/*
   * Windfarm PowerMac thermal control. iMac G5
   *
   * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   *                    <benh@kernel.crashing.org>
   *
   * Released under the term of the GNU GPL v2.
   *
   * 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, 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
  ");
  		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
  ");
  		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.
  ");
  	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM
  ",
  	    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
  ",
  		       rc);
  		wf_smu_failure_state |= FAILURE_SENSOR;
  		return;
  	}
  
  	DBG("wf_smu: System Fans tick ! HD temp: %d.%03d
  ",
  	    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
  ", (int)new_setpoint);
  
  	scaled = ((((s64)new_setpoint) * (s64)st->scale0) >> 12) + st->offset0;
  
  	DBG("wf_smu: scaled setpoint: %d RPM
  ", (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
  ", (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
  ",
  			       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
  ",
  			       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
  ");
  		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)
  ", 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.
  ");
  	DBG("    ttarged=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM
  ",
  	    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
  "
  	       "for this machine model, max fan speed
  ");
  
  	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
  ",
  		       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
  ",
  		       rc);
  		wf_smu_failure_state |= FAILURE_SENSOR;
  		return;
  	}
  
  	DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d
  ",
  	    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
  ", (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
  ", (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
  ", 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 !
  ");
  		wf_smu_create_sys_fans();
  		wf_smu_create_cpu_fans();
  		wf_smu_started = 1;
  	}
  
  	/* 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
  ",
  		    ((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
  ",
  		    ((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
  ",
  	       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",
  		.owner	= THIS_MODULE,
  	},
  };
  
  
  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");