Commit | Line | Data |
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850dc321 BH |
1 | /* |
2 | * Windfarm PowerMac thermal control. AD7417 sensors | |
3 | * | |
4 | * Copyright 2012 Benjamin Herrenschmidt, IBM Corp. | |
5 | * | |
6 | * Released under the term of the GNU GPL v2. | |
7 | */ | |
8 | ||
9 | #include <linux/types.h> | |
10 | #include <linux/errno.h> | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/delay.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/wait.h> | |
16 | #include <linux/i2c.h> | |
17 | #include <asm/prom.h> | |
18 | #include <asm/machdep.h> | |
19 | #include <asm/io.h> | |
20 | #include <asm/sections.h> | |
21 | ||
22 | #include "windfarm.h" | |
23 | #include "windfarm_mpu.h" | |
24 | ||
25 | #define VERSION "1.0" | |
26 | ||
27 | struct wf_ad7417_priv { | |
28 | struct kref ref; | |
29 | struct i2c_client *i2c; | |
30 | u8 config; | |
31 | u8 cpu; | |
32 | const struct mpu_data *mpu; | |
33 | struct wf_sensor sensors[5]; | |
34 | struct mutex lock; | |
35 | }; | |
36 | ||
37 | static int wf_ad7417_temp_get(struct wf_sensor *sr, s32 *value) | |
38 | { | |
39 | struct wf_ad7417_priv *pv = sr->priv; | |
40 | u8 buf[2]; | |
41 | s16 raw; | |
42 | int rc; | |
43 | ||
44 | *value = 0; | |
45 | mutex_lock(&pv->lock); | |
46 | ||
47 | /* Read temp register */ | |
48 | buf[0] = 0; | |
49 | rc = i2c_master_send(pv->i2c, buf, 1); | |
50 | if (rc < 0) | |
51 | goto error; | |
52 | rc = i2c_master_recv(pv->i2c, buf, 2); | |
53 | if (rc < 0) | |
54 | goto error; | |
55 | ||
56 | /* Read a a 16-bit signed value */ | |
57 | raw = be16_to_cpup((__le16 *)buf); | |
58 | ||
59 | /* Convert 8.8-bit to 16.16 fixed point */ | |
60 | *value = ((s32)raw) << 8; | |
61 | ||
62 | mutex_unlock(&pv->lock); | |
63 | return 0; | |
64 | ||
65 | error: | |
66 | mutex_unlock(&pv->lock); | |
67 | return -1; | |
68 | } | |
69 | ||
70 | /* | |
71 | * Scaling factors for the AD7417 ADC converters (except | |
72 | * for the CPU diode which is obtained from the EEPROM). | |
73 | * Those values are obtained from the property list of | |
74 | * the darwin driver | |
75 | */ | |
76 | #define ADC_12V_CURRENT_SCALE 0x0320 /* _AD2 */ | |
77 | #define ADC_CPU_VOLTAGE_SCALE 0x00a0 /* _AD3 */ | |
78 | #define ADC_CPU_CURRENT_SCALE 0x1f40 /* _AD4 */ | |
79 | ||
80 | static void wf_ad7417_adc_convert(struct wf_ad7417_priv *pv, | |
81 | int chan, s32 raw, s32 *value) | |
82 | { | |
83 | switch(chan) { | |
84 | case 1: /* Diode */ | |
85 | *value = (raw * (s32)pv->mpu->mdiode + | |
86 | ((s32)pv->mpu->bdiode << 12)) >> 2; | |
87 | break; | |
88 | case 2: /* 12v current */ | |
89 | *value = raw * ADC_12V_CURRENT_SCALE; | |
90 | break; | |
91 | case 3: /* core voltage */ | |
92 | *value = raw * ADC_CPU_VOLTAGE_SCALE; | |
93 | break; | |
94 | case 4: /* core current */ | |
95 | *value = raw * ADC_CPU_CURRENT_SCALE; | |
96 | break; | |
97 | } | |
98 | } | |
99 | ||
100 | static int wf_ad7417_adc_get(struct wf_sensor *sr, s32 *value) | |
101 | { | |
102 | struct wf_ad7417_priv *pv = sr->priv; | |
103 | int chan = sr - pv->sensors; | |
104 | int i, rc; | |
105 | u8 buf[2]; | |
106 | u16 raw; | |
107 | ||
108 | *value = 0; | |
109 | mutex_lock(&pv->lock); | |
110 | for (i = 0; i < 10; i++) { | |
111 | /* Set channel */ | |
112 | buf[0] = 1; | |
113 | buf[1] = (pv->config & 0x1f) | (chan << 5); | |
114 | rc = i2c_master_send(pv->i2c, buf, 2); | |
115 | if (rc < 0) | |
116 | goto error; | |
117 | ||
118 | /* Wait for conversion */ | |
119 | msleep(1); | |
120 | ||
121 | /* Switch to data register */ | |
122 | buf[0] = 4; | |
