1 files changed, 740 insertions, 0 deletions

diff --git a/kernel/drivers/macintosh/windfarm_rm31.c b/kernel/drivers/macintosh/windfarm_rm31.c
new file mode 100644
index 000000000..82fc86a90
--- /dev/null
+++ b/kernel/drivers/macintosh/windfarm_rm31.c
@@ -0,0 +1,740 @@
+/*
+ * Windfarm PowerMac thermal control.
+ * Control loops for RackMack3,1 (Xserve G5)
+ *
+ * Copyright (C) 2012 Benjamin Herrenschmidt, IBM Corp.
+ *
+ * Use and redistribute under the terms of the GNU GPL v2.
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <asm/prom.h>
+#include <asm/smu.h>
+
+#include "windfarm.h"
+#include "windfarm_pid.h"
+#include "windfarm_mpu.h"
+
+#define VERSION "1.0"
+
+#undef DEBUG
+#undef LOTSA_DEBUG
+
+#ifdef DEBUG
+#define DBG(args...)	printk(args)
+#else
+#define DBG(args...)	do { } while(0)
+#endif
+
+#ifdef LOTSA_DEBUG
+#define DBG_LOTS(args...)	printk(args)
+#else
+#define DBG_LOTS(args...)	do { } while(0)
+#endif
+
+/* define this to force CPU overtemp to 60 degree, useful for testing
+ * the overtemp code
+ */
+#undef HACKED_OVERTEMP
+
+/* We currently only handle 2 chips */
+#define NR_CHIPS	2
+#define NR_CPU_FANS	3 * NR_CHIPS
+
+/* Controls and sensors */
+static struct wf_sensor *sens_cpu_temp[NR_CHIPS];
+static struct wf_sensor *sens_cpu_volts[NR_CHIPS];
+static struct wf_sensor *sens_cpu_amps[NR_CHIPS];
+static struct wf_sensor *backside_temp;
+static struct wf_sensor *slots_temp;
+static struct wf_sensor *dimms_temp;
+
+static struct wf_control *cpu_fans[NR_CHIPS][3];
+static struct wf_control *backside_fan;
+static struct wf_control *slots_fan;
+static struct wf_control *cpufreq_clamp;
+
+/* We keep a temperature history for average calculation of 180s */
+#define CPU_TEMP_HIST_SIZE	180
+
+/* PID loop state */
+static const struct mpu_data *cpu_mpu_data[NR_CHIPS];
+static struct wf_cpu_pid_state cpu_pid[NR_CHIPS];
+static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
+static int cpu_thist_pt;
+static s64 cpu_thist_total;
+static s32 cpu_all_tmax = 100 << 16;
+static struct wf_pid_state backside_pid;
+static int backside_tick;
+static struct wf_pid_state slots_pid;
+static int slots_tick;
+static int slots_speed;
+static struct wf_pid_state dimms_pid;
+static int dimms_output_clamp;
+
+static int nr_chips;
+static bool have_all_controls;
+static bool have_all_sensors;
+static bool started;
+
+static int failure_state;
+#define FAILURE_SENSOR		1
+#define FAILURE_FAN		2
+#define FAILURE_PERM		4
+#define FAILURE_LOW_OVERTEMP	8
+#define FAILURE_HIGH_OVERTEMP	16
+
+/* Overtemp values */
+#define LOW_OVER_AVERAGE	0
+#define LOW_OVER_IMMEDIATE	(10 << 16)
+#define LOW_OVER_CLEAR		((-10) << 16)
+#define HIGH_OVER_IMMEDIATE	(14 << 16)
+#define HIGH_OVER_AVERAGE	(10 << 16)
+#define HIGH_OVER_IMMEDIATE	(14 << 16)
+
+
+static void cpu_max_all_fans(void)
+{
+	int i;
+
+	/* We max all CPU fans in case of a sensor error. We also do the
+	 * cpufreq clamping now, even if it's supposedly done later by the
+	 * generic code anyway, we do it earlier here to react faster
+	 */
+	if (cpufreq_clamp)
+		wf_control_set_max(cpufreq_clamp);
+	for (i = 0; i < nr_chips; i++) {
+		if (cpu_fans[i][0])
