powerpc/windfarm: Add Fan Control Unit controls for G5s

The FCU operates the fans on the earlier generation G5 machines,
this module will be used by upcoming windfarm drivers.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 617 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_fcu_controls.c b/drivers/macintosh/windfarm_fcu_controls.c
new file mode 100644
index 000000000000..871f8b4cf367
--- /dev/null
+++ b/drivers/macintosh/windfarm_fcu_controls.c
@@ -0,0 +1,617 @@
+/*
+ * Windfarm PowerMac thermal control. FCU fan control
+ *
+ * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
+ *
+ * Released under the term of the GNU GPL v2.
+ */
+#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/wait.h>
+#include <linux/i2c.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/sections.h>
+
+#include "windfarm.h"
+#include "windfarm_mpu.h"
+
+#define VERSION "1.0"
+
+#ifdef DEBUG
+#define DBG(args...)    printk(args)
+#else
+#define DBG(args...)    do { } while(0)
+#endif
+
+/*
+ * This option is "weird" :) Basically, if you define this to 1
+ * the control loop for the RPMs fans (not PWMs) will apply the
+ * correction factor obtained from the PID to the actual RPM
+ * speed read from the FCU.
+ *
+ * If you define the below constant to 0, then it will be
+ * applied to the setpoint RPM speed, that is basically the
+ * speed we proviously "asked" for.
+ *
+ * I'm not sure which of these Apple's algorithm is supposed
+ * to use
+ */
+#define RPM_PID_USE_ACTUAL_SPEED        1
+
+/* Default min/max for pumps */
+#define CPU_PUMP_OUTPUT_MAX             3200
+#define CPU_PUMP_OUTPUT_MIN             1250
+
+#define FCU_FAN_RPM             0
+#define FCU_FAN_PWM             1
+
+struct wf_fcu_priv {
+        struct kref             ref;
+        struct i2c_client       *i2c;
+        struct mutex            lock;
+        struct list_head        fan_list;
+        int                     rpm_shift;
+};
+
+struct wf_fcu_fan {
+        struct list_head        link;
+        int                     id;
+        s32                     min, max, target;
+        struct wf_fcu_priv      *fcu_priv;
+        struct wf_control       ctrl;
+};
+
+static void wf_fcu_release(struct kref *ref)
+{
+        struct wf_fcu_priv *pv = container_of(ref, struct wf_fcu_priv, ref);
+
+        kfree(pv);
+}
+
+static void wf_fcu_fan_release(struct wf_control *ct)
+{
+        struct wf_fcu_fan *fan = ct->priv;
+
+        kref_put(&fan->fcu_priv->ref, wf_fcu_release);
+        kfree(fan);
+}
+
+static int wf_fcu_read_reg(struct wf_fcu_priv *pv, int reg,
+                           unsigned char *buf, int nb)
+{
+        int tries, nr, nw;
+
+        mutex_lock(&pv->lock);
+
+        buf[0] = reg;
+        tries = 0;
+        for (;;) {
+                nw = i2c_master_send(pv->i2c, buf, 1);
+                if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
+                        break;
+                msleep(10);
+                ++tries;
+        }
+        if (nw <= 0) {
+                pr_err("Failure writing address to FCU: %d", nw);
+                nr = nw;
+                goto bail;
+        }
+        tries = 0;
+        for (;;) {
+                nr = i2c_master_recv(pv->i2c, buf, nb);
+                if (nr > 0 || (nr < 0 && nr != -ENODEV) || tries >= 100)
+                        break;
+                msleep(10);
+                ++tries;
+        }
+        if (nr <= 0)
+                pr_err("wf_fcu: Failure reading data from FCU: %d", nw);
+ bail:
+        mutex_unlock(&pv->lock);
+        return nr;
+}
+
+static int wf_fcu_write_reg(struct wf_fcu_priv *pv, int reg,
+                            const unsigned char *ptr, int nb)
+{
+        int tries, nw;
+        unsigned char buf[16];
+
+        buf[0] = reg;
+        memcpy(buf+1, ptr, nb);
+        ++nb;
+        tries = 0;
+        for (;;) {
+                nw = i2c_master_send(pv->i2c, buf, nb);
+                if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
