[PATCH] pmac: Improved G4 "windtunnel" fan controller

From: Benjamin Herrenschmidt
Date: Sat Mar 20 2004 - 21:32:57 EST


Please apply,
Ben.

-----Forwarded Message-----
From: Samuel Rydh <samuel@xxxxxxxxx>
To: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Subject: Improved G4 "windtunnel" fan controller
Date: Sat, 20 Mar 2004 14:54:53 +0100


Hi Ben,

Here is an improved version of the G4 "windtunnel" fan controller.
It depends on the keywest bugfix...

/Samuel


===== drivers/macintosh/therm_windtunnel.c 1.1 vs edited =====
--- 1.1/drivers/macintosh/therm_windtunnel.c Thu Feb 5 07:23:52 2004
+++ edited/drivers/macintosh/therm_windtunnel.c Sat Mar 20 14:45:16 2004
@@ -1,24 +1,23 @@
/*
* Creation Date: <2003/03/14 20:54:13 samuel>
- * Time-stamp: <2003/03/15 18:55:53 samuel>
+ * Time-stamp: <2004/03/20 14:20:59 samuel>
*
* <therm_windtunnel.c>
*
- * The G4 "windtunnel" has a single fan controlled by a
- * DS1775 fan controller and an ADM1030 thermostat.
+ * 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 ADM censor
+ * 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 OSX.
+ * 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). Other machines might have
- * a different thermal design. It is tuned for a CPU
+ * 1.25 MHz Dual G4 (March 03). It is tuned for a CPU
* temperatur around 57 C.
*
- * Copyright (C) 2003 Samuel Rydh (samuel@xxxxxxxxx)
+ * Copyright (C) 2003, 2004 Samuel Rydh (samuel@xxxxxxxxx)
*
* Loosely based upon 'thermostat.c' written by Benjamin Herrenschmidt
*
@@ -38,50 +37,37 @@
#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@xxxxxxxxx>");
-MODULE_DESCRIPTION("Apple G4 (windtunnel) fan driver");
-MODULE_LICENSE("GPL");
+#include <asm/of_device.h>

#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_probe( struct i2c_adapter *adapter, int addr, int kind);

-static int do_detect( struct i2c_adapter *adapter, int addr, int kind);
+/* 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 };
+
+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 error;
- struct timer_list timer;

int overheat_temp; /* 100% fan at this temp */
int overheat_hyst;
@@ -95,37 +81,54 @@
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_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 }
+ 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, 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, 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 )
{
@@ -159,37 +162,32 @@
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, 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 );
+ printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
+
+ x.fan_level = fan_setting;
}

static void
-poll_temp( void *param )
+poll_temp( void )
{
- int temp = read_reg( x.thermostat, 0, 2 );
- int i, level, casetemp;
+ int temp, i, level, casetemp;
+
+ temp = read_reg( x.thermostat, 0, 2 );

/* this actually occurs when the computer is loaded */
if( temp < 0 )
- goto out;
+ return;

casetemp = read_reg(x.fan, 0x0b, 1) << 8;
casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
@@ -197,37 +195,117 @@
if( LOG_TEMP && x.temp != temp ) {
print_temp("CPU-temp: ", temp );
print_temp(", Case: ", casetemp );
- printk(", Fan: %d\n", x.fan_level );
+ printk(", Fan: %d\n", 11-x.fan_level );
}
x.temp = temp;
x.casetemp = casetemp;

level = -1;
- for( i=0; (temp & 0xffff) > fan_down_table[i].temp ; i++ )
+ for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
;
if( i < x.downind )
- level = fan_down_table[i].fan_setting;
+ level = fan_table[i].fan_down_setting;
x.downind = i;

