Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[linux-2.6.git] / drivers / macintosh / windfarm_lm75_sensor.c
1 /*
2  * Windfarm PowerMac thermal control. LM75 sensor
3  *
4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5  *                    <benh@kernel.crashing.org>
6  *
7  * Released under the term of the GNU GPL v2.
8  */
9
10 #include <linux/types.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/wait.h>
17 #include <linux/i2c.h>
18 #include <asm/prom.h>
19 #include <asm/machdep.h>
20 #include <asm/io.h>
21 #include <asm/system.h>
22 #include <asm/sections.h>
23 #include <asm/pmac_low_i2c.h>
24
25 #include "windfarm.h"
26
27 #define VERSION "0.2"
28
29 #undef DEBUG
30
31 #ifdef DEBUG
32 #define DBG(args...)    printk(args)
33 #else
34 #define DBG(args...)    do { } while(0)
35 #endif
36
37 struct wf_lm75_sensor {
38         int                     ds1775 : 1;
39         int                     inited : 1;
40         struct  i2c_client      *i2c;
41         struct  wf_sensor       sens;
42 };
43 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
44
45 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
46 {
47         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
48         s32 data;
49
50         if (lm->i2c == NULL)
51                 return -ENODEV;
52
53         /* Init chip if necessary */
54         if (!lm->inited) {
55                 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
56
57                 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
58                     sr->name, cfg);
59
60                 /* clear shutdown bit, keep other settings as left by
61                  * the firmware for now
62                  */
63                 cfg_new = cfg & ~0x01;
64                 i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
65                 lm->inited = 1;
66
67                 /* If we just powered it up, let's wait 200 ms */
68                 msleep(200);
69         }
70
71         /* Read temperature register */
72         data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
73         data <<= 8;
74         *value = data;
75
76         return 0;
77 }
78
79 static void wf_lm75_release(struct wf_sensor *sr)
80 {
81         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
82
83         kfree(lm);
84 }
85
86 static struct wf_sensor_ops wf_lm75_ops = {
87         .get_value      = wf_lm75_get,
88         .release        = wf_lm75_release,
89         .owner          = THIS_MODULE,
90 };
91
92 static int wf_lm75_probe(struct i2c_client *client,
93                          const struct i2c_device_id *id)
94 {
95         struct wf_lm75_sensor *lm;
96         int rc;
97
98         lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
99         if (lm == NULL)
100                 return -ENODEV;
101
102         lm->inited = 0;
103         lm->ds1775 = id->driver_data;
104         lm->i2c = client;
105         lm->sens.name = client->dev.platform_data;
106         lm->sens.ops = &wf_lm75_ops;
107         i2c_set_clientdata(client, lm);
108
109         rc = wf_register_sensor(&lm->sens);
110         if (rc)
111                 kfree(lm);
112
113         return rc;
114 }
115
116 static struct i2c_driver wf_lm75_driver;
117
118 static struct i2c_client *wf_lm75_create(struct i2c_adapter *adapter,
119                                              u8 addr, int ds1775,
120                                              const char *loc)
121 {
122         struct i2c_board_info info;
123         struct i2c_client *client;
124         char *name;
125
126         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
127             ds1775 ? "ds1775" : "lm75", addr);
128
129         /* Usual rant about sensor names not beeing very consistent in
130          * the device-tree, oh well ...
131          * Add more entries below as you deal with more setups
132          */
133         if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
134                 name = "hd-temp";
135         else if (!strcmp(loc, "Incoming Air Temp"))
136                 name = "incoming-air-temp";
137         else if (!strcmp(loc, "ODD Temp"))
138                 name = "optical-drive-temp";
139         else if (!strcmp(loc, "HD Temp"))
140                 name = "hard-drive-temp";
141         else
142                 goto fail;
143
144         memset(&info, 0, sizeof(struct i2c_board_info));
145         info.addr = (addr >> 1) & 0x7f;
146         info.platform_data = name;
147         strlcpy(info.type, ds1775 ? "wf_ds1775" : "wf_lm75", I2C_NAME_SIZE);
148
149         client = i2c_new_device(adapter, &info);
150         if (client == NULL) {
151                 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
152                        ds1775 ? "ds1775" : "lm75", name);
153                 goto fail;
154         }
155
156         /*
157          * Let i2c-core delete that device on driver removal.
158          * This is safe because i2c-core holds the core_lock mutex for us.
159          */
160         list_add_tail(&client->detected, &wf_lm75_driver.clients);
161         return client;
162  fail:
163         return NULL;
164 }
165
166 static int wf_lm75_attach(struct i2c_adapter *adapter)
167 {
168         struct device_node *busnode, *dev;
169         struct pmac_i2c_bus *bus;
170
171         DBG("wf_lm75: adapter %s detected\n", adapter->name);
172
173         bus = pmac_i2c_adapter_to_bus(adapter);
174         if (bus == NULL)
175                 return -ENODEV;
176         busnode = pmac_i2c_get_bus_node(bus);
177
178         DBG("wf_lm75: bus found, looking for device...\n");
179
180         /* Now look for lm75(s) in there */
181         for (dev = NULL;
182              (dev = of_get_next_child(busnode, dev)) != NULL;) {
183                 const char *loc =
184                         of_get_property(dev, "hwsensor-location", NULL);
185                 u8 addr;
186
187                 /* We must re-match the adapter in order to properly check
188                  * the channel on multibus setups
189                  */
190                 if (!pmac_i2c_match_adapter(dev, adapter))
191                         continue;
192                 addr = pmac_i2c_get_dev_addr(dev);
193                 if (loc == NULL || addr == 0)
194                         continue;
195                 /* real lm75 */
196                 if (of_device_is_compatible(dev, "lm75"))
197                         wf_lm75_create(adapter, addr, 0, loc);
198                 /* ds1775 (compatible, better resolution */
199                 else if (of_device_is_compatible(dev, "ds1775"))
200                         wf_lm75_create(adapter, addr, 1, loc);
201         }
202         return 0;
203 }
204
205 static int wf_lm75_remove(struct i2c_client *client)
206 {
207         struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
208
209         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
210
211         /* Mark client detached */
212         lm->i2c = NULL;
213
214         /* release sensor */
215         wf_unregister_sensor(&lm->sens);
216
217         return 0;
218 }
219
220 static const struct i2c_device_id wf_lm75_id[] = {
221         { "wf_lm75", 0 },
222         { "wf_ds1775", 1 },
223         { }
224 };
225
226 static struct i2c_driver wf_lm75_driver = {
227         .driver = {
228                 .name   = "wf_lm75",
229         },
230         .attach_adapter = wf_lm75_attach,
231         .probe          = wf_lm75_probe,
232         .remove         = wf_lm75_remove,
233         .id_table       = wf_lm75_id,
234 };
235
236 static int __init wf_lm75_sensor_init(void)
237 {
238         /* Don't register on old machines that use therm_pm72 for now */
239         if (of_machine_is_compatible("PowerMac7,2") ||
240             of_machine_is_compatible("PowerMac7,3") ||
241             of_machine_is_compatible("RackMac3,1"))
242                 return -ENODEV;
243         return i2c_add_driver(&wf_lm75_driver);
244 }
245
246 static void __exit wf_lm75_sensor_exit(void)
247 {
248         i2c_del_driver(&wf_lm75_driver);
249 }
250
251
252 module_init(wf_lm75_sensor_init);
253 module_exit(wf_lm75_sensor_exit);
254
255 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
256 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
257 MODULE_LICENSE("GPL");
258