/*
* Creation Date: <2003/03/14 20:54:13 samuel>
* Time-stamp: <2003/03/15 18:55:53 samuel>
*
* <therm_windtunnel.c>
*
* The G4 "windtunnel" has a single fan controlled by a
* DS1775 fan controller and an ADM1030 thermostat.
*
* The fan controller is equipped with a temperature sensor
* which measures the case temperature. The ADM censor
* measures the CPU temperature. This driver tunes the
* behavior of the fan. It is based upon empirical observations
* of the 'AppleFan' driver under OSX.
*
* WARNING: This driver has only been testen on Apple's
* 1.25 MHz Dual G4 (March 03). Other machines might have
* a different thermal design. It is tuned for a CPU
* temperatur around 57 C.
*
* Copyright (C) 2003 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/config.h>
#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/workqueue.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/sections.h>
MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
MODULE_DESCRIPTION("Apple G4 (windtunnel) fan driver");
MODULE_LICENSE("GPL");
#define LOG_TEMP 0 /* continously log temperature */
/* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
static unsigned short normal_i2c[] = { 0x49, 0x2c, I2C_CLIENT_END };
static unsigned short normal_i2c_range[] = { 0x48, 0x4f, 0x2c, 0x2f, I2C_CLIENT_END };
static struct work_struct poll_work;
I2C_CLIENT_INSMOD;
#define I2C_DRIVERID_G4FAN 0x9001 /* fixme */
#define THERMOSTAT_CLIENT_ID 1
#define FAN_CLIENT_ID 2
struct temp_range {
u8 high; /* start the fan */
u8 low; /* stop the fan */
};
struct apple_thermal_info {
u8 id; /* implementation ID */
u8 fan_count; /* number of fans */
u8 thermostat_count; /* number of thermostats */
u8 unused[5];
struct temp_range ranges[4]; /* temperature ranges (may be [])*/
};
static int do_detect( struct i2c_adapter *adapter, int addr, int kind);
static struct {
struct i2c_client *thermostat;
struct i2c_client *fan;
int error;
struct timer_list timer;
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;
static struct {
int temp;
int fan_setting;
} fan_up_table[] = {
{ 0x0000, 11 }, /* min fan */
{ 0x3900, 8 }, /* 57.0 C */
{ 0x3a4a, 7 }, /* 58.3 C */
{ 0x3ad3, 6 }, /* 58.8 C */
{ 0x3b3c, 5 }, /* 59.2 C */
{ 0x3b94, 4 }, /* 59.6 C */
{ 0x3be3, 3 }, /* 58.9 C */
{ 0x3c29, 2 }, /* 59.2 C */
{ 0xffff, 1 } /* on fire */
};
static struct {
int temp;
int fan_setting;
} fan_down_table[] = {
{ 0x3700, 11 }, /* 55.0 C */
{ 0x374a, 6 },
{ 0x3800, 7 }, /* 56.0 C */
{ 0x3900, 8 }, /* 57.0 C */
{ 0x3a4a, 7 }, /* 58.3 C */
{ 0x3ad3, 6 }, /* 58.8 C */
{ 0x3b3c, 5 }, /* 59.2 C */
{ 0x3b94, 4 }, /* 58.9 C */
{ 0x3be3, 3 }, /* 58.9 C */
{ 0x3c29, 2 }, /* 59.2 C */
{ 0xffff, 1 }
};
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
print_temp( const char *s, int temp )
{
printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
}
static void
tune_fan( int fan_setting )
{
int val = (fan_setting << 3) | 7;
x.fan_level = fan_setting;
//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(" Tuning fan: %d (%02x)\n", fan_setting, val );
}
static void
poll_temp( void *param )
{
int temp = read_reg( x.thermostat, 0, 2 );
int i, level, casetemp;
/* this actually occurs when the computer is loaded */
if( temp < 0 )
goto out;
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", x.fan_level );
}
x.temp = temp;
x.casetemp = casetemp;
level = -1;
for( i=0; (temp & 0xffff) > fan_down_table[i].temp ; i++ )
;
if( i < x.downind )
level = fan_down_table[i].fan_setting;
x.downind = i;
for( i=0; (temp & 0xfffe) >= fan_up_table[i+1].temp ; i++ )
;
if( x.upind < i )
level = fan_up_table[i].fan_setting;
x.upind = i;
if( level >= 0 )
tune_fan( level );
out:
