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1/*
2 * Real Time Clock driver for Wolfson Microelectronics WM831x
3 *
4 * Copyright (C) 2009 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/time.h>
18#include <linux/rtc.h>
19#include <linux/slab.h>
20#include <linux/bcd.h>
21#include <linux/interrupt.h>
22#include <linux/ioctl.h>
23#include <linux/completion.h>
24#include <linux/mfd/wm831x/core.h>
25#include <linux/delay.h>
26#include <linux/platform_device.h>
27#include <linux/random.h>
28
29/*
30 * R16416 (0x4020) - RTC Write Counter
31 */
32#define WM831X_RTC_WR_CNT_MASK 0xFFFF /* RTC_WR_CNT - [15:0] */
33#define WM831X_RTC_WR_CNT_SHIFT 0 /* RTC_WR_CNT - [15:0] */
34#define WM831X_RTC_WR_CNT_WIDTH 16 /* RTC_WR_CNT - [15:0] */
35
36/*
37 * R16417 (0x4021) - RTC Time 1
38 */
39#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
40#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
41#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
42
43/*
44 * R16418 (0x4022) - RTC Time 2
45 */
46#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
47#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
48#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
49
50/*
51 * R16419 (0x4023) - RTC Alarm 1
52 */
53#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
54#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
55#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
56
57/*
58 * R16420 (0x4024) - RTC Alarm 2
59 */
60#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
61#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
62#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
63
64/*
65 * R16421 (0x4025) - RTC Control
66 */
67#define WM831X_RTC_VALID 0x8000 /* RTC_VALID */
68#define WM831X_RTC_VALID_MASK 0x8000 /* RTC_VALID */
69#define WM831X_RTC_VALID_SHIFT 15 /* RTC_VALID */
70#define WM831X_RTC_VALID_WIDTH 1 /* RTC_VALID */
71#define WM831X_RTC_SYNC_BUSY 0x4000 /* RTC_SYNC_BUSY */
72#define WM831X_RTC_SYNC_BUSY_MASK 0x4000 /* RTC_SYNC_BUSY */
73#define WM831X_RTC_SYNC_BUSY_SHIFT 14 /* RTC_SYNC_BUSY */
74#define WM831X_RTC_SYNC_BUSY_WIDTH 1 /* RTC_SYNC_BUSY */
75#define WM831X_RTC_ALM_ENA 0x0400 /* RTC_ALM_ENA */
76#define WM831X_RTC_ALM_ENA_MASK 0x0400 /* RTC_ALM_ENA */
77#define WM831X_RTC_ALM_ENA_SHIFT 10 /* RTC_ALM_ENA */
78#define WM831X_RTC_ALM_ENA_WIDTH 1 /* RTC_ALM_ENA */
79#define WM831X_RTC_PINT_FREQ_MASK 0x0070 /* RTC_PINT_FREQ - [6:4] */
80#define WM831X_RTC_PINT_FREQ_SHIFT 4 /* RTC_PINT_FREQ - [6:4] */
81#define WM831X_RTC_PINT_FREQ_WIDTH 3 /* RTC_PINT_FREQ - [6:4] */
82
83/*
84 * R16422 (0x4026) - RTC Trim
85 */
86#define WM831X_RTC_TRIM_MASK 0x03FF /* RTC_TRIM - [9:0] */
87#define WM831X_RTC_TRIM_SHIFT 0 /* RTC_TRIM - [9:0] */
88#define WM831X_RTC_TRIM_WIDTH 10 /* RTC_TRIM - [9:0] */
89
90#define WM831X_SET_TIME_RETRIES 5
91#define WM831X_GET_TIME_RETRIES 5
92
93struct wm831x_rtc {
94 struct wm831x *wm831x;
95 struct rtc_device *rtc;
96 unsigned int alarm_enabled:1;
97};
98
99static void wm831x_rtc_add_randomness(struct wm831x *wm831x)
100{
101 int ret;
102 u16 reg;
103
104 /*
105 * The write counter contains a pseudo-random number which is
106 * regenerated every time we set the RTC so it should be a
107 * useful per-system source of entropy.
