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.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
35struct wf_lm75_sensor {
36 unsigned int ds1775 : 1;
37 unsigned 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
43static 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(client: lm->i2c, command: 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(client: lm->i2c, command: 1, value: cfg_new);
63 lm->inited = 1;
64
65 /* If we just powered it up, let's wait 200 ms */
66 msleep(msecs: 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
77static void wf_lm75_release(struct wf_sensor *sr)
78{
79 struct wf_lm75_sensor *lm = wf_to_lm75(sr);
80
81 kfree(objp: lm);
82}
83
84static 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
90static int wf_lm75_probe(struct i2c_client *client)
91{
92 const struct i2c_device_id *id = i2c_client_get_device_id(client);
93 struct wf_lm75_sensor *lm;
94 int rc, ds1775;
95 const char *name, *loc;
96
97 if (id)
98 ds1775 = id->driver_data;
99 else
100 ds1775 = !!of_device_get_match_data(dev: &client->dev);
101
102 DBG("wf_lm75: creating %s device at address 0x%02x\n",
103 ds1775 ? "ds1775" : "lm75", client->addr);
104
105 loc = of_get_property(node: client->dev.of_node, name: "hwsensor-location", NULL);
106 if (!loc) {
107 dev_warn(&client->dev, "Missing hwsensor-location property!\n");
108 return -ENXIO;
109 }
110
111 /* Usual rant about sensor names not beeing very consistent in
112 * the device-tree, oh well ...
113 * Add more entries below as you deal with more setups
114 */
115 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
116 name = "hd-temp";
117 else if (!strcmp(loc, "Incoming Air Temp"))
118 name = "incoming-air-temp";
119 else if (!strcmp(loc, "ODD Temp"))
120 name = "optical-drive-temp";
121 else if (!strcmp(loc, "HD Temp"))
122 name = "hard-drive-temp";
123 else if (!strcmp(loc, "PCI SLOTS"))
124 name = "slots-temp";
125 else if (!strcmp(loc, "CPU A INLET"))
126 name = "cpu-inlet-temp-0";
127 else if (!strcmp(loc, "CPU B INLET"))
128 name = "cpu-inlet-temp-1";
129 else
130 return -ENXIO;
131
132
133 lm = kzalloc(size: sizeof(struct wf_lm75_sensor), GFP_KERNEL);
134 if (lm == NULL)
135 return -ENODEV;
136
137 lm->inited = 0;
138 lm->ds1775 = ds1775;
139 lm->i2c = client;
140 lm->sens.name = name;
141 lm->sens.ops = &wf_lm75_ops;
142 i2c_set_clientdata(client, data: lm);
143
144 rc = wf_register_sensor(sr: &lm->sens);
145 if (rc)
146 kfree(objp: lm);
147 return rc;
148}
149
150static void wf_lm75_remove(struct i2c_client *client)
151{
152 struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
153
154 /* Mark client detached */
155 lm->i2c = NULL;
156
157 /* release sensor */
158 wf_unregister_sensor(sr: &lm->sens);
159}
160
161static const struct i2c_device_id wf_lm75_id[] = {
162 { "MAC,lm75", 0 },
163 { "MAC,ds1775", 1 },
164 { }
165};
166MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
167
168static const struct of_device_id wf_lm75_of_id[] = {
169 { .compatible = "lm75", .data = (void *)0},
170 { .compatible = "ds1775", .data = (void *)1 },
171 { }
172};
173MODULE_DEVICE_TABLE(of, wf_lm75_of_id);
174
175static struct i2c_driver wf_lm75_driver = {
176 .driver = {
177 .name = "wf_lm75",
178 .of_match_table = wf_lm75_of_id,
179 },
180 .probe = wf_lm75_probe,
181 .remove = wf_lm75_remove,
182 .id_table = wf_lm75_id,
183};
184
185module_i2c_driver(wf_lm75_driver);
186
187MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
188MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
189MODULE_LICENSE("GPL");
190
191

source code of linux/drivers/macintosh/windfarm_lm75_sensor.c