[POWERPC] windfarm: Add PowerMac 12,1 support

This implements a new driver named windfarm_pm121, which drives the
fans on PowerMac 12,1 machines : iMac G5 iSight (rev C) 17" and
20".  It's based on the windfarm_pm81 driver from Benjamin
Herrenschmidt.

This includes fixes from David Woodhouse correcting the names of some
of the sensors.

Signed-off-by: Étienne Bersac <bersace@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 1040 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_pm121.c b/drivers/macintosh/windfarm_pm121.c
new file mode 100644
index 000000000000..66ec4fb115bb
--- /dev/null
+++ b/drivers/macintosh/windfarm_pm121.c
@@ -0,0 +1,1040 @@
+/*
+ * Windfarm PowerMac thermal control. iMac G5 iSight
+ *
+ * (c) Copyright 2007 Étienne Bersac <bersace@gmail.com>
+ *
+ * Bits & pieces from windfarm_pm81.c by (c) Copyright 2005 Benjamin
+ * Herrenschmidt, IBM Corp. <benh@kernel.crashing.org>
+ *
+ * Released under the term of the GNU GPL v2.
+ *
+ *
+ *
+ * PowerMac12,1
+ * ============
+ *
+ *
+ * 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 8.10 snapshot property lists (note however
+ * that none of the code has been re-used, it's a complete
+ * re-implementation
+ *
+ * There is two models using PowerMac12,1. Model 2 is iMac G5 iSight
+ * 17" while Model 3 is iMac G5 20". They do have both the same
+ * controls with a tiny difference. The control-ids of hard-drive-fan
+ * and cpu-fan is swapped.
+ *
+ *
+ * Target Correction :
+ *
+ * controls have a target correction calculated as :
+ *
+ * new_min = ((((average_power * slope) >> 16) + offset) >> 16) + min_value
+ * new_value = max(new_value, max(new_min, 0))
+ *
+ * OD Fan control correction.
+ *
+ * # model_id: 2
+ *   offset             : -19563152
+ *   slope              :  1956315
+ *
+ * # model_id: 3
+ *   offset             : -15650652
+ *   slope              :  1565065
+ *
+ * HD Fan control correction.
+ *
+ * # model_id: 2
+ *   offset             : -15650652
+ *   slope              :  1565065
+ *
+ * # model_id: 3
+ *   offset             : -19563152
+ *   slope              :  1956315
+ *
+ * CPU Fan control correction.
+ *
+ * # model_id: 2
+ *   offset             : -25431900
+ *   slope              :  2543190
+ *
+ * # model_id: 3
+ *   offset             : -15650652
+ *   slope              :  1565065
+ *
+ *
+ * Target rubber-banding :
+ *
+ * Some controls have a target correction which depends on another
+ * control value. The correction is computed in the following way :
+ *
+ * new_min = ref_value * slope + offset
+ *
+ * ref_value is the value of the reference control. If new_min is
+ * greater than 0, then we correct the target value using :
+ *
+ * new_target = max (new_target, new_min >> 16)
+ *
+ *
+ * # model_id : 2
+ *   control    : cpu-fan
+ *   ref        : optical-drive-fan
+ *   offset     : -15650652
+ *   slope      : 1565065
+ *
+ * # model_id : 3
+ *   control    : optical-drive-fan
+ *   ref        : hard-drive-fan
+ *   offset     : -32768000
+ *   slope      : 65536
+ *
+ *
+ * In order to have the moste efficient correction with those
+ * dependencies, we must trigger HD loop before OD loop before CPU
+ * loop.
+ *
+ *
+ * The various control loops found in Darwin config file are:
+ *
+ * HD Fan control loop.
+ *
+ * # model_id: 2
+ *   control        : hard-drive-fan
+ *   sensor         : hard-drive-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x002D70A3
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x370000
+ *                    Interval = 5s
+ *
+ * # model_id: 3
+ *   control        : hard-drive-fan
+ *   sensor         : hard-drive-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x002170A3
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x370000
+ *                    Interval = 5s
+ *
+ * OD Fan control loop.
+ *
+ * # model_id: 2
+ *   control        : optical-drive-fan
+ *   sensor         : optical-drive-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x001FAE14
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x320000
+ *                    Interval = 5s
+ *
+ * # model_id: 3
+ *   control        : optical-drive-fan
+ *   sensor         : optical-drive-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x001FAE14
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x320000
+ *                    Interval = 5s
+ *
+ * GPU Fan control loop.