108 */
109 ret = wm831x_reg_read(wm831x, WM831X_RTC_WRITE_COUNTER);
110 if (ret >= 0) {
111 reg = ret;
112 add_device_randomness(®, sizeof(reg));
113 } else {
114 dev_warn(wm831x->dev, "Failed to read RTC write counter: %d\n",
115 ret);
116 }
117}
118
119/*
120 * Read current time and date in RTC
121 */
122static int wm831x_rtc_readtime(struct device *dev, struct rtc_time *tm)
123{
124 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
125 struct wm831x *wm831x = wm831x_rtc->wm831x;
126 u16 time1[2], time2[2];
127 int ret;
128 int count = 0;
129
130 /* Has the RTC been programmed? */
131 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
132 if (ret < 0) {
133 dev_err(dev, "Failed to read RTC control: %d\n", ret);
134 return ret;
135 }
136 if (!(ret & WM831X_RTC_VALID)) {
137 dev_dbg(dev, "RTC not yet configured\n");
138 return -EINVAL;
139 }
140
141 /* Read twice to make sure we don't read a corrupt, partially
142 * incremented, value.
143 */
144 do {
145 ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
146 2, time1);
147 if (ret != 0)
148 continue;
149
150 ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
151 2, time2);
152 if (ret != 0)
153 continue;
154
155 if (memcmp(time1, time2, sizeof(time1)) == 0) {
156 u32 time = (time1[0] << 16) | time1[1];
157
158 rtc_time_to_tm(time, tm);
159 return rtc_valid_tm(tm);
160 }
161
162 } while (++count < WM831X_GET_TIME_RETRIES);
163
164 dev_err(dev, "Timed out reading current time\n");
165
166 return -EIO;
167}
168
169/*
170 * Set current time and date in RTC
171 */
172static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
173{
174 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
175 struct wm831x *wm831x = wm831x_rtc->wm831x;
176 struct rtc_time new_tm;
177 unsigned long new_time;
178 int ret;
179 int count = 0;
180
181 ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
182 (time >> 16) & 0xffff);
183 if (ret < 0) {
184 dev_err(dev, "Failed to write TIME_1: %d\n", ret);
185 return ret;
186 }
187
188 ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
189 if (ret < 0) {
190 dev_err(dev, "Failed to write TIME_2: %d\n", ret);
191 return ret;
192 }
193
194 /* Wait for the update to complete - should happen first time
195 * round but be conservative.
196 */
197 do {
198 msleep(1);
199
200 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
201 if (ret < 0)
202 ret = WM831X_RTC_SYNC_BUSY;
203 } while (!(ret & WM831X_RTC_SYNC_BUSY) &&
204 ++count < WM831X_SET_TIME_RETRIES);
205
206 if (ret & WM831X_RTC_SYNC_BUSY) {
207 dev_err(dev, "Timed out writing RTC update\n");
208 return -EIO;
209 }
210
211 /* Check that the update was accepted; security features may
212 * have caused the update to be ignored.
213 */
214 ret = wm831x_rtc_readtime(dev, &new_tm);
215 if (ret < 0)
216 return ret;
217
218 ret = rtc_tm_to_time(&new_tm, &new_time);
219 if (ret < 0) {
220 dev_err(dev, "Failed to convert time: %d\n", ret);
221 return ret;
222 }
223
224 /* Allow a second of change in case of tick */
225 if (new_time - time > 1) {
226 dev_err(dev, "RTC update not permitted by hardware\n");
227 return -EPERM;
228 }
229
230 return 0;
231}
232
233/*
234 * Read alarm time and date in RTC
235 */
236static int wm831x_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
237{
238 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
239 int ret;
240 u16 data[2];
241 u32 time;
242
243 ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
244 2, data);
245 if (ret != 0) {
246 dev_err(dev, "Failed to read alarm time: %d\n", ret);
247 return ret;
248 }
249
250 time = (data[0] << 16) | data[1];
251
252 rtc_time_to_tm(time, &alrm->time);
253
254 ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
255 if (ret < 0) {
256 dev_err(dev, "Failed to read RTC control: %d\n", ret);
257 return ret;
258 }
259
260 if (ret & WM831X_RTC_ALM_ENA)
261 alrm->enabled = 1;
262 else
