// SPDX-License-Identifier: GPL-2.0-only /* * Windfarm PowerMac thermal control. iMac G5 * * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. * <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 8.2 snapshot property lists (note however * that none of the code has been re-used, it's a complete re-implementation * * The various control loops found in Darwin config file are: * * PowerMac8,1 and PowerMac8,2 * =========================== * * System Fans control loop. Different based on models. In addition to the * usual PID algorithm, the control loop gets 2 additional pairs of linear * scaling factors (scale/offsets) expressed as 4.12 fixed point values * signed offset, unsigned scale) * * The targets are modified such as: * - the linked control (second control) gets the target value as-is * (typically the drive fan) * - the main control (first control) gets the target value scaled with * the first pair of factors, and is then modified as below * - the value of the target of the CPU Fan control loop is retrieved, * scaled with the second pair of factors, and the max of that and * the scaled target is applied to the main control. * * # model_id: 2 * controls : system-fan, drive-bay-fan * sensors : hd-temp * PID params : G_d = 0x15400000 * G_p = 0x00200000 * G_r = 0x000002fd * History = 2 entries * Input target = 0x3a0000 * Interval = 5s * linear-factors : offset = 0xff38 scale = 0x0ccd * offset = 0x0208 scale = 0x07ae * * # model_id: 3 * controls : system-fan, drive-bay-fan * sensors : hd-temp * PID params : G_d = 0x08e00000 * G_p = 0x00566666 * G_r = 0x0000072b * History = 2 entries * Input target = 0x350000 * Interval = 5s * linear-factors : offset = 0xff38 scale = 0x0ccd * offset = 0x0000 scale = 0x0000 * * # model_id: 5 * controls : system-fan * sensors : hd-temp * PID params : G_d = 0x15400000 * G_p = 0x00233333 * G_r = 0x000002fd * History = 2 entries * Input target = 0x3a0000 * Interval = 5s * linear-factors : offset = 0x0000 scale = 0x1000 * offset = 0x0091 scale = 0x0bae * * CPU Fan control loop. The loop is identical for all models. it * has an additional pair of scaling factor. This is used to scale the * systems fan control loop target result (the one before it gets scaled * by the System Fans control loop itself). Then, the max value of the * calculated target value and system fan value is sent to the fans * * controls : cpu-fan * sensors : cpu-temp cpu-power * PID params : From SMU sdb partition * linear-factors : offset = 0xfb50 scale = 0x1000 * * CPU Slew control loop. Not implemented. The cpufreq driver in linux is * completely separate for now, though we could find a way to link it, either * as a client reacting to overtemp notifications, or directling monitoring * the CPU temperature * * WARNING ! The CPU control loop requires the CPU tmax for the current * operating point. However, we currently are completely separated from * the cpufreq driver and thus do not know what the current operating * point is. Fortunately, we also do not have any hardware supporting anything * but operating point 0 at the moment, thus we just peek that value directly * from the SDB partition. If we ever end up with actually slewing the system * clock and thus changing operating points, we'll have to find a way to * communicate with the CPU freq driver; */ #include <linux/types.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/delay.