+ *
+ * # model_id: 2
+ *   control        : hard-drive-fan
+ *   sensor         : gpu-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x002A6666
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x5A0000
+ *                    Interval = 5s
+ *
+ * # model_id: 3
+ *   control        : cpu-fan
+ *   sensor         : gpu-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x0010CCCC
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x500000
+ *                    Interval = 5s
+ *
+ * KODIAK (aka northbridge) Fan control loop.
+ *
+ * # model_id: 2
+ *   control        : optical-drive-fan
+ *   sensor         : north-bridge-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x003BD70A
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x550000
+ *                    Interval = 5s
+ *
+ * # model_id: 3
+ *   control        : hard-drive-fan
+ *   sensor         : north-bridge-temp
+ *   PID params     : G_d = 0x00000000
+ *                    G_p = 0x0030F5C2
+ *                    G_r = 0x00019999
+ *                    History = 2 entries
+ *                    Input target = 0x550000
+ *                    Interval = 5s
+ *
+ * CPU Fan control loop.
+ *
+ *   control        : cpu-fan
+ *   sensors        : cpu-temp, cpu-power
+ *   PID params     : from SDB partition
+ *
+ *
+ * CPU Slew control loop.
+ *
+ *   control        : cpufreq-clamp
+ *   sensor         : cpu-temp
+ *
+ */
+
+#undef  DEBUG
+
+#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/system.h>
+#include <asm/sections.h>
+#include <asm/smu.h>
+
+#include "windfarm.h"
+#include "windfarm_pid.h"
+
+#define VERSION "0.3"
+
+static int pm121_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_cpu_voltage;
+static struct wf_sensor *sensor_cpu_current;
+static struct wf_sensor *sensor_gpu_temp;
+static struct wf_sensor *sensor_north_bridge_temp;
+static struct wf_sensor *sensor_hard_drive_temp;
+static struct wf_sensor *sensor_optical_drive_temp;
+static struct wf_sensor *sensor_incoming_air_temp; /* unused ! */
+
+enum {
+        FAN_CPU,
+        FAN_HD,
+        FAN_OD,
+        CPUFREQ,
+        N_CONTROLS
+};
+static struct wf_control *controls[N_CONTROLS] = {};
+
+/* Set to kick the control loop into life */
+static int pm121_all_controls_ok, pm121_all_sensors_ok, pm121_started;
+
+enum {
+        FAILURE_FAN             = 1 << 0,
+        FAILURE_SENSOR          = 1 << 1,
+        FAILURE_OVERTEMP        = 1 << 2
+};
+
+/* All sys loops. Note the HD before the OD loop in order to have it
+   run before. */
+enum {
+        LOOP_GPU,               /* control = hd or cpu, but luckily,
+                                   it doesn't matter */
+        LOOP_HD,                /* control = hd */
+        LOOP_KODIAK,            /* control = hd or od */
+        LOOP_OD,                /* control = od */
+        N_LOOPS
+};
+
+static const char *loop_names[N_LOOPS] = {
+        "GPU",
+        "HD",
+        "KODIAK",
+        "OD",
+};
+
+#define PM121_NUM_CONFIGS       2
+
+static unsigned int pm121_failure_state;
+static int pm121_readjust, pm121_skipping;
+static s32 average_power;
+
+struct pm121_correction {
+        int     offset;
+        int     slope;
+};
+
+static struct pm121_correction corrections[N_CONTROLS][PM121_NUM_CONFIGS] = {
+        /* FAN_OD */
+        {
+                /* MODEL 2 */
+                { .offset       = -19563152,
+                  .slope        =  1956315
+                },
+                /* MODEL 3 */
+                { .offset       = -15650652,
+                  .slope        =  1565065
+                },
+        },
+        /* FAN_HD */
+        {
+                /* MODEL 2 */
+                { .offset       = -15650652,
+                  .slope        =  1565065
+                },
+                /* MODEL 3 */
+                { .offset       = -19563152,
+                  .slope        =  1956315
+                },
+        },
+        /* FAN_CPU */
+        {
+                /* MODEL 2 */
+                { .offset       = -25431900,
+                  .slope        =  2543190
+                },
+                /* MODEL 3 */
+                { .offset       = -15650652,
+                  .slope        =  1565065
+                },
+        },
+        /* CPUFREQ has no correction (and is not implemented at all) */
+};
+
+struct pm121_connection {
+        unsigned int    control_id;
+        unsigned int    ref_id;
+        struct pm121_correction correction;
+};
+
+static struct pm121_connection pm121_connections[] = {
+        /* MODEL 2 */
+        { .control_id   = FAN_CPU,
+          .ref_id       = FAN_OD,
+          { .offset     = -32768000,
+            .slope      =  65536
+          }
+        },
+        /* MODEL 3 */
+        { .control_id   = FAN_OD,
+          .ref_id       = FAN_HD,
+          { .offset     = -32768000,
+            .slope      =  65536
+          }
+        },
+};
+
+/* pointer to the current model connection */
+static struct pm121_connection *pm121_connection;
+
+/*
+ * ****** System Fans Control Loop ******
+ *
+ */
+
+/* Since each loop handles only one control and we want to avoid
+ * writing virtual control, we store the control correction with the
+ * loop params. Some data are not set, there are common to all loop
+ * and thus, hardcoded.
