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path: root/drivers/rtc/rtc-wm831x.c
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Diffstat (limited to 'drivers/rtc/rtc-wm831x.c')
-rw-r--r--drivers/rtc/rtc-wm831x.c523
1 files changed, 523 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-wm831x.c b/drivers/rtc/rtc-wm831x.c
new file mode 100644
index 000000000000..79795cdf6ed8
--- /dev/null
+++ b/drivers/rtc/rtc-wm831x.c
@@ -0,0 +1,523 @@
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/bcd.h>
20#include <linux/interrupt.h>
21#include <linux/ioctl.h>
22#include <linux/completion.h>
23#include <linux/mfd/wm831x/core.h>
24#include <linux/delay.h>
25#include <linux/platform_device.h>
26
27
28/*
29 * R16416 (0x4020) - RTC Write Counter
30 */
31#define WM831X_RTC_WR_CNT_MASK 0xFFFF /* RTC_WR_CNT - [15:0] */
32#define WM831X_RTC_WR_CNT_SHIFT 0 /* RTC_WR_CNT - [15:0] */
33#define WM831X_RTC_WR_CNT_WIDTH 16 /* RTC_WR_CNT - [15:0] */
34
35/*
36 * R16417 (0x4021) - RTC Time 1
37 */
38#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
39#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
40#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
41
42/*
43 * R16418 (0x4022) - RTC Time 2
44 */
45#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
46#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
47#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
48
49/*
50 * R16419 (0x4023) - RTC Alarm 1
51 */
52#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
53#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
54#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
55
56/*
57 * R16420 (0x4024) - RTC Alarm 2
58 */
59#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
60#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
61#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
62
63/*
64 * R16421 (0x4025) - RTC Control
65 */
66#define WM831X_RTC_VALID 0x8000 /* RTC_VALID */
67#define WM831X_RTC_VALID_MASK 0x8000 /* RTC_VALID */
68#define WM831X_RTC_VALID_SHIFT 15 /* RTC_VALID */
69#define WM831X_RTC_VALID_WIDTH 1 /* RTC_VALID */
70#define WM831X_RTC_SYNC_BUSY 0x4000 /* RTC_SYNC_BUSY */
71#define WM831X_RTC_SYNC_BUSY_MASK 0x4000 /* RTC_SYNC_BUSY */
72#define WM831X_RTC_SYNC_BUSY_SHIFT 14 /* RTC_SYNC_BUSY */
73#define WM831X_RTC_SYNC_BUSY_WIDTH 1 /* RTC_SYNC_BUSY */
74#define WM831X_RTC_ALM_ENA 0x0400 /* RTC_ALM_ENA */
75#define WM831X_RTC_ALM_ENA_MASK 0x0400 /* RTC_ALM_ENA */
76#define WM831X_RTC_ALM_ENA_SHIFT 10 /* RTC_ALM_ENA */
77#define WM831X_RTC_ALM_ENA_WIDTH 1 /* RTC_ALM_ENA */
78#define WM831X_RTC_PINT_FREQ_MASK 0x0070 /* RTC_PINT_FREQ - [6:4] */
79#define WM831X_RTC_PINT_FREQ_SHIFT 4 /* RTC_PINT_FREQ - [6:4] */
80#define WM831X_RTC_PINT_FREQ_WIDTH 3 /* RTC_PINT_FREQ - [6:4] */
81
82/*
83 * R16422 (0x4026) - RTC Trim
84 */
85#define WM831X_RTC_TRIM_MASK 0x03FF /* RTC_TRIM - [9:0] */
86#define WM831X_RTC_TRIM_SHIFT 0 /* RTC_TRIM - [9:0] */
87#define WM831X_RTC_TRIM_WIDTH 10 /* RTC_TRIM - [9:0] */
88
89#define WM831X_SET_TIME_RETRIES 5
90#define WM831X_GET_TIME_RETRIES 5
91
92struct wm831x_rtc {
93 struct wm831x *wm831x;
94 struct rtc_device *rtc;
95 unsigned int alarm_enabled:1;
96};
97
98/*
99 * Read current time and date in RTC
100 */
101static int wm831x_rtc_readtime(struct device *dev, struct rtc_time *tm)
102{
103 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
104 struct wm831x *wm831x = wm831x_rtc->wm831x;
105 u16 time1[2], time2[2];
106 int ret;
107 int count = 0;
108
109 /* Has the RTC been programmed? */
110 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
111 if (ret < 0) {
112 dev_err(dev, "Failed to read RTC control: %d\n", ret);
113 return ret;
114 }
115 if (!(ret & WM831X_RTC_VALID)) {
116 dev_dbg(dev, "RTC not yet configured\n");
117 return -EINVAL;
118 }
119
120 /* Read twice to make sure we don't read a corrupt, partially
121 * incremented, value.