x.timer.expires = jiffies + 8*HZ;
add_timer( &x.timer );
}
static void
schedule_poll( unsigned long t )
{
schedule_work(&poll_work);
}
/************************************************************************/
/* i2c probing and setup */
/************************************************************************/
static int
do_attach( struct i2c_adapter *adapter )
{
return i2c_probe( adapter, &addr_data, &do_detect );
}
static int
do_detach( struct i2c_client *client )
{
int err;
printk("do_detach: id %d\n", client->id );
if( (err=i2c_detach_client(client)) ) {
printk("failed to detach thermostat client\n");
return err;
}
kfree( client );
return 0;
}
static struct i2c_driver g4fan_driver = {
.name = "Apple G4 Thermostat/Fan",
.id = I2C_DRIVERID_G4FAN,
.flags = I2C_DF_NOTIFY,
.attach_adapter = &do_attach,
.detach_client = &do_detach,
.command = NULL,
};
static int
detect_fan( struct i2c_client *cl )
{
/* 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 detected at %02x\n", cl->addr );
if( x.fan ) {
x.error |= 2;
goto out;
}
x.fan = cl;
cl->id = FAN_CLIENT_ID;
strncpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
if( i2c_attach_client( cl ) )
goto out;
return 0;
out:
if( cl != x.fan )
kfree( cl );
return 0;
}
static int
detect_thermostat( struct i2c_client *cl )
{
int hyst_temp, os_temp, temp;
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 detected at %02x\n", cl->addr );
print_temp("Temp: ", temp );
print_temp(" Hyst: ", hyst_temp );
print_temp(" OS: ", os_temp );
printk("\n");
if( x.thermostat ) {
x.error |= 1;
goto out;
}
x.temp = temp;
x.thermostat = cl;
x.overheat_temp = os_temp;
x.overheat_hyst = hyst_temp;
cl->id = THERMOSTAT_CLIENT_ID;
strncpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
if( i2c_attach_client( cl ) )
goto out;
return 0;
out:
kfree( cl );
return 0;
}
static int
do_detect( struct i2c_adapter *adapter, int addr, int kind )
{
struct i2c_client *cl;
if( strncmp(adapter->name, "uni-n", 5) )
return 0;
if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
| I2C_FUNC_SMBUS_WRITE_BYTE) )
return 0;
if( !(cl=kmalloc( sizeof(struct i2c_client), GFP_KERNEL )) )
return -ENOMEM;
memset( cl, 0, sizeof(struct i2c_client) );
cl->addr = addr;
cl->adapter = adapter;
cl->driver = &g4fan_driver;
cl->flags = 0;
if( addr < 0x48 )
return detect_fan( cl );
return detect_thermostat( cl );
}
#define PRINT_REG( r ) printk("reg %02x = %02x\n", r, read_reg(x.fan, r, 1) )
static int __init
g4fan_init( void )
{
struct apple_thermal_info *info;
struct device_node *np;
int ret, val;
np = of_find_node_by_name(NULL, "power-mgt");
if (np == NULL)
return -ENODEV;
info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL);
of_node_put(np);
if (info == NULL)
return -ENODEV;
/* check for G4 "Windtunnel" SMP */
if( machine_is_compatible("PowerMac3,6") ) {
if( info->id != 3 ) {
printk(KERN_ERR "g4fan: design id %d unknown\n", info->id);
return -ENODEV;
}
} else {
printk(KERN_ERR "g4fan: unsupported machine type\n");
return -ENODEV;
}
if( (ret=i2c_add_driver(&g4fan_driver)) )
return ret;
if( !x.thermostat || !x.fan ) {
i2c_del_driver(&g4fan_driver );
return -ENODEV;
}
/* 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.upind = x.downind = 1;
tune_fan( fan_up_table[x.upind].fan_setting );
INIT_WORK(&poll_work, poll_temp, NULL);
init_timer( &x.timer );
x.timer.expires = jiffies + 8*HZ;
x.timer.function = schedule_poll;
add_timer( &x.timer );
return 0;
}
static void __exit
g4fan_exit( void )
{
del_timer( &x.timer );
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 );
i2c_del_driver( &g4fan_driver );
}
module_init(g4fan_init);
module_exit(g4fan_exit);
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