+                        break;
+                msleep(10);
+                ++tries;
+        }
+        if (nw < 0)
+                pr_err("wf_fcu: Failure writing to FCU: %d", nw);
+        return nw;
+}
+
+static int wf_fcu_fan_set_rpm(struct wf_control *ct, s32 value)
+{
+        struct wf_fcu_fan *fan = ct->priv;
+        struct wf_fcu_priv *pv = fan->fcu_priv;
+        int rc, shift = pv->rpm_shift;
+        unsigned char buf[2];
+
+        if (value < fan->min)
+                value = fan->min;
+        if (value > fan->max)
+                value = fan->max;
+
+        if (fan->target && fan->target == value)
+                return 0;
+        fan->target = value;
+
+        buf[0] = value >> (8 - shift);
+        buf[1] = value << shift;
+        rc = wf_fcu_write_reg(pv, 0x10 + (fan->id * 2), buf, 2);
+        if (rc < 0)
+                return -EIO;
+        return 0;
+}
+
+static int wf_fcu_fan_get_rpm(struct wf_control *ct, s32 *value)
+{
+        struct wf_fcu_fan *fan = ct->priv;
+        struct wf_fcu_priv *pv = fan->fcu_priv;
+        int rc, reg_base, shift = pv->rpm_shift;
+        unsigned char failure;
+        unsigned char active;
+        unsigned char buf[2];
+
+        rc = wf_fcu_read_reg(pv, 0xb, &failure, 1);
+        if (rc != 1)
+                return -EIO;
+        if ((failure & (1 << fan->id)) != 0)
+                return -EFAULT;
+        rc = wf_fcu_read_reg(pv, 0xd, &active, 1);
+        if (rc != 1)
+                return -EIO;
+        if ((active & (1 << fan->id)) == 0)
+                return -ENXIO;
+
+        /* Programmed value or real current speed */
+#if RPM_PID_USE_ACTUAL_SPEED
+        reg_base = 0x11;
+#else
+        reg_base = 0x10;
+#endif
+        rc = wf_fcu_read_reg(pv, reg_base + (fan->id * 2), buf, 2);
+        if (rc != 2)
+                return -EIO;
+
+        *value = (buf[0] << (8 - shift)) | buf[1] >> shift;
+
+        return 0;
+}
+
+static int wf_fcu_fan_set_pwm(struct wf_control *ct, s32 value)
+{
+        struct wf_fcu_fan *fan = ct->priv;
+        struct wf_fcu_priv *pv = fan->fcu_priv;
+        unsigned char buf[2];
+        int rc;
+
+        if (value < fan->min)
+                value = fan->min;
+        if (value > fan->max)
+                value = fan->max;
+
+        if (fan->target && fan->target == value)
+                return 0;
+        fan->target = value;
+
+        value = (value * 2559) / 1000;
+        buf[0] = value;
+        rc = wf_fcu_write_reg(pv, 0x30 + (fan->id * 2), buf, 1);
+        if (rc < 0)
+                return -EIO;
+        return 0;
+}
+
+static int wf_fcu_fan_get_pwm(struct wf_control *ct, s32 *value)
+{
+        struct wf_fcu_fan *fan = ct->priv;
+        struct wf_fcu_priv *pv = fan->fcu_priv;
+        unsigned char failure;
+        unsigned char active;
+        unsigned char buf[2];
+        int rc;
+
+        rc = wf_fcu_read_reg(pv, 0x2b, &failure, 1);
+        if (rc != 1)
+                return -EIO;
+        if ((failure & (1 << fan->id)) != 0)
+                return -EFAULT;
+        rc = wf_fcu_read_reg(pv, 0x2d, &active, 1);
+        if (rc != 1)
+                return -EIO;
+        if ((active & (1 << fan->id)) == 0)
+                return -ENXIO;
+
+        rc = wf_fcu_read_reg(pv, 0x30 + (fan->id * 2), buf, 1);
+        if (rc != 1)
+                return -EIO;
+
+        *value = (((s32)buf[0]) * 1000) / 2559;
+
+        return 0;
+}
+
+static s32 wf_fcu_fan_min(struct wf_control *ct)
+{
+        struct wf_fcu_fan *fan = ct->priv;
+
+        return fan->min;
+}
+
+static s32 wf_fcu_fan_max(struct wf_control *ct)
+{
+        struct wf_fcu_fan *fan = ct->priv;
+
+        return fan->max;
+}
+
+static const struct wf_control_ops wf_fcu_fan_rpm_ops = {
+        .set_value      = wf_fcu_fan_set_rpm,
+        .get_value      = wf_fcu_fan_get_rpm,
+        .get_min        = wf_fcu_fan_min,
+        .get_max        = wf_fcu_fan_max,
+        .release        = wf_fcu_fan_release,
+        .owner          = THIS_MODULE,
