Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[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
35 static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
36 {
37         struct wf_6690_sensor *max = wf_to_6690(sr);
38         s32 data;
39
40         if (max->i2c == NULL)
41                 return -ENODEV;
42
43         /* chip gets initialized by firmware */
44         data = i2c_smbus_read_byte_data(max->i2c, MAX6690_EXTERNAL_TEMP);
45         if (data < 0)
46                 return data;
47         *value = data << 16;
48         return 0;
49 }
50
51 static void wf_max6690_release(struct wf_sensor *sr)
52 {
53         struct wf_6690_sensor *max = wf_to_6690(sr);
54
55         kfree(max);
56 }
57
58 static struct wf_sensor_ops wf_max6690_ops = {
59         .get_value      = wf_max6690_get,
60         .release        = wf_max6690_release,
61         .owner          = THIS_MODULE,
62 };
63
64 static int wf_max6690_probe(struct i2c_client *client,
65                             const struct i2c_device_id *id)
66 {
67         struct wf_6690_sensor *max;
68         int rc;
69
70         max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
71         if (max == NULL) {
72                 printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor: "
73                        "no memory\n");
74                 return -ENOMEM;
75         }
76
77         max->i2c = client;
78         max->sens.name = client->dev.platform_data;
79         max->sens.ops = &wf_max6690_ops;
80         i2c_set_clientdata(client, max);
81
82         rc = wf_register_sensor(&max->sens);
83         if (rc) {
84                 kfree(max);
85         }
86
87         return rc;
88 }
89
90 static struct i2c_driver wf_max6690_driver;
91
92 static struct i2c_client *wf_max6690_create(struct i2c_adapter *adapter,
93                                             u8 addr, const char *loc)
94 {
95         struct i2c_board_info info;
96         struct i2c_client *client;
97         char *name;
98
99         if (!strcmp(loc, "BACKSIDE"))
100                 name = "backside-temp";
101         else if (!strcmp(loc, "NB Ambient"))
102                 name = "north-bridge-temp";
103         else if (!strcmp(loc, "GPU Ambient"))
104                 name = "gpu-temp";
105         else
106                 goto fail;
107
108         memset(&info, 0, sizeof(struct i2c_board_info));
109         info.addr = addr >> 1;
110         info.platform_data = name;
111         strlcpy(info.type, "wf_max6690", I2C_NAME_SIZE);
112
113         client = i2c_new_device(adapter, &info);
114         if (client == NULL) {
115                 printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
116                 goto fail;
117         }
118
119         /*
120          * Let i2c-core delete that device on driver removal.
121          * This is safe because i2c-core holds the core_lock mutex for us.
122          */
123         list_add_tail(&client->detected, &wf_max6690_driver.clients);
124         return client;
125
126  fail:
127         return NULL;
128 }
129
130 static int wf_max6690_attach(struct i2c_adapter *adapter)
131 {
132         struct device_node *busnode, *dev = NULL;
133         struct pmac_i2c_bus *bus;
134         const char *loc;
135
136         bus = pmac_i2c_adapter_to_bus(adapter);
137         if (bus == NULL)
138                 return -ENODEV;
139         busnode = pmac_i2c_get_bus_node(bus);
140
141         while ((dev = of_get_next_child(busnode, dev)) != NULL) {
142                 u8 addr;
143
144                 /* We must re-match the adapter in order to properly check
145                  * the channel on multibus setups
146                  */
147                 if (!pmac_i2c_match_adapter(dev, adapter))
148                         continue;
149                 if (!of_device_is_compatible(dev, "max6690"))
150                         continue;
151                 addr = pmac_i2c_get_dev_addr(dev);
152                 loc = of_get_property(dev, "hwsensor-location", NULL);
153                 if (loc == NULL || addr == 0)
154                         continue;
155                 printk("found max6690, loc=%s addr=0x%02x\n", loc, addr);
156                 wf_max6690_create(adapter, addr, loc);
157         }
158
159         return 0;
160 }
161
162 static int wf_max6690_remove(struct i2c_client *client)
163 {
164         struct wf_6690_sensor *max = i2c_get_clientdata(client);
165
166         max->i2c = NULL;
167         wf_unregister_sensor(&max->sens);
168
169         return 0;
170 }
171
172 static const struct i2c_device_id wf_max6690_id[] = {
173         { "wf_max6690", 0 },
174         { }
175 };
176
177 static struct i2c_driver wf_max6690_driver = {
178         .driver = {
179                 .name           = "wf_max6690",
180         },
181         .attach_adapter = wf_max6690_attach,
182         .probe          = wf_max6690_probe,
183         .remove         = wf_max6690_remove,
184         .id_table       = wf_max6690_id,
185 };
186
187 static int __init wf_max6690_sensor_init(void)
188 {
189         /* Don't register on old machines that use therm_pm72 for now */
190         if (of_machine_is_compatible("PowerMac7,2") ||
191             of_machine_is_compatible("PowerMac7,3") ||
192             of_machine_is_compatible("RackMac3,1"))
193                 return -ENODEV;
194         return i2c_add_driver(&wf_max6690_driver);
195 }
196
197 static void __exit wf_max6690_sensor_exit(void)
198 {
199         i2c_del_driver(&wf_max6690_driver);
200 }
201
202 module_init(wf_max6690_sensor_init);
203 module_exit(wf_max6690_sensor_exit);
204
205 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
206 MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
207 MODULE_LICENSE("GPL");