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/spinlock.h> #include <linux/wait.h> #include <linux/kmod.h> #include <linux/device.h> #include <linux/platform_device.h> #include <asm/prom.h> #include <asm/machdep.h> #include <asm/io.h> #include <asm/sections.h> #include <asm/smu.h> #include "windfarm.h" #include "windfarm_pid.h" #define VERSION "0.4" #undef DEBUG #ifdef DEBUG #define DBG(args...) printk(args) #else #define DBG(args...) do { } while(0) #endif /* define this to force CPU overtemp to 74 degree, useful for testing * the overtemp code */ #undef HACKED_OVERTEMP static int wf_smu_mach_model; /* machine model id */ /* Controls & sensors */ static struct wf_sensor *sensor_cpu_power; static struct wf_sensor *sensor_cpu_temp; static struct wf_sensor *sensor_hd_temp; static struct wf_control *fan_cpu_main; static struct wf_control *fan_hd; static struct wf_control *fan_system; static struct wf_control *cpufreq_clamp; /* Set to kick the control loop into life */ static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok; static bool wf_smu_started; /* Failure handling.. could be nicer */ #define FAILURE_FAN 0x01 #define FAILURE_SENSOR 0x02 #define FAILURE_OVERTEMP 0x04 static unsigned int wf_smu_failure_state; static int wf_smu_readjust, wf_smu_skipping; static bool wf_smu_overtemp; /* * ****** System Fans Control Loop ****** * */ /* Parameters for the System Fans control loop. Parameters * not in this table such as interval, history size, ... * are common to all versions and thus hard coded for now. */ struct wf_smu_sys_fans_param { int model_id; s32 itarget; s32 gd, gp, gr; s16 offset0; u16 scale0; s16 offset1; u16 scale1; }; #define WF_SMU_SYS_FANS_INTERVAL 5 #define WF_SMU_SYS_FANS_HISTORY_SIZE 2 /* State data used by the system fans control loop */ struct wf_smu_sys_fans_state { int ticks; s32 sys_setpoint; s32 hd_setpoint; s16 offset0; u16 scale0; s16 offset1; u16 scale1; struct wf_pid_state pid; }; /* * Configs for SMU System Fan control loop */ static struct wf_smu_sys_fans_param wf_smu_sys_all_params[] = { /* Model ID 2 */ { .model_id = 2, .itarget = 0x3a0000, .gd = 0x15400000, .gp = 0x00200000, .gr = 0x000002fd, .offset0 = 0xff38, .scale0 = 0x0ccd, .offset1 = 0x0208, .scale1 = 0x07ae, }, /* Model ID 3 */ { .model_id = 3, .itarget = 0x350000, .gd = 0x08e00000, .gp = 0x00566666, .gr = 0x0000072b, .offset0 = 0xff38, .scale0 = 0x0ccd, .offset1 = 0x0000, .scale1 = 0x0000, }, /* Model ID 5 */ { .model_id = 5, .itarget = 0x3a0000, .gd = 0x15400000, .gp = 0x00233333, .gr = 0x000002fd, .offset0 = 0x0000, .scale0 = 0x1000, .offset1 = 0x0091, .scale1 = 0x0bae, }, }; #define WF_SMU_SYS_FANS_NUM_CONFIGS ARRAY_SIZE(wf_smu_sys_all_params) static struct wf_smu_sys_fans_state *wf_smu_sys_fans; /* * ****** CPU Fans Control Loop ****** * */ #define WF_SMU_CPU_FANS_INTERVAL 1 #define WF_SMU_CPU_FANS_MAX_HISTORY 16 #define WF_SMU_CPU_FANS_SIBLING_SCALE 0x00001000 #define WF_SMU_CPU_FANS_SIBLING_OFFSET 0xfffffb50 /* State data used by the cpu fans control loop */ struct wf_smu_cpu_fans_state { int ticks; s32 cpu_setpoint; s32 scale; s32 offset; struct wf_cpu_pid_state pid; }; static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans; /* * ***** Implementation ***** * */ static void wf_smu_create_sys_fans(void) { struct wf_smu_sys_fans_param *param = NULL; struct wf_pid_param pid_param; int i; /* First, locate the params for this model */ for (i = 0; i < WF_SMU_SYS_FANS_NUM_CONFIGS; i++) if (wf_smu_sys_all_params[i].model_id == wf_smu_mach_model) { param = &wf_smu_sys_all_params[i]; break; } /* No params found, put fans to max */ if (param == NULL) { printk(KERN_WARNING "windfarm: System fan config not found " "for this machine model, max fan speed\n"); goto fail; } /* Alloc & initialize state */ wf_smu_sys_fans = kmalloc(sizeof(struct wf_smu_sys_fans_state), GFP_KERNEL); if (wf_smu_sys_fans == NULL) { printk(KERN_WARNING "windfarm: Memory allocation error" " max fan speed\n"); goto fail; } wf_smu_sys_fans->ticks = 1; wf_smu_sys_fans->scale0 = param->scale0; wf_smu_sys_fans->offset0 = param->offset0; wf_smu_sys_fans->scale1 = param->scale1; wf_smu_sys_fans->offset1 = param->offset1; /* Fill PID params */ pid_param.gd = param->gd; pid_param.gp = param->gp; pid_param.gr = param->gr; pid_param.interval = WF_SMU_SYS_FANS_INTERVAL; pid_param.history_len = WF_SMU_SYS_FANS_HISTORY_SIZE; pid_param.itarget = param->itarget; pid_param.min = wf_control_get_min(fan_system); pid_param.max = wf_control_get_max(fan_system); if (fan_hd) { pid_param.min = max(pid_param.min, wf_control_get_min(fan_hd)); pid_param.max = min(pid_param.max, wf_control_get_max(fan_hd)); } wf_pid_init(&wf_smu_sys_fans->pid, &pid_param); DBG("wf: System Fan control initialized.