/*
* Device driver for the thermostats & fan controller of the
* Apple G5 "PowerMac7,2" desktop machines.
*
* (c) Copyright IBM Corp. 2003-2004
*
* Maintained by: Benjamin Herrenschmidt
* <benh@kernel.crashing.org>
*
*
* The algorithm used is the PID control algorithm, used the same
* way the published Darwin code does, using the same values that
* are present in the Darwin 7.0 snapshot property lists.
*
* As far as the CPUs control loops are concerned, I use the
* calibration & PID constants provided by the EEPROM,
* I do _not_ embed any value from the property lists, as the ones
* provided by Darwin 7.0 seem to always have an older version that
* what I've seen on the actual computers.
* It would be interesting to verify that though. Darwin has a
* version code of 1.0.0d11 for all control loops it seems, while
* so far, the machines EEPROMs contain a dataset versioned 1.0.0f
*
* Darwin doesn't provide source to all parts, some missing
* bits like the AppleFCU driver or the actual scale of some
* of the values returned by sensors had to be "guessed" some
* way... or based on what Open Firmware does.
*
* I didn't yet figure out how to get the slots power consumption
* out of the FCU, so that part has not been implemented yet and
* the slots fan is set to a fixed 50% PWM, hoping this value is
* safe enough ...
*
* Note: I have observed strange oscillations of the CPU control
* loop on a dual G5 here. When idle, the CPU exhaust fan tend to
* oscillates slowly (over several minutes) between the minimum
* of 300RPMs and approx. 1000 RPMs. I don't know what is causing
* this, it could be some incorrect constant or an error in the
* way I ported the algorithm, or it could be just normal. I
* don't have full understanding on the way Apple tweaked the PID
* algorithm for the CPU control, it is definitely not a standard
* implementation...
*
* TODO: - Check MPU structure version/signature
* - Add things like /sbin/overtemp for non-critical
* overtemp conditions so userland can take some policy
* decisions, like slewing down CPUs
* - Deal with fan and i2c failures in a better way
*
* History:
*
* Nov. 13, 2003 : 0.5
* - First release
*
* Nov. 14, 2003 : 0.6
* - Read fan speed from FCU, low level fan routines now deal
* with errors & check fan status, though higher level don't
* do much.
* - Move a bunch of definitions to .h file
*
* Nov. 18, 2003 : 0.7
* - Fix build on ppc64 kernel
* - Move back statics definitions to .c file
* - Avoid calling schedule_timeout with a negative number
*
* Dec. 18, 2003 : 0.8
* - Fix typo when reading back fan speed on 2 CPU machines
*
* Mar. 11, 2004 : 0.9
* - Rework code accessing the ADC chips, make it more robust and
* closer to the chip spec. Also make sure it is configured properly,
* I've seen yet unexplained cases where on startup, I would have stale
* values in the configuration register
* - Switch back to use of target fan speed for PID, thus lowering
* pressure on i2c
*/
#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/spinlock.h>
#include <linux/smp_lock.h>
#include <linux/wait.h>
#include <linux/reboot.h>
#include <linux/kmod.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.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 "therm_pm72.h"
#define VERSION "0.9"
#undef DEBUG
#ifdef DEBUG
#define DBG(args...) printk(args)
#else
#define DBG(args...) do { } while(0)
#endif
/*
* Driver statics
*/
static struct of_device * of_dev;
static struct i2c_adapter * u3_0;
static struct i2c_adapter * u3_1;
static struct i2c_client * fcu;
static struct cpu_pid_state cpu_state[2];
static struct backside_pid_state backside_state;
static struct drives_pid_state drives_state;
static int state;
static int cpu_count;
static pid_t ctrl_task;
static struct completion ctrl_complete;
static int critical_state;
static DECLARE_MUTEX(driver_lock);
/*
* i2c_driver structure to attach to the host i2c controller
*/
static int therm_pm72_attach(struct i2c_adapter *adapter);
static int therm_pm72_detach(struct i2c_adapter *adapter);
static struct i2c_driver therm_pm72_driver =