122 */
123 do {
124 ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
125 2, time1);
126 if (ret != 0)
127 continue;
128
129 ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
130 2, time2);
131 if (ret != 0)
132 continue;
133
134 if (memcmp(time1, time2, sizeof(time1)) == 0) {
135 u32 time = (time1[0] << 16) | time1[1];
136
137 rtc_time_to_tm(time, tm);
138 return rtc_valid_tm(tm);
139 }
140
141 } while (++count < WM831X_GET_TIME_RETRIES);
142
143 dev_err(dev, "Timed out reading current time\n");
144
145 return -EIO;
146}
147
148/*
149 * Set current time and date in RTC
150 */
151static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
152{
153 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
154 struct wm831x *wm831x = wm831x_rtc->wm831x;
155 struct rtc_time new_tm;
156 unsigned long new_time;
157 int ret;
158 int count = 0;
159
160 ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
161 (time >> 16) & 0xffff);
162 if (ret < 0) {
163 dev_err(dev, "Failed to write TIME_1: %d\n", ret);
164 return ret;
165 }
166
167 ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
168 if (ret < 0) {
169 dev_err(dev, "Failed to write TIME_2: %d\n", ret);
170 return ret;
171 }
172
173 /* Wait for the update to complete - should happen first time
174 * round but be conservative.
175 */
176 do {
177 msleep(1);
178
179 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
180 if (ret < 0)
181 ret = WM831X_RTC_SYNC_BUSY;
182 } while (!(ret & WM831X_RTC_SYNC_BUSY) &&
183 ++count < WM831X_SET_TIME_RETRIES);
184
185 if (ret & WM831X_RTC_SYNC_BUSY) {
186 dev_err(dev, "Timed out writing RTC update\n");
187 return -EIO;
188 }
189
190 /* Check that the update was accepted; security features may
191 * have caused the update to be ignored.
192 */
193 ret = wm831x_rtc_readtime(dev, &new_tm);
194 if (ret < 0)
195 return ret;
196
197 ret = rtc_tm_to_time(&new_tm, &new_time);
198 if (ret < 0) {
199 dev_err(dev, "Failed to convert time: %d\n", ret);
200 return ret;
201 }
202
203 /* Allow a second of change in case of tick */
204 if (new_time - time > 1) {
205 dev_err(dev, "RTC update not permitted by hardware\n");
206 return -EPERM;
207 }
208
209 return 0;
210}
211
212/*
213 * Read alarm time and date in RTC
214 */
215static int wm831x_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
216{
217 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
218 int ret;
219 u16 data[2];
220 u32 time;
221
222 ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
223 2, data);
224 if (ret != 0) {
225 dev_err(dev, "Failed to read alarm time: %d\n", ret);
226 return ret;
227 }
228
229 time = (data[0] << 16) | data[1];
230
231 rtc_time_to_tm(time, &alrm->time);
232
233 ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
234 if (ret < 0) {
235 dev_err(dev, "Failed to read RTC control: %d\n", ret);
236 return ret;
237 }
238
239 if (ret & WM831X_RTC_ALM_ENA)
240 alrm->enabled = 1;
241 else
242 alrm->enabled = 0;
243
244 return 0;
245}
246
247static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
248{
249 wm831x_rtc->alarm_enabled = 0;
250
251 return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
252 WM831X_RTC_ALM_ENA, 0);
253}
254
255static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
256{
257 wm831x_rtc->alarm_enabled = 1;
258
