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 <linux/of_device.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_lm75_sensor {
37 int ds1775 : 1;
38 int inited : 1;
39 struct i2c_client *i2c;
40 struct wf_sensor sens;
41 };
42 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
43
wf_lm75_get(struct wf_sensor * sr,s32 * value)44 static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
45 {
46 struct wf_lm75_sensor *lm = wf_to_lm75(sr);
47 s32 data;
48
49 if (lm->i2c == NULL)
50 return -ENODEV;
51
52 /* Init chip if necessary */
53 if (!lm->inited) {
54 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
55
56 DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
57 sr->name, cfg);
58
59 /* clear shutdown bit, keep other settings as left by
60 * the firmware for now
61 */
62 cfg_new = cfg & ~0x01;
63 i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
64 lm->inited = 1;
65
66 /* If we just powered it up, let's wait 200 ms */
67 msleep(200);
68 }
69
70 /* Read temperature register */
71 data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
72 data <<= 8;
73 *value = data;
74
75 return 0;
76 }
77
wf_lm75_release(struct wf_sensor * sr)78 static void wf_lm75_release(struct wf_sensor *sr)
79 {
80 struct wf_lm75_sensor *lm = wf_to_lm75(sr);
81
82 kfree(lm);
83 }
84
85 static const struct wf_sensor_ops wf_lm75_ops = {
86 .get_value = wf_lm75_get,
87 .release = wf_lm75_release,
88 .owner = THIS_MODULE,
89 };
90
wf_lm75_probe(struct i2c_client * client,const struct i2c_device_id * id)91 static int wf_lm75_probe(struct i2c_client *client,
92 const struct i2c_device_id *id)
93 {
94 struct wf_lm75_sensor *lm;
95 int rc, ds1775;
96 const char *name, *loc;
97
98 if (id)
99 ds1775 = id->driver_data;
100 else
101 ds1775 = !!of_device_get_match_data(&client->dev);
102
103 DBG("wf_lm75: creating %s device at address 0x%02x\n",
104 ds1775 ? "ds1775" : "lm75", client->addr);
105
106 loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
107 if (!loc) {
108 dev_warn(&client->dev, "Missing hwsensor-location property!\n");
109 return -ENXIO;
110 }
111
112 /* Usual rant about sensor names not beeing very consistent in
113 * the device-tree, oh well ...
114 * Add more entries below as you deal with more setups
115 */
116 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
117 name = "hd-temp";
118 else if (!strcmp(loc, "Incoming Air Temp"))
119 name = "incoming-air-temp";
120 else if (!strcmp(loc, "ODD Temp"))
121 name = "optical-drive-temp";
122 else if (!strcmp(loc, "HD Temp"))
123 name = "hard-drive-temp";
124 else if (!strcmp(loc, "PCI SLOTS"))
125 name = "slots-temp";
126 else if (!strcmp(loc, "CPU A INLET"))
127 name = "cpu-inlet-temp-0";
128 else if (!strcmp(loc, "CPU B INLET"))
129 name = "cpu-inlet-temp-1";
130 else
131 return -ENXIO;
132
133
134 lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
135 if (lm == NULL)
136 return -ENODEV;
137
138 lm->inited = 0;
139 lm->ds1775 = ds1775;
140 lm->i2c = client;
141 lm->sens.name = name;
142 lm->sens.ops = &wf_lm75_ops;
143 i2c_set_clientdata(client, lm);
144
145 rc = wf_register_sensor(&lm->sens);
146 if (rc)
147 kfree(lm);
148 return rc;
149 }
150
wf_lm75_remove(struct i2c_client * client)151 static int wf_lm75_remove(struct i2c_client *client)
152 {
153 struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
154
155 /* Mark client detached */
156 lm->i2c = NULL;
157
158 /* release sensor */
159 wf_unregister_sensor(&lm->sens);
160
161 return 0;
162 }
163
164 static const struct i2c_device_id wf_lm75_id[] = {
165 { "MAC,lm75", 0 },
166 { "MAC,ds1775", 1 },
167 { }
168 };
169 MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
170
171 static const struct of_device_id wf_lm75_of_id[] = {
172 { .compatible = "lm75", .data = (void *)0},
173 { .compatible = "ds1775", .data = (void *)1 },
174 { }
175 };
176 MODULE_DEVICE_TABLE(of, wf_lm75_of_id);
177
178 static struct i2c_driver wf_lm75_driver = {
179 .driver = {
180 .name = "wf_lm75",
181 .of_match_table = wf_lm75_of_id,
182 },
183 .probe = wf_lm75_probe,
184 .remove = wf_lm75_remove,
185 .id_table = wf_lm75_id,
186 };
187
188 module_i2c_driver(wf_lm75_driver);
189
190 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
191 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
192 MODULE_LICENSE("GPL");
193
194