powerpc/windfarm: Add Fan Control Unit controls for G5s
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>
Wed, 18 Apr 2012 22:16:55 +0000 (22:16 +0000)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>
Mon, 30 Apr 2012 05:37:25 +0000 (15:37 +1000)
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>
drivers/macintosh/windfarm_fcu_controls.c [new file with mode: 0644]

diff --git a/drivers/macintosh/windfarm_fcu_controls.c b/drivers/macintosh/windfarm_fcu_controls.c
new file mode 100644 (file)
index 0000000..871f8b4
--- /dev/null
@@ -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");
+