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v4.6
  1/*
  2 * RTC driver for Rockchip RK808
  3 *
  4 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
  5 *
  6 * Author: Chris Zhong <zyw@rock-chips.com>
  7 * Author: Zhang Qing <zhangqing@rock-chips.com>
  8 *
  9 * This program is free software; you can redistribute it and/or modify it
 10 * under the terms and conditions of the GNU General Public License,
 11 * version 2, as published by the Free Software Foundation.
 12 *
 13 * This program is distributed in the hope it will be useful, but WITHOUT
 14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 15 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 16 * more details.
 17 */
 18
 19#include <linux/module.h>
 20#include <linux/kernel.h>
 21#include <linux/rtc.h>
 22#include <linux/bcd.h>
 23#include <linux/mfd/rk808.h>
 24#include <linux/platform_device.h>
 25#include <linux/i2c.h>
 26
 27/* RTC_CTRL_REG bitfields */
 28#define BIT_RTC_CTRL_REG_STOP_RTC_M		BIT(0)
 29
 30/* RK808 has a shadowed register for saving a "frozen" RTC time.
 31 * When user setting "GET_TIME" to 1, the time will save in this shadowed
 32 * register. If set "READSEL" to 1, user read rtc time register, actually
 33 * get the time of that moment. If we need the real time, clr this bit.
 34 */
 35#define BIT_RTC_CTRL_REG_RTC_GET_TIME		BIT(6)
 36#define BIT_RTC_CTRL_REG_RTC_READSEL_M		BIT(7)
 37#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M	BIT(3)
 38#define RTC_STATUS_MASK		0xFE
 39
 40#define SECONDS_REG_MSK		0x7F
 41#define MINUTES_REG_MAK		0x7F
 42#define HOURS_REG_MSK		0x3F
 43#define DAYS_REG_MSK		0x3F
 44#define MONTHS_REG_MSK		0x1F
 45#define YEARS_REG_MSK		0xFF
 46#define WEEKS_REG_MSK		0x7
 47
 48/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
 49
 50#define NUM_TIME_REGS	(RK808_WEEKS_REG - RK808_SECONDS_REG + 1)
 51#define NUM_ALARM_REGS	(RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)
 52
 53struct rk808_rtc {
 54	struct rk808 *rk808;
 55	struct rtc_device *rtc;
 56	int irq;
 57};
 58
 59/*
 60 * The Rockchip calendar used by the RK808 counts November with 31 days. We use
 61 * these translation functions to convert its dates to/from the Gregorian
 62 * calendar used by the rest of the world. We arbitrarily define Jan 1st, 2016
 63 * as the day when both calendars were in sync, and treat all other dates
 64 * relative to that.
 65 * NOTE: Other system software (e.g. firmware) that reads the same hardware must
 66 * implement this exact same conversion algorithm, with the same anchor date.
 67 */
 68static time64_t nov2dec_transitions(struct rtc_time *tm)
 69{
 70	return (tm->tm_year + 1900) - 2016 + (tm->tm_mon + 1 > 11 ? 1 : 0);
 71}
 72
 73static void rockchip_to_gregorian(struct rtc_time *tm)
 74{
 75	/* If it's Nov 31st, rtc_tm_to_time64() will count that like Dec 1st */
 76	time64_t time = rtc_tm_to_time64(tm);
 77	rtc_time64_to_tm(time + nov2dec_transitions(tm) * 86400, tm);
 78}
 79
 80static void gregorian_to_rockchip(struct rtc_time *tm)
 81{
 82	time64_t extra_days = nov2dec_transitions(tm);
 83	time64_t time = rtc_tm_to_time64(tm);
 84	rtc_time64_to_tm(time - extra_days * 86400, tm);
 85
 86	/* Compensate if we went back over Nov 31st (will work up to 2381) */
 87	if (nov2dec_transitions(tm) < extra_days) {
 88		if (tm->tm_mon + 1 == 11)
 89			tm->tm_mday++;	/* This may result in 31! */
 90		else
 91			rtc_time64_to_tm(time - (extra_days - 1) * 86400, tm);
 92	}
 93}
 94
 95/* Read current time and date in RTC */
 96static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)
 97{
 98	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
 99	struct rk808 *rk808 = rk808_rtc->rk808;
100	u8 rtc_data[NUM_TIME_REGS];
101	int ret;
102
103	/* Force an update of the shadowed registers right now */
104	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
105				 BIT_RTC_CTRL_REG_RTC_GET_TIME,
106				 BIT_RTC_CTRL_REG_RTC_GET_TIME);
107	if (ret) {
108		dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
109		return ret;
110	}
111
112	/*
113	 * After we set the GET_TIME bit, the rtc time can't be read
114	 * immediately. So we should wait up to 31.25 us, about one cycle of
115	 * 32khz. If we clear the GET_TIME bit here, the time of i2c transfer
116	 * certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.