+			wf_control_set_max(cpu_fans[i][0]);
+		if (cpu_fans[i][1])
+			wf_control_set_max(cpu_fans[i][1]);
+		if (cpu_fans[i][2])
+			wf_control_set_max(cpu_fans[i][2]);
+	}
+}
+
+static int cpu_check_overtemp(s32 temp)
+{
+	int new_state = 0;
+	s32 t_avg, t_old;
+	static bool first = true;
+
+	/* First check for immediate overtemps */
+	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
+		new_state |= FAILURE_LOW_OVERTEMP;
+		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
+			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
+			       " temperature !\n");
+	}
+	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
+		new_state |= FAILURE_HIGH_OVERTEMP;
+		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
+			printk(KERN_ERR "windfarm: Critical overtemp due to"
+			       " immediate CPU temperature !\n");
+	}
+
+	/*
+	 * The first time around, initialize the array with the first
+	 * temperature reading
+	 */
+	if (first) {
+		int i;
+
+		cpu_thist_total = 0;
+		for (i = 0; i < CPU_TEMP_HIST_SIZE; i++) {
+			cpu_thist[i] = temp;
+			cpu_thist_total += temp;
+		}
+		first = false;
+	}
+
+	/*
+	 * We calculate a history of max temperatures and use that for the
+	 * overtemp management
+	 */
+	t_old = cpu_thist[cpu_thist_pt];
+	cpu_thist[cpu_thist_pt] = temp;
+	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
+	cpu_thist_total -= t_old;
+	cpu_thist_total += temp;
+	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
+
+	DBG_LOTS("  t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
+		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
+
+	/* Now check for average overtemps */
+	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
+		new_state |= FAILURE_LOW_OVERTEMP;
+		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
+			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
+			       " temperature !\n");
+	}
+	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
+		new_state |= FAILURE_HIGH_OVERTEMP;
+		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
+			printk(KERN_ERR "windfarm: Critical overtemp due to"
+			       " average CPU temperature !\n");
+	}
+
+	/* Now handle overtemp conditions. We don't currently use the windfarm
+	 * overtemp handling core as it's not fully suited to the needs of those
+	 * new machine. This will be fixed later.
+	 */
+	if (new_state) {
+		/* High overtemp -> immediate shutdown */
+		if (new_state & FAILURE_HIGH_OVERTEMP)
+			machine_power_off();
+		if ((failure_state & new_state) != new_state)
+			cpu_max_all_fans();
+		failure_state |= new_state;
+	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
+		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
+		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
+		failure_state &= ~FAILURE_LOW_OVERTEMP;
+	}
+
+	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
+}
+
+static int read_one_cpu_vals(int cpu, s32 *temp, s32 *power)
+{
+	s32 dtemp, volts, amps;
+	int rc;
+
+	/* Get diode temperature */
+	rc = wf_sensor_get(sens_cpu_temp[cpu], &dtemp);
+	if (rc) {
+		DBG("  CPU%d: temp reading error !\n", cpu);
+		return -EIO;
+	}
+	DBG_LOTS("  CPU%d: temp   = %d.%03d\n", cpu, FIX32TOPRINT((dtemp)));
