2 * Windfarm PowerMac thermal control. MAX6690 sensor.
4 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
6 * Use and redistribute under the terms of the GNU GPL v2.
8 #include <linux/types.h>
9 #include <linux/errno.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <linux/i2c.h>
15 #include <asm/pmac_low_i2c.h>
21 /* This currently only exports the external temperature sensor,
22 since that's all the control loops need. */
24 /* Some MAX6690 register numbers */
25 #define MAX6690_INTERNAL_TEMP 0
26 #define MAX6690_EXTERNAL_TEMP 1
28 struct wf_6690_sensor {
29 struct i2c_client *i2c;
30 struct wf_sensor sens;
33 #define wf_to_6690(x) container_of((x), struct wf_6690_sensor, sens)
35 static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
37 struct wf_6690_sensor *max = wf_to_6690(sr);
43 /* chip gets initialized by firmware */
44 data = i2c_smbus_read_byte_data(max->i2c, MAX6690_EXTERNAL_TEMP);
51 static void wf_max6690_release(struct wf_sensor *sr)
53 struct wf_6690_sensor *max = wf_to_6690(sr);
58 static struct wf_sensor_ops wf_max6690_ops = {
59 .get_value = wf_max6690_get,
60 .release = wf_max6690_release,
64 static int wf_max6690_probe(struct i2c_client *client,
65 const struct i2c_device_id *id)
67 const char *name, *loc;
68 struct wf_6690_sensor *max;
71 loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
73 dev_warn(&client->dev, "Missing hwsensor-location property!\n");
78 * We only expose the external temperature register for
79 * now as this is all we need for our control loops
81 if (!strcmp(loc, "BACKSIDE") || !strcmp(loc, "SYS CTRLR AMBIENT"))
82 name = "backside-temp";
83 else if (!strcmp(loc, "NB Ambient"))
84 name = "north-bridge-temp";
85 else if (!strcmp(loc, "GPU Ambient"))
90 max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
92 printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor: "
98 max->sens.name = (char *)name; /* XXX fix constness in structure */
99 max->sens.ops = &wf_max6690_ops;
100 i2c_set_clientdata(client, max);
102 rc = wf_register_sensor(&max->sens);
108 static int wf_max6690_remove(struct i2c_client *client)
110 struct wf_6690_sensor *max = i2c_get_clientdata(client);
113 wf_unregister_sensor(&max->sens);
118 static const struct i2c_device_id wf_max6690_id[] = {
119 { "MAC,max6690", 0 },
122 MODULE_DEVICE_TABLE(i2c, wf_max6690_id);
124 static struct i2c_driver wf_max6690_driver = {
126 .name = "wf_max6690",
128 .probe = wf_max6690_probe,
129 .remove = wf_max6690_remove,
130 .id_table = wf_max6690_id,
133 static int __init wf_max6690_sensor_init(void)
135 return i2c_add_driver(&wf_max6690_driver);
138 static void __exit wf_max6690_sensor_exit(void)
140 i2c_del_driver(&wf_max6690_driver);
143 module_init(wf_max6690_sensor_init);
144 module_exit(wf_max6690_sensor_exit);
146 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
147 MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
148 MODULE_LICENSE("GPL");