263 alrm->enabled = 0;
264
265 return 0;
266}
267
268static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
269{
270 wm831x_rtc->alarm_enabled = 0;
271
272 return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
273 WM831X_RTC_ALM_ENA, 0);
274}
275
276static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
277{
278 wm831x_rtc->alarm_enabled = 1;
279
280 return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
281 WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
282}
283
284static int wm831x_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
285{
286 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
287 struct wm831x *wm831x = wm831x_rtc->wm831x;
288 int ret;
289 unsigned long time;
290
291 ret = rtc_tm_to_time(&alrm->time, &time);
292 if (ret < 0) {
293 dev_err(dev, "Failed to convert time: %d\n", ret);
294 return ret;
295 }
296
297 ret = wm831x_rtc_stop_alarm(wm831x_rtc);
298 if (ret < 0) {
299 dev_err(dev, "Failed to stop alarm: %d\n", ret);
300 return ret;
301 }
302
303 ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
304 (time >> 16) & 0xffff);
305 if (ret < 0) {
306 dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
307 return ret;
308 }
309
310 ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
311 if (ret < 0) {
312 dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
313 return ret;
314 }
315
316 if (alrm->enabled) {
317 ret = wm831x_rtc_start_alarm(wm831x_rtc);
318 if (ret < 0) {
319 dev_err(dev, "Failed to start alarm: %d\n", ret);
320 return ret;
321 }
322 }
323
324 return 0;
325}
326
327static int wm831x_rtc_alarm_irq_enable(struct device *dev,
328 unsigned int enabled)
329{
330 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
331
332 if (enabled)
333 return wm831x_rtc_start_alarm(wm831x_rtc);
334 else
335 return wm831x_rtc_stop_alarm(wm831x_rtc);
336}
337
338static irqreturn_t wm831x_alm_irq(int irq, void *data)
339{
340 struct wm831x_rtc *wm831x_rtc = data;
341
342 rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_AF);
343
344 return IRQ_HANDLED;
345}
346
347static const struct rtc_class_ops wm831x_rtc_ops = {
348 .read_time = wm831x_rtc_readtime,
349 .set_mmss = wm831x_rtc_set_mmss,
350 .read_alarm = wm831x_rtc_readalarm,
351 .set_alarm = wm831x_rtc_setalarm,
352 .alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
353};
354
355#ifdef CONFIG_PM
356/* Turn off the alarm if it should not be a wake source. */
357static int wm831x_rtc_suspend(struct device *dev)
358{
359 struct platform_device *pdev = to_platform_device(dev);
360 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
361 int ret, enable;
362
363 if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
364 enable = WM831X_RTC_ALM_ENA;
365 else
366 enable = 0;
367
368 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
369 WM831X_RTC_ALM_ENA, enable);
370 if (ret != 0)
371 dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
372
373 return 0;
374}
375
376/* Enable the alarm if it should be enabled (in case it was disabled to
377 * prevent use as a wake source).
378 */
379static int wm831x_rtc_resume(struct device *dev)
380{
381 struct platform_device *pdev = to_platform_device(dev);
382 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
383 int ret;
384
385 if (wm831x_rtc->alarm_enabled) {
386 ret = wm831x_rtc_start_alarm(wm831x_rtc);
387 if (ret != 0)
388 dev_err(&pdev->dev,
389 "Failed to restart RTC alarm: %d\n", ret);
390 }
391
392 return 0;
393}
394
395/* Unconditionally disable the alarm */
396static int wm831x_rtc_freeze(struct device *dev)
397{
398 struct platform_device *pdev = to_platform_device(dev);
399 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
400 int ret;
401
402 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
403 WM831X_RTC_ALM_ENA, 0);
404 if (ret != 0)
405 dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
406
407 return 0;
408}