259 return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
260 WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
261}
262
263static int wm831x_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
264{
265 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
266 struct wm831x *wm831x = wm831x_rtc->wm831x;
267 int ret;
268 unsigned long time;
269
270 ret = rtc_tm_to_time(&alrm->time, &time);
271 if (ret < 0) {
272 dev_err(dev, "Failed to convert time: %d\n", ret);
273 return ret;
274 }
275
276 ret = wm831x_rtc_stop_alarm(wm831x_rtc);
277 if (ret < 0) {
278 dev_err(dev, "Failed to stop alarm: %d\n", ret);
279 return ret;
280 }
281
282 ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
283 (time >> 16) & 0xffff);
284 if (ret < 0) {
285 dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
286 return ret;
287 }
288
289 ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
290 if (ret < 0) {
291 dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
292 return ret;
293 }
294
295 if (alrm->enabled) {
296 ret = wm831x_rtc_start_alarm(wm831x_rtc);
297 if (ret < 0) {
298 dev_err(dev, "Failed to start alarm: %d\n", ret);
299 return ret;
300 }
301 }
302
303 return 0;
304}
305
306static int wm831x_rtc_alarm_irq_enable(struct device *dev,
307 unsigned int enabled)
308{
309 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
310
311 if (enabled)
312 return wm831x_rtc_start_alarm(wm831x_rtc);
313 else
314 return wm831x_rtc_stop_alarm(wm831x_rtc);
315}
316
317static int wm831x_rtc_update_irq_enable(struct device *dev,
318 unsigned int enabled)
319{
320 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
321 int val;
322
323 if (enabled)
324 val = 1 << WM831X_RTC_PINT_FREQ_SHIFT;
325 else
326 val = 0;
327
328 return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
329 WM831X_RTC_PINT_FREQ_MASK, val);
330}
331
332static irqreturn_t wm831x_alm_irq(int irq, void *data)
333{
334 struct wm831x_rtc *wm831x_rtc = data;
335
336 rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_AF);
337
338 return IRQ_HANDLED;
339}
340
341static irqreturn_t wm831x_per_irq(int irq, void *data)
342{
343 struct wm831x_rtc *wm831x_rtc = data;
344
345 rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_UF);
346
347 return IRQ_HANDLED;
348}
349
350static const struct rtc_class_ops wm831x_rtc_ops = {
351 .read_time = wm831x_rtc_readtime,
352 .set_mmss = wm831x_rtc_set_mmss,
353 .read_alarm = wm831x_rtc_readalarm,
354 .set_alarm = wm831x_rtc_setalarm,
355 .alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
356 .update_irq_enable = wm831x_rtc_update_irq_enable,
357};
358
359#ifdef CONFIG_PM
360/* Turn off the alarm if it should not be a wake source. */
361static int wm831x_rtc_suspend(struct device *dev)
362{
363 struct platform_device *pdev = to_platform_device(dev);
364 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
365 int ret, enable;
366
367 if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
368 enable = WM831X_RTC_ALM_ENA;
369 else
370 enable = 0;
371
372 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
373 WM831X_RTC_ALM_ENA, enable);
374 if (ret != 0)
375 dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
376
377 return 0;
378}
379
380/* Enable the alarm if it should be enabled (in case it was disabled to
381 * prevent use as a wake source).
