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linux/drivers/macintosh/therm_windtunnel.c
Benjamin Herrenschmidt 0365ba7fb1 [PATCH] ppc64: SMU driver update & i2c support 
The SMU is the "system controller" chip used by Apple recent G5 machines
including the iMac G5.  It drives things like fans, i2c busses, real time
clock, etc...

The current kernel contains a very crude driver that doesn't do much more
than reading the real time clock synchronously.  This is a completely
rewritten driver that provides interrupt based command queuing, a userland
interface, and an i2c/smbus driver for accessing the devices hanging off
the SMU i2c busses like temperature sensors.  This driver is a basic block
for upcoming work on thermal control for those machines, among others.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22 22:17:35 -07:00

534 lines
12 KiB
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/*
* 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/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 <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/sections.h>
#include <asm/of_device.h>
#include <asm/macio.h>
#define LOG_TEMP 0 /* continously log temperature */
#define I2C_DRIVERID_G4FAN 0x9001 /* fixme */
static int do_probe( struct i2c_adapter *adapter, int addr, int kind);
/* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
0x4c, 0x4d, 0x4e, 0x4f,
0x2c, 0x2d, 0x2e, 0x2f,
I2C_CLIENT_END };
I2C_CLIENT_INSMOD;
static struct {
volatile int running;
struct completion completion;
pid_t poll_task;
struct semaphore 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;
/* 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 ); */
device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
}
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 )
{
daemonize("g4fand");
down( &x.lock );
setup_hardware();
while( x.running ) {
up( &x.lock );
msleep_interruptible(8000);
down( &x.lock );
poll_temp();
}
restore_regs();
up( &x.lock );
complete_and_exit( &x.completion, 0 );
}
/************************************************************************/
/* i2c probing and setup */
/************************************************************************/
static int
do_attach( struct i2c_adapter *adapter )
{
int ret = 0;
if( strncmp(adapter->name, "uni-n", 5) )
return 0;
if( !x.running ) {
ret = i2c_probe( adapter, &addr_data, &do_probe );
if( x.thermostat && x.fan ) {
x.running = 1;
init_completion( &x.completion );
x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL );
}
}
return ret;
}
static int
do_detach( struct i2c_client *client )
{
int err;
if( (err=i2c_detach_client(client)) )
printk(KERN_ERR "failed to detach thermostat client\n");
else {
if( x.running ) {
x.running = 0;
wait_for_completion( &x.completion );
}
if( client == x.thermostat )
x.thermostat = NULL;
else if( client == x.fan )
x.fan = NULL;
else {
printk(KERN_ERR "g4fan: bad client\n");
}
kfree( client );
}
return err;
}
static struct i2c_driver g4fan_driver = {
.owner = THIS_MODULE,
.name = "therm_windtunnel",
.id = I2C_DRIVERID_G4FAN,
.flags = I2C_DF_NOTIFY,
.attach_adapter = do_attach,
.detach_client = do_detach,
};
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 );
strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
if( !i2c_attach_client(cl) )
x.fan = cl;
out:
if( cl != x.fan )
kfree( cl );
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;
strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
if( !i2c_attach_client(cl) )
x.thermostat = cl;
out:
if( cl != x.thermostat )
kfree( cl );
return 0;
}
static int
do_probe( struct i2c_adapter *adapter, int addr, int kind )
{
struct i2c_client *cl;
if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
| I2C_FUNC_SMBUS_WRITE_BYTE) )
return 0;
if( !(cl=kmalloc(sizeof(*cl), 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 attach_fan( cl );
return attach_thermostat( cl );
}
/************************************************************************/
/* 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 )
{
return i2c_del_driver( &g4fan_driver );
}
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 )
{
struct apple_thermal_info *info;
struct device_node *np;
init_MUTEX( &x.lock );
if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
return -ENODEV;
info = (struct apple_thermal_info*)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_driver( &therm_of_driver );
return 0;
}
static void __exit
g4fan_exit( void )
{
of_unregister_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");
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