+ */
+struct pm121_sys_param {
+        /* purely informative since we use mach_model-2 as index */
+        int                     model_id;
+        struct wf_sensor        **sensor; /* use sensor_id instead ? */
+        s32                     gp, itarget;
+        unsigned int            control_id;
+};
+
+static struct pm121_sys_param
+pm121_sys_all_params[N_LOOPS][PM121_NUM_CONFIGS] = {
+        /* GPU Fan control loop */
+        {
+                { .model_id     = 2,
+                  .sensor       = &sensor_gpu_temp,
+                  .gp           = 0x002A6666,
+                  .itarget      = 0x5A0000,
+                  .control_id   = FAN_HD,
+                },
+                { .model_id     = 3,
+                  .sensor       = &sensor_gpu_temp,
+                  .gp           = 0x0010CCCC,
+                  .itarget      = 0x500000,
+                  .control_id   = FAN_CPU,
+                },
+        },
+        /* HD Fan control loop */
+        {
+                { .model_id     = 2,
+                  .sensor       = &sensor_hard_drive_temp,
+                  .gp           = 0x002D70A3,
+                  .itarget      = 0x370000,
+                  .control_id   = FAN_HD,
+                },
+                { .model_id     = 3,
+                  .sensor       = &sensor_hard_drive_temp,
+                  .gp           = 0x002170A3,
+                  .itarget      = 0x370000,
+                  .control_id   = FAN_HD,
+                },
+        },
+        /* KODIAK Fan control loop */
+        {
+                { .model_id     = 2,
+                  .sensor       = &sensor_north_bridge_temp,
+                  .gp           = 0x003BD70A,
+                  .itarget      = 0x550000,
+                  .control_id   = FAN_OD,
+                },
+                { .model_id     = 3,
+                  .sensor       = &sensor_north_bridge_temp,
+                  .gp           = 0x0030F5C2,
+                  .itarget      = 0x550000,
+                  .control_id   = FAN_HD,
+                },
+        },
+        /* OD Fan control loop */
+        {
+                { .model_id     = 2,
+                  .sensor       = &sensor_optical_drive_temp,
+                  .gp           = 0x001FAE14,
+                  .itarget      = 0x320000,
+                  .control_id   = FAN_OD,
+                },
+                { .model_id     = 3,
+                  .sensor       = &sensor_optical_drive_temp,
+                  .gp           = 0x001FAE14,
+                  .itarget      = 0x320000,
+                  .control_id   = FAN_OD,
+                },
+        },
+};
+
+/* the hardcoded values */
+#define PM121_SYS_GD            0x00000000
+#define PM121_SYS_GR            0x00019999
+#define PM121_SYS_HISTORY_SIZE  2
+#define PM121_SYS_INTERVAL      5
+
+/* State data used by the system fans control loop
+ */
+struct pm121_sys_state {
+        int                     ticks;
+        s32                     setpoint;
+        struct wf_pid_state     pid;
+};
+
+struct pm121_sys_state *pm121_sys_state[N_LOOPS] = {};
+
+/*
+ * ****** CPU Fans Control Loop ******
+ *
+ */
+
+#define PM121_CPU_INTERVAL      1
+
+/* State data used by the cpu fans control loop
+ */
+struct pm121_cpu_state {
+        int                     ticks;
+        s32                     setpoint;
+        struct wf_cpu_pid_state pid;
+};
+
+static struct pm121_cpu_state *pm121_cpu_state;
+
+
+
+/*
+ * ***** Implementation *****
+ *
+ */
+
+/* correction the value using the output-low-bound correction algo */
+static s32 pm121_correct(s32 new_setpoint,
+                         unsigned int control_id,
+                         s32 min)
+{
+        s32 new_min;
+        struct pm121_correction *correction;
+        correction = &corrections[control_id][pm121_mach_model - 2];
+
+        new_min = (average_power * correction->slope) >> 16;
+        new_min += correction->offset;
+        new_min = (new_min >> 16) + min;
+
+        return max(new_setpoint, max(new_min, 0));
+}
+
+static s32 pm121_connect(unsigned int control_id, s32 setpoint)
+{
+        s32 new_min, value, new_setpoint;
+
