diff options
author | Javier Martinez Canillas <javier.martinez@collabora.co.uk> | 2014-10-13 18:53:05 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-13 20:18:19 -0400 |
commit | a4d4121ba753737c89e42a8df22e4859069fcf25 (patch) | |
tree | 79192377d05621220a4894d674f446eb1e773a3c /drivers/rtc/rtc-max77802.c | |
parent | a20cd88e20e59ce11ebca84fac769654193c51e0 (diff) |
rtc: add driver for Maxim 77802 PMIC Real-Time-Clock
The MAX7802 PMIC has a Real-Time-Clock (RTC) with two alarms. This
patch adds support for the RTC and is based on a driver added by Simon
Glass to the Chrome OS kernel 3.8 tree.
[akpm@linux-foundation.org: add comment clarifying ffs() use]
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc/rtc-max77802.c')
-rw-r--r-- | drivers/rtc/rtc-max77802.c | 502 |
1 files changed, 502 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-max77802.c b/drivers/rtc/rtc-max77802.c new file mode 100644 index 000000000000..566471335b33 --- /dev/null +++ b/drivers/rtc/rtc-max77802.c | |||
@@ -0,0 +1,502 @@ | |||
1 | /* | ||
2 | * RTC driver for Maxim MAX77802 | ||
3 | * | ||
4 | * Copyright (C) 2013 Google, Inc | ||
5 | * | ||
6 | * Copyright (C) 2012 Samsung Electronics Co.Ltd | ||
7 | * | ||
8 | * based on rtc-max8997.c | ||
9 | * | ||
10 | * This program is free software; you can redistribute it and/or modify it | ||
11 | * under the terms of the GNU General Public License as published by the | ||
12 | * Free Software Foundation; either version 2 of the License, or (at your | ||
13 | * option) any later version. | ||
14 | * | ||
15 | */ | ||
16 | |||
17 | #include <linux/slab.h> | ||
18 | #include <linux/rtc.h> | ||
19 | #include <linux/delay.h> | ||
20 | #include <linux/mutex.h> | ||
21 | #include <linux/module.h> | ||
22 | #include <linux/platform_device.h> | ||
23 | #include <linux/mfd/max77686-private.h> | ||
24 | #include <linux/irqdomain.h> | ||
25 | #include <linux/regmap.h> | ||
26 | |||
27 | /* RTC Control Register */ | ||
28 | #define BCD_EN_SHIFT 0 | ||
29 | #define BCD_EN_MASK (1 << BCD_EN_SHIFT) | ||
30 | #define MODEL24_SHIFT 1 | ||
31 | #define MODEL24_MASK (1 << MODEL24_SHIFT) | ||
32 | /* RTC Update Register1 */ | ||
33 | #define RTC_UDR_SHIFT 0 | ||
34 | #define RTC_UDR_MASK (1 << RTC_UDR_SHIFT) | ||
35 | #define RTC_RBUDR_SHIFT 4 | ||
36 | #define RTC_RBUDR_MASK (1 << RTC_RBUDR_SHIFT) | ||
37 | /* RTC Hour register */ | ||
38 | #define HOUR_PM_SHIFT 6 | ||
39 | #define HOUR_PM_MASK (1 << HOUR_PM_SHIFT) | ||
40 | /* RTC Alarm Enable */ | ||
41 | #define ALARM_ENABLE_SHIFT 7 | ||
42 | #define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT) | ||
43 | |||
44 | /* For the RTCAE1 register, we write this value to enable the alarm */ | ||
45 | #define ALARM_ENABLE_VALUE 0x77 | ||
46 | |||
47 | #define MAX77802_RTC_UPDATE_DELAY_US 200 | ||
48 | |||
49 | enum { | ||
50 | RTC_SEC = 0, | ||
51 | RTC_MIN, | ||
52 | RTC_HOUR, | ||
53 | RTC_WEEKDAY, | ||
54 | RTC_MONTH, | ||
55 | RTC_YEAR, | ||
56 | RTC_DATE, | ||
57 | RTC_NR_TIME | ||
58 | }; | ||
59 | |||
60 | struct max77802_rtc_info { | ||
61 | struct device *dev; | ||
62 | struct max77686_dev *max77802; | ||
63 | struct i2c_client *rtc; | ||
64 | struct rtc_device *rtc_dev; | ||
65 | struct mutex lock; | ||
66 | |||
67 | struct regmap *regmap; | ||
68 | |||
69 | int virq; | ||
70 | int rtc_24hr_mode; | ||
71 | }; | ||
72 | |||
73 | enum MAX77802_RTC_OP { | ||
74 | MAX77802_RTC_WRITE, | ||