117	 */
118	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
119				 BIT_RTC_CTRL_REG_RTC_GET_TIME,
120				 0);
121	if (ret) {
122		dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
123		return ret;
124	}
125
126	ret = regmap_bulk_read(rk808->regmap, RK808_SECONDS_REG,
127			       rtc_data, NUM_TIME_REGS);
128	if (ret) {
129		dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);
130		return ret;
131	}
132
133	tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
134	tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
135	tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
136	tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
137	tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;
138	tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
139	tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
140	rockchip_to_gregorian(tm);
141	dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
142		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
143		tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
144
145	return ret;
146}
147
148/* Set current time and date in RTC */
149static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
150{
151	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
152	struct rk808 *rk808 = rk808_rtc->rk808;
153	u8 rtc_data[NUM_TIME_REGS];
154	int ret;
155
156	dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
157		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
158		tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
159	gregorian_to_rockchip(tm);
160	rtc_data[0] = bin2bcd(tm->tm_sec);
161	rtc_data[1] = bin2bcd(tm->tm_min);
162	rtc_data[2] = bin2bcd(tm->tm_hour);
163	rtc_data[3] = bin2bcd(tm->tm_mday);
164	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
165	rtc_data[5] = bin2bcd(tm->tm_year - 100);
166	rtc_data[6] = bin2bcd(tm->tm_wday);
167
168	/* Stop RTC while updating the RTC registers */
169	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
170				 BIT_RTC_CTRL_REG_STOP_RTC_M,
171				 BIT_RTC_CTRL_REG_STOP_RTC_M);
172	if (ret) {
173		dev_err(dev, "Failed to update RTC control: %d\n", ret);
174		return ret;
175	}
176
177	ret = regmap_bulk_write(rk808->regmap, RK808_SECONDS_REG,
178				rtc_data, NUM_TIME_REGS);
179	if (ret) {
180		dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);
181		return ret;
182	}
183	/* Start RTC again */
184	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
185				 BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
186	if (ret) {
187		dev_err(dev, "Failed to update RTC control: %d\n", ret);
188		return ret;
189	}
190	return 0;
191}
192
193/* Read alarm time and date in RTC */
194static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
195{
196	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
197	struct rk808 *rk808 = rk808_rtc->rk808;
198	u8 alrm_data[NUM_ALARM_REGS];
199	uint32_t int_reg;
200	int ret;
201
202	ret = regmap_bulk_read(rk808->regmap, RK808_ALARM_SECONDS_REG,
203			       alrm_data, NUM_ALARM_REGS);
204
205	alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);
206	alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);
207	alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);
208	alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);
209	alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;
210	alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;
211	rockchip_to_gregorian(&alrm->time);
212
213	ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg);
214	if (ret) {
215		dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);
216		return ret;
217	}
218
219	dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
220		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
221		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
222		alrm->time.tm_min, alrm->time.tm_sec);
223
224	alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
225
226	return 0;
227}
228
229static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)
230{
231	struct rk808 *rk808 = rk808_rtc->rk808;
232	int ret;
233
234	ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
235				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);
236
237	return ret;
238}
239
240static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)
241{
242	struct rk808 *rk808 = rk808_rtc->rk808;
