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2c162f9b | 1 | // SPDX-License-Identifier: GPL-2.0-only |
850dc321 BH |
2 | /* |
3 | * Windfarm PowerMac thermal control. AD7417 sensors | |
4 | * | |
5 | * Copyright 2012 Benjamin Herrenschmidt, IBM Corp. | |
850dc321 BH |
6 | */ |
7 | ||
8 | #include <linux/types.h> | |
9 | #include <linux/errno.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/delay.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/i2c.h> | |
16 | #include <asm/prom.h> | |
17 | #include <asm/machdep.h> | |
18 | #include <asm/io.h> | |
19 | #include <asm/sections.h> | |
20 | ||
21 | #include "windfarm.h" | |
22 | #include "windfarm_mpu.h" | |
23 | ||
24 | #define VERSION "1.0" | |
25 | ||
26 | struct wf_ad7417_priv { | |
27 | struct kref ref; | |
28 | struct i2c_client *i2c; | |
29 | u8 config; | |
30 | u8 cpu; | |
31 | const struct mpu_data *mpu; | |
32 | struct wf_sensor sensors[5]; | |
33 | struct mutex lock; | |
34 | }; | |
35 | ||
36 | static int wf_ad7417_temp_get(struct wf_sensor *sr, s32 *value) | |
37 | { | |
38 | struct wf_ad7417_priv *pv = sr->priv; | |
39 | u8 buf[2]; | |
40 | s16 raw; | |
41 | int rc; | |
42 | ||
43 | *value = 0; | |
44 | mutex_lock(&pv->lock); | |
45 | ||
46 | /* Read temp register */ | |
47 | buf[0] = 0; | |
48 | rc = i2c_master_send(pv->i2c, buf, 1); | |
49 | if (rc < 0) | |
50 | goto error; | |
51 | rc = i2c_master_recv(pv->i2c, buf, 2); | |
52 | if (rc < 0) | |
53 | goto error; | |
54 | ||
55 | /* Read a a 16-bit signed value */ | |
56 | raw = be16_to_cpup((__le16 *)buf); | |
57 | ||
58 | /* Convert 8.8-bit to 16.16 fixed point */ | |
59 | *value = ((s32)raw) << 8; | |
60 | ||
61 | mutex_unlock(&pv->lock); | |
62 | return 0; | |
63 | ||
64 | error: | |
65 | mutex_unlock(&pv->lock); | |
66 | return -1; | |
67 | } | |
68 | ||
69 | /* | |
70 | * Scaling factors for the AD7417 ADC converters (except | |
71 | * for the CPU diode which is obtained from the EEPROM). | |
72 | * Those values are obtained from the property list of | |
73 | * the darwin driver | |
74 | */ | |
75 | #define ADC_12V_CURRENT_SCALE 0x0320 /* _AD2 */ | |
76 | #define ADC_CPU_VOLTAGE_SCALE 0x00a0 /* _AD3 */ | |
77 | #define ADC_CPU_CURRENT_SCALE 0x1f40 /* _AD4 */ | |
78 | ||
79 | static void wf_ad7417_adc_convert(struct wf_ad7417_priv *pv, | |
80 | int chan, s32 raw, s32 *value) | |
81 | { | |
82 | switch(chan) { | |
83 | case 1: /* Diode */ | |
84 | *value = (raw * (s32)pv->mpu->mdiode + | |
85 | ((s32)pv->mpu->bdiode << 12)) >> 2; | |
86 | break; | |
87 | case 2: /* 12v current */ | |
88 | *value = raw * ADC_12V_CURRENT_SCALE; | |
89 | break; | |
90 | case 3: /* core voltage */ | |
91 | *value = raw * ADC_CPU_VOLTAGE_SCALE; | |
92 | break; | |
93 | case 4: /* core current */ | |
94 | *value = raw * ADC_CPU_CURRENT_SCALE; | |
95 | break; | |
96 | } | |
97 | } | |
98 | ||
99 | static int wf_ad7417_adc_get(struct wf_sensor *sr, s32 *value) | |
100 | { | |
101 | struct wf_ad7417_priv *pv = sr->priv; | |
102 | int chan = sr - pv->sensors; | |
103 | int i, rc; | |
104 | u8 buf[2]; | |
105 | u16 raw; | |
106 | ||
107 | *value = 0; | |
108 | mutex_lock(&pv->lock); | |
109 | for (i = 0; i < 10; i++) { | |
110 | /* Set channel */ | |
111 | buf[0] = 1; | |
112 | buf[1] = (pv->config & 0x1f) | (chan << 5); | |
113 | rc = i2c_master_send(pv->i2c, buf, 2); | |
114 | if (rc < 0) | |
115 | goto error; | |
116 | ||
117 | /* Wait for conversion */ | |
118 | msleep(1); | |
119 | ||
120 | /* Switch to data register */ | |
121 | buf[0] = 4; | |
122 | rc = i2c_master_send(pv->i2c, buf, 1); | |
123 | if (rc < 0) | |
124 | goto error; | |
125 | ||
126 | /* Read result */ | |
