aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/windfarm_lm75_sensor.c
blob: 4d6a90a1372bf7d3c01f484dac8c24501ddd6edf (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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
 * Windfarm PowerMac thermal control. LM75 sensor
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <benh@kernel.crashing.org>
 *
 * Released under the term of the GNU GPL v2.
 */

#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 "0.2"

#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 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;

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

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

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

	return rc;
}

static struct i2c_driver wf_lm75_driver;

static struct i2c_client *wf_lm75_create(struct i2c_adapter *adapter,
					     u8 addr, int ds1775,
					     const char *loc)
{
	struct i2c_board_info info;
	struct i2c_client *client;
	char *name;

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

	/* 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
		goto fail;

	memset(&info, 0, sizeof(struct i2c_board_info));
	info.addr = (addr >> 1) & 0x7f;
	info.platform_data = name;
	strlcpy(info.type, ds1775 ? "wf_ds1775" : "wf_lm75", I2C_NAME_SIZE);

	client = i2c_new_device(adapter, &info);
	if (client == NULL) {
		printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n",
		       ds1775 ? "ds1775" : "lm75", name);
		goto fail;
	}

	/*
	 * Let i2c-core delete that device on driver removal.
	 * This is safe because i2c-core holds the core_lock mutex for us.
	 */
	list_add_tail(&client->detected, &wf_lm75_driver.clients);
	return client;
 fail:
	return NULL;
}

static int wf_lm75_attach(struct i2c_adapter *adapter)
{
	struct device_node *busnode, *dev;
	struct pmac_i2c_bus *bus;

	DBG("wf_lm75: adapter %s detected\n", adapter->name);

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

	DBG("wf_lm75: bus found, looking for device...\n");

	/* Now look for lm75(s) in there */
	for (dev = NULL;
	     (dev = of_get_next_child(busnode, dev)) != NULL;) {
		const char *loc =
			of_get_property(dev, "hwsensor-location", 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;
		addr = pmac_i2c_get_dev_addr(dev);
		if (loc == NULL || addr == 0)
			continue;
		/* real lm75 */
		if (of_device_is_compatible(dev, "lm75"))
			wf_lm75_create(adapter, addr, 0, loc);
		/* ds1775 (compatible, better resolution */
		else if (of_device_is_compatible(dev, "ds1775"))
			wf_lm75_create(adapter, addr, 1, loc);
	}
	return 0;
}

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[] = {
	{ "wf_lm75", 0 },
	{ "wf_ds1775", 1 },
	{ }
};

static struct i2c_driver wf_lm75_driver = {
	.driver = {
		.name	= "wf_lm75",
	},
	.attach_adapter	= wf_lm75_attach,
	.probe		= wf_lm75_probe,
	.remove		= wf_lm75_remove,
	.id_table	= wf_lm75_id,
};

static int __init wf_lm75_sensor_init(void)
{
	/* Don't register on old machines that use therm_pm72 for now */
	if (of_machine_is_compatible("PowerMac7,2") ||
	    of_machine_is_compatible("PowerMac7,3") ||
	    of_machine_is_compatible("RackMac3,1"))
		return -ENODEV;
	return i2c_add_driver(&wf_lm75_driver);
}

static void __exit wf_lm75_sensor_exit(void)
{
	i2c_del_driver(&wf_lm75_driver);
}


module_init(wf_lm75_sensor_init);
module_exit(wf_lm75_sensor_exit);

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