243	int ret;
244
245	ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
246				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,
247				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
248
249	return ret;
250}
251
252static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
253{
254	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
255	struct rk808 *rk808 = rk808_rtc->rk808;
256	u8 alrm_data[NUM_ALARM_REGS];
257	int ret;
258
259	ret = rk808_rtc_stop_alarm(rk808_rtc);
260	if (ret) {
261		dev_err(dev, "Failed to stop alarm: %d\n", ret);
262		return ret;
263	}
264	dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
265		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
266		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
267		alrm->time.tm_min, alrm->time.tm_sec);
268
269	gregorian_to_rockchip(&alrm->time);
270	alrm_data[0] = bin2bcd(alrm->time.tm_sec);
271	alrm_data[1] = bin2bcd(alrm->time.tm_min);
272	alrm_data[2] = bin2bcd(alrm->time.tm_hour);
273	alrm_data[3] = bin2bcd(alrm->time.tm_mday);
274	alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);
275	alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);
276
277	ret = regmap_bulk_write(rk808->regmap, RK808_ALARM_SECONDS_REG,
278				alrm_data, NUM_ALARM_REGS);
279	if (ret) {
280		dev_err(dev, "Failed to bulk write: %d\n", ret);
281		return ret;
282	}
283	if (alrm->enabled) {
284		ret = rk808_rtc_start_alarm(rk808_rtc);
285		if (ret) {
286			dev_err(dev, "Failed to start alarm: %d\n", ret);
287			return ret;
288		}
289	}
290	return 0;
291}
292
293static int rk808_rtc_alarm_irq_enable(struct device *dev,
294				      unsigned int enabled)
295{
296	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
297
298	if (enabled)
299		return rk808_rtc_start_alarm(rk808_rtc);
300
301	return rk808_rtc_stop_alarm(rk808_rtc);
302}
303
304/*
305 * We will just handle setting the frequency and make use the framework for
306 * reading the periodic interupts.
307 *
308 * @freq: Current periodic IRQ freq:
309 * bit 0: every second
310 * bit 1: every minute
311 * bit 2: every hour
312 * bit 3: every day
313 */
314static irqreturn_t rk808_alarm_irq(int irq, void *data)
315{
316	struct rk808_rtc *rk808_rtc = data;
317	struct rk808 *rk808 = rk808_rtc->rk808;
318	struct i2c_client *client = rk808->i2c;
319	int ret;
320
321	ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
322			   RTC_STATUS_MASK);
323	if (ret) {
324		dev_err(&client->dev,
325			"%s:Failed to update RTC status: %d\n", __func__, ret);
326		return ret;
327	}
328
329	rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);
330	dev_dbg(&client->dev,
331		 "%s:irq=%d\n", __func__, irq);
332	return IRQ_HANDLED;
333}
334
335static const struct rtc_class_ops rk808_rtc_ops = {
336	.read_time = rk808_rtc_readtime,
337	.set_time = rk808_rtc_set_time,
338	.read_alarm = rk808_rtc_readalarm,
339	.set_alarm = rk808_rtc_setalarm,
340	.alarm_irq_enable = rk808_rtc_alarm_irq_enable,
341};
342
343#ifdef CONFIG_PM_SLEEP
344/* Turn off the alarm if it should not be a wake source. */
345static int rk808_rtc_suspend(struct device *dev)
346{
347	struct platform_device *pdev = to_platform_device(dev);
348	struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
349
350	if (device_may_wakeup(dev))
351		enable_irq_wake(rk808_rtc->irq);
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 rk808_rtc_resume(struct device *dev)
360{
361	struct platform_device *pdev = to_platform_device(dev);
362	struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
363
364	if (device_may_wakeup(dev))
365		disable_irq_wake(rk808_rtc->irq);
366
367	return 0;
368}
369#endif
370
371static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,
372	rk808_rtc_suspend, rk808_rtc_resume);
373
374static int rk808_rtc_probe(struct platform_device *pdev)
375{
376	struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
377	struct rk808_rtc *rk808_rtc;
378	struct rtc_time tm;
379	int ret;
380
381	rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
382	if (rk808_rtc == NULL)
383		return -ENOMEM;
384
385	platform_set_drvdata(pdev, rk808_rtc);
386	rk808_rtc->rk808 = rk808;
387
388	/* start rtc running by default, and use shadowed timer. */
389	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
390				 BIT_RTC_CTRL_REG_STOP_RTC_M |
