a0a41ad0f2b593b7eadf0320b7c121710e9004b6
[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 <linux/i2c-dev.h>
19 #include <asm/prom.h>
20 #include <asm/machdep.h>
21 #include <asm/io.h>
22 #include <asm/system.h>
23 #include <asm/sections.h>
24
25 #include "windfarm.h"
26
27 #define VERSION "0.1"
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         .owner          = THIS_MODULE,
51         .name           = "wf_lm75",
52         .flags          = I2C_DF_NOTIFY,
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
116         DBG("wf_lm75: creating  %s device at address 0x%02x\n",
117             ds1775 ? "ds1775" : "lm75", addr);
118
119         lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
120         if (lm == NULL)
121                 return NULL;
122         memset(lm, 0, sizeof(struct wf_lm75_sensor));
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         if (i2c_attach_client(&lm->i2c)) {
142                 printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
143                        ds1775 ? "ds1775" : "lm75", lm->i2c.name);
144                 goto fail;
145         }
146
147         if (wf_register_sensor(&lm->sens)) {
148                 i2c_detach_client(&lm->i2c);
149                 goto fail;
150         }
151
152         return lm;
153  fail:
154         kfree(lm);
155         return NULL;
156 }
157
158 static int wf_lm75_attach(struct i2c_adapter *adapter)
159 {
160         u8 bus_id;
161         struct device_node *smu, *bus, *dev;
162
163         /* We currently only deal with LM75's hanging off the SMU
164          * i2c busses. If we extend that driver to other/older
165          * machines, we should split this function into SMU-i2c,
166          * keywest-i2c, PMU-i2c, ...
167          */
168
169         DBG("wf_lm75: adapter %s detected\n", adapter->name);
170
171         if (strncmp(adapter->name, "smu-i2c-", 8) != 0)
172                 return 0;
173         smu = of_find_node_by_type(NULL, "smu");
174         if (smu == NULL)
175                 return 0;
176
177         /* Look for the bus in the device-tree */
178         bus_id = (u8)simple_strtoul(adapter->name + 8, NULL, 16);
179
180         DBG("wf_lm75: bus ID is %x\n", bus_id);
181
182         /* Look for sensors subdir */
183         for (bus = NULL;
184              (bus = of_get_next_child(smu, bus)) != NULL;) {
185                 u32 *reg;
186
187                 if (strcmp(bus->name, "i2c"))
188                         continue;
189                 reg = (u32 *)get_property(bus, "reg", NULL);
190                 if (reg == NULL)
191                         continue;
192                 if (bus_id == *reg)
193                         break;
194         }
195         of_node_put(smu);
196         if (bus == NULL) {
197                 printk(KERN_WARNING "windfarm: SMU i2c bus 0x%x not found"
198                        " in device-tree !\n", bus_id);
199                 return 0;
200         }
201
202         DBG("wf_lm75: bus found, looking for device...\n");
203
204         /* Now look for lm75(s) in there */
205         for (dev = NULL;
206              (dev = of_get_next_child(bus, dev)) != NULL;) {
207                 const char *loc =
208                         get_property(dev, "hwsensor-location", NULL);
209                 u32 *reg = (u32 *)get_property(dev, "reg", NULL);
210                 DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg);
211                 if (loc == NULL || reg == NULL)
212                         continue;
213                 /* real lm75 */
214                 if (device_is_compatible(dev, "lm75"))
215                         wf_lm75_create(adapter, *reg, 0, loc);
216                 /* ds1775 (compatible, better resolution */
217                 else if (device_is_compatible(dev, "ds1775"))
218                         wf_lm75_create(adapter, *reg, 1, loc);
219         }
220
221         of_node_put(bus);
222
223         return 0;
224 }
225
226 static int wf_lm75_detach(struct i2c_client *client)
227 {
228         struct wf_lm75_sensor *lm = i2c_to_lm75(client);
229
230         DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
231
232         /* Mark client detached */
233         lm->i2c.adapter = NULL;
234
235         /* release sensor */
236         wf_unregister_sensor(&lm->sens);
237
238         return 0;
239 }
240
241 static int __init wf_lm75_sensor_init(void)
242 {
243         int rc;
244
245         rc = i2c_add_driver(&wf_lm75_driver);
246         if (rc < 0)
247                 return rc;
248         return 0;
249 }
250
251 static void __exit wf_lm75_sensor_exit(void)
252 {
253         i2c_del_driver(&wf_lm75_driver);
254 }
255
256
257 module_init(wf_lm75_sensor_init);
258 module_exit(wf_lm75_sensor_exit);
259
260 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
261 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
262 MODULE_LICENSE("GPL");
263