1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Windfarm PowerMac thermal control. LM75 sensor
4 *
5 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6 * <benh@kernel.crashing.org>
7 */
8
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/wait.h>
16 #include <linux/i2c.h>
17 #include <asm/prom.h>
18 #include <asm/machdep.h>
19 #include <asm/io.h>
20 #include <asm/sections.h>
21 #include <asm/pmac_low_i2c.h>
22
23 #include "windfarm.h"
24
25 #define VERSION "1.0"
26
27 #undef DEBUG
28
29 #ifdef DEBUG
30 #define DBG(args...) printk(args)
31 #else
32 #define DBG(args...) do { } while(0)
33 #endif
34
35 struct wf_lm75_sensor {
36 int ds1775 : 1;
37 int inited : 1;
38 struct i2c_client *i2c;
39 struct wf_sensor sens;
40 };
41 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
42
wf_lm75_get(struct wf_sensor * sr,s32 * value)43 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
44 {
45 struct wf_lm75_sensor *lm = wf_to_lm75(sr);
46 s32 data;
47
48 if (lm->i2c == NULL)
49 return -ENODEV;
50
51 /* Init chip if necessary */
52 if (!lm->inited) {
53 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
54
55 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
56 sr->name, cfg);
57
58 /* clear shutdown bit, keep other settings as left by
59 * the firmware for now
60 */
61 cfg_new = cfg & ~0x01;
62 i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
63 lm->inited = 1;
64
65 /* If we just powered it up, let's wait 200 ms */
66 msleep(200);
67 }
68
69 /* Read temperature register */
70 data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
71 data <<= 8;
72 *value = data;
73
74 return 0;
75 }
76
wf_lm75_release(struct wf_sensor * sr)77 static void wf_lm75_release(struct wf_sensor *sr)
78 {
79 struct wf_lm75_sensor *lm = wf_to_lm75(sr);
80
81 kfree(lm);
82 }
83
84 static const struct wf_sensor_ops wf_lm75_ops = {
85 .get_value = wf_lm75_get,
86 .release = wf_lm75_release,
87 .owner = THIS_MODULE,
88 };
89
wf_lm75_probe(struct i2c_client * client,const struct i2c_device_id * id)90 static int wf_lm75_probe(struct i2c_client *client,
91 const struct i2c_device_id *id)
92 {
93 struct wf_lm75_sensor *lm;
94 int rc, ds1775 = id->driver_data;
95 const char *name, *loc;
96
97 DBG("wf_lm75: creating %s device at address 0x%02x\n",
98 ds1775 ? "ds1775" : "lm75", client->addr);
99
100 loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
101 if (!loc) {
102 dev_warn(&client->dev, "Missing hwsensor-location property!\n");
103 return -ENXIO;
104 }
105
106 /* Usual rant about sensor names not beeing very consistent in
107 * the device-tree, oh well ...
108 * Add more entries below as you deal with more setups
109 */
110 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
111 name = "hd-temp";
112 else if (!strcmp(loc, "Incoming Air Temp"))
113 name = "incoming-air-temp";
114 else if (!strcmp(loc, "ODD Temp"))
115 name = "optical-drive-temp";
116 else if (!strcmp(loc, "HD Temp"))
117 name = "hard-drive-temp";
118 else if (!strcmp(loc, "PCI SLOTS"))
119 name = "slots-temp";
120 else if (!strcmp(loc, "CPU A INLET"))
121 name = "cpu-inlet-temp-0";
122 else if (!strcmp(loc, "CPU B INLET"))
123 name = "cpu-inlet-temp-1";
124 else
125 return -ENXIO;
126
127
128 lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
129 if (lm == NULL)
130 return -ENODEV;
131
132 lm->inited = 0;
133 lm->ds1775 = ds1775;
134 lm->i2c = client;
135 lm->sens.name = name;
136 lm->sens.ops = &wf_lm75_ops;
137 i2c_set_clientdata(client, lm);
138
139 rc = wf_register_sensor(&lm->sens);
140 if (rc)
141 kfree(lm);
142 return rc;
143 }
144
wf_lm75_remove(struct i2c_client * client)145 static int wf_lm75_remove(struct i2c_client *client)
146 {
147 struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
148
149 DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
150
151 /* Mark client detached */
152 lm->i2c = NULL;
153
154 /* release sensor */
155 wf_unregister_sensor(&lm->sens);
156
157 return 0;
158 }
159
160 static const struct i2c_device_id wf_lm75_id[] = {
161 { "MAC,lm75", 0 },
162 { "MAC,ds1775", 1 },
163 { }
164 };
165 MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
166
167 static struct i2c_driver wf_lm75_driver = {
168 .driver = {
169 .name = "wf_lm75",
170 },
171 .probe = wf_lm75_probe,
172 .remove = wf_lm75_remove,
173 .id_table = wf_lm75_id,
174 };
175
176 module_i2c_driver(wf_lm75_driver);
177
178 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
179 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
180 MODULE_LICENSE("GPL");
181
182