/* * 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 * * * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 "); MODULE_DESCRIPTION("Driver for Apple's PowerMac7,2 G5 thermal control"); MODULE_LICENSE("GPL");