\n"); DBG(" itarged=%d.%03d, min=%d RPM, max=%d RPM\n", FIX32TOPRINT(pid_param.itarget), pid_param.min, pid_param.max); return; fail: if (fan_system) wf_control_set_max(fan_system); if (fan_hd) wf_control_set_max(fan_hd); } static void wf_smu_sys_fans_tick(struct wf_smu_sys_fans_state *st) { s32 new_setpoint, temp, scaled, cputarget; int rc; if (--st->ticks != 0) { if (wf_smu_readjust) goto readjust; return; } st->ticks = WF_SMU_SYS_FANS_INTERVAL; rc = wf_sensor_get(sensor_hd_temp, &temp); if (rc) { printk(KERN_WARNING "windfarm: HD temp sensor error %d\n", rc); wf_smu_failure_state |= FAILURE_SENSOR; return; } DBG("wf_smu: System Fans tick ! HD temp: %d.%03d\n", FIX32TOPRINT(temp)); if (temp > (st->pid.param.itarget + 0x50000)) wf_smu_failure_state |= FAILURE_OVERTEMP; new_setpoint = wf_pid_run(&st->pid, temp); DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint); scaled = ((((s64)new_setpoint) * (s64)st->scale0) >> 12) + st->offset0; DBG("wf_smu: scaled setpoint: %d RPM\n", (int)scaled); cputarget = wf_smu_cpu_fans ? wf_smu_cpu_fans->pid.target : 0; cputarget = ((((s64)cputarget) * (s64)st->scale1) >> 12) + st->offset1; scaled = max(scaled, cputarget); scaled = max(scaled, st->pid.param.min); scaled = min(scaled, st->pid.param.max); DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)scaled); if (st->sys_setpoint == scaled && new_setpoint == st->hd_setpoint) return; st->sys_setpoint = scaled; st->hd_setpoint = new_setpoint; readjust: if (fan_system && wf_smu_failure_state == 0) { rc = wf_control_set(fan_system, st->sys_setpoint); if (rc) { printk(KERN_WARNING "windfarm: Sys fan error %d\n", rc); wf_smu_failure_state |= FAILURE_FAN; } } if (fan_hd && wf_smu_failure_state == 0) { rc = wf_control_set(fan_hd, st->hd_setpoint); if (rc) { printk(KERN_WARNING "windfarm: HD fan error %d\n", rc); wf_smu_failure_state |= FAILURE_FAN; } } } static void wf_smu_create_cpu_fans(void) { struct wf_cpu_pid_param pid_param; const struct smu_sdbp_header *hdr; struct smu_sdbp_cpupiddata *piddata; struct smu_sdbp_fvt *fvt; s32 tmax, tdelta, maxpow, powadj; /* First, locate the PID params in SMU SBD */ hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL); if (hdr == 0) { printk(KERN_WARNING "windfarm: CPU PID fan config not found " "max fan speed\n"); goto fail; } piddata = (struct smu_sdbp_cpupiddata *)&hdr[1]; /* Get the FVT params for operating point 0 (the only supported one * for now) in order to get tmax */ hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL); if (hdr) { fvt = (struct smu_sdbp_fvt *)&hdr[1]; tmax = ((s32)fvt->maxtemp) << 16; } else tmax = 0x5e0000; /* 94 degree default */ /* Alloc & initialize state */ wf_smu_cpu_fans = kmalloc(sizeof(struct wf_smu_cpu_fans_state), GFP_KERNEL); if (wf_smu_cpu_fans == NULL) goto fail; wf_smu_cpu_fans->ticks = 1; wf_smu_cpu_fans->scale = WF_SMU_CPU_FANS_SIBLING_SCALE; wf_smu_cpu_fans->offset = WF_SMU_CPU_FANS_SIBLING_OFFSET; /* Fill PID params */ pid_param.interval = WF_SMU_CPU_FANS_INTERVAL; pid_param.history_len = piddata->history_len; if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) { printk(KERN_WARNING "windfarm: History size overflow on " "CPU control loop (%d)\n", piddata->history_len); pid_param.history_len = WF_CPU_PID_MAX_HISTORY; } pid_param.gd = piddata->gd; pid_param.gp = piddata->gp; pid_param.gr = piddata->gr / pid_param.history_len; tdelta = ((s32)piddata->target_temp_delta) << 16; maxpow = ((s32)piddata->max_power) << 16; powadj = ((s32)piddata->power_adj) << 16; pid_param.tmax = tmax; pid_param.ttarget = tmax - tdelta; pid_param.pmaxadj = maxpow - powadj; pid_param.min = wf_control_get_min(fan_cpu_main); pid_param.max = wf_control_get_max(fan_cpu_main); wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param); DBG("wf: CPU Fan control initialized.