+        if (pm121_connection->control_id == control_id) {
+                controls[control_id]->ops->get_value(controls[control_id],
+                                                     &value);
+                new_min = value * pm121_connection->correction.slope;
+                new_min += pm121_connection->correction.offset;
+                if (new_min > 0) {
+                        new_setpoint = max(setpoint, (new_min >> 16));
+                        if (new_setpoint != setpoint) {
+                                pr_debug("pm121: %s depending on %s, "
+                                         "corrected from %d to %d RPM\n",
+                                         controls[control_id]->name,
+                                         controls[pm121_connection->ref_id]->name,
+                                         (int) setpoint, (int) new_setpoint);
+                        }
+                } else
+                        new_setpoint = setpoint;
+        }
+        /* no connection */
+        else
+                new_setpoint = setpoint;
+
+        return new_setpoint;
+}
+
+/* FAN LOOPS */
+static void pm121_create_sys_fans(int loop_id)
+{
+        struct pm121_sys_param *param = NULL;
+        struct wf_pid_param pid_param;
+        struct wf_control *control = NULL;
+        int i;
+
+        /* First, locate the params for this model */
+        for (i = 0; i < PM121_NUM_CONFIGS; i++) {
+                if (pm121_sys_all_params[loop_id][i].model_id == pm121_mach_model) {
+                        param = &(pm121_sys_all_params[loop_id][i]);
+                        break;
+                }
+        }
+
+        /* No params found, put fans to max */
+        if (param == NULL) {
+                printk(KERN_WARNING "pm121: %s fan config not found "
+                       " for this machine model\n",
+                       loop_names[loop_id]);
+                goto fail;
+        }
+
+        control = controls[param->control_id];
+
+        /* Alloc & initialize state */
+        pm121_sys_state[loop_id] = kmalloc(sizeof(struct pm121_sys_state),
+                                           GFP_KERNEL);
+        if (pm121_sys_state[loop_id] == NULL) {
+                printk(KERN_WARNING "pm121: Memory allocation error\n");
+                goto fail;
+        }
+        pm121_sys_state[loop_id]->ticks = 1;
+
+        /* Fill PID params */
+        pid_param.gd            = PM121_SYS_GD;
+        pid_param.gp            = param->gp;
+        pid_param.gr            = PM121_SYS_GR;
+        pid_param.interval      = PM121_SYS_INTERVAL;
+        pid_param.history_len   = PM121_SYS_HISTORY_SIZE;
+        pid_param.itarget       = param->itarget;
+        pid_param.min           = control->ops->get_min(control);
+        pid_param.max           = control->ops->get_max(control);
+
+        wf_pid_init(&pm121_sys_state[loop_id]->pid, &pid_param);
+
+        pr_debug("pm121: %s Fan control loop initialized.\n"
+                 "       itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
+                 loop_names[loop_id], FIX32TOPRINT(pid_param.itarget),
+                 pid_param.min, pid_param.max);
+        return;
+
+ fail:
+        /* note that this is not optimal since another loop may still
+           control the same control */
+        printk(KERN_WARNING "pm121: failed to set up %s loop "
+               "setting \"%s\" to max speed.\n",
+               loop_names[loop_id], control->name);
+
+        if (control)
+                wf_control_set_max(control);
+}
+
+static void pm121_sys_fans_tick(int loop_id)
+{
+        struct pm121_sys_param *param;
+        struct pm121_sys_state *st;
+        struct wf_sensor *sensor;
+        struct wf_control *control;
+        s32 temp, new_setpoint;
+        int rc;
+
+        param = &(pm121_sys_all_params[loop_id][pm121_mach_model-2]);
+        st = pm121_sys_state[loop_id];
+        sensor = *(param->sensor);
+        control = controls[param->control_id];
+
+        if (--st->ticks != 0) {
+                if (pm121_readjust)
+                        goto readjust;
+                return;
+        }
+        st->ticks = PM121_SYS_INTERVAL;
+
