[PATCH] powerpc: Thermal control for dual core G5s

This patch adds a windfarm module, windfarm_pm112, for the dual core G5s
(both 2 and 4 core models), keeping the machine from getting into
vacuum-cleaner mode ;) For proper credits, the patch was initially
written by Paul Mackerras, and slightly reworked by me to add overtemp
handling among others. The patch also removes the sysfs attributes from
windfarm_pm81 and windfarm_pm91 and instead adds code to the windfarm
core to automagically expose attributes for sensor & controls.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 169 insertions, 0 deletions

diff --git a/drivers/macintosh/windfarm_max6690_sensor.c b/drivers/macintosh/windfarm_max6690_sensor.c
new file mode 100644
index 000000000000..5b9ad6ca7cba
--- /dev/null
+++ b/drivers/macintosh/windfarm_max6690_sensor.c
@@ -0,0 +1,169 @@
+/*
+ * Windfarm PowerMac thermal control.  MAX6690 sensor.
+ *
+ * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
+ *
+ * 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/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/i2c-dev.h>
+#include <asm/prom.h>
+#include <asm/pmac_low_i2c.h>
+
+#include "windfarm.h"
+
+#define VERSION "0.1"
+
+/* This currently only exports the external temperature sensor,
+   since that's all the control loops need. */
+
+/* Some MAX6690 register numbers */
+#define MAX6690_INTERNAL_TEMP   0
+#define MAX6690_EXTERNAL_TEMP   1
+
+struct wf_6690_sensor {
+        struct i2c_client       i2c;
+        struct wf_sensor        sens;
+};
+
+#define wf_to_6690(x)   container_of((x), struct wf_6690_sensor, sens)
+#define i2c_to_6690(x)  container_of((x), struct wf_6690_sensor, i2c)
+
+static int wf_max6690_attach(struct i2c_adapter *adapter);
+static int wf_max6690_detach(struct i2c_client *client);
+
+static struct i2c_driver wf_max6690_driver = {
+        .driver = {
+                .name           = "wf_max6690",
+        },
+        .attach_adapter = wf_max6690_attach,
+        .detach_client  = wf_max6690_detach,
+};
+
+static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
+{
+        struct wf_6690_sensor *max = wf_to_6690(sr);
+        s32 data;
+
+        if (max->i2c.adapter == NULL)
+                return -ENODEV;
+
+        /* chip gets initialized by firmware */
+        data = i2c_smbus_read_byte_data(&max->i2c, MAX6690_EXTERNAL_TEMP);
+        if (data < 0)
+                return data;
+        *value = data << 16;
+        return 0;
+}
+
+static void wf_max6690_release(struct wf_sensor *sr)
+{
+        struct wf_6690_sensor *max = wf_to_6690(sr);
+
+        if (max->i2c.adapter) {
+                i2c_detach_client(&max->i2c);
+                max->i2c.adapter = NULL;
+        }
+        kfree(max);
+}
+
+static struct wf_sensor_ops wf_max6690_ops = {
+        .get_value      = wf_max6690_get,
+        .release        = wf_max6690_release,
+        .owner          = THIS_MODULE,
+};
+
+static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr)
+{
+        struct wf_6690_sensor *max;
+        char *name = "u4-temp";
+
+        max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
+        if (max == NULL) {
+                printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: "
+                       "no memory\n", name);
+                return;
+        }
+
+        max->sens.ops = &wf_max6690_ops;
+        max->sens.name = name;
+        max->i2c.addr = addr >> 1;
+        max->i2c.adapter = adapter;
+        max->i2c.driver = &wf_max6690_driver;
+        strncpy(max->i2c.name, name, I2C_NAME_SIZE-1);
+
+        if (i2c_attach_client(&max->i2c)) {
+                printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
+                goto fail;
+        }
+
+        if (wf_register_sensor(&max->sens)) {
+                i2c_detach_client(&max->i2c);
+                goto fail;
+        }
+
+        return;
+
+ fail:
+        kfree(max);
+}
+
+static int wf_max6690_attach(struct i2c_adapter *adapter)
+{
+        struct device_node *busnode, *dev = NULL;
+        struct pmac_i2c_bus *bus;
+        const char *loc;
+        u32 *reg;
+
+        bus = pmac_i2c_adapter_to_bus(adapter);
+        if (bus == NULL)
+                return -ENODEV;
+        busnode = pmac_i2c_get_bus_node(bus);
+
+        while ((dev = of_get_next_child(busnode, dev)) != NULL) {
+                if (!device_is_compatible(dev, "max6690"))
+                        continue;
+                loc = get_property(dev, "hwsensor-location", NULL);
+                reg = (u32 *) get_property(dev, "reg", NULL);
+                if (!loc || !reg)
+                        continue;
+                printk("found max6690, loc=%s reg=%x\n", loc, *reg);
+                if (strcmp(loc, "BACKSIDE"))
+                        continue;
+                wf_max6690_create(adapter, *reg);
+        }
+
+        return 0;
+}
+
+static int wf_max6690_detach(struct i2c_client *client)
+{
+        struct wf_6690_sensor *max = i2c_to_6690(client);
+
+        max->i2c.adapter = NULL;
+        wf_unregister_sensor(&max->sens);
+
+        return 0;
+}
+
+static int __init wf_max6690_sensor_init(void)
+{
+        return i2c_add_driver(&wf_max6690_driver);
+}
+
+static void __exit wf_max6690_sensor_exit(void)
+{
+        i2c_del_driver(&wf_max6690_driver);
+}
+
+module_init(wf_max6690_sensor_init);
+module_exit(wf_max6690_sensor_exit);
+
+MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
+MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
+MODULE_LICENSE("GPL");