+};
+
+static const struct wf_control_ops wf_fcu_fan_pwm_ops = {
+        .set_value      = wf_fcu_fan_set_pwm,
+        .get_value      = wf_fcu_fan_get_pwm,
+        .get_min        = wf_fcu_fan_min,
+        .get_max        = wf_fcu_fan_max,
+        .release        = wf_fcu_fan_release,
+        .owner          = THIS_MODULE,
+};
+
+static void __devinit wf_fcu_get_pump_minmax(struct wf_fcu_fan *fan)
+{
+        const struct mpu_data *mpu = wf_get_mpu(0);
+        u16 pump_min = 0, pump_max = 0xffff;
+        u16 tmp[4];
+
+        /* Try to fetch pumps min/max infos from eeprom */
+        if (mpu) {
+                memcpy(&tmp, mpu->processor_part_num, 8);
+                if (tmp[0] != 0xffff && tmp[1] != 0xffff) {
+                        pump_min = max(pump_min, tmp[0]);
+                        pump_max = min(pump_max, tmp[1]);
+                }
+                if (tmp[2] != 0xffff && tmp[3] != 0xffff) {
+                        pump_min = max(pump_min, tmp[2]);
+                        pump_max = min(pump_max, tmp[3]);
+                }
+        }
+
+        /* Double check the values, this _IS_ needed as the EEPROM on
+         * some dual 2.5Ghz G5s seem, at least, to have both min & max
+         * same to the same value ... (grrrr)
+         */
+        if (pump_min == pump_max || pump_min == 0 || pump_max == 0xffff) {
+                pump_min = CPU_PUMP_OUTPUT_MIN;
+                pump_max = CPU_PUMP_OUTPUT_MAX;
+        }
+
+        fan->min = pump_min;
+        fan->max = pump_max;
+
+        DBG("wf_fcu: pump min/max for %s set to: [%d..%d] RPM\n",
+            fan->ctrl.name, pump_min, pump_max);
+}
+
+static void __devinit wf_fcu_get_rpmfan_minmax(struct wf_fcu_fan *fan)
+{
+        struct wf_fcu_priv *pv = fan->fcu_priv;
+        const struct mpu_data *mpu0 = wf_get_mpu(0);
+        const struct mpu_data *mpu1 = wf_get_mpu(1);
+
+        /* Default */
+        fan->min = 2400 >> pv->rpm_shift;
+        fan->max = 56000 >> pv->rpm_shift;
+
+        /* CPU fans have min/max in MPU */
+        if (mpu0 && !strcmp(fan->ctrl.name, "cpu-front-fan-0")) {
+                fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);
+                fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);
+                goto bail;
+        }
+        if (mpu1 && !strcmp(fan->ctrl.name, "cpu-front-fan-1")) {
+                fan->min = max(fan->min, (s32)mpu1->rminn_intake_fan);
+                fan->max = min(fan->max, (s32)mpu1->rmaxn_intake_fan);
+                goto bail;
+        }
+        if (mpu0 && !strcmp(fan->ctrl.name, "cpu-rear-fan-0")) {
+                fan->min = max(fan->min, (s32)mpu0->rminn_exhaust_fan);
+                fan->max = min(fan->max, (s32)mpu0->rmaxn_exhaust_fan);
+                goto bail;
+        }
+        if (mpu1 && !strcmp(fan->ctrl.name, "cpu-rear-fan-1")) {
+                fan->min = max(fan->min, (s32)mpu1->rminn_exhaust_fan);
+                fan->max = min(fan->max, (s32)mpu1->rmaxn_exhaust_fan);
+                goto bail;
+        }
+        /* Rackmac variants, we just use mpu0 intake */
+        if (!strncmp(fan->ctrl.name, "cpu-fan", 7)) {
+                fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);
+                fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);
+                goto bail;
+        }
+ bail:
+        DBG("wf_fcu: fan min/max for %s set to: [%d..%d] RPM\n",
+            fan->ctrl.name, fan->min, fan->max);
+}
+
+static void __devinit wf_fcu_add_fan(struct wf_fcu_priv *pv,
+                                     const char *name,
+                                     int type, int id)
+{
+        struct wf_fcu_fan *fan;
+
+        fan = kzalloc(sizeof(*fan), GFP_KERNEL);
+        if (!fan)
+                return;
+        fan->fcu_priv = pv;
+        fan->id = id;
+        fan->ctrl.name = name;
+        fan->ctrl.priv = fan;
+
+        /* min/max is oddball but the code comes from
+         * therm_pm72 which seems to work so ...
