// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Windfarm PowerMac thermal control. SMU based 1 CPU desktop control loops
   *
   * (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:
   *
   * PowerMac9,1
   * ===========
   *
   * Has 3 control loops: CPU fans is similar to PowerMac8,1 (though it doesn't
   * try to play with other control loops fans). Drive bay is rather basic PID
   * with one sensor and one fan. Slots area is a bit different as the Darwin
   * driver is supposed to be capable of working in a special "AGP" mode which
   * involves the presence of an AGP sensor and an AGP fan (possibly on the
   * AGP card itself). I can't deal with that special mode as I don't have
   * access to those additional sensor/fans for now (though ultimately, it would
   * be possible to add sensor objects for them) so I'm only implementing the
   * basic PCI slot control loop
   */
  
  #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

  /* 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_sensor	*sensor_slots_power;
  static struct wf_control *fan_cpu_main;
  static struct wf_control *fan_cpu_second;
  static struct wf_control *fan_cpu_third;
  static struct wf_control *fan_hd;
  static struct wf_control *fan_slots;
  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;

  static bool wf_smu_overtemp;

  
  /* 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;
  
  /*
   * ****** CPU Fans Control Loop ******
   *
   */
  
  
  #define WF_SMU_CPU_FANS_INTERVAL	1
  #define WF_SMU_CPU_FANS_MAX_HISTORY	16
  
  /* State data used by the cpu fans control loop
   */
  struct wf_smu_cpu_fans_state {
  	int			ticks;
  	s32			cpu_setpoint;
  	struct wf_cpu_pid_state	pid;
  };
  
  static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
  
  
  
  /*
   * ****** Drive Fan Control Loop ******
   *
   */
  
  struct wf_smu_drive_fans_state {
  	int			ticks;
  	s32			setpoint;
  	struct wf_pid_state	pid;
  };
  
  static struct wf_smu_drive_fans_state *wf_smu_drive_fans;
  
  /*
   * ****** Slots Fan Control Loop ******
   *
   */
  
  struct wf_smu_slots_fans_state {
  	int			ticks;
  	s32			setpoint;
  	struct wf_pid_state	pid;
  };
  
  static struct wf_smu_slots_fans_state *wf_smu_slots_fans;
  
  /*
   * ***** Implementation *****
   *
   */
  
  
  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;
  
  	/* 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("    ttarget=%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;
  	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);
  
  	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;
  		}
  	}
  	if (fan_cpu_second && wf_smu_failure_state == 0) {

  		rc = wf_control_set(fan_cpu_second, st->cpu_setpoint);

  		if (rc) {
  			printk(KERN_WARNING "windfarm: CPU second fan"
  			       " error %d
  ", rc);
  			wf_smu_failure_state |= FAILURE_FAN;
  		}
  	}
  	if (fan_cpu_third && wf_smu_failure_state == 0) {

  		rc = wf_control_set(fan_cpu_third, st->cpu_setpoint);

  		if (rc) {
  			printk(KERN_WARNING "windfarm: CPU third fan"
  			       " error %d
  ", rc);
  			wf_smu_failure_state |= FAILURE_FAN;
  		}
  	}
  }
  
  static void wf_smu_create_drive_fans(void)
  {
  	struct wf_pid_param param = {
  		.interval	= 5,
  		.history_len	= 2,
  		.gd		= 0x01e00000,
  		.gp		= 0x00500000,
  		.gr		= 0x00000000,
  		.itarget	= 0x00200000,
  	};
  
  	/* Alloc & initialize state */
  	wf_smu_drive_fans = kmalloc(sizeof(struct wf_smu_drive_fans_state),
  					GFP_KERNEL);
  	if (wf_smu_drive_fans == NULL) {
  		printk(KERN_WARNING "windfarm: Memory allocation error"
  		       " max fan speed
  ");
  		goto fail;
  	}
         	wf_smu_drive_fans->ticks = 1;
  
  	/* Fill PID params */
  	param.additive = (fan_hd->type == WF_CONTROL_RPM_FAN);

  	param.min = wf_control_get_min(fan_hd);
  	param.max = wf_control_get_max(fan_hd);

  	wf_pid_init(&wf_smu_drive_fans->pid, &param);
  
  	DBG("wf: Drive Fan control initialized.
  ");
  	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM
  ",
  	    FIX32TOPRINT(param.itarget), param.min, param.max);
  	return;
  
   fail:
  	if (fan_hd)
  		wf_control_set_max(fan_hd);
  }
  
  static void wf_smu_drive_fans_tick(struct wf_smu_drive_fans_state *st)
  {
  	s32 new_setpoint, temp;
  	int rc;
  
  	if (--st->ticks != 0) {
  		if (wf_smu_readjust)
  			goto readjust;
  		return;
  	}
  	st->ticks = st->pid.param.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: Drive 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
  ", (int)new_setpoint);
  
  	if (st->setpoint == new_setpoint)
  		return;
  	st->setpoint = new_setpoint;
   readjust:
  	if (fan_hd && wf_smu_failure_state == 0) {

  		rc = wf_control_set(fan_hd, st->setpoint);

  		if (rc) {
  			printk(KERN_WARNING "windfarm: HD fan error %d
  ",
  			       rc);
  			wf_smu_failure_state |= FAILURE_FAN;
  		}
  	}
  }
  
  static void wf_smu_create_slots_fans(void)
  {
  	struct wf_pid_param param = {
  		.interval	= 1,
  		.history_len	= 8,
  		.gd		= 0x00000000,
  		.gp		= 0x00000000,
  		.gr		= 0x00020000,
  		.itarget	= 0x00000000
  	};
  
