alistair23-linux/drivers/macintosh/therm_windtunnel.c
Lyonel Vincent b8e4a7dae5 powerpc/powermac: Thermal control turns system off too eagerly
On certain PowerMacs, a module (therm_windtunnel) controls various
thermal settings (it can report CPU/case temperature, change speed
of internal fans, etc.)

By default, the hardware thermal control has a temperature limit to
protect the computer from damages (the default limit seems to be 80°C)
but therm_windtunnel.c reduces it to an anormaly low value (65°C),
which means that he computer will shut down randomly when hit by direct
sun light or during summer (summer in France can be quite hot), actually
possibly losing data instead of protecting it.

The overheat limit in therm_windtunnel.c:253-254 should be set to 75°C
and 70°C instead of 65°C and 60°C respectively.

From: Lyonel Vincent <lyonel@ezix.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-02 15:46:00 +10:00

529 lines
12 KiB
C

/*
* Creation Date: <2003/03/14 20:54:13 samuel>
* Time-stamp: <2004/03/20 14:20:59 samuel>
*
* <therm_windtunnel.c>
*
* The G4 "windtunnel" has a single fan controlled by an
* ADM1030 fan controller and a DS1775 thermostat.
*
* The fan controller is equipped with a temperature sensor
* which measures the case temperature. The DS1775 sensor
* measures the CPU temperature. This driver tunes the
* behavior of the fan. It is based upon empirical observations
* of the 'AppleFan' driver under Mac OS X.
*
* WARNING: This driver has only been testen on Apple's
* 1.25 MHz Dual G4 (March 03). It is tuned for a CPU
* temperatur around 57 C.
*
* Copyright (C) 2003, 2004 Samuel Rydh (samuel@ibrium.se)
*
* Loosely based upon 'thermostat.c' written by Benjamin Herrenschmidt
*
* 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
*
*/
#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/kthread.h>
#include <linux/of_platform.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/sections.h>
#include <asm/macio.h>
#define LOG_TEMP 0 /* continously log temperature */
static struct {
volatile int running;
struct task_struct *poll_task;
struct mutex lock;
struct of_device *of_dev;
struct i2c_client *thermostat;
struct i2c_client *fan;
int overheat_temp; /* 100% fan at this temp */
int overheat_hyst;
int temp;
int casetemp;
int fan_level; /* active fan_table setting */
int downind;
int upind;
int r0, r1, r20, r23, r25; /* saved register */
} x;
#define T(x,y) (((x)<<8) | (y)*0x100/10 )
static struct {
int fan_down_setting;
int temp;
int fan_up_setting;
} fan_table[] = {
{ 11, T(0,0), 11 }, /* min fan */
{ 11, T(55,0), 11 },
{ 6, T(55,3), 11 },
{ 7, T(56,0), 11 },
{ 8, T(57,0), 8 },
{ 7, T(58,3), 7 },
{ 6, T(58,8), 6 },
{ 5, T(59,2), 5 },
{ 4, T(59,6), 4 },
{ 3, T(59,9), 3 },
{ 2, T(60,1), 2 },
{ 1, 0xfffff, 1 } /* on fire */
};
static void
print_temp( const char *s, int temp )
{
printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
}
static ssize_t
show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
{
return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
}
static ssize_t
show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
{
return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
}
static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
/************************************************************************/
/* controller thread */
/************************************************************************/
static int
write_reg( struct i2c_client *cl, int reg, int data, int len )
{
u8 tmp[3];
if( len < 1 || len > 2 || data < 0 )
return -EINVAL;
tmp[0] = reg;
tmp[1] = (len == 1) ? data : (data >> 8);
tmp[2] = data;
len++;
if( i2c_master_send(cl, tmp, len) != len )
return -ENODEV;
return 0;
}
static int
read_reg( struct i2c_client *cl, int reg, int len )
{
u8 buf[2];
if( len != 1 && len != 2 )
return -EINVAL;
buf[0] = reg;
if( i2c_master_send(cl, buf, 1) != 1 )
return -ENODEV;
if( i2c_master_recv(cl, buf, len) != len )
return -ENODEV;