391				 BIT_RTC_CTRL_REG_RTC_READSEL_M,
392				 BIT_RTC_CTRL_REG_RTC_READSEL_M);
393	if (ret) {
394		dev_err(&pdev->dev,
395			"Failed to update RTC control: %d\n", ret);
396		return ret;
397	}
398
399	ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
400			   RTC_STATUS_MASK);
401	if (ret) {
402		dev_err(&pdev->dev,
403			"Failed to write RTC status: %d\n", ret);
404			return ret;
405	}
406
407	/* set init time */
408	ret = rk808_rtc_readtime(&pdev->dev, &tm);
409	if (ret) {
410		dev_err(&pdev->dev, "Failed to read RTC time\n");
411		return ret;
412	}
413	ret = rtc_valid_tm(&tm);
414	if (ret)
415		dev_warn(&pdev->dev, "invalid date/time\n");
416
417	device_init_wakeup(&pdev->dev, 1);
418
419	rk808_rtc->rtc = devm_rtc_device_register(&pdev->dev, "rk808-rtc",
420						  &rk808_rtc_ops, THIS_MODULE);
421	if (IS_ERR(rk808_rtc->rtc)) {
422		ret = PTR_ERR(rk808_rtc->rtc);
423		return ret;
424	}
425
426	rk808_rtc->irq = platform_get_irq(pdev, 0);
427	if (rk808_rtc->irq < 0) {
428		if (rk808_rtc->irq != -EPROBE_DEFER)
429			dev_err(&pdev->dev, "Wake up is not possible as irq = %d\n",
430				rk808_rtc->irq);
431		return rk808_rtc->irq;
432	}
433
434	/* request alarm irq of rk808 */
435	ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,
436					rk808_alarm_irq, 0,
437					"RTC alarm", rk808_rtc);
438	if (ret) {
439		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
440			rk808_rtc->irq, ret);
441	}
442
443	return ret;
444}
445
446static struct platform_driver rk808_rtc_driver = {
447	.probe = rk808_rtc_probe,
448	.driver = {
449		.name = "rk808-rtc",
450		.pm = &rk808_rtc_pm_ops,
451	},
452};
453
454module_platform_driver(rk808_rtc_driver);
455
456MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
457MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
458MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");
459MODULE_LICENSE("GPL");
460MODULE_ALIAS("platform:rk808-rtc");
v4.6
  1/*
  2 * RTC driver for Rockchip RK808
  3 *
  4 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
  5 *
  6 * Author: Chris Zhong <zyw@rock-chips.com>
  7 * Author: Zhang Qing <zhangqing@rock-chips.com>
  8 *
  9 * This program is free software; you can redistribute it and/or modify it
 10 * under the terms and conditions of the GNU General Public License,
 11 * version 2, as published by the Free Software Foundation.
 12 *
 13 * This program is distributed in the hope it will be useful, but WITHOUT
 14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 15 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 16 * more details.
 17 */
 18
 19#include <linux/module.h>
 20#include <linux/kernel.h>
 21#include <linux/rtc.h>
 22#include <linux/bcd.h>
 23#include <linux/mfd/rk808.h>
 24#include <linux/platform_device.h>
 25#include <linux/i2c.h>
 26
 27/* RTC_CTRL_REG bitfields */
 28#define BIT_RTC_CTRL_REG_STOP_RTC_M		BIT(0)
 29
 30/* RK808 has a shadowed register for saving a "frozen" RTC time.
 31 * When user setting "GET_TIME" to 1, the time will save in this shadowed
 32 * register. If set "READSEL" to 1, user read rtc time register, actually
 33 * get the time of that moment. If we need the real time, clr this bit.
 34 */
 35#define BIT_RTC_CTRL_REG_RTC_GET_TIME		BIT(6)
 36#define BIT_RTC_CTRL_REG_RTC_READSEL_M		BIT(7)
 37#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M	BIT(3)
 38#define RTC_STATUS_MASK		0xFE
 39
 40#define SECONDS_REG_MSK		0x7F
 41#define MINUTES_REG_MAK		0x7F
 42#define HOURS_REG_MSK		0x3F
 43#define DAYS_REG_MSK		0x3F
 44#define MONTHS_REG_MSK		0x1F
 45#define YEARS_REG_MSK		0xFF
 46#define WEEKS_REG_MSK		0x7
 47
 48/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
 49
 50#define NUM_TIME_REGS	(RK808_WEEKS_REG - RK808_SECONDS_REG + 1)
 51#define NUM_ALARM_REGS	(RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)
 52
 53struct rk808_rtc {
 54	struct rk808 *rk808;
 55	struct rtc_device *rtc;
 56	int irq;
 57};
 58
 59/*
 60 * The Rockchip calendar used by the RK808 counts November with 31 days. We use
 61 * these translation functions to convert its dates to/from the Gregorian
 62 * calendar used by the rest of the world. We arbitrarily define Jan 1st, 2016
 63 * as the day when both calendars were in sync, and treat all other dates
 64 * relative to that.
