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>
14 #include <linux/i2c-dev.h>
16 #include <asm/pmac_low_i2c.h>
22 /* This currently only exports the external temperature sensor,
23 since that's all the control loops need. */
25 /* Some MAX6690 register numbers */
26 #define MAX6690_INTERNAL_TEMP 0
27 #define MAX6690_EXTERNAL_TEMP 1
29 struct wf_6690_sensor {
30 struct i2c_client i2c;
31 struct wf_sensor sens;
34 #define wf_to_6690(x) container_of((x), struct wf_6690_sensor, sens)
35 #define i2c_to_6690(x) container_of((x), struct wf_6690_sensor, i2c)
37 static int wf_max6690_attach(struct i2c_adapter *adapter);
38 static int wf_max6690_detach(struct i2c_client *client);
40 static struct i2c_driver wf_max6690_driver = {
44 .attach_adapter = wf_max6690_attach,
45 .detach_client = wf_max6690_detach,
48 static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
50 struct wf_6690_sensor *max = wf_to_6690(sr);
53 if (max->i2c.adapter == NULL)
56 /* chip gets initialized by firmware */
57 data = i2c_smbus_read_byte_data(&max->i2c, MAX6690_EXTERNAL_TEMP);
64 static void wf_max6690_release(struct wf_sensor *sr)
66 struct wf_6690_sensor *max = wf_to_6690(sr);
68 if (max->i2c.adapter) {
69 i2c_detach_client(&max->i2c);
70 max->i2c.adapter = NULL;
75 static struct wf_sensor_ops wf_max6690_ops = {
76 .get_value = wf_max6690_get,
77 .release = wf_max6690_release,
81 static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr)
83 struct wf_6690_sensor *max;
84 char *name = "u4-temp";
86 max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
88 printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: "
93 max->sens.ops = &wf_max6690_ops;
94 max->sens.name = name;
95 max->i2c.addr = addr >> 1;
96 max->i2c.adapter = adapter;
97 max->i2c.driver = &wf_max6690_driver;
98 strncpy(max->i2c.name, name, I2C_NAME_SIZE-1);
100 if (i2c_attach_client(&max->i2c)) {
101 printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
105 if (wf_register_sensor(&max->sens)) {
106 i2c_detach_client(&max->i2c);
116 static int wf_max6690_attach(struct i2c_adapter *adapter)
118 struct device_node *busnode, *dev = NULL;
119 struct pmac_i2c_bus *bus;
123 bus = pmac_i2c_adapter_to_bus(adapter);
126 busnode = pmac_i2c_get_bus_node(bus);
128 while ((dev = of_get_next_child(busnode, dev)) != NULL) {
129 if (!device_is_compatible(dev, "max6690"))
131 loc = get_property(dev, "hwsensor-location", NULL);
132 reg = (u32 *) get_property(dev, "reg", NULL);
135 printk("found max6690, loc=%s reg=%x\n", loc, *reg);
136 if (strcmp(loc, "BACKSIDE"))
138 wf_max6690_create(adapter, *reg);
144 static int wf_max6690_detach(struct i2c_client *client)
146 struct wf_6690_sensor *max = i2c_to_6690(client);
148 max->i2c.adapter = NULL;
149 wf_unregister_sensor(&max->sens);
154 static int __init wf_max6690_sensor_init(void)
156 return i2c_add_driver(&wf_max6690_driver);
159 static void __exit wf_max6690_sensor_exit(void)
161 i2c_del_driver(&wf_max6690_driver);
164 module_init(wf_max6690_sensor_init);
165 module_exit(wf_max6690_sensor_exit);
167 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
168 MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
169 MODULE_LICENSE("GPL");