aboutsummaryrefslogtreecommitdiff
path: root/drivers/macintosh/windfarm_max6690_sensor.c
blob: e207a90d6b2762fa887bdfdc30344958f00a8373 (plain)
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
182
183
184
185
186
187
/*
 * Windfarm PowerMac thermal control.  MAX6690 sensor.
 *
 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
 *
 * Use and redistribute under the terms of the GNU GPL v2.
 */
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <asm/prom.h>
#include <asm/pmac_low_i2c.h>

#include "windfarm.h"

#define VERSION "0.2"

/* This currently only exports the external temperature sensor,
   since that's all the control loops need. */

/* Some MAX6690 register numbers */
#define MAX6690_INTERNAL_TEMP	0
#define MAX6690_EXTERNAL_TEMP	1

struct wf_6690_sensor {
	struct i2c_client	i2c;
	struct wf_sensor	sens;
};

#define wf_to_6690(x)	container_of((x), struct wf_6690_sensor, sens)
#define i2c_to_6690(x)	container_of((x), struct wf_6690_sensor, i2c)

static int wf_max6690_attach(struct i2c_adapter *adapter);
static int wf_max6690_detach(struct i2c_client *client);

static struct i2c_driver wf_max6690_driver = {
	.driver = {
		.name		= "wf_max6690",
	},
	.attach_adapter	= wf_max6690_attach,
	.detach_client	= wf_max6690_detach,
};

static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
{
	struct wf_6690_sensor *max = wf_to_6690(sr);
	s32 data;

	if (max->i2c.adapter == NULL)
		return -ENODEV;

	/* chip gets initialized by firmware */
	data = i2c_smbus_read_byte_data(&max->i2c, MAX6690_EXTERNAL_TEMP);
	if (data < 0)
		return data;
	*value = data << 16;
	return 0;
}

static void wf_max6690_release(struct wf_sensor *sr)
{
	struct wf_6690_sensor *max = wf_to_6690(sr);

	if (max->i2c.adapter) {
		i2c_detach_client(&max->i2c);
		max->i2c.adapter = NULL;
	}
	kfree(max);
}

static struct wf_sensor_ops wf_max6690_ops = {
	.get_value	= wf_max6690_get,
	.release	= wf_max6690_release,
	.owner		= THIS_MODULE,
};

static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr,
			      const char *loc)
{
	struct wf_6690_sensor *max;
	char *name;

	max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
	if (max == NULL) {
		printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: "
		       "no memory\n", loc);
		return;
	}

	if (!strcmp(loc, "BACKSIDE"))
		name = "backside-temp";
	else if (!strcmp(loc, "NB Ambient"))
		name = "north-bridge-temp";
	else if (!strcmp(loc, "GPU Ambient"))
		name = "gpu-temp";
	else
		goto fail;

	max->sens.ops = &wf_max6690_ops;
	max->sens.name = name;
	max->i2c.addr = addr >> 1;
	max->i2c.adapter = adapter;
	max->i2c.driver = &wf_max6690_driver;
	strncpy(max->i2c.name, name, I2C_NAME_SIZE-1);

	if (i2c_attach_client(&max->i2c)) {
		printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
		goto fail;
	}

	if (wf_register_sensor(&max->sens)) {
		i2c_detach_client(&max->i2c);
		goto fail;
	}

	return;

 fail:
	kfree(max);
}

static int wf_max6690_attach(struct i2c_adapter *adapter)
{
	struct device_node *busnode, *dev = NULL;
	struct pmac_i2c_bus *bus;
	const char *loc;

	bus = pmac_i2c_adapter_to_bus(adapter);
	if (bus == NULL)
		return -ENODEV;
	busnode = pmac_i2c_get_bus_node(bus);

	while ((dev = of_get_next_child(busnode, dev)) != NULL) {
		u8 addr;

		/* We must re-match the adapter in order to properly check
		 * the channel on multibus setups
		 */
		if (!pmac_i2c_match_adapter(dev, adapter))
			continue;
		if (!of_device_is_compatible(dev, "max6690"))
			continue;
		addr = pmac_i2c_get_dev_addr(dev);
		loc = of_get_property(dev, "hwsensor-location", NULL);
		if (loc == NULL || addr == 0)
			continue;
		printk("found max6690, loc=%s addr=0x%02x\n", loc, addr);
		wf_max6690_create(adapter, addr, loc);
	}

	return 0;
}

static int wf_max6690_detach(struct i2c_client *client)
{
	struct wf_6690_sensor *max = i2c_to_6690(client);

	max->i2c.adapter = NULL;
	wf_unregister_sensor(&max->sens);

	return 0;
}

static int __init wf_max6690_sensor_init(void)
{
	/* Don't register on old machines that use therm_pm72 for now */
	if (machine_is_compatible("PowerMac7,2") ||
	    machine_is_compatible("PowerMac7,3") ||
	    machine_is_compatible("RackMac3,1"))
		return -ENODEV;
	return i2c_add_driver(&wf_max6690_driver);
}

static void __exit wf_max6690_sensor_exit(void)
{
	i2c_del_driver(&wf_max6690_driver);
}

module_init(wf_max6690_sensor_init);
module_exit(wf_max6690_sensor_exit);

MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
MODULE_LICENSE("GPL");