 65 * NOTE: Other system software (e.g. firmware) that reads the same hardware must
 66 * implement this exact same conversion algorithm, with the same anchor date.
 67 */
 68static time64_t nov2dec_transitions(struct rtc_time *tm)
 69{
 70	return (tm->tm_year + 1900) - 2016 + (tm->tm_mon + 1 > 11 ? 1 : 0);
 71}
 72
 73static void rockchip_to_gregorian(struct rtc_time *tm)
 74{
 75	/* If it's Nov 31st, rtc_tm_to_time64() will count that like Dec 1st */
 76	time64_t time = rtc_tm_to_time64(tm);
 77	rtc_time64_to_tm(time + nov2dec_transitions(tm) * 86400, tm);
 78}
 79
 80static void gregorian_to_rockchip(struct rtc_time *tm)
 81{
 82	time64_t extra_days = nov2dec_transitions(tm);
 83	time64_t time = rtc_tm_to_time64(tm);
 84	rtc_time64_to_tm(time - extra_days * 86400, tm);
 85
 86	/* Compensate if we went back over Nov 31st (will work up to 2381) */
 87	if (nov2dec_transitions(tm) < extra_days) {
 88		if (tm->tm_mon + 1 == 11)
 89			tm->tm_mday++;	/* This may result in 31! */
 90		else
 91			rtc_time64_to_tm(time - (extra_days - 1) * 86400, tm);
 92	}
 93}
 94
 95/* Read current time and date in RTC */
 96static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)
 97{
 98	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
 99	struct rk808 *rk808 = rk808_rtc->rk808;
100	u8 rtc_data[NUM_TIME_REGS];
101	int ret;
102
103	/* Force an update of the shadowed registers right now */
104	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
105				 BIT_RTC_CTRL_REG_RTC_GET_TIME,
106				 BIT_RTC_CTRL_REG_RTC_GET_TIME);
107	if (ret) {
108		dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
109		return ret;
110	}
111
112	/*
113	 * After we set the GET_TIME bit, the rtc time can't be read
114	 * immediately. So we should wait up to 31.25 us, about one cycle of
115	 * 32khz. If we clear the GET_TIME bit here, the time of i2c transfer
116	 * certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.
117	 */
118	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
119				 BIT_RTC_CTRL_REG_RTC_GET_TIME,
120				 0);
121	if (ret) {
122		dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
123		return ret;
124	}
125
126	ret = regmap_bulk_read(rk808->regmap, RK808_SECONDS_REG,
127			       rtc_data, NUM_TIME_REGS);
128	if (ret) {
129		dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);
130		return ret;
131	}
132
133	tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
134	tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
135	tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
136	tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
137	tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;
138	tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
139	tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
140	rockchip_to_gregorian(tm);
141	dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
142		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
143		tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
144
145	return ret;
146}
147
148/* Set current time and date in RTC */
149static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
150{
151	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
152	struct rk808 *rk808 = rk808_rtc->rk808;
153	u8 rtc_data[NUM_TIME_REGS];
154	int ret;
155
156	dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
157		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
158		tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
159	gregorian_to_rockchip(tm);
160	rtc_data[0] = bin2bcd(tm->tm_sec);
161	rtc_data[1] = bin2bcd(tm->tm_min);
162	rtc_data[2] = bin2bcd(tm->tm_hour);
163	rtc_data[3] = bin2bcd(tm->tm_mday);
164	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
165	rtc_data[5] = bin2bcd(tm->tm_year - 100);
166	rtc_data[6] = bin2bcd(tm->tm_wday);
167
168	/* Stop RTC while updating the RTC registers */
169	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
170				 BIT_RTC_CTRL_REG_STOP_RTC_M,
171				 BIT_RTC_CTRL_REG_STOP_RTC_M);
172	if (ret) {
173		dev_err(dev, "Failed to update RTC control: %d\n", ret);
174		return ret;
175	}
176