return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
}
static void
tune_fan( int fan_setting )
{
int val = (fan_setting << 3) | 7;
/* write_reg( x.fan, 0x24, val, 1 ); */
write_reg( x.fan, 0x25, val, 1 );
write_reg( x.fan, 0x20, 0, 1 );
print_temp("CPU-temp: ", x.temp );
if( x.casetemp )
print_temp(", Case: ", x.casetemp );
printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
x.fan_level = fan_setting;
}
static void
poll_temp( void )
{
int temp, i, level, casetemp;
temp = read_reg( x.thermostat, 0, 2 );
/* this actually occurs when the computer is loaded */
if( temp < 0 )
return;
casetemp = read_reg(x.fan, 0x0b, 1) << 8;
casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
if( LOG_TEMP && x.temp != temp ) {
print_temp("CPU-temp: ", temp );
print_temp(", Case: ", casetemp );
printk(", Fan: %d\n", 11-x.fan_level );
}
x.temp = temp;
x.casetemp = casetemp;
level = -1;
for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
;
if( i < x.downind )
level = fan_table[i].fan_down_setting;
x.downind = i;
for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
;
if( x.upind < i )
level = fan_table[i].fan_up_setting;
x.upind = i;
if( level >= 0 )
tune_fan( level );
}
static void
setup_hardware( void )
{
int val;
int err;
/* save registers (if we unload the module) */
x.r0 = read_reg( x.fan, 0x00, 1 );
x.r1 = read_reg( x.fan, 0x01, 1 );
x.r20 = read_reg( x.fan, 0x20, 1 );
x.r23 = read_reg( x.fan, 0x23, 1 );
x.r25 = read_reg( x.fan, 0x25, 1 );
/* improve measurement resolution (convergence time 1.5s) */
if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
val |= 0x60;
if( write_reg( x.thermostat, 1, val, 1 ) )
printk("Failed writing config register\n");
}
/* disable interrupts and TAC input */
write_reg( x.fan, 0x01, 0x01, 1 );
/* enable filter */
write_reg( x.fan, 0x23, 0x91, 1 );
/* remote temp. controls fan */
write_reg( x.fan, 0x00, 0x95, 1 );
/* The thermostat (which besides measureing temperature controls
* has a THERM output which puts the fan on 100%) is usually
* set to kick in at 80 C (chip default). We reduce this a bit
* to be on the safe side (OSX doesn't)...
*/
if( x.overheat_temp == (80 << 8) ) {
x.overheat_temp = 75 << 8;
x.overheat_hyst = 70 << 8;
write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
write_reg( x.thermostat, 3, x.overheat_temp, 2 );
print_temp("Reducing overheating limit to ", x.overheat_temp );
print_temp(" (Hyst: ", x.overheat_hyst );
printk(")\n");
}
/* set an initial fan setting */
x.downind = 0xffff;
x.upind = -1;
/* tune_fan( fan_up_table[x.upind].fan_setting ); */
err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
if (err)
printk(KERN_WARNING
"Failed to create temperature attribute file(s).\n");
}
static void
restore_regs( void )
{
device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
write_reg( x.fan, 0x01, x.r1, 1 );
write_reg( x.fan, 0x20, x.r20, 1 );
write_reg( x.fan, 0x23, x.r23, 1 );
write_reg( x.fan, 0x25, x.r25, 1 );
write_reg( x.fan, 0x00, x.r0, 1 );
}
static int control_loop(void *dummy)
{
mutex_lock(&x.lock);
setup_hardware();
mutex_unlock(&x.lock);
for (;;) {
msleep_interruptible(8000);
if (kthread_should_stop())
break;
mutex_lock(&x.lock);
poll_temp();
mutex_unlock(&x.lock);
}
mutex_lock(&x.lock);
restore_regs();
mutex_unlock(&x.lock);
return 0;
}
/************************************************************************/
/* i2c probing and setup */
/************************************************************************/
static int
do_attach( struct i2c_adapter *adapter )
{
/* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
static const unsigned short scan_ds1775[] = {
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
I2C_CLIENT_END
};
static const unsigned short scan_adm1030[] = {
0x2c, 0x2d, 0x2e, 0x2f,
I2C_CLIENT_END
};
if( strncmp(adapter->name, "uni-n", 5) )
return 0;
if( !x.running ) {
struct i2c_board_info info;
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "therm_ds1775", I2C_NAME_SIZE);