+         */
+        if (type == FCU_FAN_RPM) {
+                if (!strncmp(name, "cpu-pump", strlen("cpu-pump")))
+                        wf_fcu_get_pump_minmax(fan);
+                else
+                        wf_fcu_get_rpmfan_minmax(fan);
+                fan->ctrl.type = WF_CONTROL_RPM_FAN;
+                fan->ctrl.ops = &wf_fcu_fan_rpm_ops;
+        } else {
+                fan->min = 10;
+                fan->max = 100;
+                fan->ctrl.type = WF_CONTROL_PWM_FAN;
+                fan->ctrl.ops = &wf_fcu_fan_pwm_ops;
+        }
+
+        if (wf_register_control(&fan->ctrl)) {
+                pr_err("wf_fcu: Failed to register fan %s\n", name);
+                kfree(fan);
+                return;
+        }
+        list_add(&fan->link, &pv->fan_list);
+        kref_get(&pv->ref);
+}
+
+static void __devinit wf_fcu_lookup_fans(struct wf_fcu_priv *pv)
+{
+        /* Translation of device-tree location properties to
+         * windfarm fan names
+         */
+        static const struct {
+                const char *dt_name;    /* Device-tree name */
+                const char *ct_name;    /* Control name */
+        } loc_trans[] = {
+                { "BACKSIDE",           "backside-fan",         },
+                { "SYS CTRLR FAN",      "backside-fan",         },
+                { "DRIVE BAY",          "drive-bay-fan",        },
+                { "SLOT",               "slots-fan",            },
+                { "PCI FAN",            "slots-fan",            },
+                { "CPU A INTAKE",       "cpu-front-fan-0",      },
+                { "CPU A EXHAUST",      "cpu-rear-fan-0",       },
+                { "CPU B INTAKE",       "cpu-front-fan-1",      },
+                { "CPU B EXHAUST",      "cpu-rear-fan-1",       },
+                { "CPU A PUMP",         "cpu-pump-0",           },
+                { "CPU B PUMP",         "cpu-pump-1",           },
+                { "CPU A 1",            "cpu-fan-a-0",          },
+                { "CPU A 2",            "cpu-fan-b-0",          },
+                { "CPU A 3",            "cpu-fan-c-0",          },
+                { "CPU B 1",            "cpu-fan-a-1",          },
+                { "CPU B 2",            "cpu-fan-b-1",          },
+                { "CPU B 3",            "cpu-fan-c-1",          },
+        };
+        struct device_node *np = NULL, *fcu = pv->i2c->dev.of_node;
+        int i;
+
+        DBG("Looking up FCU controls in device-tree...\n");
+
+        while ((np = of_get_next_child(fcu, np)) != NULL) {
+                int id, type = -1;
+                const char *loc;
+                const char *name;
+                const u32 *reg;
+
+                DBG(" control: %s, type: %s\n", np->name, np->type);
+
+                /* Detect control type */
+                if (!strcmp(np->type, "fan-rpm-control") ||
+                    !strcmp(np->type, "fan-rpm"))
+                        type = FCU_FAN_RPM;
+                if (!strcmp(np->type, "fan-pwm-control") ||
+                    !strcmp(np->type, "fan-pwm"))
+                        type = FCU_FAN_PWM;
+                /* Only care about fans for now */
+                if (type == -1)
+                        continue;
+
+                /* Lookup for a matching location */
+                loc = of_get_property(np, "location", NULL);
+                reg = of_get_property(np, "reg", NULL);
+                if (loc == NULL || reg == NULL)
+                        continue;
+                DBG(" matching location: %s, reg: 0x%08x\n", loc, *reg);
+
+                for (i = 0; i < ARRAY_SIZE(loc_trans); i++) {
+                        if (strncmp(loc, loc_trans[i].dt_name,
+                                    strlen(loc_trans[i].dt_name)))
+                                continue;
+                        name = loc_trans[i].ct_name;
+
+                        DBG(" location match, name: %s\n", name);
+
+                        if (type == FCU_FAN_RPM)
+                                id = ((*reg) - 0x10) / 2;
+                        else
+                                id = ((*reg) - 0x30) / 2;
+                        if (id > 7) {