+        rc = sensor->ops->get_value(sensor, &temp);
+        if (rc) {
+                printk(KERN_WARNING "windfarm: %s sensor error %d\n",
+                       sensor->name, rc);
+                pm121_failure_state |= FAILURE_SENSOR;
+                return;
+        }
+
+        pr_debug("pm121: %s Fan tick ! %s: %d.%03d\n",
+                 loop_names[loop_id], sensor->name,
+                 FIX32TOPRINT(temp));
+
+        new_setpoint = wf_pid_run(&st->pid, temp);
+
+        /* correction */
+        new_setpoint = pm121_correct(new_setpoint,
+                                     param->control_id,
+                                     st->pid.param.min);
+        /* linked corretion */
+        new_setpoint = pm121_connect(param->control_id, new_setpoint);
+
+        if (new_setpoint == st->setpoint)
+                return;
+        st->setpoint = new_setpoint;
+        pr_debug("pm121: %s corrected setpoint: %d RPM\n",
+                 control->name, (int)new_setpoint);
+ readjust:
+        if (control && pm121_failure_state == 0) {
+                rc = control->ops->set_value(control, st->setpoint);
+                if (rc) {
+                        printk(KERN_WARNING "windfarm: %s fan error %d\n",
+                               control->name, rc);
+                        pm121_failure_state |= FAILURE_FAN;
+                }
+        }
+}
+
+
+/* CPU LOOP */
+static void pm121_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;
+        struct wf_control *fan_cpu;
+        s32 tmax, tdelta, maxpow, powadj;
+
+        fan_cpu = controls[FAN_CPU];
+
+        /* First, locate the PID params in SMU SBD */
+        hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
+        if (hdr == 0) {
+                printk(KERN_WARNING "pm121: CPU PID fan config not found.\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 */
+        pm121_cpu_state = kmalloc(sizeof(struct pm121_cpu_state),
+                                  GFP_KERNEL);
+        if (pm121_cpu_state == NULL)
+                goto fail;
+        pm121_cpu_state->ticks = 1;
+
+        /* Fill PID params */
+        pid_param.interval = PM121_CPU_INTERVAL;
+        pid_param.history_len = piddata->history_len;
+        if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
+                printk(KERN_WARNING "pm121: 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 = fan_cpu->ops->get_min(fan_cpu);
+        pid_param.max = fan_cpu->ops->get_max(fan_cpu);
+
+        wf_cpu_pid_init(&pm121_cpu_state->pid, &pid_param);
+
+        pr_debug("pm121: CPU Fan control initialized.\n");
+        pr_debug("       ttarged=%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 "pm121: CPU fan config not found, max fan speed\n");
+
+        if (controls[CPUFREQ])
+                wf_control_set_max(controls[CPUFREQ]);
+        if (fan_cpu)
+                wf_control_set_max(fan_cpu);
+}
+
+
+static void pm121_cpu_fans_tick(struct pm121_cpu_state *st)
+{
+        s32 new_setpoint, temp, power;
+        struct wf_control *fan_cpu = NULL;
+        int rc;
+
+        if (--st->ticks != 0) {
+                if (pm121_readjust)
+                        goto readjust;
+                return;
+        }
+        st->ticks = PM121_CPU_INTERVAL;
+
+        fan_cpu = controls[FAN_CPU];
+
+        rc = sensor_cpu_temp->ops->get_value(sensor_cpu_temp, &temp);
+        if (rc) {
+                printk(KERN_WARNING "pm121: CPU temp sensor error %d\n",
+                       rc);
+                pm121_failure_state |= FAILURE_SENSOR;
+                return;
+        }
+
+        rc = sensor_cpu_power->ops->get_value(sensor_cpu_power, &power);
+        if (rc) {
+                printk(KERN_WARNING "pm121: CPU power sensor error %d\n",
+                       rc);
+                pm121_failure_state |= FAILURE_SENSOR;
+                return;
+        }
+
+        pr_debug("pm121: CPU Fans tick ! CPU temp: %d.%03d°C, power: %d.%03d\n",
+                 FIX32TOPRINT(temp), FIX32TOPRINT(power));
+
+        if (temp > st->pid.param.tmax)
+                pm121_failure_state |= FAILURE_OVERTEMP;
+
+        new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
