1 files changed, 698 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_pm112.c b/drivers/macintosh/windfarm_pm112.c
new file mode 100644
index 000000000000..c2a4e689c784
--- /dev/null
+++ b/drivers/macintosh/windfarm_pm112.c
@@ -0,0 +1,698 @@
+/*
+ * Windfarm PowerMac thermal control.
+ * Control loops for machines with SMU and PPC970MP processors.
+ *
+ * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
+ * Copyright (C) 2006 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"
+
+#define VERSION "0.2"
+
+#define 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, 4 cores... */
+#define NR_CHIPS        2
+#define NR_CORES        4
+#define NR_CPU_FANS     3 * NR_CHIPS
+
+/* Controls and sensors */
+static struct wf_sensor *sens_cpu_temp[NR_CORES];
+static struct wf_sensor *sens_cpu_power[NR_CORES];
+static struct wf_sensor *hd_temp;
+static struct wf_sensor *slots_power;
+static struct wf_sensor *u4_temp;
+
+static struct wf_control *cpu_fans[NR_CPU_FANS];
+static char *cpu_fan_names[NR_CPU_FANS] = {
+        "cpu-rear-fan-0",
+        "cpu-rear-fan-1",
+        "cpu-front-fan-0",
+        "cpu-front-fan-1",
+        "cpu-pump-0",
+        "cpu-pump-1",
+};
+static struct wf_control *cpufreq_clamp;
+
+/* Second pump isn't required (and isn't actually present) */
+#define CPU_FANS_REQD           (NR_CPU_FANS - 2)
+#define FIRST_PUMP              4
+#define LAST_PUMP               5
+
+/* We keep a temperature history for average calculation of 180s */
+#define CPU_TEMP_HIST_SIZE      180
+
+/* Scale factor for fan speed, *100 */
+static int cpu_fan_scale[NR_CPU_FANS] = {
+        100,
+        100,
+        97,             /* inlet fans run at 97% of exhaust fan */
+        97,
+        100,            /* updated later */
+        100,            /* updated later */
+};
+
+static struct wf_control *backside_fan;
+static struct wf_control *slots_fan;
+static struct wf_control *drive_bay_fan;
+
+/* PID loop state */
+static struct wf_cpu_pid_state cpu_pid[NR_CORES];
+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 int cpu_last_target;
+static struct wf_pid_state backside_pid;
+static int backside_tick;
+static struct wf_pid_state slots_pid;
+static int slots_started;
+static struct wf_pid_state drive_bay_pid;
+static int drive_bay_tick;
+
+static int nr_cores;
+static int have_all_controls;
+static int have_all_sensors;
+static int 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)
+
+
+/* Implementation... */
+static int create_cpu_loop(int cpu)
+{
+        int chip = cpu / 2;
+        int core = cpu & 1;
+        struct smu_sdbp_header *hdr;
+        struct smu_sdbp_cpupiddata *piddata;
+        struct wf_cpu_pid_param pid;
+        struct wf_control *main_fan = cpu_fans[0];
+        s32 tmax;
+        int fmin;
+
+        /* Get PID params from the appropriate SAT */
+        hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL);
+        if (hdr == NULL) {
+                printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n");
+                return -EINVAL;
+        }
+        piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
+
+        /* Get FVT params to get Tmax; if not found, assume default */
+        hdr = smu_sat_get_sdb_partition(chip, 0xC4 + core, NULL);
+        if (hdr) {
+                struct smu_sdbp_fvt *fvt = (struct smu_sdbp_fvt *)&hdr[1];
+                tmax = fvt->maxtemp << 16;
+        } else
+                tmax = 95 << 16;        /* default to 95 degrees C */
+
+        /* We keep a global tmax for overtemp calculations */
+        if (tmax < cpu_all_tmax)
+                cpu_all_tmax = tmax;
+
+        /*
+         * Darwin has a minimum fan speed of 1000 rpm for the 4-way and
+         * 515 for the 2-way.  That appears to be overkill, so for now,
+         * impose a minimum of 750 or 515.