409#else
410#define wm831x_rtc_suspend NULL
411#define wm831x_rtc_resume NULL
412#define wm831x_rtc_freeze NULL
413#endif
414
415static int wm831x_rtc_probe(struct platform_device *pdev)
416{
417 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
418 struct wm831x_rtc *wm831x_rtc;
419 int alm_irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "ALM"));
420 int ret = 0;
421
422 wm831x_rtc = devm_kzalloc(&pdev->dev, sizeof(*wm831x_rtc), GFP_KERNEL);
423 if (wm831x_rtc == NULL)
424 return -ENOMEM;
425
426 platform_set_drvdata(pdev, wm831x_rtc);
427 wm831x_rtc->wm831x = wm831x;
428
429 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
430 if (ret < 0) {
431 dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
432 goto err;
433 }
434 if (ret & WM831X_RTC_ALM_ENA)
435 wm831x_rtc->alarm_enabled = 1;
436
437 device_init_wakeup(&pdev->dev, 1);
438
439 wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
440 &wm831x_rtc_ops, THIS_MODULE);
441 if (IS_ERR(wm831x_rtc->rtc)) {
442 ret = PTR_ERR(wm831x_rtc->rtc);
443 goto err;
444 }
445
446 ret = request_threaded_irq(alm_irq, NULL, wm831x_alm_irq,
447 IRQF_TRIGGER_RISING, "RTC alarm",
448 wm831x_rtc);
449 if (ret != 0) {
450 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
451 alm_irq, ret);
452 }
453
454 wm831x_rtc_add_randomness(wm831x);
455
456 return 0;
457
458err:
459 return ret;
460}
461
462static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
463{
464 struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
465 int alm_irq = platform_get_irq_byname(pdev, "ALM");
466
467 free_irq(alm_irq, wm831x_rtc);
468 rtc_device_unregister(wm831x_rtc->rtc);
469
470 return 0;
471}
472
473static const struct dev_pm_ops wm831x_rtc_pm_ops = {
474 .suspend = wm831x_rtc_suspend,
475 .resume = wm831x_rtc_resume,
476
477 .freeze = wm831x_rtc_freeze,
478 .thaw = wm831x_rtc_resume,
479 .restore = wm831x_rtc_resume,
480
481 .poweroff = wm831x_rtc_suspend,
482};
483
484static struct platform_driver wm831x_rtc_driver = {
485 .probe = wm831x_rtc_probe,
486 .remove = __devexit_p(wm831x_rtc_remove),
487 .driver = {
488 .name = "wm831x-rtc",
489 .pm = &wm831x_rtc_pm_ops,
490 },
491};
492
493module_platform_driver(wm831x_rtc_driver);
494
495MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
496MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
497MODULE_LICENSE("GPL");
498MODULE_ALIAS("platform:wm831x-rtc");
1/*
2 * Real Time Clock driver for Wolfson Microelectronics WM831x
3 *
4 * Copyright (C) 2009 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/time.h>
18#include <linux/rtc.h>
19#include <linux/slab.h>
20#include <linux/bcd.h>
21#include <linux/interrupt.h>
22#include <linux/ioctl.h>
23#include <linux/completion.h>
24#include <linux/mfd/wm831x/core.h>
25#include <linux/delay.h>
26#include <linux/platform_device.h>
27
28
29/*
30 * R16416 (0x4020) - RTC Write Counter
31 */
32#define WM831X_RTC_WR_CNT_MASK 0xFFFF /* RTC_WR_CNT - [15:0] */
33#define WM831X_RTC_WR_CNT_SHIFT 0 /* RTC_WR_CNT - [15:0] */
34#define WM831X_RTC_WR_CNT_WIDTH 16 /* RTC_WR_CNT - [15:0] */
35
36/*
37 * R16417 (0x4021) - RTC Time 1
38 */
39#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
40#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
41#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
42
43/*
44 * R16418 (0x4022) - RTC Time 2
45 */
46#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
47#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
48#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
49
50/*
51 * R16419 (0x4023) - RTC Alarm 1
52 */
53#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
54#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
55#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
56
57/*
58 * R16420 (0x4024) - RTC Alarm 2
59 */
60#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
61#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