+
+        /* correction */
+        new_setpoint = pm121_correct(new_setpoint,
+                                     FAN_CPU,
+                                     st->pid.param.min);
+
+        /* connected correction */
+        new_setpoint = pm121_connect(FAN_CPU, new_setpoint);
+
+        if (st->setpoint == new_setpoint)
+                return;
+        st->setpoint = new_setpoint;
+        pr_debug("pm121: CPU corrected setpoint: %d RPM\n", (int)new_setpoint);
+
+ readjust:
+        if (fan_cpu && pm121_failure_state == 0) {
+                rc = fan_cpu->ops->set_value(fan_cpu, st->setpoint);
+                if (rc) {
+                        printk(KERN_WARNING "pm121: %s fan error %d\n",
+                               fan_cpu->name, rc);
+                        pm121_failure_state |= FAILURE_FAN;
+                }
+        }
+}
+
+/*
+ * ****** Common ******
+ *
+ */
+
+static void pm121_tick(void)
+{
+        unsigned int last_failure = pm121_failure_state;
+        unsigned int new_failure;
+        s32 total_power;
+        int i;
+
+        if (!pm121_started) {
+                pr_debug("pm121: creating control loops !\n");
+                for (i = 0; i < N_LOOPS; i++)
+                        pm121_create_sys_fans(i);
+
+                pm121_create_cpu_fans();
+                pm121_started = 1;
+        }
+
+        /* skipping ticks */
+        if (pm121_skipping && --pm121_skipping)
+                return;
+
+        /* compute average power */
+        total_power = 0;
+        for (i = 0; i < pm121_cpu_state->pid.param.history_len; i++)
+                total_power += pm121_cpu_state->pid.powers[i];
+
+        average_power = total_power / pm121_cpu_state->pid.param.history_len;
+
+
+        pm121_failure_state = 0;
+        for (i = 0 ; i < N_LOOPS; i++) {
+                if (pm121_sys_state[i])
+                        pm121_sys_fans_tick(i);
+        }
+
+        if (pm121_cpu_state)
+                pm121_cpu_fans_tick(pm121_cpu_state);
+
+        pm121_readjust = 0;
+        new_failure = pm121_failure_state & ~last_failure;
+
+        /* If entering failure mode, clamp cpufreq and ramp all
+         * fans to full speed.
+         */
+        if (pm121_failure_state && !last_failure) {
+                for (i = 0; i < N_CONTROLS; i++) {
+                        if (controls[i])
+                                wf_control_set_max(controls[i]);
+                }
+        }
+
+        /* If leaving failure mode, unclamp cpufreq and readjust
+         * all fans on next iteration
+         */
+        if (!pm121_failure_state && last_failure) {
+                if (controls[CPUFREQ])
+                        wf_control_set_min(controls[CPUFREQ]);
+                pm121_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();
+                pm121_skipping = 2;
+        }
+
+        /* 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 (new_failure == 0 && last_failure & FAILURE_OVERTEMP)
+                wf_clear_overtemp();
+}
+
+
+static struct wf_control* pm121_register_control(struct wf_control *ct,
+                                                 const char *match,
+                                                 unsigned int id)
+{
+        if (controls[id] == NULL && !strcmp(ct->name, match)) {
+                if (wf_get_control(ct) == 0)
+                        controls[id] = ct;
+        }
+        return controls[id];
+}
+
+static void pm121_new_control(struct wf_control *ct)
+{
+        int all = 1;
+
+        if (pm121_all_controls_ok)
+                return;
+
+        all = pm121_register_control(ct, "optical-drive-fan", FAN_OD) && all;
+        all = pm121_register_control(ct, "hard-drive-fan", FAN_HD) && all;
+        all = pm121_register_control(ct, "cpu-fan", FAN_CPU) && all;
+        all = pm121_register_control(ct, "cpufreq-clamp", CPUFREQ) && all;
+
+        if (all)
+                pm121_all_controls_ok = 1;
+}
+
+
+
+
+static struct wf_sensor* pm121_register_sensor(struct wf_sensor *sensor,
+                                               const char *match,
+                                               struct wf_sensor **var)
+{