382 */
383static int wm831x_rtc_resume(struct device *dev)
384{
385 struct platform_device *pdev = to_platform_device(dev);
386 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
387 int ret;
388
389 if (wm831x_rtc->alarm_enabled) {
390 ret = wm831x_rtc_start_alarm(wm831x_rtc);
391 if (ret != 0)
392 dev_err(&pdev->dev,
393 "Failed to restart RTC alarm: %d\n", ret);
394 }
395
396 return 0;
397}
398
399/* Unconditionally disable the alarm */
400static int wm831x_rtc_freeze(struct device *dev)
401{
402 struct platform_device *pdev = to_platform_device(dev);
403 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
404 int ret;
405
406 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
407 WM831X_RTC_ALM_ENA, 0);
408 if (ret != 0)
409 dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
410
411 return 0;
412}
413#else
414#define wm831x_rtc_suspend NULL
415#define wm831x_rtc_resume NULL
416#define wm831x_rtc_freeze NULL
417#endif
418
419static int wm831x_rtc_probe(struct platform_device *pdev)
420{
421 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
422 struct wm831x_rtc *wm831x_rtc;
423 int per_irq = platform_get_irq_byname(pdev, "PER");
424 int alm_irq = platform_get_irq_byname(pdev, "ALM");
425 int ret = 0;
426
427 wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL);
428 if (wm831x_rtc == NULL)
429 return -ENOMEM;
430
431 platform_set_drvdata(pdev, wm831x_rtc);
432 wm831x_rtc->wm831x = wm831x;
433
434 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
435 if (ret < 0) {
436 dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
437 goto err;
438 }
439 if (ret & WM831X_RTC_ALM_ENA)
440 wm831x_rtc->alarm_enabled = 1;
441
442 device_init_wakeup(&pdev->dev, 1);
443
444 wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
445 &wm831x_rtc_ops, THIS_MODULE);
446 if (IS_ERR(wm831x_rtc->rtc)) {
447 ret = PTR_ERR(wm831x_rtc->rtc);
448 goto err;
449 }
450
451 ret = wm831x_request_irq(wm831x, per_irq, wm831x_per_irq,
452 IRQF_TRIGGER_RISING, "wm831x_rtc_per",
453 wm831x_rtc);
454 if (ret != 0) {
455 dev_err(&pdev->dev, "Failed to request periodic IRQ %d: %d\n",
456 per_irq, ret);
457 }
458
459 ret = wm831x_request_irq(wm831x, alm_irq, wm831x_alm_irq,
460 IRQF_TRIGGER_RISING, "wm831x_rtc_alm",
461 wm831x_rtc);
462 if (ret != 0) {
463 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
464 alm_irq, ret);
465 }
466
467 return 0;
468
469err:
470 kfree(wm831x_rtc);
471 return ret;
472}
473
474static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
475{
476 struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
477 int per_irq = platform_get_irq_byname(pdev, "PER");
478 int alm_irq = platform_get_irq_byname(pdev, "ALM");
479
480 wm831x_free_irq(wm831x_rtc->wm831x, alm_irq, wm831x_rtc);
481 wm831x_free_irq(wm831x_rtc->wm831x, per_irq, wm831x_rtc);
482 rtc_device_unregister(wm831x_rtc->rtc);
483 kfree(wm831x_rtc);
484
485 return 0;
486}
487
488static struct dev_pm_ops wm831x_rtc_pm_ops = {
489 .suspend = wm831x_rtc_suspend,
490 .resume = wm831x_rtc_resume,
491
492 .freeze = wm831x_rtc_freeze,
493 .thaw = wm831x_rtc_resume,
494 .restore = wm831x_rtc_resume,
495
496 .poweroff = wm831x_rtc_suspend,
497};
498
499static struct platform_driver wm831x_rtc_driver = {
500 .probe = wm831x_rtc_probe,
501 .remove = __devexit_p(wm831x_rtc_remove),
502 .driver = {
503 .name = "wm831x-rtc",
504 .pm = &wm831x_rtc_pm_ops,
505 },
506};
507
508static int __init wm831x_rtc_init(void)
509{
510 return platform_driver_register(&wm831x_rtc_driver);
511}
512module_init(wm831x_rtc_init);
513
514static void __exit wm831x_rtc_exit(void)
515{
516 platform_driver_unregister(&wm831x_rtc_driver);
517}
518module_exit(wm831x_rtc_exit);
519
520MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
521MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
522MODULE_LICENSE("GPL");
523MODULE_ALIAS("platform:wm831x-rtc");
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-27 05:01:58 -0500