62#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
63
64/*
65 * R16421 (0x4025) - RTC Control
66 */
67#define WM831X_RTC_VALID 0x8000 /* RTC_VALID */
68#define WM831X_RTC_VALID_MASK 0x8000 /* RTC_VALID */
69#define WM831X_RTC_VALID_SHIFT 15 /* RTC_VALID */
70#define WM831X_RTC_VALID_WIDTH 1 /* RTC_VALID */
71#define WM831X_RTC_SYNC_BUSY 0x4000 /* RTC_SYNC_BUSY */
72#define WM831X_RTC_SYNC_BUSY_MASK 0x4000 /* RTC_SYNC_BUSY */
73#define WM831X_RTC_SYNC_BUSY_SHIFT 14 /* RTC_SYNC_BUSY */
74#define WM831X_RTC_SYNC_BUSY_WIDTH 1 /* RTC_SYNC_BUSY */
75#define WM831X_RTC_ALM_ENA 0x0400 /* RTC_ALM_ENA */
76#define WM831X_RTC_ALM_ENA_MASK 0x0400 /* RTC_ALM_ENA */
77#define WM831X_RTC_ALM_ENA_SHIFT 10 /* RTC_ALM_ENA */
78#define WM831X_RTC_ALM_ENA_WIDTH 1 /* RTC_ALM_ENA */
79#define WM831X_RTC_PINT_FREQ_MASK 0x0070 /* RTC_PINT_FREQ - [6:4] */
80#define WM831X_RTC_PINT_FREQ_SHIFT 4 /* RTC_PINT_FREQ - [6:4] */
81#define WM831X_RTC_PINT_FREQ_WIDTH 3 /* RTC_PINT_FREQ - [6:4] */
82
83/*
84 * R16422 (0x4026) - RTC Trim
85 */
86#define WM831X_RTC_TRIM_MASK 0x03FF /* RTC_TRIM - [9:0] */
87#define WM831X_RTC_TRIM_SHIFT 0 /* RTC_TRIM - [9:0] */
88#define WM831X_RTC_TRIM_WIDTH 10 /* RTC_TRIM - [9:0] */
89
90#define WM831X_SET_TIME_RETRIES 5
91#define WM831X_GET_TIME_RETRIES 5
92
93struct wm831x_rtc {
94 struct wm831x *wm831x;
95 struct rtc_device *rtc;
96 unsigned int alarm_enabled:1;
97};
98
99/*
100 * Read current time and date in RTC
101 */
102static int wm831x_rtc_readtime(struct device *dev, struct rtc_time *tm)
103{
104 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
105 struct wm831x *wm831x = wm831x_rtc->wm831x;
106 u16 time1[2], time2[2];
107 int ret;
108 int count = 0;
109
110 /* Has the RTC been programmed? */
111 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
112 if (ret < 0) {
113 dev_err(dev, "Failed to read RTC control: %d\n", ret);
114 return ret;
115 }
116 if (!(ret & WM831X_RTC_VALID)) {
117 dev_dbg(dev, "RTC not yet configured\n");
118 return -EINVAL;
119 }
120
121 /* Read twice to make sure we don't read a corrupt, partially
122 * incremented, value.
123 */
124 do {
125 ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
126 2, time1);
127 if (ret != 0)
128 continue;
129
130 ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
131 2, time2);
132 if (ret != 0)
133 continue;
134
135 if (memcmp(time1, time2, sizeof(time1)) == 0) {
136 u32 time = (time1[0] << 16) | time1[1];
137
138 rtc_time_to_tm(time, tm);
139 return rtc_valid_tm(tm);
140 }
141
142 } while (++count < WM831X_GET_TIME_RETRIES);
143
144 dev_err(dev, "Timed out reading current time\n");
145
146 return -EIO;
147}
148
149/*
150 * Set current time and date in RTC
151 */
152static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
153{
154 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
155 struct wm831x *wm831x = wm831x_rtc->wm831x;
156 struct rtc_time new_tm;
157 unsigned long new_time;
158 int ret;
159 int count = 0;
160
161 ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
162 (time >> 16) & 0xffff);
163 if (ret < 0) {
164 dev_err(dev, "Failed to write TIME_1: %d\n", ret);
165 return ret;
166 }
167
168 ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
169 if (ret < 0) {
170 dev_err(dev, "Failed to write TIME_2: %d\n", ret);
171 return ret;
172 }
173
174 /* Wait for the update to complete - should happen first time
175 * round but be conservative.
176 */
177 do {
178 msleep(1);
179
180 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
181 if (ret < 0)
182 ret = WM831X_RTC_SYNC_BUSY;
183 } while (!(ret & WM831X_RTC_SYNC_BUSY) &&
184 ++count < WM831X_SET_TIME_RETRIES);
185
186 if (ret & WM831X_RTC_SYNC_BUSY) {
187 dev_err(dev, "Timed out writing RTC update\n");
188 return -EIO;
189 }
190
191 /* Check that the update was accepted; security features may
192 * have caused the update to be ignored.