123 | rc = i2c_master_send(pv->i2c, buf, 1); | |
124 | if (rc < 0) | |
125 | goto error; | |
126 | ||
127 | /* Read result */ | |
128 | rc = i2c_master_recv(pv->i2c, buf, 2); | |
129 | if (rc < 0) | |
130 | goto error; | |
131 | ||
132 | /* Read a a 16-bit signed value */ | |
133 | raw = be16_to_cpup((__le16 *)buf) >> 6; | |
134 | wf_ad7417_adc_convert(pv, chan, raw, value); | |
135 | ||
136 | dev_vdbg(&pv->i2c->dev, "ADC chan %d [%s]" | |
137 | " raw value: 0x%x, conv to: 0x%08x\n", | |
138 | chan, sr->name, raw, *value); | |
139 | ||
140 | mutex_unlock(&pv->lock); | |
141 | return 0; | |
142 | ||
143 | error: | |
144 | dev_dbg(&pv->i2c->dev, | |
145 | "Error reading ADC, try %d...\n", i); | |
146 | if (i < 9) | |
147 | msleep(10); | |
148 | } | |
149 | mutex_unlock(&pv->lock); | |
150 | return -1; | |
151 | } | |
152 | ||
153 | static void wf_ad7417_release(struct kref *ref) | |
154 | { | |
155 | struct wf_ad7417_priv *pv = container_of(ref, | |
156 | struct wf_ad7417_priv, ref); | |
157 | kfree(pv); | |
158 | } | |
159 | ||
160 | static void wf_ad7417_sensor_release(struct wf_sensor *sr) | |
161 | { | |
162 | struct wf_ad7417_priv *pv = sr->priv; | |
163 | ||
164 | kfree(sr->name); | |
165 | kref_put(&pv->ref, wf_ad7417_release); | |
166 | } | |
167 | ||
168 | static const struct wf_sensor_ops wf_ad7417_temp_ops = { | |
169 | .get_value = wf_ad7417_temp_get, | |
170 | .release = wf_ad7417_sensor_release, | |
171 | .owner = THIS_MODULE, | |
172 | }; | |
173 | ||
174 | static const struct wf_sensor_ops wf_ad7417_adc_ops = { | |
175 | .get_value = wf_ad7417_adc_get, | |
176 | .release = wf_ad7417_sensor_release, | |
177 | .owner = THIS_MODULE, | |
178 | }; | |
179 | ||
1da42fb6 GKH |
180 | static void wf_ad7417_add_sensor(struct wf_ad7417_priv *pv, |
181 | int index, const char *name, | |
182 | const struct wf_sensor_ops *ops) | |
850dc321 BH |
183 | { |
184 | pv->sensors[index].name = kasprintf(GFP_KERNEL, "%s-%d", name, pv->cpu); | |
185 | pv->sensors[index].priv = pv; | |
186 | pv->sensors[index].ops = ops; | |
187 | if (!wf_register_sensor(&pv->sensors[index])) | |
188 | kref_get(&pv->ref); | |
189 | } | |
190 | ||
1da42fb6 | 191 | static void wf_ad7417_init_chip(struct wf_ad7417_priv *pv) |
850dc321 BH |
192 | { |
193 | int rc; | |
194 | u8 buf[2]; | |
195 | u8 config = 0; | |
196 | ||
197 | /* | |
198 | * Read ADC the configuration register and cache it. We | |
199 | * also make sure Config2 contains proper values, I've seen | |
200 | * cases where we got stale grabage in there, thus preventing | |
201 | * proper reading of conv. values | |
202 | */ | |
203 | ||
204 | /* Clear Config2 */ | |
205 | buf[0] = 5; | |
206 | buf[1] = 0; | |
207 | i2c_master_send(pv->i2c, buf, 2); | |
208 | ||
209 | /* Read & cache Config1 */ | |
210 | buf[0] = 1; | |
211 | rc = i2c_master_send(pv->i2c, buf, 1); | |
212 | if (rc > 0) { | |
213 | rc = i2c_master_recv(pv->i2c, buf, 1); | |
214 | if (rc > 0) { | |
215 | config = buf[0]; | |
216 | ||
217 | dev_dbg(&pv->i2c->dev, "ADC config reg: %02x\n", | |
218 | config); | |
219 | ||
220 | /* Disable shutdown mode */ | |
221 | config &= 0xfe; | |
222 | buf[0] = 1; | |
223 | buf[1] = config; | |
224 | rc = i2c_master_send(pv->i2c, buf, 2); | |
225 | } | |
226 | } | |
227 | if (rc <= 0) | |
228 | dev_err(&pv->i2c->dev, "Error reading ADC config\n"); | |
229 | ||
230 | pv->config = config; | |
231 | } | |
232 | ||
1da42fb6 GKH |
233 | static int wf_ad7417_probe(struct i2c_client *client, |
234 | const struct i2c_device_id *id) | |
850dc321 BH |
235 | { |
236 | struct wf_ad7417_priv *pv; | |
237 | const struct mpu_data *mpu; | |
