1/*
2 * Windfarm PowerMac thermal control. LM75 sensor
3 *
4 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5 *                    <benh@kernel.crashing.org>
6 *
7 * Released under the term of the GNU GPL v2.
8 */
9
10#include <linux/types.h>
11#include <linux/errno.h>
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/slab.h>
15#include <linux/init.h>
16#include <linux/wait.h>
17#include <linux/i2c.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
36struct 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
44static 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
78static 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
85static struct wf_sensor_ops wf_lm75_ops = {
86	.get_value	= wf_lm75_get,
87	.release	= wf_lm75_release,
88	.owner		= THIS_MODULE,
89};
90
91static 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 = id->driver_data;
96	const char *name, *loc;
97
98	DBG("wf_lm75: creating  %s device at address 0x%02x\n",
99	    ds1775 ? "ds1775" : "lm75", client->addr);
100
101	loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
102	if (!loc) {
103		dev_warn(&client->dev, "Missing hwsensor-location property!\n");
104		return -ENXIO;
105	}
106
107	/* Usual rant about sensor names not beeing very consistent in
108	 * the device-tree, oh well ...
109	 * Add more entries below as you deal with more setups
110	 */
111	if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
112		name = "hd-temp";
113	else if (!strcmp(loc, "Incoming Air Temp"))
114		name = "incoming-air-temp";
115	else if (!strcmp(loc, "ODD Temp"))
116		name = "optical-drive-temp";
117	else if (!strcmp(loc, "HD Temp"))
118		name = "hard-drive-temp";
119	else if (!strcmp(loc, "PCI SLOTS"))
120		name = "slots-temp";
121	else if (!strcmp(loc, "CPU A INLET"))
122		name = "cpu-inlet-temp-0";
123	else if (!strcmp(loc, "CPU B INLET"))
124		name = "cpu-inlet-temp-1";
125	else
126		return -ENXIO;
127
128
129	lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
130	if (lm == NULL)
131		return -ENODEV;
132
133	lm->inited = 0;
134	lm->ds1775 = ds1775;
135	lm->i2c = client;
136	lm->sens.name = name;
137	lm->sens.ops = &wf_lm75_ops;
138	i2c_set_clientdata(client, lm);
139
140	rc = wf_register_sensor(&lm->sens);
141	if (rc)
142		kfree(lm);
143	return rc;
144}
145
146static int wf_lm75_remove(struct i2c_client *client)
147{
148	struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
149
150	DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
151
152	/* Mark client detached */
153	lm->i2c = NULL;
154
155	/* release sensor */
156	wf_unregister_sensor(&lm->sens);
157
158	return 0;
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 struct i2c_driver wf_lm75_driver = {
169	.driver = {
170		.name	= "wf_lm75",
171	},
172	.probe		= wf_lm75_probe,
173	.remove		= wf_lm75_remove,
174	.id_table	= wf_lm75_id,
175};
176
177module_i2c_driver(wf_lm75_driver);
178
179MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
180MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
181MODULE_LICENSE("GPL");
182
183