193 */
194 ret = wm831x_rtc_readtime(dev, &new_tm);
195 if (ret < 0)
196 return ret;
197
198 ret = rtc_tm_to_time(&new_tm, &new_time);
199 if (ret < 0) {
200 dev_err(dev, "Failed to convert time: %d\n", ret);
201 return ret;
202 }
203
204 /* Allow a second of change in case of tick */
205 if (new_time - time > 1) {
206 dev_err(dev, "RTC update not permitted by hardware\n");
207 return -EPERM;
208 }
209
210 return 0;
211}
212
213/*
214 * Read alarm time and date in RTC
215 */
216static int wm831x_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
217{
218 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
219 int ret;
220 u16 data[2];
221 u32 time;
222
223 ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
224 2, data);
225 if (ret != 0) {
226 dev_err(dev, "Failed to read alarm time: %d\n", ret);
227 return ret;
228 }
229
230 time = (data[0] << 16) | data[1];
231
232 rtc_time_to_tm(time, &alrm->time);
233
234 ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
235 if (ret < 0) {
236 dev_err(dev, "Failed to read RTC control: %d\n", ret);
237 return ret;
238 }
239
240 if (ret & WM831X_RTC_ALM_ENA)
241 alrm->enabled = 1;
242 else
243 alrm->enabled = 0;
244
245 return 0;
246}
247
248static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
249{
250 wm831x_rtc->alarm_enabled = 0;
251
252 return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
253 WM831X_RTC_ALM_ENA, 0);
254}
255
256static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
257{
258 wm831x_rtc->alarm_enabled = 1;
259
260 return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
261 WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
262}
263
264static int wm831x_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
265{
266 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
267 struct wm831x *wm831x = wm831x_rtc->wm831x;
268 int ret;
269 unsigned long time;
270
271 ret = rtc_tm_to_time(&alrm->time, &time);
272 if (ret < 0) {
273 dev_err(dev, "Failed to convert time: %d\n", ret);
274 return ret;
275 }
276
277 ret = wm831x_rtc_stop_alarm(wm831x_rtc);
278 if (ret < 0) {
279 dev_err(dev, "Failed to stop alarm: %d\n", ret);
280 return ret;
281 }
282
283 ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
284 (time >> 16) & 0xffff);
285 if (ret < 0) {
286 dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
287 return ret;
288 }
289
290 ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
291 if (ret < 0) {
292 dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
293 return ret;
294 }
295
296 if (alrm->enabled) {
297 ret = wm831x_rtc_start_alarm(wm831x_rtc);
298 if (ret < 0) {
299 dev_err(dev, "Failed to start alarm: %d\n", ret);
300 return ret;
301 }
302 }
303
304 return 0;
305}
306
307static int wm831x_rtc_alarm_irq_enable(struct device *dev,
308 unsigned int enabled)
309{
310 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
311
312 if (enabled)
313 return wm831x_rtc_start_alarm(wm831x_rtc);
314 else
315 return wm831x_rtc_stop_alarm(wm831x_rtc);
316}
317
318static irqreturn_t wm831x_alm_irq(int irq, void *data)
319{
320 struct wm831x_rtc *wm831x_rtc = data;
321
322 rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_AF);
323
324 return IRQ_HANDLED;
325}
326
327static irqreturn_t wm831x_per_irq(int irq, void *data)
328{
329 struct wm831x_rtc *wm831x_rtc = data;
330
331 rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_UF);
332
333 return IRQ_HANDLED;
334}
335
336static const struct rtc_class_ops wm831x_rtc_ops = {
337 .read_time = wm831x_rtc_readtime,
338 .set_mmss = wm831x_rtc_set_mmss,
339 .read_alarm = wm831x_rtc_readalarm,
340 .set_alarm = wm831x_rtc_setalarm,
341 .alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
342};
343
344#ifdef CONFIG_PM
345/* Turn off the alarm if it should not be a wake source. */
346static int wm831x_rtc_suspend(struct device *dev)
347{
348 struct platform_device *pdev = to_platform_device(dev);
349 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
350 int ret, enable;
351
352 if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
353 enable = WM831X_RTC_ALM_ENA;
354 else
355 enable = 0;
356
357 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
358 WM831X_RTC_ALM_ENA, enable);
359 if (ret != 0)
360 dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
361
362 return 0;
363}
364
365/* Enable the alarm if it should be enabled (in case it was disabled to
366 * prevent use as a wake source).