  	/* Alloc & initialize state */
  	wf_smu_slots_fans = kmalloc(sizeof(struct wf_smu_slots_fans_state),
  					GFP_KERNEL);
  	if (wf_smu_slots_fans == NULL) {
  		printk(KERN_WARNING "windfarm: Memory allocation error"
  		       " max fan speed
  ");
  		goto fail;
  	}
         	wf_smu_slots_fans->ticks = 1;
  
  	/* Fill PID params */
  	param.additive = (fan_slots->type == WF_CONTROL_RPM_FAN);

  	param.min = wf_control_get_min(fan_slots);
  	param.max = wf_control_get_max(fan_slots);

  	wf_pid_init(&wf_smu_slots_fans->pid, &param);
  
  	DBG("wf: Slots Fan control initialized.
  ");
  	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM
  ",
  	    FIX32TOPRINT(param.itarget), param.min, param.max);
  	return;
  
   fail:
  	if (fan_slots)
  		wf_control_set_max(fan_slots);
  }
  
  static void wf_smu_slots_fans_tick(struct wf_smu_slots_fans_state *st)
  {
  	s32 new_setpoint, power;
  	int rc;
  
  	if (--st->ticks != 0) {
  		if (wf_smu_readjust)
  			goto readjust;
  		return;
  	}
  	st->ticks = st->pid.param.interval;

  	rc = wf_sensor_get(sensor_slots_power, &power);

  	if (rc) {
  		printk(KERN_WARNING "windfarm: Slots power sensor error %d
  ",
  		       rc);
  		wf_smu_failure_state |= FAILURE_SENSOR;
  		return;
  	}
  
  	DBG("wf_smu: Slots Fans tick ! Slots power: %d.%03d
  ",
  	    FIX32TOPRINT(power));
  
  #if 0 /* Check what makes a good overtemp condition */
  	if (power > (st->pid.param.itarget + 0x50000))
  		wf_smu_failure_state |= FAILURE_OVERTEMP;
  #endif
  
  	new_setpoint = wf_pid_run(&st->pid, power);
  
  	DBG("wf_smu: new_setpoint: %d
  ", (int)new_setpoint);
  
  	if (st->setpoint == new_setpoint)
  		return;
  	st->setpoint = new_setpoint;
   readjust:
  	if (fan_slots && wf_smu_failure_state == 0) {

  		rc = wf_control_set(fan_slots, st->setpoint);

  		if (rc) {
  			printk(KERN_WARNING "windfarm: Slots 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_drive_fans();
  		wf_smu_create_slots_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_drive_fans)
  		wf_smu_drive_fans_tick(wf_smu_drive_fans);
  	if (wf_smu_slots_fans)
  		wf_smu_slots_fans_tick(wf_smu_slots_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_cpu_main)
  			wf_control_set_max(fan_cpu_main);
  		if (fan_cpu_second)
  			wf_control_set_max(fan_cpu_second);
  		if (fan_cpu_third)
  			wf_control_set_max(fan_cpu_third);
  		if (fan_hd)
  			wf_control_set_max(fan_hd);
  		if (fan_slots)
  			wf_control_set_max(fan_slots);
  	}
  
  	/* 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-rear-fan-0")) {

  		if (wf_get_control(ct) == 0)

  			fan_cpu_main = ct;

  	}
  
  	if (fan_cpu_second == NULL && !strcmp(ct->name, "cpu-rear-fan-1")) {
  		if (wf_get_control(ct) == 0)
  			fan_cpu_second = ct;
  	}
  
  	if (fan_cpu_third == NULL && !strcmp(ct->name, "cpu-front-fan-0")) {
  		if (wf_get_control(ct) == 0)
  			fan_cpu_third = ct;
  	}
  
  	if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
  		if (wf_get_control(ct) == 0)
  			cpufreq_clamp = ct;
  	}
  
  	if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) {

  		if (wf_get_control(ct) == 0)

  			fan_hd = ct;

  	}
  
  	if (fan_slots == NULL && !strcmp(ct->name, "slots-fan")) {

  		if (wf_get_control(ct) == 0)

  			fan_slots = ct;

  	}
  
  	if (fan_cpu_main && (fan_cpu_second || fan_cpu_third) && fan_hd &&
  	    fan_slots && 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_slots_power == NULL && !strcmp(sr->name, "slots-power")) {

  		if (wf_get_sensor(sr) == 0)

  			sensor_slots_power = sr;

  	}
  
  	if (sensor_cpu_power && sensor_cpu_temp &&
  	    sensor_hd_temp && sensor_slots_power)
  		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)
  {
  	printk(KERN_INFO "windfarm: Initializing for Desktop G5 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);

  	if (sensor_slots_power)

  		wf_put_sensor(sensor_slots_power);

  
  	/* Release all controls */

  	if (fan_cpu_main)

  		wf_put_control(fan_cpu_main);

  	if (fan_cpu_second)
  		wf_put_control(fan_cpu_second);
  	if (fan_cpu_third)
  		wf_put_control(fan_cpu_third);

  	if (fan_hd)

  		wf_put_control(fan_hd);

  	if (fan_slots)

  		wf_put_control(fan_slots);

  	if (cpufreq_clamp)
  		wf_put_control(cpufreq_clamp);
  
  	/* Destroy control loops state structures */

  	kfree(wf_smu_slots_fans);
  	kfree(wf_smu_drive_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("PowerMac9,1"))

  		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 PowerMac9,1");
  MODULE_LICENSE("GPL");

  MODULE_ALIAS("platform:windfarm");