{
.name = "therm_pm72",
.id = 0xDEADBEEF,
.flags = I2C_DF_NOTIFY,
.attach_adapter = therm_pm72_attach,
.detach_adapter = therm_pm72_detach,
};
static inline void wait_ms(unsigned int ms)
{
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(1 + (ms * HZ + 999) / 1000);
}
/*
* Utility function to create an i2c_client structure and
* attach it to one of u3 adapters
*/
static struct i2c_client *attach_i2c_chip(int id, const char *name)
{
struct i2c_client *clt;
struct i2c_adapter *adap;
if (id & 0x100)
adap = u3_1;
else
adap = u3_0;
if (adap == NULL)
return NULL;
clt = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
if (clt == NULL)
return NULL;
memset(clt, 0, sizeof(struct i2c_client));
clt->addr = (id >> 1) & 0x7f;
clt->adapter = adap;
clt->driver = &therm_pm72_driver;
clt->id = 0xDEADBEEF;
strncpy(clt->name, name, I2C_NAME_SIZE-1);
if (i2c_attach_client(clt)) {
printk(KERN_ERR "therm_pm72: Failed to attach to i2c ID 0x%x\n", id);
kfree(clt);
return NULL;
}
return clt;
}
/*
* Utility function to get rid of the i2c_client structure
* (will also detach from the adapter hopepfully)
*/
static void detach_i2c_chip(struct i2c_client *clt)
{
i2c_detach_client(clt);
kfree(clt);
}
/*
* Here are the i2c chip access wrappers
*/
static void initialize_adc(struct cpu_pid_state *state)
{
int rc;
u8 buf[2];
/* Read ADC the configuration register and cache it. We
* also make sure Config2 contains proper values, I've seen
* cases where we got stale grabage in there, thus preventing
* proper reading of conv. values
*/
/* Clear Config2 */
buf[0] = 5;
buf[1] = 0;
i2c_master_send(state->monitor, buf, 2);
/* Read & cache Config1 */
buf[0] = 1;
rc = i2c_master_send(state->monitor, buf, 1);
if (rc > 0) {
rc = i2c_master_recv(state->monitor, buf, 1);
if (rc > 0) {
state->adc_config = buf[0];
DBG("ADC config reg: %02x\n", state->adc_config);
/* Disable shutdown mode */
state->adc_config &= 0xfe;
buf[0] = 1;
buf[1] = state->adc_config;
rc = i2c_master_send(state->monitor, buf, 2);
}
}
if (rc <= 0)
printk(KERN_ERR "therm_pm72: Error reading ADC config"
" register !\n");
}
static int read_smon_adc(struct cpu_pid_state *state, int chan)
{
int rc, data, tries = 0;
u8 buf[2];
for (;;) {
/* Set channel */
buf[0] = 1;
buf[1] = (state->adc_config & 0x1f) | (chan << 5);
rc = i2c_master_send(state->monitor, buf, 2);
if (rc <= 0)
goto error;
/* Wait for convertion */
wait_ms(1);
/* Switch to data register */
buf[0] = 4;
rc = i2c_master_send(state->monitor, buf, 1);
if (rc <= 0)
goto error;
/* Read result */
rc = i2c_master_recv(state->monitor, buf, 2);
if (rc < 0)
goto error;
data = ((u16)buf[0]) << 8 | (u16)buf[1];
return data >> 6;
error:
DBG("Error reading ADC, retrying...\n");
if (++tries > 10) {
printk(KERN_ERR "therm_pm72: Error reading ADC !\n");
return -1;
}
wait_ms(10);
}
}
static int fan_read_reg(int reg, unsigned char *buf, int nb)
{
int tries, nr, nw;
buf[0] = reg;
tries = 0;
for (;;) {
nw = i2c_master_send(fcu, buf, 1);
if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
break;
wait_ms(10);
++tries;
}
if (nw <= 0) {
printk(KERN_ERR "Failure writing address to FCU: %d", nw);
return -EIO;
}
tries = 0;
for (;;) {
nr = i2c_master_recv(fcu, buf, nb);
if (nr > 0 || (nr < 0 && nr != ENODEV) || tries >= 100)
break;
wait_ms(10);
++tries;
}
if (nr <= 0)
printk(KERN_ERR "Failure reading data from FCU: %d", nw);
return nr;
}
static int fan_write_reg(int reg, const unsigned char *ptr, int nb)
{
int tries, nw;
unsigned char buf[16];
buf[0] = reg;
memcpy(buf+1, ptr, nb);
++nb;
tries = 0;
for (;;) {
nw = i2c_master_send(fcu, buf, nb);
if (nw > 0 || (nw < 0 && nw != EIO) || tries >= 100)
break;
wait_ms(10);
++tries;
}
if (nw < 0)
printk(KERN_ERR "Failure writing to FCU: %d", nw);
return nw;
}
static int set_rpm_fan(int fan, int rpm)
{
unsigned char buf[2];
int rc;
if (rpm < 300)
rpm = 300;
else if (rpm > 8191)
rpm = 8191;
buf[0] = rpm >> 5;
buf[1] = rpm << 3;
rc = fan_write_reg(0x10 + (fan * 2), buf, 2);
if (rc < 0)
return -EIO;
return 0;
}
static int get_rpm_fan(int fan, int programmed)
{
unsigned char failure;