367 */
368static int wm831x_rtc_resume(struct device *dev)
369{
370 struct platform_device *pdev = to_platform_device(dev);
371 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
372 int ret;
373
374 if (wm831x_rtc->alarm_enabled) {
375 ret = wm831x_rtc_start_alarm(wm831x_rtc);
376 if (ret != 0)
377 dev_err(&pdev->dev,
378 "Failed to restart RTC alarm: %d\n", ret);
379 }
380
381 return 0;
382}
383
384/* Unconditionally disable the alarm */
385static int wm831x_rtc_freeze(struct device *dev)
386{
387 struct platform_device *pdev = to_platform_device(dev);
388 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
389 int ret;
390
391 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
392 WM831X_RTC_ALM_ENA, 0);
393 if (ret != 0)
394 dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
395
396 return 0;
397}
398#else
399#define wm831x_rtc_suspend NULL
400#define wm831x_rtc_resume NULL
401#define wm831x_rtc_freeze NULL
402#endif
403
404static int wm831x_rtc_probe(struct platform_device *pdev)
405{
406 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
407 struct wm831x_rtc *wm831x_rtc;
408 int per_irq = platform_get_irq_byname(pdev, "PER");
409 int alm_irq = platform_get_irq_byname(pdev, "ALM");
410 int ret = 0;
411
412 wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL);
413 if (wm831x_rtc == NULL)
414 return -ENOMEM;
415
416 platform_set_drvdata(pdev, wm831x_rtc);
417 wm831x_rtc->wm831x = wm831x;
418
419 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
420 if (ret < 0) {
421 dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
422 goto err;
423 }
424 if (ret & WM831X_RTC_ALM_ENA)
425 wm831x_rtc->alarm_enabled = 1;
426
427 device_init_wakeup(&pdev->dev, 1);
428
429 wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
430 &wm831x_rtc_ops, THIS_MODULE);
431 if (IS_ERR(wm831x_rtc->rtc)) {
432 ret = PTR_ERR(wm831x_rtc->rtc);
433 goto err;
434 }
435
436 ret = request_threaded_irq(per_irq, NULL, wm831x_per_irq,
437 IRQF_TRIGGER_RISING, "RTC period",
438 wm831x_rtc);
439 if (ret != 0) {
440 dev_err(&pdev->dev, "Failed to request periodic IRQ %d: %d\n",
441 per_irq, ret);
442 }
443
444 ret = request_threaded_irq(alm_irq, NULL, wm831x_alm_irq,
445 IRQF_TRIGGER_RISING, "RTC alarm",
446 wm831x_rtc);
447 if (ret != 0) {
448 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
449 alm_irq, ret);
450 }
451
452 return 0;
453
454err:
455 kfree(wm831x_rtc);
456 return ret;
457}
458
459static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
460{
461 struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
462 int per_irq = platform_get_irq_byname(pdev, "PER");
463 int alm_irq = platform_get_irq_byname(pdev, "ALM");
464
465 free_irq(alm_irq, wm831x_rtc);
466 free_irq(per_irq, wm831x_rtc);
467 rtc_device_unregister(wm831x_rtc->rtc);
468 kfree(wm831x_rtc);
469
470 return 0;
471}
472
473static const struct dev_pm_ops wm831x_rtc_pm_ops = {
474 .suspend = wm831x_rtc_suspend,
475 .resume = wm831x_rtc_resume,
476
477 .freeze = wm831x_rtc_freeze,
478 .thaw = wm831x_rtc_resume,
479 .restore = wm831x_rtc_resume,
480
481 .poweroff = wm831x_rtc_suspend,
482};
483
484static struct platform_driver wm831x_rtc_driver = {
485 .probe = wm831x_rtc_probe,
486 .remove = __devexit_p(wm831x_rtc_remove),
487 .driver = {
488 .name = "wm831x-rtc",
489 .pm = &wm831x_rtc_pm_ops,
490 },
491};
492
493static int __init wm831x_rtc_init(void)
494{
495 return platform_driver_register(&wm831x_rtc_driver);
496}
497module_init(wm831x_rtc_init);
498
499static void __exit wm831x_rtc_exit(void)
500{
501 platform_driver_unregister(&wm831x_rtc_driver);
502}
503module_exit(wm831x_rtc_exit);
504
505MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
506MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
507MODULE_LICENSE("GPL");
508MODULE_ALIAS("platform:wm831x-rtc");