75 | MAX77802_RTC_READ, | ||
76 | }; | ||
77 | |||
78 | static void max77802_rtc_data_to_tm(u8 *data, struct rtc_time *tm, | ||
79 | int rtc_24hr_mode) | ||
80 | { | ||
81 | tm->tm_sec = data[RTC_SEC] & 0xff; | ||
82 | tm->tm_min = data[RTC_MIN] & 0xff; | ||
83 | if (rtc_24hr_mode) | ||
84 | tm->tm_hour = data[RTC_HOUR] & 0x1f; | ||
85 | else { | ||
86 | tm->tm_hour = data[RTC_HOUR] & 0x0f; | ||
87 | if (data[RTC_HOUR] & HOUR_PM_MASK) | ||
88 | tm->tm_hour += 12; | ||
89 | } | ||
90 | |||
91 | /* Only a single bit is set in data[], so fls() would be equivalent */ | ||
92 | tm->tm_wday = ffs(data[RTC_WEEKDAY] & 0xff) - 1; | ||
93 | tm->tm_mday = data[RTC_DATE] & 0x1f; | ||
94 | tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1; | ||
95 | |||
96 | tm->tm_year = data[RTC_YEAR] & 0xff; | ||
97 | tm->tm_yday = 0; | ||
98 | tm->tm_isdst = 0; | ||
99 | } | ||
100 | |||
101 | static int max77802_rtc_tm_to_data(struct rtc_time *tm, u8 *data) | ||
102 | { | ||
103 | data[RTC_SEC] = tm->tm_sec; | ||
104 | data[RTC_MIN] = tm->tm_min; | ||
105 | data[RTC_HOUR] = tm->tm_hour; | ||
106 | data[RTC_WEEKDAY] = 1 << tm->tm_wday; | ||
107 | data[RTC_DATE] = tm->tm_mday; | ||
108 | data[RTC_MONTH] = tm->tm_mon + 1; | ||
109 | data[RTC_YEAR] = tm->tm_year; | ||
110 | |||
111 | return 0; | ||
112 | } | ||
113 | |||
114 | static int max77802_rtc_update(struct max77802_rtc_info *info, | ||
115 | enum MAX77802_RTC_OP op) | ||
116 | { | ||
117 | int ret; | ||
118 | unsigned int data; | ||
119 | |||
120 | if (op == MAX77802_RTC_WRITE) | ||
121 | data = 1 << RTC_UDR_SHIFT; | ||
122 | else | ||
123 | data = 1 << RTC_RBUDR_SHIFT; | ||
124 | |||
125 | ret = regmap_update_bits(info->max77802->regmap, | ||
126 | MAX77802_RTC_UPDATE0, data, data); | ||
127 | if (ret < 0) | ||
128 | dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n", | ||
129 | __func__, ret, data); | ||
130 | else { | ||
131 | /* Minimum delay required before RTC update. */ | ||
132 | usleep_range(MAX77802_RTC_UPDATE_DELAY_US, | ||
133 | MAX77802_RTC_UPDATE_DELAY_US * 2); | ||
134 | } | ||
135 | |||
136 | return ret; | ||
137 | } | ||
138 | |||
139 | static int max77802_rtc_read_time(struct device *dev, struct rtc_time *tm) | ||
140 | { | ||
141 | struct max77802_rtc_info *info = dev_get_drvdata(dev); | ||
142 | u8 data[RTC_NR_TIME]; | ||
143 | int ret; | ||
144 | |||
145 | mutex_lock(&info->lock); | ||
146 | |||
147 | ret = max77802_rtc_update(info, MAX77802_RTC_READ); | ||
148 | if (ret < 0) | ||
149 | goto out; | ||
150 | |||
151 | ret = regmap_bulk_read(info->max77802->regmap, | ||
152 | MAX77802_RTC_SEC, data, RTC_NR_TIME); | ||
153 | if (ret < 0) { | ||
154 | dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, | ||
155 | ret); | ||
156 | goto out; | ||
157 | } | ||
158 | |||
159 | max77802_rtc_data_to_tm(data, tm, info->rtc_24hr_mode); | ||
160 | |||
161 | ret = rtc_valid_tm(tm); | ||
162 | |||
163 | out: | ||
164 | mutex_unlock(&info->lock); | ||
165 | return ret; | ||
166 | } | ||
167 | |||
168 | static int max77802_rtc_set_time(struct device *dev, struct rtc_time *tm) | ||
169 | { | ||
170 | struct max77802_rtc_info *info = dev_get_drvdata(dev); | ||
171 | u8 data[RTC_NR_TIME]; | ||
172 | int ret; | ||
173 | |||
174 | ret = max77802_rtc_tm_to_data(tm, data); | ||
175 | if (ret < 0) | ||
176 | return ret; | ||
177 | |||
178 | mutex_lock(&info->lock); | ||
179 | |||
