[PATCH] macintosh: cleanup the use of i2c headers
[linux-2.6.git] / drivers / macintosh / windfarm_max6690_sensor.c
1 /*
2  * Windfarm PowerMac thermal control.  MAX6690 sensor.
3  *
4  * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
5  *
6  * Use and redistribute under the terms of the GNU GPL v2.
7  */
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 <asm/prom.h>
15 #include <asm/pmac_low_i2c.h>
16
17 #include "windfarm.h"
18
19 #define VERSION "0.2"
20
21 /* This currently only exports the external temperature sensor,
22    since that's all the control loops need. */
23
24 /* Some MAX6690 register numbers */
25 #define MAX6690_INTERNAL_TEMP   0
26 #define MAX6690_EXTERNAL_TEMP   1
27
28 struct wf_6690_sensor {
29         struct i2c_client       i2c;
30         struct wf_sensor        sens;
31 };
32
33 #define wf_to_6690(x)   container_of((x), struct wf_6690_sensor, sens)
34 #define i2c_to_6690(x)  container_of((x), struct wf_6690_sensor, i2c)
35
36 static int wf_max6690_attach(struct i2c_adapter *adapter);
37 static int wf_max6690_detach(struct i2c_client *client);
38
39 static struct i2c_driver wf_max6690_driver = {
40         .driver = {
41                 .name           = "wf_max6690",
42         },
43         .attach_adapter = wf_max6690_attach,
44         .detach_client  = wf_max6690_detach,
45 };
46
47 static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
48 {
49         struct wf_6690_sensor *max = wf_to_6690(sr);
50         s32 data;
51
52         if (max->i2c.adapter == NULL)
53                 return -ENODEV;
54
55         /* chip gets initialized by firmware */
56         data = i2c_smbus_read_byte_data(&max->i2c, MAX6690_EXTERNAL_TEMP);
57         if (data < 0)
58                 return data;
59         *value = data << 16;
60         return 0;
61 }
62
63 static void wf_max6690_release(struct wf_sensor *sr)
64 {
65         struct wf_6690_sensor *max = wf_to_6690(sr);
66
67         if (max->i2c.adapter) {
68                 i2c_detach_client(&max->i2c);
69                 max->i2c.adapter = NULL;
70         }
71         kfree(max);
72 }
73
74 static struct wf_sensor_ops wf_max6690_ops = {
75         .get_value      = wf_max6690_get,
76         .release        = wf_max6690_release,
77         .owner          = THIS_MODULE,
78 };
79
80 static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr)
81 {
82         struct wf_6690_sensor *max;
83         char *name = "backside-temp";
84
85         max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
86         if (max == NULL) {
87                 printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: "
88                        "no memory\n", name);
89                 return;
90         }
91
92         max->sens.ops = &wf_max6690_ops;
93         max->sens.name = name;
94         max->i2c.addr = addr >> 1;
95         max->i2c.adapter = adapter;
96         max->i2c.driver = &wf_max6690_driver;
97         strncpy(max->i2c.name, name, I2C_NAME_SIZE-1);
98
99         if (i2c_attach_client(&max->i2c)) {
100                 printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
101                 goto fail;
102         }
103
104         if (wf_register_sensor(&max->sens)) {
105                 i2c_detach_client(&max->i2c);
106                 goto fail;
107         }
108
109         return;
110
111  fail:
112         kfree(max);
113 }
114
115 static int wf_max6690_attach(struct i2c_adapter *adapter)
116 {
117         struct device_node *busnode, *dev = NULL;
118         struct pmac_i2c_bus *bus;
119         const char *loc;
120
121         bus = pmac_i2c_adapter_to_bus(adapter);
122         if (bus == NULL)
123                 return -ENODEV;
124         busnode = pmac_i2c_get_bus_node(bus);
125
126         while ((dev = of_get_next_child(busnode, dev)) != NULL) {
127                 u8 addr;
128
129                 /* We must re-match the adapter in order to properly check
130                  * the channel on multibus setups
131                  */
132                 if (!pmac_i2c_match_adapter(dev, adapter))
133                         continue;
134                 if (!device_is_compatible(dev, "max6690"))
135                         continue;
136                 addr = pmac_i2c_get_dev_addr(dev);
137                 loc = get_property(dev, "hwsensor-location", NULL);
138                 if (loc == NULL || addr == 0)
139                         continue;
140                 printk("found max6690, loc=%s addr=0x%02x\n", loc, addr);
141                 if (strcmp(loc, "BACKSIDE"))
142                         continue;
143                 wf_max6690_create(adapter, addr);
144         }
145
146         return 0;
147 }
148
149 static int wf_max6690_detach(struct i2c_client *client)
150 {
151         struct wf_6690_sensor *max = i2c_to_6690(client);
152
153         max->i2c.adapter = NULL;
154         wf_unregister_sensor(&max->sens);
155
156         return 0;
157 }
158
159 static int __init wf_max6690_sensor_init(void)
160 {
161         /* Don't register on old machines that use therm_pm72 for now */
162         if (machine_is_compatible("PowerMac7,2") ||
163             machine_is_compatible("PowerMac7,3") ||
164             machine_is_compatible("RackMac3,1"))
165                 return -ENODEV;
166         return i2c_add_driver(&wf_max6690_driver);
167 }
168
169 static void __exit wf_max6690_sensor_exit(void)
170 {
171         i2c_del_driver(&wf_max6690_driver);
172 }
173
174 module_init(wf_max6690_sensor_init);
175 module_exit(wf_max6690_sensor_exit);
176
177 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
178 MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
179 MODULE_LICENSE("GPL");