+	*temp = dtemp;
+
+	/* Get voltage */
+	rc = wf_sensor_get(sens_cpu_volts[cpu], &volts);
+	if (rc) {
+		DBG("  CPU%d, volts reading error !\n", cpu);
+		return -EIO;
+	}
+	DBG_LOTS("  CPU%d: volts  = %d.%03d\n", cpu, FIX32TOPRINT((volts)));
+
+	/* Get current */
+	rc = wf_sensor_get(sens_cpu_amps[cpu], &amps);
+	if (rc) {
+		DBG("  CPU%d, current reading error !\n", cpu);
+		return -EIO;
+	}
+	DBG_LOTS("  CPU%d: amps   = %d.%03d\n", cpu, FIX32TOPRINT((amps)));
+
+	/* Calculate power */
+
+	/* Scale voltage and current raw sensor values according to fixed scales
+	 * obtained in Darwin and calculate power from I and V
+	 */
+	*power = (((u64)volts) * ((u64)amps)) >> 16;
+
+	DBG_LOTS("  CPU%d: power  = %d.%03d\n", cpu, FIX32TOPRINT((*power)));
+
+	return 0;
+
+}
+
+static void cpu_fans_tick(void)
+{
+	int err, cpu, i;
+	s32 speed, temp, power, t_max = 0;
+
+	DBG_LOTS("* cpu fans_tick_split()\n");
+
+	for (cpu = 0; cpu < nr_chips; ++cpu) {
+		struct wf_cpu_pid_state *sp = &cpu_pid[cpu];
+
+		/* Read current speed */
+		wf_control_get(cpu_fans[cpu][0], &sp->target);
+
+		err = read_one_cpu_vals(cpu, &temp, &power);
+		if (err) {
+			failure_state |= FAILURE_SENSOR;
+			cpu_max_all_fans();
+			return;
+		}
+
+		/* Keep track of highest temp */
+		t_max = max(t_max, temp);
+
+		/* Handle possible overtemps */
+		if (cpu_check_overtemp(t_max))
+			return;
+
+		/* Run PID */
+		wf_cpu_pid_run(sp, power, temp);
+
+		DBG_LOTS("  CPU%d: target = %d RPM\n", cpu, sp->target);
+
+		/* Apply DIMMs clamp */
+		speed = max(sp->target, dimms_output_clamp);
+
+		/* Apply result to all cpu fans */
+		for (i = 0; i < 3; i++) {
+			err = wf_control_set(cpu_fans[cpu][i], speed);
+			if (err) {
+				pr_warning("wf_rm31: Fan %s reports error %d\n",
+					   cpu_fans[cpu][i]->name, err);
+				failure_state |= FAILURE_FAN;
+			}
+		}
+	}
+}
+
+/* Implementation... */
+static int cpu_setup_pid(int cpu)
+{
+	struct wf_cpu_pid_param pid;
+	const struct mpu_data *mpu = cpu_mpu_data[cpu];
+	s32 tmax, ttarget, ptarget;
+	int fmin, fmax, hsize;
+
+	/* Get PID params from the appropriate MPU EEPROM */
+	tmax = mpu->tmax << 16;
+	ttarget = mpu->ttarget << 16;
+	ptarget = ((s32)(mpu->pmaxh - mpu->padjmax)) << 16;
+
+	DBG("wf_72: CPU%d ttarget = %d.%03d, tmax = %d.%03d\n",
+	    cpu, FIX32TOPRINT(ttarget), FIX32TOPRINT(tmax));
+
+	/* We keep a global tmax for overtemp calculations */
+	if (tmax < cpu_all_tmax)
+		cpu_all_tmax = tmax;
+
+	/* Set PID min/max by using the rear fan min/max */
+	fmin = wf_control_get_min(cpu_fans[cpu][0]);
+	fmax = wf_control_get_max(cpu_fans[cpu][0]);
+	DBG("wf_72: CPU%d max RPM range = [%d..%d]\n", cpu, fmin, fmax);
+
+	/* History size */
+	hsize = min_t(int, mpu->tguardband, WF_PID_MAX_HISTORY);
+	DBG("wf_72: CPU%d history size = %d\n", cpu, hsize);
+
+	/* Initialize PID loop */
+	pid.interval	= 1;	/* seconds */
+	pid.history_len = hsize;
+	pid.gd		= mpu->pid_gd;
+	pid.gp		= mpu->pid_gp;
+	pid.gr		= mpu->pid_gr;
+	pid.tmax	= tmax;
+	pid.ttarget	= ttarget;
+	pid.pmaxadj	= ptarget;
+	pid.min		= fmin;
+	pid.max		= fmax;
+
+	wf_cpu_pid_init(&cpu_pid[cpu], &pid);