177	ret = regmap_bulk_write(rk808->regmap, RK808_SECONDS_REG,
178				rtc_data, NUM_TIME_REGS);
179	if (ret) {
180		dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);
181		return ret;
182	}
183	/* Start RTC again */
184	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
185				 BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
186	if (ret) {
187		dev_err(dev, "Failed to update RTC control: %d\n", ret);
188		return ret;
189	}
190	return 0;
191}
192
193/* Read alarm time and date in RTC */
194static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
195{
196	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
197	struct rk808 *rk808 = rk808_rtc->rk808;
198	u8 alrm_data[NUM_ALARM_REGS];
199	uint32_t int_reg;
200	int ret;
201
202	ret = regmap_bulk_read(rk808->regmap, RK808_ALARM_SECONDS_REG,
203			       alrm_data, NUM_ALARM_REGS);
204
205	alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);
206	alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);
207	alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);
208	alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);
209	alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;
210	alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;
211	rockchip_to_gregorian(&alrm->time);
212
213	ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg);
214	if (ret) {
215		dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);
216		return ret;
217	}
218
219	dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
220		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
221		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
222		alrm->time.tm_min, alrm->time.tm_sec);
223
224	alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
225
226	return 0;
227}
228
229static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)
230{
231	struct rk808 *rk808 = rk808_rtc->rk808;
232	int ret;
233
234	ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
235				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);
236
237	return ret;
238}
239
240static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)
241{
242	struct rk808 *rk808 = rk808_rtc->rk808;
243	int ret;
244
245	ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
246				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,
247				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
248
249	return ret;
250}
251
252static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
253{
254	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
255	struct rk808 *rk808 = rk808_rtc->rk808;
256	u8 alrm_data[NUM_ALARM_REGS];
257	int ret;
258
259	ret = rk808_rtc_stop_alarm(rk808_rtc);
260	if (ret) {
261		dev_err(dev, "Failed to stop alarm: %d\n", ret);
262		return ret;
263	}
264	dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
265		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
266		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
267		alrm->time.tm_min, alrm->time.tm_sec);
268
269	gregorian_to_rockchip(&alrm->time);
270	alrm_data[0] = bin2bcd(alrm->time.tm_sec);
271	alrm_data[1] = bin2bcd(alrm->time.tm_min);
272	alrm_data[2] = bin2bcd(alrm->time.tm_hour);
273	alrm_data[3] = bin2bcd(alrm->time.tm_mday);
274	alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);
275	alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);
276
277	ret = regmap_bulk_write(rk808->regmap, RK808_ALARM_SECONDS_REG,
278				alrm_data, NUM_ALARM_REGS);
279	if (ret) {
280		dev_err(dev, "Failed to bulk write: %d\n", ret);
281		return ret;
282	}
283	if (alrm->enabled) {
284		ret = rk808_rtc_start_alarm(rk808_rtc);
285		if (ret) {
286			dev_err(dev, "Failed to start alarm: %d\n", ret);
287			return ret;
288		}
289	}
290	return 0;
291}
292
293static int rk808_rtc_alarm_irq_enable(struct device *dev,
294				      unsigned int enabled)
295{
296	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
297
298	if (enabled)
299		return rk808_rtc_start_alarm(rk808_rtc);
300
301	return rk808_rtc_stop_alarm(rk808_rtc);
302}
303
304/*
305 * We will just handle setting the frequency and make use the framework for
306 * reading the periodic interupts.
