module_init(thermostat_init);
module_exit(thermostat_exit);