238 | const char *loc; | |
239 | int cpu_nr; | |
240 | ||
241 | loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL); | |
242 | if (!loc) { | |
243 | dev_warn(&client->dev, "Missing hwsensor-location property!\n"); | |
244 | return -ENXIO; | |
245 | } | |
246 | ||
247 | /* | |
248 | * Identify which CPU we belong to by looking at the first entry | |
249 | * in the hwsensor-location list | |
250 | */ | |
251 | if (!strncmp(loc, "CPU A", 5)) | |
252 | cpu_nr = 0; | |
253 | else if (!strncmp(loc, "CPU B", 5)) | |
254 | cpu_nr = 1; | |
255 | else { | |
256 | pr_err("wf_ad7417: Can't identify location %s\n", loc); | |
257 | return -ENXIO; | |
258 | } | |
259 | mpu = wf_get_mpu(cpu_nr); | |
260 | if (!mpu) { | |
261 | dev_err(&client->dev, "Failed to retrieve MPU data\n"); | |
262 | return -ENXIO; | |
263 | } | |
264 | ||
265 | pv = kzalloc(sizeof(struct wf_ad7417_priv), GFP_KERNEL); | |
266 | if (pv == NULL) | |
267 | return -ENODEV; | |
268 | ||
269 | kref_init(&pv->ref); | |
270 | mutex_init(&pv->lock); | |
271 | pv->i2c = client; | |
272 | pv->cpu = cpu_nr; | |
273 | pv->mpu = mpu; | |
274 | dev_set_drvdata(&client->dev, pv); | |
275 | ||
276 | /* Initialize the chip */ | |
277 | wf_ad7417_init_chip(pv); | |
278 | ||
279 | /* | |
280 | * We cannot rely on Apple device-tree giving us child | |
281 | * node with the names of the individual sensors so we | |
282 | * just hard code what we know about them | |
283 | */ | |
284 | wf_ad7417_add_sensor(pv, 0, "cpu-amb-temp", &wf_ad7417_temp_ops); | |
285 | wf_ad7417_add_sensor(pv, 1, "cpu-diode-temp", &wf_ad7417_adc_ops); | |
286 | wf_ad7417_add_sensor(pv, 2, "cpu-12v-current", &wf_ad7417_adc_ops); | |
287 | wf_ad7417_add_sensor(pv, 3, "cpu-voltage", &wf_ad7417_adc_ops); | |
288 | wf_ad7417_add_sensor(pv, 4, "cpu-current", &wf_ad7417_adc_ops); | |
289 | ||
290 | return 0; | |
291 | } | |
292 | ||
1da42fb6 | 293 | static int wf_ad7417_remove(struct i2c_client *client) |
850dc321 BH |
294 | { |
295 | struct wf_ad7417_priv *pv = dev_get_drvdata(&client->dev); | |
296 | int i; | |
297 | ||
298 | /* Mark client detached */ | |
299 | pv->i2c = NULL; | |
300 | ||
301 | /* Release sensor */ | |
302 | for (i = 0; i < 5; i++) | |
303 | wf_unregister_sensor(&pv->sensors[i]); | |
304 | ||
305 | kref_put(&pv->ref, wf_ad7417_release); | |
306 | ||
307 | return 0; | |
308 | } | |
309 | ||
310 | static const struct i2c_device_id wf_ad7417_id[] = { | |
311 | { "MAC,ad7417", 0 }, | |
312 | { } | |
313 | }; | |
314 | MODULE_DEVICE_TABLE(i2c, wf_ad7417_id); | |
315 | ||
316 | static struct i2c_driver wf_ad7417_driver = { | |
317 | .driver = { | |
318 | .name = "wf_ad7417", | |
319 | }, | |
320 | .probe = wf_ad7417_probe, | |
321 | .remove = wf_ad7417_remove, | |
322 | .id_table = wf_ad7417_id, | |
323 | }; | |
324 | ||
1da42fb6 | 325 | static int wf_ad7417_init(void) |
850dc321 BH |
326 | { |
327 | /* This is only supported on these machines */ | |
328 | if (!of_machine_is_compatible("PowerMac7,2") && | |
329 | !of_machine_is_compatible("PowerMac7,3") && | |
330 | !of_machine_is_compatible("RackMac3,1")) | |
331 | return -ENODEV; | |
332 | ||
333 | return i2c_add_driver(&wf_ad7417_driver); | |
334 | } | |
335 | ||
1da42fb6 | 336 | static void wf_ad7417_exit(void) |
850dc321 BH |
337 | { |
338 | i2c_del_driver(&wf_ad7417_driver); | |
339 | } | |
340 | ||
341 | module_init(wf_ad7417_init); | |
342 | module_exit(wf_ad7417_exit); | |
343 | ||
344 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
345 | MODULE_DESCRIPTION("ad7417 sensor driver for PowerMacs"); | |
346 | MODULE_LICENSE("GPL"); | |
347 |