unsigned char active;
unsigned char buf[2];
int rc, reg_base;
rc = fan_read_reg(0xb, &failure, 1);
if (rc != 1)
return -EIO;
if ((failure & (1 << fan)) != 0)
return -EFAULT;
rc = fan_read_reg(0xd, &active, 1);
if (rc != 1)
return -EIO;
if ((active & (1 << fan)) == 0)
return -ENXIO;
/* Programmed value or real current speed */
reg_base = programmed ? 0x10 : 0x11;
rc = fan_read_reg(reg_base + (fan * 2), buf, 2);
if (rc != 2)
return -EIO;
return (buf[0] << 5) | buf[1] >> 3;
}
static int set_pwm_fan(int fan, int pwm)
{
unsigned char buf[2];
int rc;
if (pwm < 10)
pwm = 10;
else if (pwm > 100)
pwm = 100;
pwm = (pwm * 2559) / 1000;
buf[0] = pwm;
rc = fan_write_reg(0x30 + (fan * 2), buf, 1);
if (rc < 0)
return rc;
return 0;
}
static int get_pwm_fan(int fan)
{
unsigned char failure;
unsigned char active;
unsigned char buf[2];
int rc;
rc = fan_read_reg(0x2b, &failure, 1);
if (rc != 1)
return -EIO;
if ((failure & (1 << fan)) != 0)
return -EFAULT;
rc = fan_read_reg(0x2d, &active, 1);
if (rc != 1)
return -EIO;
if ((active & (1 << fan)) == 0)
return -ENXIO;
/* Programmed value or real current speed */
rc = fan_read_reg(0x30 + (fan * 2), buf, 1);
if (rc != 1)
return -EIO;
return (buf[0] * 1000) / 2559;
}
/*
* Utility routine to read the CPU calibration EEPROM data
* from the device-tree
*/
static int read_eeprom(int cpu, struct mpu_data *out)
{
struct device_node *np;
char nodename[64];
u8 *data;
int len;
/* prom.c routine for finding a node by path is a bit brain dead
* and requires exact @xxx unit numbers. This is a bit ugly but
* will work for these machines
*/
sprintf(nodename, "/u3@0,f8000000/i2c@f8001000/cpuid@a%d", cpu ? 2 : 0);
np = of_find_node_by_path(nodename);
if (np == NULL) {
printk(KERN_ERR "therm_pm72: Failed to retreive cpuid node from device-tree\n");
return -ENODEV;
}
data = (u8 *)get_property(np, "cpuid", &len);
if (data == NULL) {
printk(KERN_ERR "therm_pm72: Failed to retreive cpuid property from device-tree\n");
of_node_put(np);
return -ENODEV;
}
memcpy(out, data, sizeof(struct mpu_data));
of_node_put(np);
return 0;
}
/*
* Now, unfortunately, sysfs doesn't give us a nice void * we could
* pass around to the attribute functions, so we don't really have
* choice but implement a bunch of them...
*
* That sucks a bit, we take the lock because FIX32TOPRINT evaluates
* the input twice... I accept patches :)
*/
#define BUILD_SHOW_FUNC_FIX(name, data) \
static ssize_t show_##name(struct device *dev, char *buf) \
{ \
ssize_t r; \
down(&driver_lock); \
r = sprintf(buf, "%d.%03d", FIX32TOPRINT(data)); \
up(&driver_lock); \
return r; \
}
#define BUILD_SHOW_FUNC_INT(name, data) \
static ssize_t show_##name(struct device *dev, char *buf) \
{ \
return sprintf(buf, "%d", data); \
}
BUILD_SHOW_FUNC_FIX(cpu0_temperature, cpu_state[0].last_temp)
BUILD_SHOW_FUNC_FIX(cpu0_voltage, cpu_state[0].voltage)
BUILD_SHOW_FUNC_FIX(cpu0_current, cpu_state[0].current_a)
BUILD_SHOW_FUNC_INT(cpu0_exhaust_fan_rpm, cpu_state[0].rpm)
BUILD_SHOW_FUNC_INT(cpu0_intake_fan_rpm, cpu_state[0].intake_rpm)
BUILD_SHOW_FUNC_FIX(cpu1_temperature, cpu_state[1].last_temp)
BUILD_SHOW_FUNC_FIX(cpu1_voltage, cpu_state[1].voltage)
BUILD_SHOW_FUNC_FIX(cpu1_current, cpu_state[1].current_a)
BUILD_SHOW_FUNC_INT(cpu1_exhaust_fan_rpm, cpu_state[1].rpm)
BUILD_SHOW_FUNC_INT(cpu1_intake_fan_rpm, cpu_state[1].intake_rpm)
BUILD_SHOW_FUNC_FIX(backside_temperature, backside_state.last_temp)
BUILD_SHOW_FUNC_INT(backside_fan_pwm, backside_state.pwm)
BUILD_SHOW_FUNC_FIX(drives_temperature, drives_state.last_temp)
BUILD_SHOW_FUNC_INT(drives_fan_rpm, drives_state.rpm)
static DEVICE_ATTR(cpu0_temperature,S_IRUGO,show_cpu0_temperature,NULL);
static DEVICE_ATTR(cpu0_voltage,S_IRUGO,show_cpu0_voltage,NULL);
static DEVICE_ATTR(cpu0_current,S_IRUGO,show_cpu0_current,NULL);
static DEVICE_ATTR(cpu0_exhaust_fan_rpm,S_IRUGO,show_cpu0_exhaust_fan_rpm,NULL);
static DEVICE_ATTR(cpu0_intake_fan_rpm,S_IRUGO,show_cpu0_intake_fan_rpm,NULL);
static DEVICE_ATTR(cpu1_temperature,S_IRUGO,show_cpu1_temperature,NULL);
static DEVICE_ATTR(cpu1_voltage,S_IRUGO,show_cpu1_voltage,NULL);