127 | rc = i2c_master_recv(pv->i2c, buf, 2); | |
128 | if (rc < 0) | |
129 | goto error; | |
130 | ||
131 | /* Read a a 16-bit signed value */ | |
132 | raw = be16_to_cpup((__le16 *)buf) >> 6; | |
133 | wf_ad7417_adc_convert(pv, chan, raw, value); | |
134 | ||
135 | dev_vdbg(&pv->i2c->dev, "ADC chan %d [%s]" | |
136 | " raw value: 0x%x, conv to: 0x%08x\n", | |
137 | chan, sr->name, raw, *value); | |
138 | ||
139 | mutex_unlock(&pv->lock); | |
140 | return 0; | |
141 | ||
142 | error: | |
143 | dev_dbg(&pv->i2c->dev, | |
144 | "Error reading ADC, try %d...\n", i); | |
145 | if (i < 9) | |
146 | msleep(10); | |
147 | } | |
148 | mutex_unlock(&pv->lock); | |
149 | return -1; | |
150 | } | |
151 | ||
152 | static void wf_ad7417_release(struct kref *ref) | |
153 | { | |
154 | struct wf_ad7417_priv *pv = container_of(ref, | |
155 | struct wf_ad7417_priv, ref); | |
156 | kfree(pv); | |
157 | } | |
158 | ||
159 | static void wf_ad7417_sensor_release(struct wf_sensor *sr) | |
160 | { | |
161 | struct wf_ad7417_priv *pv = sr->priv; | |
162 | ||
163 | kfree(sr->name); | |
164 | kref_put(&pv->ref, wf_ad7417_release); | |
165 | } | |
166 | ||
167 | static const struct wf_sensor_ops wf_ad7417_temp_ops = { | |
168 | .get_value = wf_ad7417_temp_get, | |
169 | .release = wf_ad7417_sensor_release, | |
170 | .owner = THIS_MODULE, | |
171 | }; | |
172 | ||
173 | static const struct wf_sensor_ops wf_ad7417_adc_ops = { | |
174 | .get_value = wf_ad7417_adc_get, | |
175 | .release = wf_ad7417_sensor_release, | |
176 | .owner = THIS_MODULE, | |
177 | }; | |
178 | ||
1da42fb6 GKH |
179 | static void wf_ad7417_add_sensor(struct wf_ad7417_priv *pv, |
180 | int index, const char *name, | |
181 | const struct wf_sensor_ops *ops) | |
850dc321 BH |
182 | { |
183 | pv->sensors[index].name = kasprintf(GFP_KERNEL, "%s-%d", name, pv->cpu); | |
184 | pv->sensors[index].priv = pv; | |
185 | pv->sensors[index].ops = ops; | |
186 | if (!wf_register_sensor(&pv->sensors[index])) | |
187 | kref_get(&pv->ref); | |
188 | } | |
189 | ||
1da42fb6 | 190 | static void wf_ad7417_init_chip(struct wf_ad7417_priv *pv) |
850dc321 BH |
191 | { |
192 | int rc; | |
193 | u8 buf[2]; | |
194 | u8 config = 0; | |
195 | ||
196 | /* | |
197 | * Read ADC the configuration register and cache it. We | |
198 | * also make sure Config2 contains proper values, I've seen | |
199 | * cases where we got stale grabage in there, thus preventing | |
200 | * proper reading of conv. values | |
201 | */ | |
202 | ||
203 | /* Clear Config2 */ | |
204 | buf[0] = 5; | |
205 | buf[1] = 0; | |
206 | i2c_master_send(pv->i2c, buf, 2); | |
207 | ||
208 | /* Read & cache Config1 */ | |
209 | buf[0] = 1; | |
210 | rc = i2c_master_send(pv->i2c, buf, 1); | |
211 | if (rc > 0) { | |
212 | rc = i2c_master_recv(pv->i2c, buf, 1); | |
213 | if (rc > 0) { | |
214 | config = buf[0]; | |
215 | ||
216 | dev_dbg(&pv->i2c->dev, "ADC config reg: %02x\n", | |
217 | config); | |
218 | ||
219 | /* Disable shutdown mode */ | |
220 | config &= 0xfe; | |
221 | buf[0] = 1; | |
222 | buf[1] = config; | |
223 | rc = i2c_master_send(pv->i2c, buf, 2); | |
224 | } | |
225 | } | |
226 | if (rc <= 0) | |
227 | dev_err(&pv->i2c->dev, "Error reading ADC config\n"); | |
228 | ||
229 | pv->config = config; | |
230 | } | |
231 | ||
1da42fb6 GKH |
232 | static int wf_ad7417_probe(struct i2c_client *client, |
233 | const struct i2c_device_id *id) | |
850dc321 BH |
234 | { |
235 | struct wf_ad7417_priv *pv; | |
236 | const struct mpu_data *mpu; | |
237 | const char *loc; | |
238 | int cpu_nr; | |
239 | ||
240 | loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL); | |
241 | if (!loc) { | |
242 | dev_warn(&client->dev, "Missing hwsensor-location property!\n"); | |