307 *
308 * @freq: Current periodic IRQ freq:
309 * bit 0: every second
310 * bit 1: every minute
311 * bit 2: every hour
312 * bit 3: every day
313 */
314static irqreturn_t rk808_alarm_irq(int irq, void *data)
315{
316	struct rk808_rtc *rk808_rtc = data;
317	struct rk808 *rk808 = rk808_rtc->rk808;
318	struct i2c_client *client = rk808->i2c;
319	int ret;
320
321	ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
322			   RTC_STATUS_MASK);
323	if (ret) {
324		dev_err(&client->dev,
325			"%s:Failed to update RTC status: %d\n", __func__, ret);
326		return ret;
327	}
328
329	rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);
330	dev_dbg(&client->dev,
331		 "%s:irq=%d\n", __func__, irq);
332	return IRQ_HANDLED;
333}
334
335static const struct rtc_class_ops rk808_rtc_ops = {
336	.read_time = rk808_rtc_readtime,
337	.set_time = rk808_rtc_set_time,
338	.read_alarm = rk808_rtc_readalarm,
339	.set_alarm = rk808_rtc_setalarm,
340	.alarm_irq_enable = rk808_rtc_alarm_irq_enable,
341};
342
343#ifdef CONFIG_PM_SLEEP
344/* Turn off the alarm if it should not be a wake source. */
345static int rk808_rtc_suspend(struct device *dev)
346{
347	struct platform_device *pdev = to_platform_device(dev);
348	struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
349
350	if (device_may_wakeup(dev))
351		enable_irq_wake(rk808_rtc->irq);
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 rk808_rtc_resume(struct device *dev)
360{
361	struct platform_device *pdev = to_platform_device(dev);
362	struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
363
364	if (device_may_wakeup(dev))
365		disable_irq_wake(rk808_rtc->irq);
366
367	return 0;
368}
369#endif
370
371static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,
372	rk808_rtc_suspend, rk808_rtc_resume);
373
374static int rk808_rtc_probe(struct platform_device *pdev)
375{
376	struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
377	struct rk808_rtc *rk808_rtc;
378	struct rtc_time tm;
379	int ret;
380
381	rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
382	if (rk808_rtc == NULL)
383		return -ENOMEM;
384
385	platform_set_drvdata(pdev, rk808_rtc);
386	rk808_rtc->rk808 = rk808;
387
388	/* start rtc running by default, and use shadowed timer. */
389	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
390				 BIT_RTC_CTRL_REG_STOP_RTC_M |
391				 BIT_RTC_CTRL_REG_RTC_READSEL_M,
392				 BIT_RTC_CTRL_REG_RTC_READSEL_M);
393	if (ret) {
394		dev_err(&pdev->dev,
395			"Failed to update RTC control: %d\n", ret);
396		return ret;
397	}
398
399	ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
400			   RTC_STATUS_MASK);
401	if (ret) {
402		dev_err(&pdev->dev,
403			"Failed to write RTC status: %d\n", ret);
404			return ret;
405	}
406
407	/* set init time */
408	ret = rk808_rtc_readtime(&pdev->dev, &tm);
409	if (ret) {
410		dev_err(&pdev->dev, "Failed to read RTC time\n");
411		return ret;
412	}
413	ret = rtc_valid_tm(&tm);
414	if (ret)
415		dev_warn(&pdev->dev, "invalid date/time\n");
416
417	device_init_wakeup(&pdev->dev, 1);
418
419	rk808_rtc->rtc = devm_rtc_device_register(&pdev->dev, "rk808-rtc",
420						  &rk808_rtc_ops, THIS_MODULE);
421	if (IS_ERR(rk808_rtc->rtc)) {
422		ret = PTR_ERR(rk808_rtc->rtc);
423		return ret;
424	}
425
426	rk808_rtc->irq = platform_get_irq(pdev, 0);
427	if (rk808_rtc->irq < 0) {
428		if (rk808_rtc->irq != -EPROBE_DEFER)
429			dev_err(&pdev->dev, "Wake up is not possible as irq = %d\n",
430				rk808_rtc->irq);
431		return rk808_rtc->irq;
432	}
433
434	/* request alarm irq of rk808 */
435	ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,
436					rk808_alarm_irq, 0,
437					"RTC alarm", rk808_rtc);
438	if (ret) {
439		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
440			rk808_rtc->irq, ret);
441	}
442
443	return ret;
444}
445
446static struct platform_driver rk808_rtc_driver = {
447	.probe = rk808_rtc_probe,
448	.driver = {
449		.name = "rk808-rtc",
450		.pm = &rk808_rtc_pm_ops,
451	},
452};
453
454module_platform_driver(rk808_rtc_driver);
455
456MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
457MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
458MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");
459MODULE_LICENSE("GPL");
460MODULE_ALIAS("platform:rk808-rtc");