Merge branches 'release' and 'doc' into release
[linux-2.6] / 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 #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c)
45
46 static int wf_lm75_attach(struct i2c_adapter *adapter);
47 static int wf_lm75_detach(struct i2c_client *client);
48
49 static struct i2c_driver wf_lm75_driver = {
50         .driver = {
51                 .name   = "wf_lm75",
52         },
53         .attach_adapter = wf_lm75_attach,
54         .detach_client  = wf_lm75_detach,
55 };
56
57 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
58 {
59         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
60         s32 data;
61
62         if (lm->i2c.adapter == NULL)
63                 return -ENODEV;
64
65         /* Init chip if necessary */
66         if (!lm->inited) {
67                 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1);
68
69                 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
70                     sr->name, cfg);
71
72                 /* clear shutdown bit, keep other settings as left by
73                  * the firmware for now
74                  */
75                 cfg_new = cfg & ~0x01;
76                 i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new);
77                 lm->inited = 1;
78
79                 /* If we just powered it up, let's wait 200 ms */
80                 msleep(200);
81         }
82
83         /* Read temperature register */
84         data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0));
85         data <<= 8;
86         *value = data;
87
88         return 0;
89 }
90
91 static void wf_lm75_release(struct wf_sensor *sr)
92 {
93         struct wf_lm75_sensor *lm = wf_to_lm75(sr);
94
95         /* check if client is registered and detach from i2c */
96         if (lm->i2c.adapter) {
97                 i2c_detach_client(&lm->i2c);
98                 lm->i2c.adapter = NULL;
99         }
100
101         kfree(lm);
102 }
103
104 static struct wf_sensor_ops wf_lm75_ops = {
105         .get_value      = wf_lm75_get,
106         .release        = wf_lm75_release,
107         .owner          = THIS_MODULE,
108 };
109
110 static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter,
111                                              u8 addr, int ds1775,
112                                              const char *loc)
113 {
114         struct wf_lm75_sensor *lm;
115         int rc;
116
117         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
118             ds1775 ? "ds1775" : "lm75", addr);
119
120         lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
121         if (lm == NULL)
122                 return NULL;
123
124         /* Usual rant about sensor names not beeing very consistent in
125          * the device-tree, oh well ...
126          * Add more entries below as you deal with more setups
127          */
128         if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
129                 lm->sens.name = "hd-temp";
130         else
131                 goto fail;
132
133         lm->inited = 0;
134         lm->sens.ops = &wf_lm75_ops;
135         lm->ds1775 = ds1775;
136         lm->i2c.addr = (addr >> 1) & 0x7f;
137         lm->i2c.adapter = adapter;
138         lm->i2c.driver = &wf_lm75_driver;
139         strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1);
140
141         rc = i2c_attach_client(&lm->i2c);
142         if (rc) {
143                 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c,"
144                        " err %d\n", ds1775 ? "ds1775" : "lm75",
145                        lm->i2c.name, rc);
146                 goto fail;
147         }
148
149         if (wf_register_sensor(&lm->sens)) {
150                 i2c_detach_client(&lm->i2c);
151                 goto fail;
152         }
153
154         return lm;
155  fail:
156         kfree(lm);
157         return NULL;
158 }
159
160 static int wf_lm75_attach(struct i2c_adapter *adapter)
161 {
162         struct device_node *busnode, *dev;
163         struct pmac_i2c_bus *bus;
164
165         DBG("wf_lm75: adapter %s detected\n", adapter->name);
166
167         bus = pmac_i2c_adapter_to_bus(adapter);
168         if (bus == NULL)
169                 return -ENODEV;
170         busnode = pmac_i2c_get_bus_node(bus);
171
172         DBG("wf_lm75: bus found, looking for device...\n");
173
174         /* Now look for lm75(s) in there */
175         for (dev = NULL;
176              (dev = of_get_next_child(busnode, dev)) != NULL;) {
177                 const char *loc =
178                         of_get_property(dev, "hwsensor-location", NULL);
179                 u8 addr;
180
181                 /* We must re-match the adapter in order to properly check
182                  * the channel on multibus setups
183                  */
184                 if (!pmac_i2c_match_adapter(dev, adapter))
185                         continue;
186                 addr = pmac_i2c_get_dev_addr(dev);
187                 if (loc == NULL || addr == 0)
188                         continue;
189                 /* real lm75 */
190                 if (of_device_is_compatible(dev, "lm75"))
191                         wf_lm75_create(adapter, addr, 0, loc);
192                 /* ds1775 (compatible, better resolution */
193                 else if (of_device_is_compatible(dev, "ds1775"))
194                         wf_lm75_create(adapter, addr, 1, loc);
195         }
196         return 0;
197 }
198
199 static int wf_lm75_detach(struct i2c_client *client)
200 {
201         struct wf_lm75_sensor *lm = i2c_to_lm75(client);
202
203         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
204
205         /* Mark client detached */
206         lm->i2c.adapter = NULL;
207
208         /* release sensor */
209         wf_unregister_sensor(&lm->sens);
210
211         return 0;
212 }
213
214 static int __init wf_lm75_sensor_init(void)
215 {
216         /* Don't register on old machines that use therm_pm72 for now */
217         if (machine_is_compatible("PowerMac7,2") ||
218             machine_is_compatible("PowerMac7,3") ||
219             machine_is_compatible("RackMac3,1"))
220                 return -ENODEV;
221         return i2c_add_driver(&wf_lm75_driver);
222 }
223
224 static void __exit wf_lm75_sensor_exit(void)
225 {
226         i2c_del_driver(&wf_lm75_driver);
227 }
228
229
230 module_init(wf_lm75_sensor_init);
231 module_exit(wf_lm75_sensor_exit);
232
233 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
234 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
235 MODULE_LICENSE("GPL");
236