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path: root/drivers/macintosh/windfarm_max6690_sensor.c
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Diffstat (limited to 'drivers/macintosh/windfarm_max6690_sensor.c')
-rw-r--r--drivers/macintosh/windfarm_max6690_sensor.c169
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");