blob: a0a41ad0f2b593b7eadf0320b7c121710e9004b6 [file] [log] [blame]
Benjamin Herrenschmidt75722d32005-11-07 16:08:17 +11001/*
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
37struct 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
46static int wf_lm75_attach(struct i2c_adapter *adapter);
47static int wf_lm75_detach(struct i2c_client *client);
48
49static 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
57static 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
91static 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
104static struct wf_sensor_ops wf_lm75_ops = {
105 .get_value = wf_lm75_get,
106 .release = wf_lm75_release,
107 .owner = THIS_MODULE,
108};
109
110static 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
158static 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
226static 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
241static 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
251static void __exit wf_lm75_sensor_exit(void)
252{
253 i2c_del_driver(&wf_lm75_driver);
254}
255
256
257module_init(wf_lm75_sensor_init);
258module_exit(wf_lm75_sensor_exit);
259
260MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
261MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
262MODULE_LICENSE("GPL");
263