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 
36 struct 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 
44 static 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 
78 static 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 
85 static const struct wf_sensor_ops wf_lm75_ops = {
86 	.get_value	= wf_lm75_get,
87 	.release	= wf_lm75_release,
88 	.owner		= THIS_MODULE,
89 };
90 
91 static 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 
146 static 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 
161 static const struct i2c_device_id wf_lm75_id[] = {
162 	{ "MAC,lm75", 0 },
163 	{ "MAC,ds1775", 1 },
164 	{ }
165 };
166 MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
167 
168 static 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 
177 module_i2c_driver(wf_lm75_driver);
178 
179 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
180 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
181 MODULE_LICENSE("GPL");
182 
183