blob: 3b6e6a67e765b34e7efd7e5cb82eea63a930d31e [file] [log] [blame]
Mark Brown35c86bf2009-08-27 19:59:05 +02001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090019#include <linux/slab.h>
Mark Brown35c86bf2009-08-27 19:59:05 +020020#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
Mark Brown35c86bf2009-08-27 19:59:05 +0200318static 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
Mark Brown35c86bf2009-08-27 19:59:05 +0200327static const struct rtc_class_ops wm831x_rtc_ops = {
328 .read_time = wm831x_rtc_readtime,
329 .set_mmss = wm831x_rtc_set_mmss,
330 .read_alarm = wm831x_rtc_readalarm,
331 .set_alarm = wm831x_rtc_setalarm,
332 .alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
Mark Brown35c86bf2009-08-27 19:59:05 +0200333};
334
335#ifdef CONFIG_PM
336/* Turn off the alarm if it should not be a wake source. */
337static int wm831x_rtc_suspend(struct device *dev)
338{
339 struct platform_device *pdev = to_platform_device(dev);
340 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
341 int ret, enable;
342
343 if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
344 enable = WM831X_RTC_ALM_ENA;
345 else
346 enable = 0;
347
348 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
349 WM831X_RTC_ALM_ENA, enable);
350 if (ret != 0)
351 dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
352
353 return 0;
354}
355
356/* Enable the alarm if it should be enabled (in case it was disabled to
357 * prevent use as a wake source).
358 */
359static int wm831x_rtc_resume(struct device *dev)
360{
361 struct platform_device *pdev = to_platform_device(dev);
362 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
363 int ret;
364
365 if (wm831x_rtc->alarm_enabled) {
366 ret = wm831x_rtc_start_alarm(wm831x_rtc);
367 if (ret != 0)
368 dev_err(&pdev->dev,
369 "Failed to restart RTC alarm: %d\n", ret);
370 }
371
372 return 0;
373}
374
375/* Unconditionally disable the alarm */
376static int wm831x_rtc_freeze(struct device *dev)
377{
378 struct platform_device *pdev = to_platform_device(dev);
379 struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
380 int ret;
381
382 ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
383 WM831X_RTC_ALM_ENA, 0);
384 if (ret != 0)
385 dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
386
387 return 0;
388}
389#else
390#define wm831x_rtc_suspend NULL
391#define wm831x_rtc_resume NULL
392#define wm831x_rtc_freeze NULL
393#endif
394
395static int wm831x_rtc_probe(struct platform_device *pdev)
396{
397 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
398 struct wm831x_rtc *wm831x_rtc;
Mark Brown35c86bf2009-08-27 19:59:05 +0200399 int alm_irq = platform_get_irq_byname(pdev, "ALM");
400 int ret = 0;
401
Mark Brown5f85d202012-01-10 15:10:44 -0800402 wm831x_rtc = devm_kzalloc(&pdev->dev, sizeof(*wm831x_rtc), GFP_KERNEL);
Mark Brown35c86bf2009-08-27 19:59:05 +0200403 if (wm831x_rtc == NULL)
404 return -ENOMEM;
405
406 platform_set_drvdata(pdev, wm831x_rtc);
407 wm831x_rtc->wm831x = wm831x;
408
409 ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
410 if (ret < 0) {
411 dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
412 goto err;
413 }
414 if (ret & WM831X_RTC_ALM_ENA)
415 wm831x_rtc->alarm_enabled = 1;
416
417 device_init_wakeup(&pdev->dev, 1);
418
419 wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
420 &wm831x_rtc_ops, THIS_MODULE);
421 if (IS_ERR(wm831x_rtc->rtc)) {
422 ret = PTR_ERR(wm831x_rtc->rtc);
423 goto err;
424 }
425
Mark Brown5815e5d2010-05-24 14:33:51 -0700426 ret = request_threaded_irq(alm_irq, NULL, wm831x_alm_irq,
427 IRQF_TRIGGER_RISING, "RTC alarm",
428 wm831x_rtc);
Mark Brown35c86bf2009-08-27 19:59:05 +0200429 if (ret != 0) {
430 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
431 alm_irq, ret);
432 }
433
434 return 0;
435
436err:
Mark Brown35c86bf2009-08-27 19:59:05 +0200437 return ret;
438}
439
440static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
441{
442 struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
Mark Brown35c86bf2009-08-27 19:59:05 +0200443 int alm_irq = platform_get_irq_byname(pdev, "ALM");
444
Mark Brown5815e5d2010-05-24 14:33:51 -0700445 free_irq(alm_irq, wm831x_rtc);
Mark Brown35c86bf2009-08-27 19:59:05 +0200446 rtc_device_unregister(wm831x_rtc->rtc);
Mark Brown35c86bf2009-08-27 19:59:05 +0200447
448 return 0;
449}
450
Alexey Dobriyan47145212009-12-14 18:00:08 -0800451static const struct dev_pm_ops wm831x_rtc_pm_ops = {
Mark Brown35c86bf2009-08-27 19:59:05 +0200452 .suspend = wm831x_rtc_suspend,
453 .resume = wm831x_rtc_resume,
454
455 .freeze = wm831x_rtc_freeze,
456 .thaw = wm831x_rtc_resume,
457 .restore = wm831x_rtc_resume,
458
459 .poweroff = wm831x_rtc_suspend,
460};
461
462static struct platform_driver wm831x_rtc_driver = {
463 .probe = wm831x_rtc_probe,
464 .remove = __devexit_p(wm831x_rtc_remove),
465 .driver = {
466 .name = "wm831x-rtc",
467 .pm = &wm831x_rtc_pm_ops,
468 },
469};
470
Axel Lin0c4eae62012-01-10 15:10:48 -0800471module_platform_driver(wm831x_rtc_driver);
Mark Brown35c86bf2009-08-27 19:59:05 +0200472
473MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
474MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
475MODULE_LICENSE("GPL");
476MODULE_ALIAS("platform:wm831x-rtc");