+	cpu_pid[cpu].target = 4000;
+	
+	return 0;
+}
+
+/* Backside/U3 fan */
+static struct wf_pid_param backside_param = {
+	.interval	= 1,
+	.history_len	= 2,
+	.gd		= 0x00500000,
+	.gp		= 0x0004cccc,
+	.gr		= 0,
+	.itarget	= 70 << 16,
+	.additive	= 0,
+	.min		= 20,
+	.max		= 100,
+};
+
+/* DIMMs temperature (clamp the backside fan) */
+static struct wf_pid_param dimms_param = {
+	.interval	= 1,
+	.history_len	= 20,
+	.gd		= 0,
+	.gp		= 0,
+	.gr		= 0x06553600,
+	.itarget	= 50 << 16,
+	.additive	= 0,
+	.min		= 4000,
+	.max		= 14000,
+};
+
+static void backside_fan_tick(void)
+{
+	s32 temp, dtemp;
+	int speed, dspeed, fan_min;
+	int err;
+
+	if (!backside_fan || !backside_temp || !dimms_temp || !backside_tick)
+		return;
+	if (--backside_tick > 0)
+		return;
+	backside_tick = backside_pid.param.interval;
+
+	DBG_LOTS("* backside fans tick\n");
+
+	/* Update fan speed from actual fans */
+	err = wf_control_get(backside_fan, &speed);
+	if (!err)
+		backside_pid.target = speed;
+
+	err = wf_sensor_get(backside_temp, &temp);
+	if (err) {
+		printk(KERN_WARNING "windfarm: U3 temp sensor error %d\n",
+		       err);
+		failure_state |= FAILURE_SENSOR;
+		wf_control_set_max(backside_fan);
+		return;
+	}
+	speed = wf_pid_run(&backside_pid, temp);
+
+	DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
+		 FIX32TOPRINT(temp), speed);
+
+	err = wf_sensor_get(dimms_temp, &dtemp);
+	if (err) {
+		printk(KERN_WARNING "windfarm: DIMMs temp sensor error %d\n",
+		       err);
+		failure_state |= FAILURE_SENSOR;
+		wf_control_set_max(backside_fan);
+		return;
+	}
+	dspeed = wf_pid_run(&dimms_pid, dtemp);
+	dimms_output_clamp = dspeed;
+
+	fan_min = (dspeed * 100) / 14000;
+	fan_min = max(fan_min, backside_param.min);
+	speed = max(speed, fan_min);
+
+	err = wf_control_set(backside_fan, speed);
+	if (err) {
+		printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
+		failure_state |= FAILURE_FAN;
+	}
+}
+
+static void backside_setup_pid(void)
+{
+	/* first time initialize things */
+	s32 fmin = wf_control_get_min(backside_fan);
+	s32 fmax = wf_control_get_max(backside_fan);
+	struct wf_pid_param param;
+
+	param = backside_param;
+	param.min = max(param.min, fmin);
+	param.max = min(param.max, fmax);
+	wf_pid_init(&backside_pid, &param);
+
+	param = dimms_param;
+	wf_pid_init(&dimms_pid, &param);
+
+	backside_tick = 1;
+
+	pr_info("wf_rm31: Backside control loop started.\n");
+}
+
+/* Slots fan */
+static const struct wf_pid_param slots_param = {
+	.interval	= 1,
+	.history_len	= 20,
+	.gd		= 0,
+	.gp		= 0,
+	.gr		= 0x00100000,
+	.itarget	= 3200000,
+	.additive	= 0,
+	.min		= 20,
+	.max		= 100,
+};
+
+static void slots_fan_tick(void)
+{
+	s32 temp;
+	int speed;
+	int err;
+
+	if (!slots_fan || !slots_temp || !slots_tick)
+		return;
+	if (--slots_tick > 0)
+		return;
+	slots_tick = slots_pid.param.interval;
+
+	DBG_LOTS("* slots fans tick\n");
+
+	err = wf_sensor_get(slots_temp, &temp);
+	if (err) {
+		pr_warning("wf_rm31: slots temp sensor error %d\n", err);
+		failure_state |= FAILURE_SENSOR;
+		wf_control_set_max(slots_fan);
+		return;
+	}
+	speed = wf_pid_run(&slots_pid, temp);
+
+	DBG_LOTS("slots PID temp=%d.%.3d speed=%d\n",
