windfarm_lm87_sensor.c
3.99 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/*
* Windfarm PowerMac thermal control. LM87 sensor
*
* Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
*
* Released under the term of the GNU GPL v2.
*
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/i2c.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/sections.h>
#include <asm/pmac_low_i2c.h>
#include "windfarm.h"
#define VERSION "1.0"
#undef DEBUG
#ifdef DEBUG
#define DBG(args...) printk(args)
#else
#define DBG(args...) do { } while(0)
#endif
struct wf_lm87_sensor {
struct i2c_client *i2c;
struct wf_sensor sens;
};
#define wf_to_lm87(c) container_of(c, struct wf_lm87_sensor, sens)
static int wf_lm87_read_reg(struct i2c_client *chip, int reg)
{
int rc, tries = 0;
u8 buf;
for (;;) {
/* Set address */
buf = (u8)reg;
rc = i2c_master_send(chip, &buf, 1);
if (rc <= 0)
goto error;
rc = i2c_master_recv(chip, &buf, 1);
if (rc <= 0)
goto error;
return (int)buf;
error:
DBG("wf_lm87: Error reading LM87, retrying...\n");
if (++tries > 10) {
printk(KERN_ERR "wf_lm87: Error reading LM87 !\n");
return -EIO;
}
msleep(10);
}
}
static int wf_lm87_get(struct wf_sensor *sr, s32 *value)
{
struct wf_lm87_sensor *lm = sr->priv;
s32 temp;
if (lm->i2c == NULL)
return -ENODEV;
#define LM87_INT_TEMP 0x27
/* Read temperature register */
temp = wf_lm87_read_reg(lm->i2c, LM87_INT_TEMP);
if (temp < 0)
return temp;
*value = temp << 16;
return 0;
}
static void wf_lm87_release(struct wf_sensor *sr)
{
struct wf_lm87_sensor *lm = wf_to_lm87(sr);
kfree(lm);
}
static struct wf_sensor_ops wf_lm87_ops = {
.get_value = wf_lm87_get,
.release = wf_lm87_release,
.owner = THIS_MODULE,
};
static int wf_lm87_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct wf_lm87_sensor *lm;
const char *name = NULL, *loc;
struct device_node *np = NULL;
int rc;
/*
* The lm87 contains a whole pile of sensors, additionally,
* the Xserve G5 has several lm87's. However, for now we only
* care about the internal temperature sensor
*/
while ((np = of_get_next_child(client->dev.of_node, np)) != NULL) {
if (strcmp(np->name, "int-temp"))
continue;
loc = of_get_property(np, "location", NULL);
if (!loc)
continue;
if (strstr(loc, "DIMM"))
name = "dimms-temp";
else if (strstr(loc, "Processors"))
name = "between-cpus-temp";
if (name) {
of_node_put(np);
break;
}
}
if (!name) {
pr_warning("wf_lm87: Unsupported sensor %s\n",
client->dev.of_node->full_name);
return -ENODEV;
}
lm = kzalloc(sizeof(struct wf_lm87_sensor), GFP_KERNEL);
if (lm == NULL)
return -ENODEV;
lm->i2c = client;
lm->sens.name = name;
lm->sens.ops = &wf_lm87_ops;
lm->sens.priv = lm;
i2c_set_clientdata(client, lm);
rc = wf_register_sensor(&lm->sens);
if (rc)
kfree(lm);
return rc;
}
static int wf_lm87_remove(struct i2c_client *client)
{
struct wf_lm87_sensor *lm = i2c_get_clientdata(client);
DBG("wf_lm87: i2c detatch called for %s\n", lm->sens.name);
/* Mark client detached */
lm->i2c = NULL;
/* release sensor */
wf_unregister_sensor(&lm->sens);
return 0;
}
static const struct i2c_device_id wf_lm87_id[] = {
{ "MAC,lm87cimt", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, wf_lm87_id);
static struct i2c_driver wf_lm87_driver = {
.driver = {
.name = "wf_lm87",
},
.probe = wf_lm87_probe,
.remove = wf_lm87_remove,
.id_table = wf_lm87_id,
};
static int __init wf_lm87_sensor_init(void)
{
/* We only support this on the Xserve */
if (!of_machine_is_compatible("RackMac3,1"))
return -ENODEV;
return i2c_add_driver(&wf_lm87_driver);
}
static void __exit wf_lm87_sensor_exit(void)
{
i2c_del_driver(&wf_lm87_driver);
}
module_init(wf_lm87_sensor_init);
module_exit(wf_lm87_sensor_exit);
MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("LM87 sensor objects for PowerMacs thermal control");
MODULE_LICENSE("GPL");