243 | return -ENXIO; | |
244 | } | |
245 | ||
246 | /* | |
247 | * Identify which CPU we belong to by looking at the first entry | |
248 | * in the hwsensor-location list | |
249 | */ | |
250 | if (!strncmp(loc, "CPU A", 5)) | |
251 | cpu_nr = 0; | |
252 | else if (!strncmp(loc, "CPU B", 5)) | |
253 | cpu_nr = 1; | |
254 | else { | |
255 | pr_err("wf_ad7417: Can't identify location %s\n", loc); | |
256 | return -ENXIO; | |
257 | } | |
258 | mpu = wf_get_mpu(cpu_nr); | |
259 | if (!mpu) { | |
260 | dev_err(&client->dev, "Failed to retrieve MPU data\n"); | |
261 | return -ENXIO; | |
262 | } | |
263 | ||
264 | pv = kzalloc(sizeof(struct wf_ad7417_priv), GFP_KERNEL); | |
265 | if (pv == NULL) | |
266 | return -ENODEV; | |
267 | ||
268 | kref_init(&pv->ref); | |
269 | mutex_init(&pv->lock); | |
270 | pv->i2c = client; | |
271 | pv->cpu = cpu_nr; | |
272 | pv->mpu = mpu; | |
273 | dev_set_drvdata(&client->dev, pv); | |
274 | ||
275 | /* Initialize the chip */ | |
276 | wf_ad7417_init_chip(pv); | |
277 | ||
278 | /* | |
279 | * We cannot rely on Apple device-tree giving us child | |
280 | * node with the names of the individual sensors so we | |
281 | * just hard code what we know about them | |
282 | */ | |
283 | wf_ad7417_add_sensor(pv, 0, "cpu-amb-temp", &wf_ad7417_temp_ops); | |
284 | wf_ad7417_add_sensor(pv, 1, "cpu-diode-temp", &wf_ad7417_adc_ops); | |
285 | wf_ad7417_add_sensor(pv, 2, "cpu-12v-current", &wf_ad7417_adc_ops); | |
286 | wf_ad7417_add_sensor(pv, 3, "cpu-voltage", &wf_ad7417_adc_ops); | |
287 | wf_ad7417_add_sensor(pv, 4, "cpu-current", &wf_ad7417_adc_ops); | |
288 | ||
289 | return 0; | |
290 | } | |
291 | ||
1da42fb6 | 292 | static int wf_ad7417_remove(struct i2c_client *client) |
850dc321 BH |
293 | { |
294 | struct wf_ad7417_priv *pv = dev_get_drvdata(&client->dev); | |
295 | int i; | |
296 | ||
297 | /* Mark client detached */ | |
298 | pv->i2c = NULL; | |
299 | ||
300 | /* Release sensor */ | |
301 | for (i = 0; i < 5; i++) | |
302 | wf_unregister_sensor(&pv->sensors[i]); | |
303 | ||
304 | kref_put(&pv->ref, wf_ad7417_release); | |
305 | ||
306 | return 0; | |
307 | } | |
308 | ||
309 | static const struct i2c_device_id wf_ad7417_id[] = { | |
310 | { "MAC,ad7417", 0 }, | |
311 | { } | |
312 | }; | |
313 | MODULE_DEVICE_TABLE(i2c, wf_ad7417_id); | |
314 | ||
bcf3588d WS |
315 | static const struct of_device_id wf_ad7417_of_id[] = { |
316 | { .compatible = "ad7417", }, | |
317 | { } | |
318 | }; | |
319 | MODULE_DEVICE_TABLE(of, wf_ad7417_of_id); | |
320 | ||
850dc321 BH |
321 | static struct i2c_driver wf_ad7417_driver = { |
322 | .driver = { | |
323 | .name = "wf_ad7417", | |
bcf3588d | 324 | .of_match_table = wf_ad7417_of_id, |
850dc321 BH |
325 | }, |
326 | .probe = wf_ad7417_probe, | |
327 | .remove = wf_ad7417_remove, | |
328 | .id_table = wf_ad7417_id, | |
329 | }; | |
330 | ||
1da42fb6 | 331 | static int wf_ad7417_init(void) |
850dc321 BH |
332 | { |
333 | /* This is only supported on these machines */ | |
334 | if (!of_machine_is_compatible("PowerMac7,2") && | |
335 | !of_machine_is_compatible("PowerMac7,3") && | |
336 | !of_machine_is_compatible("RackMac3,1")) | |
337 | return -ENODEV; | |
338 | ||
339 | return i2c_add_driver(&wf_ad7417_driver); | |
340 | } | |
341 | ||
1da42fb6 | 342 | static void wf_ad7417_exit(void) |
850dc321 BH |
343 | { |
344 | i2c_del_driver(&wf_ad7417_driver); | |
345 | } | |
346 | ||
347 | module_init(wf_ad7417_init); | |
348 | module_exit(wf_ad7417_exit); | |
349 | ||
350 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); | |
351 | MODULE_DESCRIPTION("ad7417 sensor driver for PowerMacs"); | |
352 | MODULE_LICENSE("GPL"); | |
353 |