static DEVICE_ATTR(cpu1_current,S_IRUGO,show_cpu1_current,NULL);
static DEVICE_ATTR(cpu1_exhaust_fan_rpm,S_IRUGO,show_cpu1_exhaust_fan_rpm,NULL);
static DEVICE_ATTR(cpu1_intake_fan_rpm,S_IRUGO,show_cpu1_intake_fan_rpm,NULL);
static DEVICE_ATTR(backside_temperature,S_IRUGO,show_backside_temperature,NULL);
static DEVICE_ATTR(backside_fan_pwm,S_IRUGO,show_backside_fan_pwm,NULL);
static DEVICE_ATTR(drives_temperature,S_IRUGO,show_drives_temperature,NULL);
static DEVICE_ATTR(drives_fan_rpm,S_IRUGO,show_drives_fan_rpm,NULL);
/*
* CPUs fans control loop
*/
static void do_monitor_cpu(struct cpu_pid_state *state)
{
s32 temp, voltage, current_a, power, power_target;
s32 integral, derivative, proportional, adj_in_target, sval;
s64 integ_p, deriv_p, prop_p, sum;
int i, intake, rc;
DBG("cpu %d:\n", state->index);
/* Read current fan status */
if (state->index == 0)
rc = get_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
else
rc = get_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
if (rc < 0) {
printk(KERN_WARNING "Error %d reading CPU %d exhaust fan !\n",
rc, state->index);
/* XXX What do we do now ? */
} else
state->rpm = rc;
DBG(" current rpm: %d\n", state->rpm);
/* Get some sensor readings and scale it */
temp = read_smon_adc(state, 1);
if (temp == -1) {
state->overtemp++;
return;
}
voltage = read_smon_adc(state, 3);
current_a = read_smon_adc(state, 4);
/* Fixup temperature according to diode calibration
*/
DBG(" temp raw: %04x, m_diode: %04x, b_diode: %04x\n",
temp, state->mpu.mdiode, state->mpu.bdiode);
temp = ((s32)temp * (s32)state->mpu.mdiode + ((s32)state->mpu.bdiode << 12)) >> 2;
state->last_temp = temp;
DBG(" temp: %d.%03d\n", FIX32TOPRINT(temp));
/* Check tmax, increment overtemp if we are there. At tmax+8, we go
* full blown immediately and try to trigger a shutdown
*/
if (temp >= ((state->mpu.tmax + 8) << 16)) {
printk(KERN_WARNING "Warning ! CPU %d temperature way above maximum"
" (%d) !\n",
state->index, temp >> 16);
state->overtemp = CPU_MAX_OVERTEMP;
} else if (temp > (state->mpu.tmax << 16))
state->overtemp++;
else
state->overtemp = 0;
if (state->overtemp >= CPU_MAX_OVERTEMP)
critical_state = 1;
if (state->overtemp > 0) {
state->rpm = state->mpu.rmaxn_exhaust_fan;
state->intake_rpm = intake = state->mpu.rmaxn_intake_fan;
goto do_set_fans;
}
/* Scale other sensor values according to fixed scales
* obtained in Darwin and calculate power from I and V
*/
state->voltage = voltage *= ADC_CPU_VOLTAGE_SCALE;
state->current_a = current_a *= ADC_CPU_CURRENT_SCALE;
power = (((u64)current_a) * ((u64)voltage)) >> 16;
/* Calculate power target value (could be done once for all)
* and convert to a 16.16 fp number
*/
power_target = ((u32)(state->mpu.pmaxh - state->mpu.padjmax)) << 16;
DBG(" current: %d.%03d, voltage: %d.%03d\n",
FIX32TOPRINT(current_a), FIX32TOPRINT(voltage));
DBG(" power: %d.%03d W, target: %d.%03d, error: %d.%03d\n", FIX32TOPRINT(power),
FIX32TOPRINT(power_target), FIX32TOPRINT(power_target - power));
/* Store temperature and power in history array */
state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
state->temp_history[state->cur_temp] = temp;
state->cur_power = (state->cur_power + 1) % state->count_power;
state->power_history[state->cur_power] = power;
state->error_history[state->cur_power] = power_target - power;
/* If first loop, fill the history table */
if (state->first) {
for (i = 0; i < (state->count_power - 1); i++) {
state->cur_power = (state->cur_power + 1) % state->count_power;
state->power_history[state->cur_power] = power;
state->error_history[state->cur_power] = power_target - power;
}
for (i = 0; i < (CPU_TEMP_HISTORY_SIZE - 1); i++) {
state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
state->temp_history[state->cur_temp] = temp;
}
state->first = 0;
}
/* Calculate the integral term normally based on the "power" values */
sum = 0;
integral = 0;
for (i = 0; i < state->count_power; i++)
integral += state->error_history[i];
integral *= CPU_PID_INTERVAL;
DBG(" integral: %08x\n", integral);
/* Calculate the adjusted input (sense value).
