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75722d39 BH |
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> | |
75722d39 BH |
18 | #include <asm/prom.h> |
19 | #include <asm/machdep.h> | |
20 | #include <asm/io.h> | |
21 | #include <asm/system.h> | |
22 | #include <asm/sections.h> | |
a28d3af2 | 23 | #include <asm/pmac_low_i2c.h> |
75722d39 BH |
24 | |
25 | #include "windfarm.h" | |
26 | ||
b55fafc5 | 27 | #define VERSION "0.2" |
75722d39 BH |
28 | |
29 | #undef DEBUG | |
30 | ||
31 | #ifdef DEBUG | |
32 | #define DBG(args...) printk(args) | |
33 | #else | |
34 | #define DBG(args...) do { } while(0) | |
35 | #endif | |
36 | ||
37 | struct wf_lm75_sensor { | |
38 | int ds1775 : 1; | |
39 | int inited : 1; | |
40 | struct i2c_client i2c; | |
41 | struct wf_sensor sens; | |
42 | }; | |
43 | #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens) | |
44 | #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c) | |
45 | ||
46 | static int wf_lm75_attach(struct i2c_adapter *adapter); | |
47 | static int wf_lm75_detach(struct i2c_client *client); | |
48 | ||
49 | static struct i2c_driver wf_lm75_driver = { | |
a33ca232 | 50 | .driver = { |
a33ca232 LR |
51 | .name = "wf_lm75", |
52 | }, | |
75722d39 BH |
53 | .attach_adapter = wf_lm75_attach, |
54 | .detach_client = wf_lm75_detach, | |
55 | }; | |
56 | ||
57 | static int wf_lm75_get(struct wf_sensor *sr, s32 *value) | |
58 | { | |
59 | struct wf_lm75_sensor *lm = wf_to_lm75(sr); | |
60 | s32 data; | |
61 | ||
62 | if (lm->i2c.adapter == NULL) | |
63 | return -ENODEV; | |
64 | ||
65 | /* Init chip if necessary */ | |
66 | if (!lm->inited) { | |
67 | u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1); | |
68 | ||
69 | DBG("wf_lm75: Initializing %s, cfg was: %02x\n", | |
70 | sr->name, cfg); | |
71 | ||
72 | /* clear shutdown bit, keep other settings as left by | |
73 | * the firmware for now | |
74 | */ | |
75 | cfg_new = cfg & ~0x01; | |
76 | i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new); | |
77 | lm->inited = 1; | |
78 | ||
79 | /* If we just powered it up, let's wait 200 ms */ | |
80 | msleep(200); | |
81 | } | |
82 | ||
83 | /* Read temperature register */ | |
84 | data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0)); | |
85 | data <<= 8; | |
86 | *value = data; | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
91 | static void wf_lm75_release(struct wf_sensor *sr) | |
92 | { | |
93 | struct wf_lm75_sensor *lm = wf_to_lm75(sr); | |
94 | ||
95 | /* check if client is registered and detach from i2c */ | |
96 | if (lm->i2c.adapter) { | |
97 | i2c_detach_client(&lm->i2c); | |
98 | lm->i2c.adapter = NULL; | |
99 | } | |
100 | ||
101 | kfree(lm); | |
102 | } | |
103 | ||
104 | static struct wf_sensor_ops wf_lm75_ops = { | |
105 | .get_value = wf_lm75_get, | |
106 | .release = wf_lm75_release, | |
107 | .owner = THIS_MODULE, | |
108 | }; | |
109 | ||
110 | static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter, | |
111 | u8 addr, int ds1775, | |
112 | const char *loc) | |
113 | { | |
114 | struct wf_lm75_sensor *lm; | |
b55fafc5 | 115 | int rc; |
75722d39 BH |
116 | |
117 | DBG("wf_lm75: creating %s device at address 0x%02x\n", | |
118 | ds1775 ? "ds1775" : "lm75", addr); | |
119 | ||
120 | lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); | |
121 | if (lm == NULL) | |
122 | return NULL; | |
123 | memset(lm, 0, sizeof(struct wf_lm75_sensor)); | |
124 | ||
125 | /* Usual rant about sensor names not beeing very consistent in | |
126 | * the device-tree, oh well ... | |
127 | * Add more entries below as you deal with more setups | |
128 | */ | |
129 | if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) | |