+         */
+        fmin = (nr_cores > 2) ? 750 : 515;
+
+        /* Initialize PID loop */
+        pid.interval = 1;       /* seconds */
+        pid.history_len = piddata->history_len;
+        pid.gd = piddata->gd;
+        pid.gp = piddata->gp;
+        pid.gr = piddata->gr / piddata->history_len;
+        pid.pmaxadj = (piddata->max_power << 16) - (piddata->power_adj << 8);
+        pid.ttarget = tmax - (piddata->target_temp_delta << 16);
+        pid.tmax = tmax;
+        pid.min = main_fan->ops->get_min(main_fan);
+        pid.max = main_fan->ops->get_max(main_fan);
+        if (pid.min < fmin)
+                pid.min = fmin;
+
+        wf_cpu_pid_init(&cpu_pid[cpu], &pid);
+        return 0;
+}
+
+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_CPU_FANS; ++i)
+                if (cpu_fans[i])
+                        wf_control_set_max(cpu_fans[i]);
+}
+
+static int cpu_check_overtemp(s32 temp)
+{
+        int new_state = 0;
+        s32 t_avg, t_old;
+
+        /* 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");
+        }
+
+        /* 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 void cpu_fans_tick(void)
+{
+        int err, cpu;
+        s32 greatest_delta = 0;
+        s32 temp, power, t_max = 0;
+        int i, t, target = 0;
+        struct wf_sensor *sr;
+        struct wf_control *ct;
+        struct wf_cpu_pid_state *sp;
+
+        DBG_LOTS(KERN_DEBUG);
+        for (cpu = 0; cpu < nr_cores; ++cpu) {
+                /* Get CPU core temperature */
+                sr = sens_cpu_temp[cpu];
+                err = sr->ops->get_value(sr, &temp);
+                if (err) {
+                        DBG("\n");
+                        printk(KERN_WARNING "windfarm: CPU %d temperature "
+                               "sensor error %d\n", cpu, err);
+                        failure_state |= FAILURE_SENSOR;
+                        cpu_max_all_fans();
+                        return;
+                }
+
+                /* Keep track of highest temp */
+                t_max = max(t_max, temp);
+
+                /* Get CPU power */
+                sr = sens_cpu_power[cpu];
+                err = sr->ops->get_value(sr, &power);
+                if (err) {
+                        DBG("\n");
+                        printk(KERN_WARNING "windfarm: CPU %d power "
+                               "sensor error %d\n", cpu, err);
+                        failure_state |= FAILURE_SENSOR;
+                        cpu_max_all_fans();
+                        return;
+                }
+
+                /* Run PID */
+                sp = &cpu_pid[cpu];
+                t = wf_cpu_pid_run(sp, power, temp);
+
+                if (cpu == 0 || sp->last_delta > greatest_delta) {
+                        greatest_delta = sp->last_delta;
+                        target = t;
+                }
+                DBG_LOTS("[%d] P=%d.%.3d T=%d.%.3d ",
+                    cpu, FIX32TOPRINT(power), FIX32TOPRINT(temp));
+        }
+        DBG_LOTS("fans = %d, t_max = %d.%03d\n", target, FIX32TOPRINT(t_max));
+
+        /* Darwin limits decrease to 20 per iteration */
+        if (target < (cpu_last_target - 20))
+                target = cpu_last_target - 20;
+        cpu_last_target = target;
+        for (cpu = 0; cpu < nr_cores; ++cpu)
+                cpu_pid[cpu].target = target;
+
+        /* Handle possible overtemps */
+        if (cpu_check_overtemp(t_max))
+                return;
+
+        /* Set fans */
+        for (i = 0; i < NR_CPU_FANS; ++i) {
+                ct = cpu_fans[i];
+                if (ct == NULL)
+                        continue;
+                err = ct->ops->set_value(ct, target * cpu_fan_scale[i] / 100);
+                if (err) {
+                        printk(KERN_WARNING "windfarm: fan %s reports "
+                               "error %d\n", ct->name, err);
+                        failure_state |= FAILURE_FAN;
+                        break;
+                }
+        }
+}
+
+/* Backside/U4 fan */
+static struct wf_pid_param backside_param = {
+        .interval       = 5,
+        .history_len    = 2,
+        .gd             = 48 << 20,
+        .gp             = 5 << 20,
+        .gr             = 0,
+        .itarget        = 64 << 16,
+        .additive       = 1,
+};
+
+static void backside_fan_tick(void)
+{
+        s32 temp;
+        int speed;
+        int err;
+
+        if (!backside_fan || !u4_temp)
+                return;
+        if (!backside_tick) {
+                /* first time; initialize things */
+                backside_param.min = backside_fan->ops->get_min(backside_fan);
+                backside_param.max = backside_fan->ops->get_max(backside_fan);
+                wf_pid_init(&backside_pid, &backside_param);
+                backside_tick = 1;
+        }
+        if (--backside_tick > 0)
+                return;