* G_r is 12.20
* integ is 16.16
* so the result is 28.36
*
* input target is mpu.ttarget, input max is mpu.tmax
*/
integ_p = ((s64)state->mpu.pid_gr) * (s64)integral;
DBG(" integ_p: %d\n", (int)(deriv_p >> 36));
sval = (state->mpu.tmax << 16) - ((integ_p >> 20) & 0xffffffff);
adj_in_target = (state->mpu.ttarget << 16);
if (adj_in_target > sval)
adj_in_target = sval;
DBG(" adj_in_target: %d.%03d, ttarget: %d\n", FIX32TOPRINT(adj_in_target),
state->mpu.ttarget);
/* Calculate the derivative term */
derivative = state->temp_history[state->cur_temp] -
state->temp_history[(state->cur_temp + CPU_TEMP_HISTORY_SIZE - 1)
% CPU_TEMP_HISTORY_SIZE];
derivative /= CPU_PID_INTERVAL;
deriv_p = ((s64)state->mpu.pid_gd) * (s64)derivative;
DBG(" deriv_p: %d\n", (int)(deriv_p >> 36));
sum += deriv_p;
/* Calculate the proportional term */
proportional = temp - adj_in_target;
prop_p = ((s64)state->mpu.pid_gp) * (s64)proportional;
DBG(" prop_p: %d\n", (int)(prop_p >> 36));
sum += prop_p;
/* Scale sum */
sum >>= 36;
DBG(" sum: %d\n", (int)sum);
state->rpm += (s32)sum;
if (state->rpm < state->mpu.rminn_exhaust_fan)
state->rpm = state->mpu.rminn_exhaust_fan;
if (state->rpm > state->mpu.rmaxn_exhaust_fan)
state->rpm = state->mpu.rmaxn_exhaust_fan;
intake = (state->rpm * CPU_INTAKE_SCALE) >> 16;
if (intake < state->mpu.rminn_intake_fan)
intake = state->mpu.rminn_intake_fan;
if (intake > state->mpu.rmaxn_intake_fan)
intake = state->mpu.rmaxn_intake_fan;
state->intake_rpm = intake;
do_set_fans:
DBG("** CPU %d RPM: %d Ex, %d In, overtemp: %d\n",
state->index, (int)state->rpm, intake, state->overtemp);
/* We should check for errors, shouldn't we ? But then, what
* do we do once the error occurs ? For FCU notified fan
* failures (-EFAULT) we probably want to notify userland
* some way...
*/
if (state->index == 0) {
set_rpm_fan(CPUA_INTAKE_FAN_RPM_ID, intake);
set_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, state->rpm);
} else {
set_rpm_fan(CPUB_INTAKE_FAN_RPM_ID, intake);
set_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, state->rpm);
}
}
/*
* Initialize the state structure for one CPU control loop
*/
static int init_cpu_state(struct cpu_pid_state *state, int index)
{
state->index = index;
state->first = 1;
state->rpm = 1000;
state->overtemp = 0;
state->adc_config = 0x00;
if (index == 0)
state->monitor = attach_i2c_chip(SUPPLY_MONITOR_ID, "CPU0_monitor");
else if (index == 1)
state->monitor = attach_i2c_chip(SUPPLY_MONITORB_ID, "CPU1_monitor");
if (state->monitor == NULL)
goto fail;
if (read_eeprom(index, &state->mpu))
goto fail;
state->count_power = state->mpu.tguardband;
if (state->count_power > CPU_POWER_HISTORY_SIZE) {
printk(KERN_WARNING "Warning ! too many power history slots\n");
state->count_power = CPU_POWER_HISTORY_SIZE;
}
DBG("CPU %d Using %d power history entries\n", index, state->count_power);
if (index == 0) {
device_create_file(&of_dev->dev, &dev_attr_cpu0_temperature);
device_create_file(&of_dev->dev, &dev_attr_cpu0_voltage);
device_create_file(&of_dev->dev, &dev_attr_cpu0_current);
device_create_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
device_create_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
} else {
device_create_file(&of_dev->dev, &dev_attr_cpu1_temperature);
device_create_file(&of_dev->dev, &dev_attr_cpu1_voltage);
device_create_file(&of_dev->dev, &dev_attr_cpu1_current);
device_create_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
device_create_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
}
return 0;
fail:
if (state->monitor)
detach_i2c_chip(state->monitor);
state->monitor = NULL;
return -ENODEV;
}
/*
* Dispose of the state data for one CPU control loop
*/
static void dispose_cpu_state(struct cpu_pid_state *state)
{
if (state->monitor == NULL)
return;
if (state->index == 0) {
device_remove_file(&of_dev->dev, &dev_attr_cpu0_temperature);
device_remove_file(&of_dev->dev, &dev_attr_cpu0_voltage);
device_remove_file(&of_dev->dev, &dev_attr_cpu0_current);
device_remove_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
device_remove_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
} else {
device_remove_file(&of_dev->dev, &dev_attr_cpu1_temperature);
device_remove_file(&of_dev->dev, &dev_attr_cpu1_voltage);
device_remove_file(&of_dev->dev, &dev_attr_cpu1_current);
device_remove_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
device_remove_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
}
detach_i2c_chip(state->monitor);
