[PATCH] G5 temperature control update
From: Benjamin Herrenschmidt
Date: Wed Mar 10 2004 - 22:16:53 EST
Hi !
This patch makes the temperature control code more robust, putting
less pressure on i2c, and work around occasional misconfiguration
of the ADC chips leading to incorrect temperature readings.
Ben.
===== drivers/macintosh/therm_pm72.c 1.1 vs edited =====
--- 1.1/drivers/macintosh/therm_pm72.c Thu Feb 5 17:23:50 2004
+++ edited/drivers/macintosh/therm_pm72.c Thu Mar 11 14:08:13 2004
@@ -2,7 +2,7 @@
* Device driver for the thermostats & fan controller of the
* Apple G5 "PowerMac7,2" desktop machines.
*
- * (c) Copyright IBM Corp. 2003
+ * (c) Copyright IBM Corp. 2003-2004
*
* Maintained by: Benjamin Herrenschmidt
* <benh@xxxxxxxxxxxxxxxxxxx>
@@ -45,7 +45,7 @@
* - Add things like /sbin/overtemp for non-critical
* overtemp conditions so userland can take some policy
* decisions, like slewing down CPUs
- * - Deal with fan failures
+ * - Deal with fan and i2c failures in a better way
*
* History:
*
@@ -63,9 +63,16 @@
* - Move back statics definitions to .c file
* - Avoid calling schedule_timeout with a negative number
*
- * Dev. 18, 2003 : 0.8
+ * 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>
@@ -94,14 +101,14 @@
#include "therm_pm72.h"
-#define VERSION "0.8"
+#define VERSION "0.9"
#undef DEBUG
#ifdef DEBUG
#define DBG(args...) printk(args)
#else
-#define DBG(args...)
+#define DBG(args...) do { } while(0)
#endif
@@ -194,14 +201,76 @@
/*
* Here are the i2c chip access wrappers
*/
-static int read_smon_adc(struct i2c_client *chip, int chan)
+
+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 ctrl;
+ int rc, data, tries = 0;
+ u8 buf[2];
- ctrl = i2c_smbus_read_byte_data(chip, 1);
- i2c_smbus_write_byte_data(chip, 1, (ctrl & 0x1f) | (chan << 5));
- wait_ms(1);
- return le16_to_cpu(i2c_smbus_read_word_data(chip, 4)) >> 6;
+ 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)
@@ -460,9 +529,13 @@
DBG(" current rpm: %d\n", state->rpm);
/* Get some sensor readings and scale it */
- temp = read_smon_adc(state->monitor, 1);
- voltage = read_smon_adc(state->monitor, 3);
- current_a = read_smon_adc(state->monitor, 4);
+ 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
*/
@@ -476,7 +549,8 @@
* 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",
+ 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))
@@ -613,6 +687,7 @@
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");
@@ -941,8 +1016,17 @@
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;
===== drivers/macintosh/therm_pm72.h 1.1 vs edited =====
--- 1.1/drivers/macintosh/therm_pm72.h Thu Feb 5 17:23:51 2004
+++ edited/drivers/macintosh/therm_pm72.h Thu Mar 11 12:32:46 2004
@@ -85,7 +85,7 @@
* I'm not sure which of these Apple's algorithm is supposed
* to use
*/
-#define RPM_PID_USE_ACTUAL_SPEED 1
+#define RPM_PID_USE_ACTUAL_SPEED 0
/*
* i2c IDs. Currently, we hard code those and assume that
@@ -220,6 +220,7 @@
s32 current_a;
s32 last_temp;
int first;
+ u8 adc_config;
};
/*
-
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