+		 FIX32TOPRINT(temp), speed);
+
+	slots_speed = speed;
+	err = wf_control_set(slots_fan, speed);
+	if (err) {
+		printk(KERN_WARNING "windfarm: slots bay fan error %d\n", err);
+		failure_state |= FAILURE_FAN;
+	}
+}
+
+static void slots_setup_pid(void)
+{
+	/* first time initialize things */
+	s32 fmin = wf_control_get_min(slots_fan);
+	s32 fmax = wf_control_get_max(slots_fan);
+	struct wf_pid_param param = slots_param;
+
+	param.min = max(param.min, fmin);
+	param.max = min(param.max, fmax);
+	wf_pid_init(&slots_pid, &param);
+	slots_tick = 1;
+
+	pr_info("wf_rm31: Slots control loop started.\n");
+}
+
+static void set_fail_state(void)
+{
+	cpu_max_all_fans();
+
+	if (backside_fan)
+		wf_control_set_max(backside_fan);
+	if (slots_fan)
+		wf_control_set_max(slots_fan);
+}
+
+static void rm31_tick(void)
+{
+	int i, last_failure;
+
+	if (!started) {
+		started = 1;
+		printk(KERN_INFO "windfarm: CPUs control loops started.\n");
+		for (i = 0; i < nr_chips; ++i) {
+			if (cpu_setup_pid(i) < 0) {
+				failure_state = FAILURE_PERM;
+				set_fail_state();
+				break;
+			}
+		}
+		DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
+
+		backside_setup_pid();
+		slots_setup_pid();
+
+#ifdef HACKED_OVERTEMP
+		cpu_all_tmax = 60 << 16;
+#endif
+	}
+
+	/* Permanent failure, bail out */
+	if (failure_state & FAILURE_PERM)
+		return;
+
+	/*
+	 * Clear all failure bits except low overtemp which will be eventually
+	 * cleared by the control loop itself
+	 */
+	last_failure = failure_state;
+	failure_state &= FAILURE_LOW_OVERTEMP;
+	backside_fan_tick();
+	slots_fan_tick();
+
+	/* We do CPUs last because they can be clamped high by
+	 * DIMM temperature
+	 */
+	cpu_fans_tick();
+
+	DBG_LOTS("  last_failure: 0x%x, failure_state: %x\n",
+		 last_failure, failure_state);
+
+	/* Check for failures. Any failure causes cpufreq clamping */
+	if (failure_state && last_failure == 0 && cpufreq_clamp)
+		wf_control_set_max(cpufreq_clamp);
+	if (failure_state == 0 && last_failure && cpufreq_clamp)
+		wf_control_set_min(cpufreq_clamp);
+
+	/* That's it for now, we might want to deal with other failures
+	 * differently in the future though
+	 */
+}
+
+static void rm31_new_control(struct wf_control *ct)
+{
+	bool all_controls;
+
+	if (!strcmp(ct->name, "cpu-fan-a-0"))
+		cpu_fans[0][0] = ct;
+	else if (!strcmp(ct->name, "cpu-fan-b-0"))
+		cpu_fans[0][1] = ct;
+	else if (!strcmp(ct->name, "cpu-fan-c-0"))
+		cpu_fans[0][2] = ct;
+	else if (!strcmp(ct->name, "cpu-fan-a-1"))
+		cpu_fans[1][0] = ct;
+	else if (!strcmp(ct->name, "cpu-fan-b-1"))
+		cpu_fans[1][1] = ct;
+	else if (!strcmp(ct->name, "cpu-fan-c-1"))
+		cpu_fans[1][2] = ct;
+	else if (!strcmp(ct->name, "backside-fan"))
+		backside_fan = ct;
+	else if (!strcmp(ct->name, "slots-fan"))
+		slots_fan = ct;
+	else if (!strcmp(ct->name, "cpufreq-clamp"))
+		cpufreq_clamp = ct;
+
+	all_controls =
+		cpu_fans[0][0] &&
+		cpu_fans[0][1] &&
+		cpu_fans[0][2] &&
+		backside_fan &&
+		slots_fan;
+	if (nr_chips > 1)
+		all_controls &=
+			cpu_fans[1][0] &&
+			cpu_fans[1][1] &&
+			cpu_fans[1][2];
+	have_all_controls = all_controls;
+}
+
+