+                                pr_warning("wf_fcu: Can't parse "
+                                       "fan ID in device-tree for %s\n",
+                                           np->full_name);
+                                break;
+                        }
+                        wf_fcu_add_fan(pv, name, type, id);
+                        break;
+                }
+        }
+}
+
+static void __devinit wf_fcu_default_fans(struct wf_fcu_priv *pv)
+{
+        /* We only support the default fans for PowerMac7,2 */
+        if (!of_machine_is_compatible("PowerMac7,2"))
+                return;
+
+        wf_fcu_add_fan(pv, "backside-fan",      FCU_FAN_PWM, 1);
+        wf_fcu_add_fan(pv, "drive-bay-fan",     FCU_FAN_RPM, 2);
+        wf_fcu_add_fan(pv, "slots-fan",         FCU_FAN_PWM, 2);
+        wf_fcu_add_fan(pv, "cpu-front-fan-0",   FCU_FAN_RPM, 3);
+        wf_fcu_add_fan(pv, "cpu-rear-fan-0",    FCU_FAN_RPM, 4);
+        wf_fcu_add_fan(pv, "cpu-front-fan-1",   FCU_FAN_RPM, 5);
+        wf_fcu_add_fan(pv, "cpu-rear-fan-1",    FCU_FAN_RPM, 6);
+}
+
+static int __devinit wf_fcu_init_chip(struct wf_fcu_priv *pv)
+{
+        unsigned char buf = 0xff;
+        int rc;
+
+        rc = wf_fcu_write_reg(pv, 0xe, &buf, 1);
+        if (rc < 0)
+                return -EIO;
+        rc = wf_fcu_write_reg(pv, 0x2e, &buf, 1);
+        if (rc < 0)
+                return -EIO;
+        rc = wf_fcu_read_reg(pv, 0, &buf, 1);
+        if (rc < 0)
+                return -EIO;
+        pv->rpm_shift = (buf == 1) ? 2 : 3;
+
+        pr_debug("wf_fcu: FCU Initialized, RPM fan shift is %d\n",
+                 pv->rpm_shift);
+
+        return 0;
+}
+
+static int __devinit wf_fcu_probe(struct i2c_client *client,
+                                  const struct i2c_device_id *id)
+{
+        struct wf_fcu_priv *pv;
+
+        pv = kzalloc(sizeof(*pv), GFP_KERNEL);
+        if (!pv)
+                return -ENOMEM;
+
+        kref_init(&pv->ref);
+        mutex_init(&pv->lock);
+        INIT_LIST_HEAD(&pv->fan_list);
+        pv->i2c = client;
+
+        /*
+         * First we must start the FCU which will query the
+         * shift value to apply to RPMs
+         */
+        if (wf_fcu_init_chip(pv)) {
+                pr_err("wf_fcu: Initialization failed !\n");
+                kfree(pv);
+                return -ENXIO;
+        }
+
+        /* First lookup fans in the device-tree */
+        wf_fcu_lookup_fans(pv);
+
+        /*
+         * Older machines don't have the device-tree entries
+         * we are looking for, just hard code the list
+         */
+        if (list_empty(&pv->fan_list))
+                wf_fcu_default_fans(pv);
+
+        /* Still no fans ? FAIL */
+        if (list_empty(&pv->fan_list)) {
+                pr_err("wf_fcu: Failed to find fans for your machine\n");
+                kfree(pv);
+                return -ENODEV;
+        }
+
+        dev_set_drvdata(&client->dev, pv);
+
+        return 0;
+}
+
+static int __devexit wf_fcu_remove(struct i2c_client *client)
+{
+        struct wf_fcu_priv *pv = dev_get_drvdata(&client->dev);
+        struct wf_fcu_fan *fan;
+
+        while (!list_empty(&pv->fan_list)) {
+                fan = list_first_entry(&pv->fan_list, struct wf_fcu_fan, link);
+                list_del(&fan->link);
+                wf_unregister_control(&fan->ctrl);
+        }
+        kref_put(&pv->ref, wf_fcu_release);
+        return 0;
+}
+
+static const struct i2c_device_id wf_fcu_id[] = {
+        { "MAC,fcu", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, wf_fcu_id);
+
+static struct i2c_driver wf_fcu_driver = {
+        .driver = {
+                .name   = "wf_fcu",
+        },
+        .probe          = wf_fcu_probe,
+        .remove         = wf_fcu_remove,
+        .id_table       = wf_fcu_id,
+};
+
+static int __init wf_fcu_init(void)
+{
+        return i2c_add_driver(&wf_fcu_driver);
+}
+
+static void __exit wf_fcu_exit(void)
+{
+        i2c_del_driver(&wf_fcu_driver);
+}
+
+
+module_init(wf_fcu_init);
+module_exit(wf_fcu_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("FCU control objects for PowerMacs thermal control");
+MODULE_LICENSE("GPL");
+