180 | ret = regmap_bulk_write(info->max77802->regmap, | ||
181 | MAX77802_RTC_SEC, data, RTC_NR_TIME); | ||
182 | if (ret < 0) { | ||
183 | dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__, | ||
184 | ret); | ||
185 | goto out; | ||
186 | } | ||
187 | |||
188 | ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); | ||
189 | |||
190 | out: | ||
191 | mutex_unlock(&info->lock); | ||
192 | return ret; | ||
193 | } | ||
194 | |||
195 | static int max77802_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) | ||
196 | { | ||
197 | struct max77802_rtc_info *info = dev_get_drvdata(dev); | ||
198 | u8 data[RTC_NR_TIME]; | ||
199 | unsigned int val; | ||
200 | int ret; | ||
201 | |||
202 | mutex_lock(&info->lock); | ||
203 | |||
204 | ret = max77802_rtc_update(info, MAX77802_RTC_READ); | ||
205 | if (ret < 0) | ||
206 | goto out; | ||
207 | |||
208 | ret = regmap_bulk_read(info->max77802->regmap, | ||
209 | MAX77802_ALARM1_SEC, data, RTC_NR_TIME); | ||
210 | if (ret < 0) { | ||
211 | dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n", | ||
212 | __func__, __LINE__, ret); | ||
213 | goto out; | ||
214 | } | ||
215 | |||
216 | max77802_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode); | ||
217 | |||
218 | alrm->enabled = 0; | ||
219 | ret = regmap_read(info->max77802->regmap, | ||
220 | MAX77802_RTC_AE1, &val); | ||
221 | if (ret < 0) { | ||
222 | dev_err(info->dev, "%s:%d fail to read alarm enable(%d)\n", | ||
223 | __func__, __LINE__, ret); | ||
224 | goto out; | ||
225 | } | ||
226 | if (val) | ||
227 | alrm->enabled = 1; | ||
228 | |||
229 | alrm->pending = 0; | ||
230 | ret = regmap_read(info->max77802->regmap, MAX77802_REG_STATUS2, &val); | ||
231 | if (ret < 0) { | ||
232 | dev_err(info->dev, "%s:%d fail to read status2 reg(%d)\n", | ||
233 | __func__, __LINE__, ret); | ||
234 | goto out; | ||
235 | } | ||
236 | |||
237 | if (val & (1 << 2)) /* RTCA1 */ | ||
238 | alrm->pending = 1; | ||
239 | |||
240 | out: | ||
241 | mutex_unlock(&info->lock); | ||
242 | return 0; | ||
243 | } | ||
244 | |||
245 | static int max77802_rtc_stop_alarm(struct max77802_rtc_info *info) | ||
246 | { | ||
247 | int ret; | ||
248 | |||
249 | if (!mutex_is_locked(&info->lock)) | ||
250 | dev_warn(info->dev, "%s: should have mutex locked\n", __func__); | ||
251 | |||
252 | ret = max77802_rtc_update(info, MAX77802_RTC_READ); | ||
253 | if (ret < 0) | ||
254 | goto out; | ||
255 | |||
256 | ret = regmap_write(info->max77802->regmap, | ||
257 | MAX77802_RTC_AE1, 0); | ||
258 | if (ret < 0) { | ||
259 | dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", | ||
260 | __func__, ret); | ||
261 | goto out; | ||
262 | } | ||
263 | |||
264 | ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); | ||
265 | out: | ||
266 | return ret; | ||
267 | } | ||
268 | |||
269 | static int max77802_rtc_start_alarm(struct max77802_rtc_info *info) | ||
270 | { | ||
271 | int ret; | ||
272 | |||
273 | if (!mutex_is_locked(&info->lock)) | ||
274 | dev_warn(info->dev, "%s: should have mutex locked\n", | ||
275 | __func__); | ||
276 | |||
277 | ret = max77802_rtc_update(info, MAX77802_RTC_READ); | ||
278 | if (ret < 0) | ||
279 | goto out; | ||
280 | |||
281 | ret = regmap_write(info->max77802->regmap, | ||
282 | MAX77802_RTC_AE1, | ||
283 | ALARM_ENABLE_VALUE); | ||
284 | |||
285 | if (ret < 0) { | ||
286 | dev_err(info->dev, "%s: fail to read alarm reg(%d)\n", | ||
287 | __func__, ret); | ||