+static void rm31_new_sensor(struct wf_sensor *sr)
+{
+	bool all_sensors;
+
+	if (!strcmp(sr->name, "cpu-diode-temp-0"))
+		sens_cpu_temp[0] = sr;
+	else if (!strcmp(sr->name, "cpu-diode-temp-1"))
+		sens_cpu_temp[1] = sr;
+	else if (!strcmp(sr->name, "cpu-voltage-0"))
+		sens_cpu_volts[0] = sr;
+	else if (!strcmp(sr->name, "cpu-voltage-1"))
+		sens_cpu_volts[1] = sr;
+	else if (!strcmp(sr->name, "cpu-current-0"))
+		sens_cpu_amps[0] = sr;
+	else if (!strcmp(sr->name, "cpu-current-1"))
+		sens_cpu_amps[1] = sr;
+	else if (!strcmp(sr->name, "backside-temp"))
+		backside_temp = sr;
+	else if (!strcmp(sr->name, "slots-temp"))
+		slots_temp = sr;
+	else if (!strcmp(sr->name, "dimms-temp"))
+		dimms_temp = sr;
+
+	all_sensors =
+		sens_cpu_temp[0] &&
+		sens_cpu_volts[0] &&
+		sens_cpu_amps[0] &&
+		backside_temp &&
+		slots_temp &&
+		dimms_temp;
+	if (nr_chips > 1)
+		all_sensors &=
+			sens_cpu_temp[1] &&
+			sens_cpu_volts[1] &&
+			sens_cpu_amps[1];
+
+	have_all_sensors = all_sensors;
+}
+
+static int rm31_wf_notify(struct notifier_block *self,
+			  unsigned long event, void *data)
+{
+	switch (event) {
+	case WF_EVENT_NEW_SENSOR:
+		rm31_new_sensor(data);
+		break;
+	case WF_EVENT_NEW_CONTROL:
+		rm31_new_control(data);
+		break;
+	case WF_EVENT_TICK:
+		if (have_all_controls && have_all_sensors)
+			rm31_tick();
+	}
+	return 0;
+}
+
+static struct notifier_block rm31_events = {
+	.notifier_call = rm31_wf_notify,
+};
+
+static int wf_rm31_probe(struct platform_device *dev)
+{
+	wf_register_client(&rm31_events);
+	return 0;
+}
+
+static int wf_rm31_remove(struct platform_device *dev)
+{
+	wf_unregister_client(&rm31_events);
+
+	/* should release all sensors and controls */
+	return 0;
+}
+
+static struct platform_driver wf_rm31_driver = {
+	.probe	= wf_rm31_probe,
+	.remove	= wf_rm31_remove,
+	.driver	= {
+		.name = "windfarm",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init wf_rm31_init(void)
+{
+	struct device_node *cpu;
+	int i;
+
+	if (!of_machine_is_compatible("RackMac3,1"))
+		return -ENODEV;
+
+	/* Count the number of CPU cores */
+	nr_chips = 0;
+	for_each_node_by_type(cpu, "cpu")
+		++nr_chips;
+	if (nr_chips > NR_CHIPS)
+		nr_chips = NR_CHIPS;
+
+	pr_info("windfarm: Initializing for desktop G5 with %d chips\n",
+		nr_chips);
+
+	/* Get MPU data for each CPU */
+	for (i = 0; i < nr_chips; i++) {
+		cpu_mpu_data[i] = wf_get_mpu(i);
+		if (!cpu_mpu_data[i]) {
+			pr_err("wf_rm31: Failed to find MPU data for CPU %d\n", i);
+			return -ENXIO;
+		}
+	}
+
+#ifdef MODULE
+	request_module("windfarm_fcu_controls");
+	request_module("windfarm_lm75_sensor");
+	request_module("windfarm_lm87_sensor");
+	request_module("windfarm_ad7417_sensor");
+	request_module("windfarm_max6690_sensor");
+	request_module("windfarm_cpufreq_clamp");
+#endif /* MODULE */
+
+	platform_driver_register(&wf_rm31_driver);
+	return 0;
+}
+
+static void __exit wf_rm31_exit(void)
+{
+	platform_driver_unregister(&wf_rm31_driver);
+}
+
+module_init(wf_rm31_init);
+module_exit(wf_rm31_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("Thermal control for Xserve G5");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:windfarm");