/*
* 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 = 65 << 8;
x.overheat_hyst = 60 << 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");