+        if (*var == NULL && !strcmp(sensor->name, match)) {
+                if (wf_get_sensor(sensor) == 0)
+                        *var = sensor;
+        }
+        return *var;
+}
+
+static void pm121_new_sensor(struct wf_sensor *sr)
+{
+        int all = 1;
+
+        if (pm121_all_sensors_ok)
+                return;
+
+        all = pm121_register_sensor(sr, "cpu-temp",
+                                    &sensor_cpu_temp) && all;
+        all = pm121_register_sensor(sr, "cpu-current",
+                                    &sensor_cpu_current) && all;
+        all = pm121_register_sensor(sr, "cpu-voltage",
+                                    &sensor_cpu_voltage) && all;
+        all = pm121_register_sensor(sr, "cpu-power",
+                                    &sensor_cpu_power) && all;
+        all = pm121_register_sensor(sr, "hard-drive-temp",
+                                    &sensor_hard_drive_temp) && all;
+        all = pm121_register_sensor(sr, "optical-drive-temp",
+                                    &sensor_optical_drive_temp) && all;
+        all = pm121_register_sensor(sr, "incoming-air-temp",
+                                    &sensor_incoming_air_temp) && all;
+        all = pm121_register_sensor(sr, "north-bridge-temp",
+                                    &sensor_north_bridge_temp) && all;
+        all = pm121_register_sensor(sr, "gpu-temp",
+                                    &sensor_gpu_temp) && all;
+
+        if (all)
+                pm121_all_sensors_ok = 1;
+}
+
+
+
+static int pm121_notify(struct notifier_block *self,
+                        unsigned long event, void *data)
+{
+        switch (event) {
+        case WF_EVENT_NEW_CONTROL:
+                pr_debug("pm121: new control %s detected\n",
+                         ((struct wf_control *)data)->name);
+                pm121_new_control(data);
+                break;
+        case WF_EVENT_NEW_SENSOR:
+                pr_debug("pm121: new sensor %s detected\n",
+                         ((struct wf_sensor *)data)->name);
+                pm121_new_sensor(data);
+                break;
+        case WF_EVENT_TICK:
+                if (pm121_all_controls_ok && pm121_all_sensors_ok)
+                        pm121_tick();
+                break;
+        }
+
+        return 0;
+}
+
+static struct notifier_block pm121_events = {
+        .notifier_call  = pm121_notify,
+};
+
+static int pm121_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];
+                pm121_mach_model = st->model_id;
+        }
+
+        pm121_connection = &pm121_connections[pm121_mach_model - 2];
+
+        printk(KERN_INFO "pm121: Initializing for iMac G5 iSight model ID %d\n",
+               pm121_mach_model);
+
+        return 0;
+}
+
+
+static int pm121_probe(struct platform_device *ddev)
+{
+        wf_register_client(&pm121_events);
+
+        return 0;
+}
+
+static int __devexit pm121_remove(struct platform_device *ddev)
+{
+        wf_unregister_client(&pm121_events);
+        return 0;
+}
+
+static struct platform_driver pm121_driver = {
+        .probe = pm121_probe,
+        .remove = __devexit_p(pm121_remove),
+        .driver = {
+                .name = "windfarm",
+                .bus = &platform_bus_type,
+        },
+};
+
+
+static int __init pm121_init(void)
+{
+        int rc = -ENODEV;
+
+        if (machine_is_compatible("PowerMac12,1"))
+                rc = pm121_init_pm();
+
+        if (rc == 0) {
+                request_module("windfarm_smu_controls");
+                request_module("windfarm_smu_sensors");
+                request_module("windfarm_smu_sat");
+                request_module("windfarm_lm75_sensor");
+                request_module("windfarm_max6690_sensor");
+                request_module("windfarm_cpufreq_clamp");
+                platform_driver_register(&pm121_driver);
+        }
+
+        return rc;
+}
+
+static void __exit pm121_exit(void)
+{
+
+        platform_driver_unregister(&pm121_driver);
+}
+
+
+module_init(pm121_init);
+module_exit(pm121_exit);
+
+MODULE_AUTHOR("Étienne Bersac <bersace@gmail.com>");
+MODULE_DESCRIPTION("Thermal control logic for iMac G5 (iSight)");
+MODULE_LICENSE("GPL");
+