state->monitor = NULL;
}
/*
* Motherboard backside & U3 heatsink fan control loop
*/
static void do_monitor_backside(struct backside_pid_state *state)
{
s32 temp, integral, derivative;
s64 integ_p, deriv_p, prop_p, sum;
int i, rc;
if (--state->ticks != 0)
return;
state->ticks = BACKSIDE_PID_INTERVAL;
DBG("backside:\n");
/* Check fan status */
rc = get_pwm_fan(BACKSIDE_FAN_PWM_ID);
if (rc < 0) {
printk(KERN_WARNING "Error %d reading backside fan !\n", rc);
/* XXX What do we do now ? */
} else
state->pwm = rc;
DBG(" current pwm: %d\n", state->pwm);
/* Get some sensor readings */
temp = i2c_smbus_read_byte_data(state->monitor, MAX6690_EXT_TEMP) << 16;
state->last_temp = temp;
DBG(" temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
FIX32TOPRINT(BACKSIDE_PID_INPUT_TARGET));
/* Store temperature and error in history array */
state->cur_sample = (state->cur_sample + 1) % BACKSIDE_PID_HISTORY_SIZE;
state->sample_history[state->cur_sample] = temp;
state->error_history[state->cur_sample] = temp - BACKSIDE_PID_INPUT_TARGET;
/* If first loop, fill the history table */
if (state->first) {
for (i = 0; i < (BACKSIDE_PID_HISTORY_SIZE - 1); i++) {
state->cur_sample = (state->cur_sample + 1) %
BACKSIDE_PID_HISTORY_SIZE;
state->sample_history[state->cur_sample] = temp;
state->error_history[state->cur_sample] =
temp - BACKSIDE_PID_INPUT_TARGET;
}
state->first = 0;
}
/* Calculate the integral term */
sum = 0;
integral = 0;
for (i = 0; i < BACKSIDE_PID_HISTORY_SIZE; i++)
integral += state->error_history[i];
integral *= BACKSIDE_PID_INTERVAL;
DBG(" integral: %08x\n", integral);
integ_p = ((s64)BACKSIDE_PID_G_r) * (s64)integral;
DBG(" integ_p: %d\n", (int)(integ_p >> 36));
sum += integ_p;
/* Calculate the derivative term */
derivative = state->error_history[state->cur_sample] -
state->error_history[(state->cur_sample + BACKSIDE_PID_HISTORY_SIZE - 1)
% BACKSIDE_PID_HISTORY_SIZE];
derivative /= BACKSIDE_PID_INTERVAL;
deriv_p = ((s64)BACKSIDE_PID_G_d) * (s64)derivative;
DBG(" deriv_p: %d\n", (int)(deriv_p >> 36));
sum += deriv_p;
/* Calculate the proportional term */
prop_p = ((s64)BACKSIDE_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
DBG(" prop_p: %d\n", (int)(prop_p >> 36));
sum += prop_p;
/* Scale sum */
sum >>= 36;
DBG(" sum: %d\n", (int)sum);
state->pwm += (s32)sum;
if (state->pwm < BACKSIDE_PID_OUTPUT_MIN)
state->pwm = BACKSIDE_PID_OUTPUT_MIN;
if (state->pwm > BACKSIDE_PID_OUTPUT_MAX)
state->pwm = BACKSIDE_PID_OUTPUT_MAX;
DBG("** BACKSIDE PWM: %d\n", (int)state->pwm);
set_pwm_fan(BACKSIDE_FAN_PWM_ID, state->pwm);
}
/*
* Initialize the state structure for the backside fan control loop
*/
static int init_backside_state(struct backside_pid_state *state)
{
state->ticks = 1;
state->first = 1;
state->pwm = 50;
state->monitor = attach_i2c_chip(BACKSIDE_MAX_ID, "backside_temp");
if (state->monitor == NULL)
return -ENODEV;
device_create_file(&of_dev->dev, &dev_attr_backside_temperature);
device_create_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
return 0;
}
/*
* Dispose of the state data for the backside control loop
*/
static void dispose_backside_state(struct backside_pid_state *state)
{
if (state->monitor == NULL)
return;
device_remove_file(&of_dev->dev, &dev_attr_backside_temperature);
device_remove_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
detach_i2c_chip(state->monitor);
state->monitor = NULL;
}
/*
* Drives bay fan control loop
*/
static void do_monitor_drives(struct drives_pid_state *state)
{
s32 temp, integral, derivative;
s64 integ_p, deriv_p, prop_p, sum;
int i, rc;
if (--state->ticks != 0)
return;
state->ticks = DRIVES_PID_INTERVAL;
DBG("drives:\n");
/* Check fan status */
rc = get_rpm_fan(DRIVES_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
if (rc < 0) {
printk(KERN_WARNING "Error %d reading drives fan !\n", rc);
/* XXX What do we do now ? */
} else
state->rpm = rc;
DBG(" current rpm: %d\n", state->rpm);
/* Get some sensor readings */
temp = le16_to_cpu(i2c_smbus_read_word_data(state->monitor, DS1775_TEMP)) << 8;
state->last_temp = temp;
DBG(" temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
FIX32TOPRINT(DRIVES_PID_INPUT_TARGET));
/* Store temperature and error in history array */
state->cur_sample = (state->cur_sample + 1) % DRIVES_PID_HISTORY_SIZE;
state->sample_history[state->cur_sample] = temp;
state->error_history[state->cur_sample] = temp - DRIVES_PID_INPUT_TARGET;
/* If first loop, fill the history table */