\n"); DBG(" ttarget=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n", FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax), pid_param.min, pid_param.max); return; fail: printk(KERN_WARNING "windfarm: CPU fan config not found\n" "for this machine model, max fan speed\n"); if (cpufreq_clamp) wf_control_set_max(cpufreq_clamp); if (fan_cpu_main) wf_control_set_max(fan_cpu_main); } static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st) { s32 new_setpoint, temp, power, systarget; int rc; if (--st->ticks != 0) { if (wf_smu_readjust) goto readjust; return; } st->ticks = WF_SMU_CPU_FANS_INTERVAL; rc = wf_sensor_get(sensor_cpu_temp, &temp); if (rc) { printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n", rc); wf_smu_failure_state |= FAILURE_SENSOR; return; } rc = wf_sensor_get(sensor_cpu_power, &power); if (rc) { printk(KERN_WARNING "windfarm: CPU power sensor error %d\n", rc); wf_smu_failure_state |= FAILURE_SENSOR; return; } DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n", FIX32TOPRINT(temp), FIX32TOPRINT(power)); #ifdef HACKED_OVERTEMP if (temp > 0x4a0000) wf_smu_failure_state |= FAILURE_OVERTEMP; #else if (temp > st->pid.param.tmax) wf_smu_failure_state |= FAILURE_OVERTEMP; #endif new_setpoint = wf_cpu_pid_run(&st->pid, power, temp); DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint); systarget = wf_smu_sys_fans ? wf_smu_sys_fans->pid.target : 0; systarget = ((((s64)systarget) * (s64)st->scale) >> 12) + st->offset; new_setpoint = max(new_setpoint, systarget); new_setpoint = max(new_setpoint, st->pid.param.min); new_setpoint = min(new_setpoint, st->pid.param.max); DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)new_setpoint); if (st->cpu_setpoint == new_setpoint) return; st->cpu_setpoint = new_setpoint; readjust: if (fan_cpu_main && wf_smu_failure_state == 0) { rc = wf_control_set(fan_cpu_main, st->cpu_setpoint); if (rc) { printk(KERN_WARNING "windfarm: CPU main fan" " error %d\n", rc); wf_smu_failure_state |= FAILURE_FAN; } } } /* * ****** Setup / Init / Misc ... ****** * */ static void wf_smu_tick(void) { unsigned int last_failure = wf_smu_failure_state; unsigned int new_failure; if (!wf_smu_started) { DBG("wf: creating control loops !\n"); wf_smu_create_sys_fans(); wf_smu_create_cpu_fans(); wf_smu_started = true; } /* Skipping ticks */ if (wf_smu_skipping && --wf_smu_skipping) return; wf_smu_failure_state = 0; if (wf_smu_sys_fans) wf_smu_sys_fans_tick(wf_smu_sys_fans); if (wf_smu_cpu_fans) wf_smu_cpu_fans_tick(wf_smu_cpu_fans); wf_smu_readjust = 0; new_failure = wf_smu_failure_state & ~last_failure; /* If entering failure mode, clamp cpufreq and ramp all * fans to full speed. */ if (wf_smu_failure_state && !last_failure) { if (cpufreq_clamp) wf_control_set_max(cpufreq_clamp); if (fan_system) wf_control_set_max(fan_system); if (fan_cpu_main) wf_control_set_max(fan_cpu_main); if (fan_hd) wf_control_set_max(fan_hd); } /* If leaving failure mode, unclamp cpufreq and readjust * all fans on next iteration */ if (!wf_smu_failure_state && last_failure) { if (cpufreq_clamp) wf_control_set_min(cpufreq_clamp); wf_smu_readjust = 1; } /* Overtemp condition detected, notify and start skipping a couple * ticks to let the temperature go down */ if (new_failure & FAILURE_OVERTEMP) { wf_set_overtemp(); wf_smu_skipping = 2; wf_smu_overtemp = true; } /* We only clear the overtemp condition if overtemp is cleared * _and_ no other failure is present. Since a sensor error will * clear the overtemp condition (can't measure temperature) at * the control loop levels, but we don't want to keep it clear * here in this case */ if (!wf_smu_failure_state && wf_smu_overtemp) { wf_clear_overtemp(); wf_smu_overtemp = false; } } static void wf_smu_new_control(struct wf_control *ct) { if (wf_smu_all_controls_ok) return; if (fan_cpu_main == NULL && !strcmp(ct->name, "cpu-fan")) { if (wf_get_control(ct) == 0) fan_cpu_main = ct; } if (fan_system == NULL && !strcmp(ct->name, "system-fan")) { if (wf_get_control(ct) == 0) fan_system = ct; } if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) { if (wf_get_control(ct) == 0) cpufreq_clamp = ct; } /* Darwin property list says the HD fan is only for model ID * 0, 1, 2 and 3 */ if (wf_smu_mach_model > 3) { if (fan_system && fan_cpu_main && cpufreq_clamp) wf_smu_all_controls_ok = 1; return; } if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) { if (wf_get_control(ct) == 0) fan_hd = ct; } if (fan_system && fan_hd && fan_cpu_main && cpufreq_clamp) wf_smu_all_controls_ok = 1; } static void wf_smu_new_sensor(struct wf_sensor *sr) { if (wf_smu_all_sensors_ok) return; if (sensor_cpu_power == NULL && !strcmp(sr->name, "cpu-power")) { if (wf_get_sensor(sr) == 0) sensor_cpu_power = sr; } if (sensor_cpu_temp == NULL && !strcmp(sr->name, "cpu-temp")) { if (wf_get_sensor(sr) == 0) sensor_cpu_temp = sr; } if (sensor_hd_temp == NULL && !strcmp(sr->name, "hd-temp")) { if (wf_get_sensor(sr) == 0) sensor_hd_temp = sr; } if (sensor_cpu_power && sensor_cpu_temp && sensor_hd_temp) wf_smu_all_sensors_ok = 1; } static int wf_smu_notify(struct notifier_block *self, unsigned long event, void *data) { switch(event) { case WF_EVENT_NEW_CONTROL: DBG("wf: new control %s detected\n", ((struct wf_control *)data)->name); wf_smu_new_control(data); wf_smu_readjust = 1; break; case WF_EVENT_NEW_SENSOR: DBG("wf: new sensor %s detected\n", ((struct wf_sensor *)data)->name); wf_smu_new_sensor(data); break; case WF_EVENT_TICK: if (wf_smu_all_controls_ok && wf_smu_all_sensors_ok) wf_smu_tick(); } return 0; } static struct notifier_block wf_smu_events = { .notifier_call = wf_smu_notify, }; static int wf_init_pm(void) { const struct smu_sdbp_header *hdr; hdr = smu_get_sdb_partition(SMU_SDB_SENSORTREE_ID, NULL); if (hdr != 0) { struct smu_sdbp_sensortree *st = (struct smu_sdbp_sensortree *)&hdr[1]; wf_smu_mach_model = st->model_id; } printk(KERN_INFO "windfarm: Initializing for iMacG5 model ID %d\n", wf_smu_mach_model); return 0; } static int wf_smu_probe(struct platform_device *ddev) { wf_register_client(&wf_smu_events); return 0; } static int wf_smu_remove(struct platform_device *ddev) { wf_unregister_client(&wf_smu_events); /* XXX We don't have yet a guarantee that our callback isn't * in progress when returning from wf_unregister_client, so * we add an arbitrary delay. I'll have to fix that in the core */ msleep(1000); /* Release all sensors */ /* One more crappy race: I don't think we have any guarantee here * that the attribute callback won't race with the sensor beeing * disposed of, and I'm not 100% certain what best way to deal * with that except by adding locks all over... I'll do that * eventually but heh, who ever rmmod this module anyway ? */ if (sensor_cpu_power) wf_put_sensor(sensor_cpu_power); if (sensor_cpu_temp) wf_put_sensor(sensor_cpu_temp); if (sensor_hd_temp) wf_put_sensor(sensor_hd_temp); /* Release all controls */ if (fan_cpu_main) wf_put_control(fan_cpu_main); if (fan_hd) wf_put_control(fan_hd); if (fan_system) wf_put_control(fan_system); if (cpufreq_clamp) wf_put_control(cpufreq_clamp); /* Destroy control loops state structures */ kfree(wf_smu_sys_fans); kfree(wf_smu_cpu_fans); return 0; } static struct platform_driver wf_smu_driver = { .probe = wf_smu_probe, .remove = wf_smu_remove, .driver = { .name = "windfarm", }, }; static int __init wf_smu_init(void) { int rc = -ENODEV; if (of_machine_is_compatible("PowerMac8,1") || of_machine_is_compatible("PowerMac8,2")) rc = wf_init_pm(); if (rc == 0) { #ifdef MODULE request_module("windfarm_smu_controls"); request_module("windfarm_smu_sensors"); request_module("windfarm_lm75_sensor"); request_module("windfarm_cpufreq_clamp"); #endif /* MODULE */ platform_driver_register(&wf_smu_driver); } return rc; } static void __exit wf_smu_exit(void) { platform_driver_unregister(&wf_smu_driver); } module_init(wf_smu_init); module_exit(wf_smu_exit); MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); MODULE_DESCRIPTION("Thermal control logic for iMac G5"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:windfarm");