[PATCH] ppc64: Thermal control for SMU based machines

This adds a new thermal control framework for PowerMac, along with the
implementation for PowerMac8,1, PowerMac8,2 (iMac G5 rev 1 and 2), and
PowerMac9,1 (latest single CPU desktop). In the future, I expect to move
the older G5 thermal control to the new framework as well.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 263 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_lm75_sensor.c b/drivers/macintosh/windfarm_lm75_sensor.c
new file mode 100644
index 000000000000..a0a41ad0f2b5
--- /dev/null
+++ b/drivers/macintosh/windfarm_lm75_sensor.c
@@ -0,0 +1,263 @@
+/*
+ * Windfarm PowerMac thermal control. LM75 sensor
+ *
+ * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ *
+ * Released under the term of the GNU GPL v2.
+ */
+
+#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 <linux/i2c-dev.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/sections.h>
+
+#include "windfarm.h"
+
+#define VERSION "0.1"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(args...)    printk(args)
+#else
+#define DBG(args...)    do { } while(0)
+#endif
+
+struct wf_lm75_sensor {
+        int                     ds1775 : 1;
+        int                     inited : 1;
+        struct  i2c_client      i2c;
+        struct  wf_sensor       sens;
+};
+#define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
+#define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c)
+
+static int wf_lm75_attach(struct i2c_adapter *adapter);
+static int wf_lm75_detach(struct i2c_client *client);
+
+static struct i2c_driver wf_lm75_driver = {
+        .owner          = THIS_MODULE,
+        .name           = "wf_lm75",
+        .flags          = I2C_DF_NOTIFY,
+        .attach_adapter = wf_lm75_attach,
+        .detach_client  = wf_lm75_detach,
+};
+
+static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
+{
+        struct wf_lm75_sensor *lm = wf_to_lm75(sr);
+        s32 data;
+
+        if (lm->i2c.adapter == NULL)
+                return -ENODEV;
+
+        /* Init chip if necessary */
+        if (!lm->inited) {
+                u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1);
+
+                DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
+                    sr->name, cfg);
+
+                /* clear shutdown bit, keep other settings as left by
+                 * the firmware for now
+                 */
+                cfg_new = cfg & ~0x01;
+                i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new);
+                lm->inited = 1;
+
+                /* If we just powered it up, let's wait 200 ms */
+                msleep(200);
+        }
+
+        /* Read temperature register */
+        data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0));
+        data <<= 8;
+        *value = data;
+
+        return 0;
+}
+
+static void wf_lm75_release(struct wf_sensor *sr)
+{
+        struct wf_lm75_sensor *lm = wf_to_lm75(sr);
+
+        /* check if client is registered and detach from i2c */
+        if (lm->i2c.adapter) {
+                i2c_detach_client(&lm->i2c);
+                lm->i2c.adapter = NULL;
+        }
+
+        kfree(lm);
+}
+
+static struct wf_sensor_ops wf_lm75_ops = {
+        .get_value      = wf_lm75_get,
+        .release        = wf_lm75_release,
+        .owner          = THIS_MODULE,
+};
+
+static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter,
+                                             u8 addr, int ds1775,
+                                             const char *loc)
+{
+        struct wf_lm75_sensor *lm;
+
+        DBG("wf_lm75: creating  %s device at address 0x%02x\n",
+            ds1775 ? "ds1775" : "lm75", addr);
+
+        lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
+        if (lm == NULL)
+                return NULL;
+        memset(lm, 0, sizeof(struct wf_lm75_sensor));
+
+        /* Usual rant about sensor names not beeing very consistent in
+         * the device-tree, oh well ...
