aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/windfarm_lm75_sensor.c
blob: 282c28a17ea1ae936dd7b9bdafd61f344fa3ef7c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Windfarm PowerMac thermal control. LM75 sensor
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <benh@kernel.crashing.org>
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/i2c.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/sections.h>
#include <asm/pmac_low_i2c.h>

#include "windfarm.h"

#define VERSION "1.0"

#undef DEBUG

#ifdef DEBUG
#define DBG(args...)	printk(args)
#else
#define DBG(args...)	do { } while(0)
#endif

struct wf_lm75_sensor {
	int			ds1775 : 1;
	int			inited : 1;
	struct i2c_client	*i2c;
	struct wf_sensor	sens;
};
#define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)

static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
{
	struct wf_lm75_sensor *lm = wf_to_lm75(sr);
	s32 data;

	if (lm->i2c == NULL)
		return -ENODEV;

	/* Init chip if necessary */
	if (!lm->inited) {
		u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);

		DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
		    sr->name, cfg);

		/* clear shutdown bit, keep other settings as left by
		 * the firmware for now
		 */
		cfg_new = cfg & ~0x01;
		i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
		lm->inited = 1;

		/* If we just powered it up, let's wait 200 ms */
		msleep(200);
	}

	/* Read temperature register */
	data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
	data <<= 8;
	*value = data;

	return 0;
}

static void wf_lm75_release(struct wf_sensor *sr)
{
	struct wf_lm75_sensor *lm = wf_to_lm75(sr);

	kfree(lm);
}

static const struct wf_sensor_ops wf_lm75_ops = {
	.get_value	= wf_lm75_get,
	.release	= wf_lm75_release,
	.owner		= THIS_MODULE,
};

static int wf_lm75_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{	
	struct wf_lm75_sensor *lm;
	int rc, ds1775 = id->driver_data;
	const char *name, *loc;

	DBG("wf_lm75: creating  %s device at address 0x%02x\n",
	    ds1775 ? "ds1775" : "lm75", client->addr);

	loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
	if (!loc) {
		dev_warn(&client->dev, "Missing hwsensor-location property!\n");
		return -ENXIO;
	}

	/* Usual rant about sensor names not beeing very consistent in
	 * the device-tree, oh well ...
	 * Add more entries below as you deal with more setups
	 */
	if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
		name = "hd-temp";
	else if (!strcmp(loc, "Incoming Air Temp"))
		name = "incoming-air-temp";
	else if (!strcmp(loc, "ODD Temp"))
		name = "optical-drive-temp";
	else if (!strcmp(loc, "HD Temp"))
		name = "hard-drive-temp";
	else if (!strcmp(loc, "PCI SLOTS"))
		name = "slots-temp";
	else if (!strcmp(loc, "CPU A INLET"))
		name = "cpu-inlet-temp-0";
	else if (!strcmp(loc, "CPU B INLET"))
		name = "cpu-inlet-temp-1";
	else
		return -ENXIO;
 	

	lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
	if (lm == NULL)
		return -ENODEV;

	lm->inited = 0;
	lm->ds1775 = ds1775;
	lm->i2c = client;
	lm->sens.name = name;
	lm->sens.ops = &wf_lm75_ops;
	i2c_set_clientdata(client, lm);

	rc = wf_register_sensor(&lm->sens);
	if (rc)
		kfree(lm);
	return rc;
}

static int wf_lm75_remove(struct i2c_client *client)
{
	struct wf_lm75_sensor *lm = i2c_get_clientdata(client);

	DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);

	/* Mark client detached */
	lm->i2c = NULL;

	/* release sensor */
	wf_unregister_sensor(&lm->sens);

	return 0;
}

static const struct i2c_device_id wf_lm75_id[] = {
	{ "MAC,lm75", 0 },
	{ "MAC,ds1775", 1 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, wf_lm75_id);

static struct i2c_driver wf_lm75_driver = {
	.driver = {
		.name	= "wf_lm75",
	},
	.probe		= wf_lm75_probe,
	.remove		= wf_lm75_remove,
	.id_table	= wf_lm75_id,
};

module_i2c_driver(wf_lm75_driver);

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
MODULE_LICENSE("GPL");