i2c_new_probed_device(adapter, &info, scan_ds1775);
strlcpy(info.type, "therm_adm1030", I2C_NAME_SIZE);
i2c_new_probed_device(adapter, &info, scan_adm1030);
if( x.thermostat && x.fan ) {
x.running = 1;
x.poll_task = kthread_run(control_loop, NULL, "g4fand");
}
}
return 0;
}
static int
do_remove(struct i2c_client *client)
{
if (x.running) {
x.running = 0;
kthread_stop(x.poll_task);
x.poll_task = NULL;
}
if (client == x.thermostat)
x.thermostat = NULL;
else if (client == x.fan)
x.fan = NULL;
else
printk(KERN_ERR "g4fan: bad client\n");
return 0;
}
static int
attach_fan( struct i2c_client *cl )
{
if( x.fan )
goto out;
/* check that this is an ADM1030 */
if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
goto out;
printk("ADM1030 fan controller [@%02x]\n", cl->addr );
x.fan = cl;
out:
return 0;
}
static int
attach_thermostat( struct i2c_client *cl )
{
int hyst_temp, os_temp, temp;
if( x.thermostat )
goto out;
if( (temp=read_reg(cl, 0, 2)) < 0 )
goto out;
/* temperature sanity check */
if( temp < 0x1600 || temp > 0x3c00 )
goto out;
hyst_temp = read_reg(cl, 2, 2);
os_temp = read_reg(cl, 3, 2);
if( hyst_temp < 0 || os_temp < 0 )
goto out;
printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
print_temp("Temp: ", temp );
print_temp(" Hyst: ", hyst_temp );
print_temp(" OS: ", os_temp );
printk("\n");
x.temp = temp;
x.overheat_temp = os_temp;
x.overheat_hyst = hyst_temp;
x.thermostat = cl;
out:
return 0;
}
enum chip { ds1775, adm1030 };
static const struct i2c_device_id therm_windtunnel_id[] = {
{ "therm_ds1775", ds1775 },
{ "therm_adm1030", adm1030 },
{ }
};
static int
do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
struct i2c_adapter *adapter = cl->adapter;
if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
| I2C_FUNC_SMBUS_WRITE_BYTE) )
return 0;
switch (id->driver_data) {
case adm1030:
return attach_fan( cl );
case ds1775:
return attach_thermostat(cl);
}
return 0;
}
static struct i2c_driver g4fan_driver = {
.driver = {
.name = "therm_windtunnel",
},
.attach_adapter = do_attach,
.probe = do_probe,
.remove = do_remove,
.id_table = therm_windtunnel_id,
};
/************************************************************************/
/* initialization / cleanup */
/************************************************************************/
static int
therm_of_probe( struct of_device *dev, const struct of_device_id *match )
{
return i2c_add_driver( &g4fan_driver );
}
static int
therm_of_remove( struct of_device *dev )
{
i2c_del_driver( &g4fan_driver );
return 0;
}
static struct of_device_id therm_of_match[] = {{
.name = "fan",
.compatible = "adm1030"
}, {}
};
static struct of_platform_driver therm_of_driver = {
.name = "temperature",
.match_table = therm_of_match,
.probe = therm_of_probe,
.remove = therm_of_remove,
};
struct apple_thermal_info {
u8 id; /* implementation ID */
u8 fan_count; /* number of fans */
u8 thermostat_count; /* number of thermostats */
u8 unused;
};
static int __init
g4fan_init( void )
{
const struct apple_thermal_info *info;
struct device_node *np;
mutex_init(&x.lock);
if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
return -ENODEV;
info = of_get_property(np, "thermal-info", NULL);
of_node_put(np);
if( !info || !machine_is_compatible("PowerMac3,6") )
return -ENODEV;
if( info->id != 3 ) {
printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
return -ENODEV;
}
if( !(np=of_find_node_by_name(NULL, "fan")) )
return -ENODEV;
x.of_dev = of_platform_device_create(np, "temperature", NULL);
of_node_put( np );
if( !x.of_dev ) {
printk(KERN_ERR "Can't register fan controller!\n");
return -ENODEV;
}
of_register_platform_driver( &therm_of_driver );
return 0;
}
static void __exit
g4fan_exit( void )
{
of_unregister_platform_driver( &therm_of_driver );
if( x.of_dev )
of_device_unregister( x.of_dev );
}
module_init(g4fan_init);
module_exit(g4fan_exit);
MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
MODULE_LICENSE("GPL");