if (state->first) {
for (i = 0; i < (DRIVES_PID_HISTORY_SIZE - 1); i++) {
state->cur_sample = (state->cur_sample + 1) %
DRIVES_PID_HISTORY_SIZE;
state->sample_history[state->cur_sample] = temp;
state->error_history[state->cur_sample] =
temp - DRIVES_PID_INPUT_TARGET;
}
state->first = 0;
}
/* Calculate the integral term */
sum = 0;
integral = 0;
for (i = 0; i < DRIVES_PID_HISTORY_SIZE; i++)
integral += state->error_history[i];
integral *= DRIVES_PID_INTERVAL;
DBG(" integral: %08x\n", integral);
integ_p = ((s64)DRIVES_PID_G_r) * (s64)integral;
DBG(" integ_p: %d\n", (int)(integ_p >> 36));
sum += integ_p;
/* Calculate the derivative term */
derivative = state->error_history[state->cur_sample] -
state->error_history[(state->cur_sample + DRIVES_PID_HISTORY_SIZE - 1)
% DRIVES_PID_HISTORY_SIZE];
derivative /= DRIVES_PID_INTERVAL;
deriv_p = ((s64)DRIVES_PID_G_d) * (s64)derivative;
DBG(" deriv_p: %d\n", (int)(deriv_p >> 36));
sum += deriv_p;
/* Calculate the proportional term */
prop_p = ((s64)DRIVES_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
DBG(" prop_p: %d\n", (int)(prop_p >> 36));
sum += prop_p;
/* Scale sum */
sum >>= 36;
DBG(" sum: %d\n", (int)sum);
state->rpm += (s32)sum;
if (state->rpm < DRIVES_PID_OUTPUT_MIN)
state->rpm = DRIVES_PID_OUTPUT_MIN;
if (state->rpm > DRIVES_PID_OUTPUT_MAX)
state->rpm = DRIVES_PID_OUTPUT_MAX;
DBG("** DRIVES RPM: %d\n", (int)state->rpm);
set_rpm_fan(DRIVES_FAN_RPM_ID, state->rpm);
}
/*
* Initialize the state structure for the drives bay fan control loop
*/
static int init_drives_state(struct drives_pid_state *state)
{
state->ticks = 1;
state->first = 1;
state->rpm = 1000;
state->monitor = attach_i2c_chip(DRIVES_DALLAS_ID, "drives_temp");
if (state->monitor == NULL)
return -ENODEV;
device_create_file(&of_dev->dev, &dev_attr_drives_temperature);
device_create_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
return 0;
}
/*
* Dispose of the state data for the drives control loop
*/
static void dispose_drives_state(struct drives_pid_state *state)
{
if (state->monitor == NULL)
return;
device_remove_file(&of_dev->dev, &dev_attr_drives_temperature);
device_remove_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
detach_i2c_chip(state->monitor);
state->monitor = NULL;
}
static int call_critical_overtemp(void)
{
char *argv[] = { critical_overtemp_path, NULL };
static char *envp[] = { "HOME=/",
"TERM=linux",
"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
NULL };
return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
}
/*
* Here's the kernel thread that calls the various control loops
*/
static int main_control_loop(void *x)
{
daemonize("kfand");
DBG("main_control_loop started\n");
down(&driver_lock);
/* Set the PCI fan once for now */
set_pwm_fan(SLOTS_FAN_PWM_ID, SLOTS_FAN_DEFAULT_PWM);
/* Initialize ADCs */
initialize_adc(&cpu_state[0]);
if (cpu_state[1].monitor != NULL)
initialize_adc(&cpu_state[1]);
up(&driver_lock);
while (state == state_attached) {
unsigned long elapsed, start;
start = jiffies;
down(&driver_lock);
do_monitor_cpu(&cpu_state[0]);
if (cpu_state[1].monitor != NULL)
do_monitor_cpu(&cpu_state[1]);
do_monitor_backside(&backside_state);
do_monitor_drives(&drives_state);
up(&driver_lock);
if (critical_state == 1) {
printk(KERN_WARNING "Temperature control detected a critical condition\n");
printk(KERN_WARNING "Attempting to shut down...\n");
if (call_critical_overtemp()) {
printk(KERN_WARNING "Can't call %s, power off now!\n",
critical_overtemp_path);
machine_power_off();
}
}
if (critical_state > 0)
critical_state++;
if (critical_state > MAX_CRITICAL_STATE) {
printk(KERN_WARNING "Shutdown timed out, power off now !\n");
machine_power_off();
}
// FIXME: Deal with signals
set_current_state(TASK_INTERRUPTIBLE);
elapsed = jiffies - start;
if (elapsed < HZ)
schedule_timeout(HZ - elapsed);
}
DBG("main_control_loop ended\n");
ctrl_task = 0;
complete_and_exit(&ctrl_complete, 0);
}
/*
* Dispose the control loops when tearing down
*/
static void dispose_control_loops(void)
{
dispose_cpu_state(&cpu_state[0]);
dispose_cpu_state(&cpu_state[1]);
dispose_backside_state(&backside_state);
dispose_drives_state(&drives_state);
}
/*
* Create the control loops. U3-0 i2c bus is up, so we can now
* get to the various sensors
*/
static int create_control_loops(void)
{
struct device_node *np;
/* Count CPUs from the device-tree, we don't care how many are
* actually used by Linux
*/
cpu_count = 0;
for (np = NULL; NULL != (np = of_find_node_by_type(np, "cpu"));)