- for( i=0; (temp & 0xfffe) >= fan_up_table[i+1].temp ; i++ )
+ for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
;
if( x.upind < i )
- level = fan_up_table[i].fan_setting;
+ level = fan_table[i].fan_up_setting;
x.upind = i;

if( level >= 0 )
tune_fan( level );
- out:
- x.timer.expires = jiffies + 8*HZ;
- add_timer( &x.timer );
+}
+
+
+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
-schedule_poll( unsigned long t )
+restore_regs( void )
{
- schedule_work(&poll_work);
+ 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 );
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout( 8*HZ );
+
+ down( &x.lock );
+ poll_temp();
+ }
+
+ restore_regs();
+ up( &x.lock );
+
+ complete_and_exit( &x.completion, 0 );
+}
+
+
/************************************************************************/
/* i2c probing and setup */
/************************************************************************/
@@ -235,7 +313,20 @@
static int
do_attach( struct i2c_adapter *adapter )
{
- return i2c_probe( adapter, &addr_data, &do_detect );
+ 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
@@ -243,13 +334,23 @@
{
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;
+ 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 );
}
- kfree( client );
- return 0;
+ return err;
}

static struct i2c_driver g4fan_driver = {
@@ -262,24 +363,21 @@
};

static int
-detect_fan( struct i2c_client *cl )
+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 detected at %02x\n", cl->addr );
+ printk("ADM1030 fan controller [@%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) );
+ strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );

- if( i2c_attach_client( cl ) )
- goto out;
- return 0;
+ if( !i2c_attach_client(cl) )
+ x.fan = cl;
out:
if( cl != x.fan )
kfree( cl );
@@ -287,10 +385,13 @@
}

static int
-detect_thermostat( struct i2c_client *cl )
+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;

@@ -302,44 +403,37 @@
if( hyst_temp < 0 || os_temp < 0 )
goto out;

- printk("DS1775 digital thermometer detected at %02x\n", cl->addr );
+ printk("DS1775 digital thermometer [@%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) );
+ strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );

- if( i2c_attach_client( cl ) )
- goto out;
- return 0;
+ if( !i2c_attach_client(cl) )
+ x.thermostat = cl;
out:
- kfree( cl );
+ if( cl != x.thermostat )
+ kfree( cl );
return 0;
}

static int
-do_detect( struct i2c_adapter *adapter, int addr, int kind )
+do_probe( 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 )) )
+ if( !(cl=kmalloc(sizeof(*cl), GFP_KERNEL)) )
return -ENOMEM;
memset( cl, 0, sizeof(struct i2c_client) );

@@ -349,108 +443,94 @@
cl->flags = 0;

if( addr < 0x48 )
- return detect_fan( cl );
- return detect_thermostat( cl );
+ return attach_fan( cl );
+ return attach_thermostat( cl );
+}
+
+
+/************************************************************************/
+/* initialization / cleanup */
+/************************************************************************/
+
+static int
+therm_of_probe( struct of_device *dev, const struct of_match *match )
+{
+ return i2c_add_driver( &g4fan_driver );
}

-#define PRINT_REG( r ) printk("reg %02x = %02x\n", r, read_reg(x.fan, r, 1) )
+static int
+therm_of_remove( struct of_device *dev )
+{
+ return i2c_del_driver( &g4fan_driver );
+}
+
+static struct of_match therm_of_match[] = {{
+ .name = "fan",
+ .type = OF_ANY_MATCH,
+ .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;
- int ret, val;
-
- np = of_find_node_by_name(NULL, "power-mgt");
- if (np == NULL)
+
+ 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 == 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 );
+ if( !info || !machine_is_compatible("PowerMac3,6") )
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");
+ if( info->id != 3 ) {
+ printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
+ return -ENODEV;
}
- /* 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 );
+ if( !(np=of_find_node_by_name(NULL, "fan")) )
+ return -ENODEV;
+ x.of_dev = of_platform_device_create( np, "temperature" );
+ of_node_put( np );

- print_temp("Reducing overheating limit to ", x.overheat_temp );
- print_temp(" (Hyst: ", x.overheat_hyst );
- printk(")\n");
+ if( !x.of_dev ) {
+ printk(KERN_ERR "Can't register fan controller!\n");
+ return -ENODEV;
}

- /* 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 );
+ of_register_driver( &therm_of_driver );
return 0;
}

static void __exit
g4fan_exit( void )
{
- del_timer( &x.timer );
+ of_unregister_driver( &therm_of_driver );

- 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 );
+ if( x.of_dev )
+ of_device_unregister( x.of_dev );
}

module_init(g4fan_init);
module_exit(g4fan_exit);

+MODULE_AUTHOR("Samuel Rydh <samuel@xxxxxxxxx>");
+MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
+MODULE_LICENSE("GPL");
--
Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

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