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ac171c46 BH |
1 | /* |
2 | * Windfarm PowerMac thermal control. MAX6690 sensor. | |
3 | * | |
4 | * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org> | |
5 | * | |
6 | * Use and redistribute under the terms of the GNU GPL v2. | |
7 | */ | |
8 | #include <linux/types.h> | |
9 | #include <linux/errno.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/i2c.h> | |
ac171c46 BH |
14 | #include <asm/prom.h> |
15 | #include <asm/pmac_low_i2c.h> | |
16 | ||
17 | #include "windfarm.h" | |
18 | ||
b55fafc5 | 19 | #define VERSION "0.2" |
ac171c46 BH |
20 | |
21 | /* This currently only exports the external temperature sensor, | |
22 | since that's all the control loops need. */ | |
23 | ||
24 | /* Some MAX6690 register numbers */ | |
25 | #define MAX6690_INTERNAL_TEMP 0 | |
26 | #define MAX6690_EXTERNAL_TEMP 1 | |
27 | ||
28 | struct wf_6690_sensor { | |
29 | struct i2c_client i2c; | |
30 | struct wf_sensor sens; | |
31 | }; | |
32 | ||
33 | #define wf_to_6690(x) container_of((x), struct wf_6690_sensor, sens) | |
34 | #define i2c_to_6690(x) container_of((x), struct wf_6690_sensor, i2c) | |
35 | ||
36 | static int wf_max6690_attach(struct i2c_adapter *adapter); | |
37 | static int wf_max6690_detach(struct i2c_client *client); | |
38 | ||
39 | static struct i2c_driver wf_max6690_driver = { | |
40 | .driver = { | |
41 | .name = "wf_max6690", | |
42 | }, | |
43 | .attach_adapter = wf_max6690_attach, | |
44 | .detach_client = wf_max6690_detach, | |
45 | }; | |
46 | ||
47 | static int wf_max6690_get(struct wf_sensor *sr, s32 *value) | |
48 | { | |
49 | struct wf_6690_sensor *max = wf_to_6690(sr); | |
50 | s32 data; | |
51 | ||
52 | if (max->i2c.adapter == NULL) | |
53 | return -ENODEV; | |
54 | ||
55 | /* chip gets initialized by firmware */ | |
56 | data = i2c_smbus_read_byte_data(&max->i2c, MAX6690_EXTERNAL_TEMP); | |
57 | if (data < 0) | |
58 | return data; | |
59 | *value = data << 16; | |
60 | return 0; | |
61 | } | |
62 | ||
63 | static void wf_max6690_release(struct wf_sensor *sr) | |
64 | { | |
65 | struct wf_6690_sensor *max = wf_to_6690(sr); | |
66 | ||
67 | if (max->i2c.adapter) { | |
68 | i2c_detach_client(&max->i2c); | |
69 | max->i2c.adapter = NULL; | |
70 | } | |
71 | kfree(max); | |
72 | } | |
73 | ||
74 | static struct wf_sensor_ops wf_max6690_ops = { | |
75 | .get_value = wf_max6690_get, | |
76 | .release = wf_max6690_release, | |
77 | .owner = THIS_MODULE, | |
78 | }; | |
79 | ||
80 | static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr) | |
81 | { | |
82 | struct wf_6690_sensor *max; | |
b55fafc5 | 83 | char *name = "backside-temp"; |
ac171c46 BH |
84 | |
85 | max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL); | |
86 | if (max == NULL) { | |
87 | printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: " | |
88 | "no memory\n", name); | |
89 | return; | |
90 | } | |
91 | ||
92 | max->sens.ops = &wf_max6690_ops; | |
93 | max->sens.name = name; | |
94 | max->i2c.addr = addr >> 1; | |
95 | max->i2c.adapter = adapter; | |
96 | max->i2c.driver = &wf_max6690_driver; | |
97 | strncpy(max->i2c.name, name, I2C_NAME_SIZE-1); | |
98 | ||
99 | if (i2c_attach_client(&max->i2c)) { | |
100 | printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n"); | |
101 | goto fail; | |
102 | } | |
103 | ||
104 | if (wf_register_sensor(&max->sens)) { | |
105 | i2c_detach_client(&max->i2c); | |
106 | goto fail; | |
107 | } | |
108 | ||
109 | return; | |
110 | ||
111 | fail: | |
112 | kfree(max); | |
113 | } | |
114 | ||
115 | static int wf_max6690_attach(struct i2c_adapter *adapter) | |
116 | { | |
117 | struct device_node *busnode, *dev = NULL; | |
118 | struct pmac_i2c_bus *bus; | |
119 | const char *loc; | |
ac171c46 BH |
120 | |
121 | bus = pmac_i2c_adapter_to_bus(adapter); | |
122 | if (bus == NULL) | |
123 | return -ENODEV; | |
124 | busnode = pmac_i2c_get_bus_node(bus); | |
125 | ||
126 | while ((dev = of_get_next_child(busnode, dev)) != NULL) { | |
b55fafc5 BH |
127 | u8 addr; |
128 | ||
129 | /* We must re-match the adapter in order to properly check | |
130 | * the channel on multibus setups | |
131 | */ | |
132 | if (!pmac_i2c_match_adapter(dev, adapter)) | |
133 | continue; | |
55b61fec | 134 | if (!of_device_is_compatible(dev, "max6690")) |
ac171c46 | 135 | continue; |
b55fafc5 | 136 | addr = pmac_i2c_get_dev_addr(dev); |
01b2726d | 137 | loc = of_get_property(dev, "hwsensor-location", NULL); |
b55fafc5 | 138 | if (loc == NULL || addr == 0) |
ac171c46 | 139 | continue; |
b55fafc5 | 140 | printk("found max6690, loc=%s addr=0x%02x\n", loc, addr); |
ac171c46 BH |
141 | if (strcmp(loc, "BACKSIDE")) |
142 | continue; | |
b55fafc5 | 143 | wf_max6690_create(adapter, addr); |
ac171c46 BH |
144 | } |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | static int wf_max6690_detach(struct i2c_client *client) | |
150 | { | |
151 | struct wf_6690_sensor *max = i2c_to_6690(client); | |
152 | ||
153 | max->i2c.adapter = NULL; | |
154 | wf_unregister_sensor(&max->sens); | |
155 | ||
156 | return 0; | |
157 | } | |
158 | ||
159 | static int __init wf_max6690_sensor_init(void) | |
160 | { | |
b55fafc5 BH |
161 | /* Don't register on old machines that use therm_pm72 for now */ |
162 | if (machine_is_compatible("PowerMac7,2") || | |
163 | machine_is_compatible("PowerMac7,3") || | |
164 | machine_is_compatible("RackMac3,1")) | |
165 | return -ENODEV; | |
ac171c46 BH |
166 | return i2c_add_driver(&wf_max6690_driver); |
167 | } | |
168 | ||
169 | static void __exit wf_max6690_sensor_exit(void) | |
170 | { | |
171 | i2c_del_driver(&wf_max6690_driver); | |
172 | } | |
173 | ||
174 | module_init(wf_max6690_sensor_init); | |
175 | module_exit(wf_max6690_sensor_exit); | |
176 | ||
177 | MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>"); | |
178 | MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control"); | |
179 | MODULE_LICENSE("GPL"); |