288 | goto out; | ||
289 | } | ||
290 | |||
291 | ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); | ||
292 | out: | ||
293 | return ret; | ||
294 | } | ||
295 | |||
296 | static int max77802_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) | ||
297 | { | ||
298 | struct max77802_rtc_info *info = dev_get_drvdata(dev); | ||
299 | u8 data[RTC_NR_TIME]; | ||
300 | int ret; | ||
301 | |||
302 | ret = max77802_rtc_tm_to_data(&alrm->time, data); | ||
303 | if (ret < 0) | ||
304 | return ret; | ||
305 | |||
306 | mutex_lock(&info->lock); | ||
307 | |||
308 | ret = max77802_rtc_stop_alarm(info); | ||
309 | if (ret < 0) | ||
310 | goto out; | ||
311 | |||
312 | ret = regmap_bulk_write(info->max77802->regmap, | ||
313 | MAX77802_ALARM1_SEC, data, RTC_NR_TIME); | ||
314 | |||
315 | if (ret < 0) { | ||
316 | dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", | ||
317 | __func__, ret); | ||
318 | goto out; | ||
319 | } | ||
320 | |||
321 | ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); | ||
322 | if (ret < 0) | ||
323 | goto out; | ||
324 | |||
325 | if (alrm->enabled) | ||
326 | ret = max77802_rtc_start_alarm(info); | ||
327 | out: | ||
328 | mutex_unlock(&info->lock); | ||
329 | return ret; | ||
330 | } | ||
331 | |||
332 | static int max77802_rtc_alarm_irq_enable(struct device *dev, | ||
333 | unsigned int enabled) | ||
334 | { | ||
335 | struct max77802_rtc_info *info = dev_get_drvdata(dev); | ||
336 | int ret; | ||
337 | |||
338 | mutex_lock(&info->lock); | ||
339 | if (enabled) | ||
340 | ret = max77802_rtc_start_alarm(info); | ||
341 | else | ||
342 | ret = max77802_rtc_stop_alarm(info); | ||
343 | mutex_unlock(&info->lock); | ||
344 | |||
345 | return ret; | ||
346 | } | ||
347 | |||
348 | static irqreturn_t max77802_rtc_alarm_irq(int irq, void *data) | ||
349 | { | ||
350 | struct max77802_rtc_info *info = data; | ||
351 | |||
352 | dev_dbg(info->dev, "%s:irq(%d)\n", __func__, irq); | ||
353 | |||
354 | rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); | ||
355 | |||
356 | return IRQ_HANDLED; | ||
357 | } | ||
358 | |||
359 | static const struct rtc_class_ops max77802_rtc_ops = { | ||
360 | .read_time = max77802_rtc_read_time, | ||
361 | .set_time = max77802_rtc_set_time, | ||
362 | .read_alarm = max77802_rtc_read_alarm, | ||
363 | .set_alarm = max77802_rtc_set_alarm, | ||
364 | .alarm_irq_enable = max77802_rtc_alarm_irq_enable, | ||
365 | }; | ||
366 | |||
367 | static int max77802_rtc_init_reg(struct max77802_rtc_info *info) | ||
368 | { | ||
369 | u8 data[2]; | ||
370 | int ret; | ||
371 | |||
372 | max77802_rtc_update(info, MAX77802_RTC_READ); | ||
373 | |||
374 | /* Set RTC control register : Binary mode, 24hour mdoe */ | ||
375 | data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); | ||
376 | data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); | ||
377 | |||
378 | info->rtc_24hr_mode = 1; | ||
379 | |||
380 | ret = regmap_bulk_write(info->max77802->regmap, | ||
381 | MAX77802_RTC_CONTROLM, data, ARRAY_SIZE(data)); | ||
382 | if (ret < 0) { | ||
383 | dev_err(info->dev, "%s: fail to write controlm reg(%d)\n", | ||
384 | __func__, ret); | ||
385 | return ret; | ||
386 | } | ||
387 | |||
388 | ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); | ||
389 | return ret; | ||
390 | } | ||
391 | |||
392 | static int max77802_rtc_probe(struct platform_device *pdev) | ||
393 | { | ||
