Commit | Line | Data |
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08fe5bc7 BH |
1 | /* |
2 | * Windfarm PowerMac thermal control. LM87 sensor | |
3 | * | |
4 | * Copyright 2012 Benjamin Herrenschmidt, IBM Corp. | |
5 | * | |
6 | * Released under the term of the GNU GPL v2. | |
7 | * | |
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/sections.h> | |
22 | #include <asm/pmac_low_i2c.h> | |
23 | ||
24 | #include "windfarm.h" | |
25 | ||
26 | #define VERSION "1.0" | |
27 | ||
28 | #undef DEBUG | |
29 | ||
30 | #ifdef DEBUG | |
31 | #define DBG(args...) printk(args) | |
32 | #else | |
33 | #define DBG(args...) do { } while(0) | |
34 | #endif | |
35 | ||
36 | struct wf_lm87_sensor { | |
37 | struct i2c_client *i2c; | |
38 | struct wf_sensor sens; | |
39 | }; | |
40 | #define wf_to_lm87(c) container_of(c, struct wf_lm87_sensor, sens) | |
41 | ||
42 | ||
43 | static int wf_lm87_read_reg(struct i2c_client *chip, int reg) | |
44 | { | |
45 | int rc, tries = 0; | |
46 | u8 buf; | |
47 | ||
48 | for (;;) { | |
49 | /* Set address */ | |
50 | buf = (u8)reg; | |
51 | rc = i2c_master_send(chip, &buf, 1); | |
52 | if (rc <= 0) | |
53 | goto error; | |
54 | rc = i2c_master_recv(chip, &buf, 1); | |
55 | if (rc <= 0) | |
56 | goto error; | |
57 | return (int)buf; | |
58 | error: | |
59 | DBG("wf_lm87: Error reading LM87, retrying...\n"); | |
60 | if (++tries > 10) { | |
61 | printk(KERN_ERR "wf_lm87: Error reading LM87 !\n"); | |
62 | return -EIO; | |
63 | } | |
64 | msleep(10); | |
65 | } | |
66 | } | |
67 | ||
68 | static int wf_lm87_get(struct wf_sensor *sr, s32 *value) | |
69 | { | |
70 | struct wf_lm87_sensor *lm = sr->priv; | |
71 | s32 temp; | |
72 | ||
73 | if (lm->i2c == NULL) | |
74 | return -ENODEV; | |
75 | ||
76 | #define LM87_INT_TEMP 0x27 | |
77 | ||
78 | /* Read temperature register */ | |
79 | temp = wf_lm87_read_reg(lm->i2c, LM87_INT_TEMP); | |
80 | if (temp < 0) | |
81 | return temp; | |
82 | *value = temp << 16; | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
87 | static void wf_lm87_release(struct wf_sensor *sr) | |
88 | { | |
89 | struct wf_lm87_sensor *lm = wf_to_lm87(sr); | |
90 | ||
91 | kfree(lm); | |
92 | } | |
93 | ||
94 | static struct wf_sensor_ops wf_lm87_ops = { | |
95 | .get_value = wf_lm87_get, | |
96 | .release = wf_lm87_release, | |
97 | .owner = THIS_MODULE, | |
98 | }; | |
99 | ||
100 | static int wf_lm87_probe(struct i2c_client *client, | |
101 | const struct i2c_device_id *id) | |
102 | { | |
103 | struct wf_lm87_sensor *lm; | |
104 | const char *name = NULL, *loc; | |
105 | struct device_node *np = NULL; | |
106 | int rc; | |
107 | ||
108 | /* | |
109 | * The lm87 contains a whole pile of sensors, additionally, | |
110 | * the Xserve G5 has several lm87's. However, for now we only | |
111 | * care about the internal temperature sensor | |
112 | */ | |
113 | while ((np = of_get_next_child(client->dev.of_node, np)) != NULL) { | |
114 | if (strcmp(np->name, "int-temp")) | |
115 | continue; | |
116 | loc = of_get_property(np, "location", NULL); | |
117 | if (!loc) | |
118 | continue; | |
119 | if (strstr(loc, "DIMM")) | |
120 | name = "dimms-temp"; | |
121 | else if (strstr(loc, "Processors")) | |
122 | name = "between-cpus-temp"; | |
123 | if (name) { | |
124 | of_node_put(np); | |
125 | break; | |
126 | } | |
127 | } | |
128 | if (!name) { | |
129 | pr_warning("wf_lm87: Unsupported sensor %s\n", | |
130 | client->dev.of_node->full_name); | |
131 | return -ENODEV; | |
132 | } | |
133 | ||
134 | lm = kzalloc(sizeof(struct wf_lm87_sensor), GFP_KERNEL); | |
135 | if (lm == NULL) | |
136 | return -ENODEV; | |
137 | ||
138 | lm->i2c = client; | |
139 | lm->sens.name = name; | |
140 | lm->sens.ops = &wf_lm87_ops; | |
141 | lm->sens.priv = lm; | |
142 | i2c_set_clientdata(client, lm); | |
143 | ||
144 | rc = wf_register_sensor(&lm->sens); | |
145 | if (rc) | |
146 | kfree(lm); | |
147 | return rc; | |
148 | } | |
149 | ||
150 | static int wf_lm87_remove(struct i2c_client *client) | |
151 | { | |
152 | struct wf_lm87_sensor *lm = i2c_get_clientdata(client); | |
153 | ||
154 | DBG("wf_lm87: i2c detatch called for %s\n", lm->sens.name); | |
155 | ||
156 | /* Mark client detached */ | |
157 | lm->i2c = NULL; | |
158 | ||
159 | /* release sensor */ | |
160 | wf_unregister_sensor(&lm->sens); | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | static const struct i2c_device_id wf_lm87_id[] = { | |
166 | { "MAC,lm87cimt", 0 }, | |
167 | { } | |
168 | }; | |
169 | MODULE_DEVICE_TABLE(i2c, wf_lm87_id); | |
170 | ||
171 | static struct i2c_driver wf_lm87_driver = { | |
172 | .driver = { | |
173 | .name = "wf_lm87", | |
174 | }, | |
175 | .probe = wf_lm87_probe, | |
176 | .remove = wf_lm87_remove, | |
177 | .id_table = wf_lm87_id, | |
178 | }; | |
179 | ||
180 | static int __init wf_lm87_sensor_init(void) | |
181 | { | |
182 | /* We only support this on the Xserve */ | |
183 | if (!of_machine_is_compatible("RackMac3,1")) | |
184 | return -ENODEV; | |
185 | ||
186 | return i2c_add_driver(&wf_lm87_driver); | |
187 | } | |
188 | ||
189 | static void __exit wf_lm87_sensor_exit(void) | |
190 | { | |
191 | i2c_del_driver(&wf_lm87_driver); | |
192 | } | |
193 | ||
194 | ||
195 | module_init(wf_lm87_sensor_init); | |
196 | module_exit(wf_lm87_sensor_exit); | |
197 | ||
198 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
199 | MODULE_DESCRIPTION("LM87 sensor objects for PowerMacs thermal control"); | |
200 | MODULE_LICENSE("GPL"); | |
201 |