cpu_count++;
DBG("counted %d CPUs in the device-tree\n", cpu_count);
/* Create control loops for everything. If any fail, everything
* fails
*/
if (init_cpu_state(&cpu_state[0], 0))
goto fail;
if (cpu_count > 1 && init_cpu_state(&cpu_state[1], 1))
goto fail;
if (init_backside_state(&backside_state))
goto fail;
if (init_drives_state(&drives_state))
goto fail;
DBG("all control loops up !\n");
return 0;
fail:
DBG("failure creating control loops, disposing\n");
dispose_control_loops();
return -ENODEV;
}
/*
* Start the control loops after everything is up, that is create
* the thread that will make them run
*/
static void start_control_loops(void)
{
init_completion(&ctrl_complete);
ctrl_task = kernel_thread(main_control_loop, NULL, SIGCHLD | CLONE_KERNEL);
}
/*
* Stop the control loops when tearing down
*/
static void stop_control_loops(void)
{
if (ctrl_task != 0)
wait_for_completion(&ctrl_complete);
}
/*
* Attach to the i2c FCU after detecting U3-1 bus
*/
static int attach_fcu(void)
{
fcu = attach_i2c_chip(FAN_CTRLER_ID, "fcu");
if (fcu == NULL)
return -ENODEV;
DBG("FCU attached\n");
return 0;
}
/*
* Detach from the i2c FCU when tearing down
*/
static void detach_fcu(void)
{
if (fcu)
detach_i2c_chip(fcu);
fcu = NULL;
}
/*
* Attach to the i2c controller. We probe the various chips based
* on the device-tree nodes and build everything for the driver to
* run, we then kick the driver monitoring thread
*/
static int therm_pm72_attach(struct i2c_adapter *adapter)
{
down(&driver_lock);
/* Check state */
if (state == state_detached)
state = state_attaching;
if (state != state_attaching) {
up(&driver_lock);
return 0;
}
/* Check if we are looking for one of these */
if (u3_0 == NULL && !strcmp(adapter->name, "u3 0")) {
u3_0 = adapter;
DBG("found U3-0, creating control loops\n");
if (create_control_loops())
u3_0 = NULL;
} else if (u3_1 == NULL && !strcmp(adapter->name, "u3 1")) {
u3_1 = adapter;
DBG("found U3-1, attaching FCU\n");
if (attach_fcu())
u3_1 = NULL;
}
/* We got all we need, start control loops */
if (u3_0 != NULL && u3_1 != NULL) {
DBG("everything up, starting control loops\n");
state = state_attached;
start_control_loops();
}
up(&driver_lock);
return 0;
}
/*
* Called on every adapter when the driver or the i2c controller
* is going away.
*/
static int therm_pm72_detach(struct i2c_adapter *adapter)
{
down(&driver_lock);
if (state != state_detached)
state = state_detaching;
/* Stop control loops if any */
DBG("stopping control loops\n");
up(&driver_lock);
stop_control_loops();
down(&driver_lock);
if (u3_0 != NULL && !strcmp(adapter->name, "u3 0")) {
DBG("lost U3-0, disposing control loops\n");
dispose_control_loops();
u3_0 = NULL;
}
if (u3_1 != NULL && !strcmp(adapter->name, "u3 1")) {
DBG("lost U3-1, detaching FCU\n");
detach_fcu();
u3_1 = NULL;
}
if (u3_0 == NULL && u3_1 == NULL)
state = state_detached;
up(&driver_lock);
return 0;
}
static int fcu_of_probe(struct of_device* dev, const struct of_match *match)
{
int rc;
state = state_detached;
rc = i2c_add_driver(&therm_pm72_driver);
if (rc < 0)
return rc;
return 0;
}
static int fcu_of_remove(struct of_device* dev)
{
i2c_del_driver(&therm_pm72_driver);
return 0;
}
static struct of_match fcu_of_match[] =
{
{
.name = OF_ANY_MATCH,
.type = "fcu",
.compatible = OF_ANY_MATCH
},
{},
};
static struct of_platform_driver fcu_of_platform_driver =
{
.name = "temperature",
.match_table = fcu_of_match,
.probe = fcu_of_probe,
.remove = fcu_of_remove
};
/*
* Check machine type, attach to i2c controller
*/
static int __init therm_pm72_init(void)
{
struct device_node *np;
if (!machine_is_compatible("PowerMac7,2"))
return -ENODEV;
printk(KERN_INFO "PowerMac G5 Thermal control driver %s\n", VERSION);
np = of_find_node_by_type(NULL, "fcu");
if (np == NULL) {
printk(KERN_ERR "Can't find FCU in device-tree !\n");
return -ENODEV;
}
of_dev = of_platform_device_create(np, "temperature");
if (of_dev == NULL) {
printk(KERN_ERR "Can't register FCU platform device !\n");
return -ENODEV;
}
of_register_driver(&fcu_of_platform_driver);
return 0;
}
static void __exit therm_pm72_exit(void)
{
of_unregister_driver(&fcu_of_platform_driver);
if (of_dev)
of_device_unregister(of_dev);
}
module_init(therm_pm72_init);
module_exit(therm_pm72_exit);
MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("Driver for Apple's PowerMac7,2 G5 thermal control");
MODULE_LICENSE("GPL");
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