+        backside_tick = backside_pid.param.interval;
+
+        err = u4_temp->ops->get_value(u4_temp, &temp);
+        if (err) {
+                printk(KERN_WARNING "windfarm: U4 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 = backside_fan->ops->set_value(backside_fan, speed);
+        if (err) {
+                printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
+                failure_state |= FAILURE_FAN;
+        }
+}
+
+/* Drive bay fan */
+static struct wf_pid_param drive_bay_prm = {
+        .interval       = 5,
+        .history_len    = 2,
+        .gd             = 30 << 20,
+        .gp             = 5 << 20,
+        .gr             = 0,
+        .itarget        = 40 << 16,
+        .additive       = 1,
+};
+
+static void drive_bay_fan_tick(void)
+{
+        s32 temp;
+        int speed;
+        int err;
+
+        if (!drive_bay_fan || !hd_temp)
+                return;
+        if (!drive_bay_tick) {
+                /* first time; initialize things */
+                drive_bay_prm.min = drive_bay_fan->ops->get_min(drive_bay_fan);
+                drive_bay_prm.max = drive_bay_fan->ops->get_max(drive_bay_fan);
+                wf_pid_init(&drive_bay_pid, &drive_bay_prm);
+                drive_bay_tick = 1;
+        }
+        if (--drive_bay_tick > 0)
+                return;
+        drive_bay_tick = drive_bay_pid.param.interval;
+
+        err = hd_temp->ops->get_value(hd_temp, &temp);
+        if (err) {
+                printk(KERN_WARNING "windfarm: drive bay temp sensor "
+                       "error %d\n", err);
+                failure_state |= FAILURE_SENSOR;
+                wf_control_set_max(drive_bay_fan);
+                return;
+        }
+        speed = wf_pid_run(&drive_bay_pid, temp);
+        DBG_LOTS("drive_bay PID temp=%d.%.3d speed=%d\n",
+                 FIX32TOPRINT(temp), speed);
+
+        err = drive_bay_fan->ops->set_value(drive_bay_fan, speed);
+        if (err) {
+                printk(KERN_WARNING "windfarm: drive bay fan error %d\n", err);
+                failure_state |= FAILURE_FAN;
+        }
+}
+
+/* PCI slots area fan */
+/* This makes the fan speed proportional to the power consumed */
+static struct wf_pid_param slots_param = {
+        .interval       = 1,
+        .history_len    = 2,
+        .gd             = 0,
+        .gp             = 0,
+        .gr             = 0x1277952,
+        .itarget        = 0,
+        .min            = 1560,
+        .max            = 3510,
+};
+
+static void slots_fan_tick(void)
+{
+        s32 power;
+        int speed;
+        int err;
+
+        if (!slots_fan || !slots_power)
+                return;
+        if (!slots_started) {
+                /* first time; initialize things */
+                wf_pid_init(&slots_pid, &slots_param);
+                slots_started = 1;
+        }
+
+        err = slots_power->ops->get_value(slots_power, &power);
+        if (err) {
+                printk(KERN_WARNING "windfarm: slots power sensor error %d\n",
+                       err);
+                failure_state |= FAILURE_SENSOR;
+                wf_control_set_max(slots_fan);
+                return;
+        }
+        speed = wf_pid_run(&slots_pid, power);
+        DBG_LOTS("slots PID power=%d.%.3d speed=%d\n",
+                 FIX32TOPRINT(power), speed);
+
+        err = slots_fan->ops->set_value(slots_fan, speed);
+        if (err) {
+                printk(KERN_WARNING "windfarm: slots fan error %d\n", err);
+                failure_state |= FAILURE_FAN;
+        }
+}
+
+static void set_fail_state(void)
+{
+        int i;
+
+        if (cpufreq_clamp)
+                wf_control_set_max(cpufreq_clamp);
+        for (i = 0; i < NR_CPU_FANS; ++i)
+                if (cpu_fans[i])
+                        wf_control_set_max(cpu_fans[i]);
+        if (backside_fan)
+                wf_control_set_max(backside_fan);
+        if (slots_fan)
+                wf_control_set_max(slots_fan);
+        if (drive_bay_fan)
+                wf_control_set_max(drive_bay_fan);
+}
+
+static void pm112_tick(void)
+{
+        int i, last_failure;
+
+        if (!started) {
+                started = 1;
+                for (i = 0; i < nr_cores; ++i) {
+                        if (create_cpu_loop(i) < 0) {
+                                failure_state = FAILURE_PERM;
+                                set_fail_state();
+                                break;
+                        }
+                }
+                DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
+
+#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;
+        cpu_fans_tick();
+        backside_fan_tick();
+        slots_fan_tick();
+        drive_bay_fan_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 pm112_new_control(struct wf_control *ct)
+{
+        int i, max_exhaust;
+
+        if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