+         * Add more entries below as you deal with more setups
+         */
+        if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
+                lm->sens.name = "hd-temp";
+        else
+                goto fail;
+
+        lm->inited = 0;
+        lm->sens.ops = &wf_lm75_ops;
+        lm->ds1775 = ds1775;
+        lm->i2c.addr = (addr >> 1) & 0x7f;
+        lm->i2c.adapter = adapter;
+        lm->i2c.driver = &wf_lm75_driver;
+        strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1);
+
+        if (i2c_attach_client(&lm->i2c)) {
+                printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
+                       ds1775 ? "ds1775" : "lm75", lm->i2c.name);
+                goto fail;
+        }
+
+        if (wf_register_sensor(&lm->sens)) {
+                i2c_detach_client(&lm->i2c);
+                goto fail;
+        }
+
+        return lm;
+ fail:
+        kfree(lm);
+        return NULL;
+}
+
+static int wf_lm75_attach(struct i2c_adapter *adapter)
+{
+        u8 bus_id;
+        struct device_node *smu, *bus, *dev;
+
+        /* We currently only deal with LM75's hanging off the SMU
+         * i2c busses. If we extend that driver to other/older
+         * machines, we should split this function into SMU-i2c,
+         * keywest-i2c, PMU-i2c, ...
+         */
+
+        DBG("wf_lm75: adapter %s detected\n", adapter->name);
+
+        if (strncmp(adapter->name, "smu-i2c-", 8) != 0)
+                return 0;
+        smu = of_find_node_by_type(NULL, "smu");
+        if (smu == NULL)
+                return 0;
+
+        /* Look for the bus in the device-tree */
+        bus_id = (u8)simple_strtoul(adapter->name + 8, NULL, 16);
+
+        DBG("wf_lm75: bus ID is %x\n", bus_id);
+
+        /* Look for sensors subdir */
+        for (bus = NULL;
+             (bus = of_get_next_child(smu, bus)) != NULL;) {
+                u32 *reg;
+
+                if (strcmp(bus->name, "i2c"))
+                        continue;
+                reg = (u32 *)get_property(bus, "reg", NULL);
+                if (reg == NULL)
+                        continue;
+                if (bus_id == *reg)
+                        break;
+        }
+        of_node_put(smu);
+        if (bus == NULL) {
+                printk(KERN_WARNING "windfarm: SMU i2c bus 0x%x not found"
+                       " in device-tree !\n", bus_id);
+                return 0;
+        }
+
+        DBG("wf_lm75: bus found, looking for device...\n");
+
+        /* Now look for lm75(s) in there */
+        for (dev = NULL;
+             (dev = of_get_next_child(bus, dev)) != NULL;) {
+                const char *loc =
+                        get_property(dev, "hwsensor-location", NULL);
+                u32 *reg = (u32 *)get_property(dev, "reg", NULL);
+                DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg);
+                if (loc == NULL || reg == NULL)
+                        continue;
+                /* real lm75 */
+                if (device_is_compatible(dev, "lm75"))
+                        wf_lm75_create(adapter, *reg, 0, loc);
+                /* ds1775 (compatible, better resolution */
+                else if (device_is_compatible(dev, "ds1775"))
+                        wf_lm75_create(adapter, *reg, 1, loc);
+        }
+
+        of_node_put(bus);
+
+        return 0;
+}
+
+static int wf_lm75_detach(struct i2c_client *client)
+{
+        struct wf_lm75_sensor *lm = i2c_to_lm75(client);
+
+        DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
+
+        /* Mark client detached */
+        lm->i2c.adapter = NULL;
+
+        /* release sensor */
+        wf_unregister_sensor(&lm->sens);
+
+        return 0;
+}
+
+static int __init wf_lm75_sensor_init(void)
+{
+        int rc;
+
+        rc = i2c_add_driver(&wf_lm75_driver);
+        if (rc < 0)
+                return rc;
+        return 0;
+}
+
+static void __exit wf_lm75_sensor_exit(void)
+{
+        i2c_del_driver(&wf_lm75_driver);
+}
+
+
+module_init(wf_lm75_sensor_init);
+module_exit(wf_lm75_sensor_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
+MODULE_LICENSE("GPL");
+