394 | struct max77686_dev *max77802 = dev_get_drvdata(pdev->dev.parent); | ||
395 | struct max77802_rtc_info *info; | ||
396 | int ret; | ||
397 | |||
398 | dev_dbg(&pdev->dev, "%s\n", __func__); | ||
399 | |||
400 | info = devm_kzalloc(&pdev->dev, sizeof(struct max77802_rtc_info), | ||
401 | GFP_KERNEL); | ||
402 | if (!info) | ||
403 | return -ENOMEM; | ||
404 | |||
405 | mutex_init(&info->lock); | ||
406 | info->dev = &pdev->dev; | ||
407 | info->max77802 = max77802; | ||
408 | info->rtc = max77802->i2c; | ||
409 | |||
410 | platform_set_drvdata(pdev, info); | ||
411 | |||
412 | ret = max77802_rtc_init_reg(info); | ||
413 | |||
414 | if (ret < 0) { | ||
415 | dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret); | ||
416 | return ret; | ||
417 | } | ||
418 | |||
419 | device_init_wakeup(&pdev->dev, 1); | ||
420 | |||
421 | info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max77802-rtc", | ||
422 | &max77802_rtc_ops, THIS_MODULE); | ||
423 | |||
424 | if (IS_ERR(info->rtc_dev)) { | ||
425 | ret = PTR_ERR(info->rtc_dev); | ||
426 | dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); | ||
427 | if (ret == 0) | ||
428 | ret = -EINVAL; | ||
429 | return ret; | ||
430 | } | ||
431 | |||
432 | if (!max77802->rtc_irq_data) { | ||
433 | dev_err(&pdev->dev, "No RTC regmap IRQ chip\n"); | ||
434 | return -EINVAL; | ||
435 | } | ||
436 | |||
437 | info->virq = regmap_irq_get_virq(max77802->rtc_irq_data, | ||
438 | MAX77686_RTCIRQ_RTCA1); | ||
439 | |||
440 | if (info->virq <= 0) { | ||
441 | dev_err(&pdev->dev, "Failed to get virtual IRQ %d\n", | ||
442 | MAX77686_RTCIRQ_RTCA1); | ||
443 | return -EINVAL; | ||
444 | } | ||
445 | |||
446 | ret = devm_request_threaded_irq(&pdev->dev, info->virq, NULL, | ||
447 | max77802_rtc_alarm_irq, 0, "rtc-alarm1", | ||
448 | info); | ||
449 | if (ret < 0) | ||
450 | dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", | ||
451 | info->virq, ret); | ||
452 | |||
453 | return ret; | ||
454 | } | ||
455 | |||
456 | #ifdef CONFIG_PM_SLEEP | ||
457 | static int max77802_rtc_suspend(struct device *dev) | ||
458 | { | ||
459 | if (device_may_wakeup(dev)) { | ||
460 | struct max77802_rtc_info *info = dev_get_drvdata(dev); | ||
461 | |||
462 | return enable_irq_wake(info->virq); | ||
463 | } | ||
464 | |||
465 | return 0; | ||
466 | } | ||
467 | |||
468 | static int max77802_rtc_resume(struct device *dev) | ||
469 | { | ||
470 | if (device_may_wakeup(dev)) { | ||
471 | struct max77802_rtc_info *info = dev_get_drvdata(dev); | ||
472 | |||
473 | return disable_irq_wake(info->virq); | ||
474 | } | ||
475 | |||
476 | return 0; | ||
477 | } | ||
478 | #endif | ||
479 | |||
480 | static SIMPLE_DEV_PM_OPS(max77802_rtc_pm_ops, | ||
481 | max77802_rtc_suspend, max77802_rtc_resume); | ||
482 | |||
483 | static const struct platform_device_id rtc_id[] = { | ||
484 | { "max77802-rtc", 0 }, | ||
485 | {}, | ||
486 | }; | ||
487 | |||
488 | static struct platform_driver max77802_rtc_driver = { | ||
489 | .driver = { | ||
490 | .name = "max77802-rtc", | ||
491 | .owner = THIS_MODULE, | ||
492 | .pm = &max77802_rtc_pm_ops, | ||
493 | }, | ||
494 | .probe = max77802_rtc_probe, | ||
495 | .id_table = rtc_id, | ||
496 | }; | ||
497 | |||
498 | module_platform_driver(max77802_rtc_driver); | ||
499 | |||
500 | MODULE_DESCRIPTION("Maxim MAX77802 RTC driver"); | ||
501 | MODULE_AUTHOR("Simon Glass <sjg@chromium.org>"); | ||
502 | MODULE_LICENSE("GPL"); | ||