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2c162f9b | 1 | // SPDX-License-Identifier: GPL-2.0-only |
08fe5bc7 BH |
2 | /* |
3 | * Windfarm PowerMac thermal control. LM87 sensor | |
4 | * | |
5 | * Copyright 2012 Benjamin Herrenschmidt, IBM Corp. | |
08fe5bc7 BH |
6 | */ |
7 | ||
8 | #include <linux/types.h> | |
9 | #include <linux/errno.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/delay.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/i2c.h> | |
a486e512 | 16 | |
08fe5bc7 BH |
17 | #include <asm/machdep.h> |
18 | #include <asm/io.h> | |
19 | #include <asm/sections.h> | |
20 | #include <asm/pmac_low_i2c.h> | |
21 | ||
22 | #include "windfarm.h" | |
23 | ||
24 | #define VERSION "1.0" | |
25 | ||
26 | #undef DEBUG | |
27 | ||
28 | #ifdef DEBUG | |
29 | #define DBG(args...) printk(args) | |
30 | #else | |
31 | #define DBG(args...) do { } while(0) | |
32 | #endif | |
33 | ||
34 | struct wf_lm87_sensor { | |
35 | struct i2c_client *i2c; | |
36 | struct wf_sensor sens; | |
37 | }; | |
38 | #define wf_to_lm87(c) container_of(c, struct wf_lm87_sensor, sens) | |
39 | ||
40 | ||
41 | static int wf_lm87_read_reg(struct i2c_client *chip, int reg) | |
42 | { | |
43 | int rc, tries = 0; | |
44 | u8 buf; | |
45 | ||
46 | for (;;) { | |
47 | /* Set address */ | |
48 | buf = (u8)reg; | |
49 | rc = i2c_master_send(chip, &buf, 1); | |
50 | if (rc <= 0) | |
51 | goto error; | |
52 | rc = i2c_master_recv(chip, &buf, 1); | |
53 | if (rc <= 0) | |
54 | goto error; | |
55 | return (int)buf; | |
56 | error: | |
57 | DBG("wf_lm87: Error reading LM87, retrying...\n"); | |
58 | if (++tries > 10) { | |
59 | printk(KERN_ERR "wf_lm87: Error reading LM87 !\n"); | |
60 | return -EIO; | |
61 | } | |
62 | msleep(10); | |
63 | } | |
64 | } | |
65 | ||
66 | static int wf_lm87_get(struct wf_sensor *sr, s32 *value) | |
67 | { | |
68 | struct wf_lm87_sensor *lm = sr->priv; | |
69 | s32 temp; | |
70 | ||
71 | if (lm->i2c == NULL) | |
72 | return -ENODEV; | |
73 | ||
74 | #define LM87_INT_TEMP 0x27 | |
75 | ||
76 | /* Read temperature register */ | |
77 | temp = wf_lm87_read_reg(lm->i2c, LM87_INT_TEMP); | |
78 | if (temp < 0) | |
79 | return temp; | |
80 | *value = temp << 16; | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | static void wf_lm87_release(struct wf_sensor *sr) | |
86 | { | |
87 | struct wf_lm87_sensor *lm = wf_to_lm87(sr); | |
88 | ||
89 | kfree(lm); | |
90 | } | |
91 | ||
de854e54 | 92 | static const struct wf_sensor_ops wf_lm87_ops = { |
08fe5bc7 BH |
93 | .get_value = wf_lm87_get, |
94 | .release = wf_lm87_release, | |
95 | .owner = THIS_MODULE, | |
96 | }; | |
97 | ||
0e2211b3 | 98 | static int wf_lm87_probe(struct i2c_client *client) |
08fe5bc7 BH |
99 | { |
100 | struct wf_lm87_sensor *lm; | |
101 | const char *name = NULL, *loc; | |
102 | struct device_node *np = NULL; | |
103 | int rc; | |
104 | ||
105 | /* | |
106 | * The lm87 contains a whole pile of sensors, additionally, | |
107 | * the Xserve G5 has several lm87's. However, for now we only | |
108 | * care about the internal temperature sensor | |
109 | */ | |
f1e0addc RH |
110 | for_each_child_of_node(client->dev.of_node, np) { |
111 | if (!of_node_name_eq(np, "int-temp")) | |
08fe5bc7 BH |
112 | continue; |
113 | loc = of_get_property(np, "location", NULL); | |
114 | if (!loc) | |
115 | continue; | |
116 | if (strstr(loc, "DIMM")) | |
117 | name = "dimms-temp"; | |
118 | else if (strstr(loc, "Processors")) | |
119 | name = "between-cpus-temp"; | |
120 | if (name) { | |
121 | of_node_put(np); | |
122 | break; | |
123 | } | |
124 | } | |
125 | if (!name) { | |
2ee9a0db KW |
126 | pr_warn("wf_lm87: Unsupported sensor %pOF\n", |
127 | client->dev.of_node); | |
08fe5bc7 BH |
128 | return -ENODEV; |
129 | } | |
130 | ||
131 | lm = kzalloc(sizeof(struct wf_lm87_sensor), GFP_KERNEL); | |
132 | if (lm == NULL) | |
133 | return -ENODEV; | |
134 | ||
135 | lm->i2c = client; | |
136 | lm->sens.name = name; | |
137 | lm->sens.ops = &wf_lm87_ops; | |
138 | lm->sens.priv = lm; | |
139 | i2c_set_clientdata(client, lm); | |
140 | ||
141 | rc = wf_register_sensor(&lm->sens); | |
142 | if (rc) | |
143 | kfree(lm); | |
144 | return rc; | |
145 | } | |
146 | ||
ed5c2f5f | 147 | static void wf_lm87_remove(struct i2c_client *client) |
08fe5bc7 BH |
148 | { |
149 | struct wf_lm87_sensor *lm = i2c_get_clientdata(client); | |
150 | ||
08fe5bc7 BH |
151 | /* Mark client detached */ |
152 | lm->i2c = NULL; | |
153 | ||
154 | /* release sensor */ | |
155 | wf_unregister_sensor(&lm->sens); | |
08fe5bc7 BH |
156 | } |
157 | ||
158 | static const struct i2c_device_id wf_lm87_id[] = { | |
159 | { "MAC,lm87cimt", 0 }, | |
160 | { } | |
161 | }; | |
162 | MODULE_DEVICE_TABLE(i2c, wf_lm87_id); | |
163 | ||
bcf3588d WS |
164 | static const struct of_device_id wf_lm87_of_id[] = { |
165 | { .compatible = "lm87cimt", }, | |
166 | { } | |
167 | }; | |
168 | MODULE_DEVICE_TABLE(of, wf_lm87_of_id); | |
169 | ||
08fe5bc7 BH |
170 | static struct i2c_driver wf_lm87_driver = { |
171 | .driver = { | |
172 | .name = "wf_lm87", | |
bcf3588d | 173 | .of_match_table = wf_lm87_of_id, |
08fe5bc7 | 174 | }, |
0e2211b3 | 175 | .probe_new = wf_lm87_probe, |
08fe5bc7 BH |
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 |