+                if (wf_get_control(ct) == 0)
+                        cpufreq_clamp = ct;
+        }
+
+        for (i = 0; i < NR_CPU_FANS; ++i) {
+                if (!strcmp(ct->name, cpu_fan_names[i])) {
+                        if (cpu_fans[i] == NULL && wf_get_control(ct) == 0)
+                                cpu_fans[i] = ct;
+                        break;
+                }
+        }
+        if (i >= NR_CPU_FANS) {
+                /* not a CPU fan, try the others */
+                if (!strcmp(ct->name, "backside-fan")) {
+                        if (backside_fan == NULL && wf_get_control(ct) == 0)
+                                backside_fan = ct;
+                } else if (!strcmp(ct->name, "slots-fan")) {
+                        if (slots_fan == NULL && wf_get_control(ct) == 0)
+                                slots_fan = ct;
+                } else if (!strcmp(ct->name, "drive-bay-fan")) {
+                        if (drive_bay_fan == NULL && wf_get_control(ct) == 0)
+                                drive_bay_fan = ct;
+                }
+                return;
+        }
+
+        for (i = 0; i < CPU_FANS_REQD; ++i)
+                if (cpu_fans[i] == NULL)
+                        return;
+
+        /* work out pump scaling factors */
+        max_exhaust = cpu_fans[0]->ops->get_max(cpu_fans[0]);
+        for (i = FIRST_PUMP; i <= LAST_PUMP; ++i)
+                if ((ct = cpu_fans[i]) != NULL)
+                        cpu_fan_scale[i] =
+                                ct->ops->get_max(ct) * 100 / max_exhaust;
+
+        have_all_controls = 1;
+}
+
+static void pm112_new_sensor(struct wf_sensor *sr)
+{
+        unsigned int i;
+
+        if (have_all_sensors)
+                return;
+        if (!strncmp(sr->name, "cpu-temp-", 9)) {
+                i = sr->name[9] - '0';
+                if (sr->name[10] == 0 && i < NR_CORES &&
+                    sens_cpu_temp[i] == NULL && wf_get_sensor(sr) == 0)
+                        sens_cpu_temp[i] = sr;
+
+        } else if (!strncmp(sr->name, "cpu-power-", 10)) {
+                i = sr->name[10] - '0';
+                if (sr->name[11] == 0 && i < NR_CORES &&
+                    sens_cpu_power[i] == NULL && wf_get_sensor(sr) == 0)
+                        sens_cpu_power[i] = sr;
+        } else if (!strcmp(sr->name, "hd-temp")) {
+                if (hd_temp == NULL && wf_get_sensor(sr) == 0)
+                        hd_temp = sr;
+        } else if (!strcmp(sr->name, "slots-power")) {
+                if (slots_power == NULL && wf_get_sensor(sr) == 0)
+                        slots_power = sr;
+        } else if (!strcmp(sr->name, "u4-temp")) {
+                if (u4_temp == NULL && wf_get_sensor(sr) == 0)
+                        u4_temp = sr;
+        } else
+                return;
+
+        /* check if we have all the sensors we need */
+        for (i = 0; i < nr_cores; ++i)
+                if (sens_cpu_temp[i] == NULL || sens_cpu_power[i] == NULL)
+                        return;
+
+        have_all_sensors = 1;
+}
+
+static int pm112_wf_notify(struct notifier_block *self,
+                           unsigned long event, void *data)
+{
+        switch (event) {
+        case WF_EVENT_NEW_SENSOR:
+                pm112_new_sensor(data);
+                break;
+        case WF_EVENT_NEW_CONTROL:
+                pm112_new_control(data);
+                break;
+        case WF_EVENT_TICK:
+                if (have_all_controls && have_all_sensors)
+                        pm112_tick();
+        }
+        return 0;
+}
+
+static struct notifier_block pm112_events = {
+        .notifier_call = pm112_wf_notify,
+};
+
+static int wf_pm112_probe(struct device *dev)
+{
+        wf_register_client(&pm112_events);
+        return 0;
+}
+
+static int wf_pm112_remove(struct device *dev)
+{
+        wf_unregister_client(&pm112_events);
+        /* should release all sensors and controls */
+        return 0;
+}
+
+static struct device_driver wf_pm112_driver = {
+        .name = "windfarm",
+        .bus = &platform_bus_type,
+        .probe = wf_pm112_probe,
+        .remove = wf_pm112_remove,
+};
+
+static int __init wf_pm112_init(void)
+{
+        struct device_node *cpu;
+
+        if (!machine_is_compatible("PowerMac11,2"))
+                return -ENODEV;
+
+        /* Count the number of CPU cores */
+        nr_cores = 0;
+        for (cpu = NULL; (cpu = of_find_node_by_type(cpu, "cpu")) != NULL; )
+                ++nr_cores;
+
+        printk(KERN_INFO "windfarm: initializing for dual-core desktop G5\n");
+        driver_register(&wf_pm112_driver);
+        return 0;
+}
+
+static void __exit wf_pm112_exit(void)
+{
+        driver_unregister(&wf_pm112_driver);
+}
+
+module_init(wf_pm112_init);
+module_exit(wf_pm112_exit);
+
+MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
+MODULE_DESCRIPTION("Thermal control for PowerMac11,2");
+MODULE_LICENSE("GPL");