130 | lm->sens.name = "hd-temp"; | |
131 | else | |
132 | goto fail; | |
133 | ||
134 | lm->inited = 0; | |
135 | lm->sens.ops = &wf_lm75_ops; | |
136 | lm->ds1775 = ds1775; | |
137 | lm->i2c.addr = (addr >> 1) & 0x7f; | |
138 | lm->i2c.adapter = adapter; | |
139 | lm->i2c.driver = &wf_lm75_driver; | |
140 | strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1); | |
141 | ||
b55fafc5 BH |
142 | rc = i2c_attach_client(&lm->i2c); |
143 | if (rc) { | |
144 | printk(KERN_ERR "windfarm: failed to attach %s %s to i2c," | |
145 | " err %d\n", ds1775 ? "ds1775" : "lm75", | |
146 | lm->i2c.name, rc); | |
75722d39 BH |
147 | goto fail; |
148 | } | |
149 | ||
150 | if (wf_register_sensor(&lm->sens)) { | |
151 | i2c_detach_client(&lm->i2c); | |
152 | goto fail; | |
153 | } | |
154 | ||
155 | return lm; | |
156 | fail: | |
157 | kfree(lm); | |
158 | return NULL; | |
159 | } | |
160 | ||
161 | static int wf_lm75_attach(struct i2c_adapter *adapter) | |
162 | { | |
a28d3af2 BH |
163 | struct device_node *busnode, *dev; |
164 | struct pmac_i2c_bus *bus; | |
75722d39 BH |
165 | |
166 | DBG("wf_lm75: adapter %s detected\n", adapter->name); | |
167 | ||
a28d3af2 BH |
168 | bus = pmac_i2c_adapter_to_bus(adapter); |
169 | if (bus == NULL) | |
170 | return -ENODEV; | |
171 | busnode = pmac_i2c_get_bus_node(bus); | |
75722d39 BH |
172 | |
173 | DBG("wf_lm75: bus found, looking for device...\n"); | |
174 | ||
175 | /* Now look for lm75(s) in there */ | |
176 | for (dev = NULL; | |
a28d3af2 | 177 | (dev = of_get_next_child(busnode, dev)) != NULL;) { |
75722d39 BH |
178 | const char *loc = |
179 | get_property(dev, "hwsensor-location", NULL); | |
b55fafc5 BH |
180 | u8 addr; |
181 | ||
182 | /* We must re-match the adapter in order to properly check | |
183 | * the channel on multibus setups | |
184 | */ | |
185 | if (!pmac_i2c_match_adapter(dev, adapter)) | |
186 | continue; | |
187 | addr = pmac_i2c_get_dev_addr(dev); | |
188 | if (loc == NULL || addr == 0) | |
75722d39 BH |
189 | continue; |
190 | /* real lm75 */ | |
191 | if (device_is_compatible(dev, "lm75")) | |
b55fafc5 | 192 | wf_lm75_create(adapter, addr, 0, loc); |
75722d39 BH |
193 | /* ds1775 (compatible, better resolution */ |
194 | else if (device_is_compatible(dev, "ds1775")) | |
b55fafc5 | 195 | wf_lm75_create(adapter, addr, 1, loc); |
75722d39 | 196 | } |
75722d39 BH |
197 | return 0; |
198 | } | |
199 | ||
200 | static int wf_lm75_detach(struct i2c_client *client) | |
201 | { | |
202 | struct wf_lm75_sensor *lm = i2c_to_lm75(client); | |
203 | ||
204 | DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); | |
205 | ||
206 | /* Mark client detached */ | |
207 | lm->i2c.adapter = NULL; | |
208 | ||
209 | /* release sensor */ | |
210 | wf_unregister_sensor(&lm->sens); | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | static int __init wf_lm75_sensor_init(void) | |
216 | { | |
b55fafc5 BH |
217 | /* Don't register on old machines that use therm_pm72 for now */ |
218 | if (machine_is_compatible("PowerMac7,2") || | |
219 | machine_is_compatible("PowerMac7,3") || | |
220 | machine_is_compatible("RackMac3,1")) | |
221 | return -ENODEV; | |
c9662b4b | 222 | return i2c_add_driver(&wf_lm75_driver); |
75722d39 BH |
223 | } |
224 | ||
225 | static void __exit wf_lm75_sensor_exit(void) | |
226 | { | |
227 | i2c_del_driver(&wf_lm75_driver); | |
228 | } | |
229 | ||
230 | ||
231 | module_init(wf_lm75_sensor_init); | |
232 | module_exit(wf_lm75_sensor_exit); | |
233 | ||
234 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
235 | MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); | |
236 | MODULE_LICENSE("GPL"); | |
237 |