blob: c169a2cd47273e11fd62cb85755cb0badbb31a94 [file] [log] [blame]
Chen-Yu Tsai9765d2d2014-08-26 11:54:55 +08001/*
2 * An RTC driver for Allwinner A31/A23
3 *
4 * Copyright (c) 2014, Chen-Yu Tsai <wens@csie.org>
5 *
6 * based on rtc-sunxi.c
7 *
8 * An RTC driver for Allwinner A10/A20
9 *
10 * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
20 * more details.
21 */
22
23#include <linux/delay.h>
24#include <linux/err.h>
25#include <linux/fs.h>
26#include <linux/init.h>
27#include <linux/interrupt.h>
28#include <linux/io.h>
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/of.h>
32#include <linux/of_address.h>
33#include <linux/of_device.h>
34#include <linux/platform_device.h>
35#include <linux/rtc.h>
36#include <linux/types.h>
37
38/* Control register */
39#define SUN6I_LOSC_CTRL 0x0000
40#define SUN6I_LOSC_CTRL_ALM_DHMS_ACC BIT(9)
41#define SUN6I_LOSC_CTRL_RTC_HMS_ACC BIT(8)
42#define SUN6I_LOSC_CTRL_RTC_YMD_ACC BIT(7)
43#define SUN6I_LOSC_CTRL_ACC_MASK GENMASK(9, 7)
44
45/* RTC */
46#define SUN6I_RTC_YMD 0x0010
47#define SUN6I_RTC_HMS 0x0014
48
49/* Alarm 0 (counter) */
50#define SUN6I_ALRM_COUNTER 0x0020
51#define SUN6I_ALRM_CUR_VAL 0x0024
52#define SUN6I_ALRM_EN 0x0028
53#define SUN6I_ALRM_EN_CNT_EN BIT(0)
54#define SUN6I_ALRM_IRQ_EN 0x002c
55#define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0)
56#define SUN6I_ALRM_IRQ_STA 0x0030
57#define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0)
58
59/* Alarm 1 (wall clock) */
60#define SUN6I_ALRM1_EN 0x0044
61#define SUN6I_ALRM1_IRQ_EN 0x0048
62#define SUN6I_ALRM1_IRQ_STA 0x004c
63#define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND BIT(0)
64
65/* Alarm config */
66#define SUN6I_ALARM_CONFIG 0x0050
67#define SUN6I_ALARM_CONFIG_WAKEUP BIT(0)
68
69/*
70 * Get date values
71 */
72#define SUN6I_DATE_GET_DAY_VALUE(x) ((x) & 0x0000001f)
73#define SUN6I_DATE_GET_MON_VALUE(x) (((x) & 0x00000f00) >> 8)
74#define SUN6I_DATE_GET_YEAR_VALUE(x) (((x) & 0x003f0000) >> 16)
75#define SUN6I_LEAP_GET_VALUE(x) (((x) & 0x00400000) >> 22)
76
77/*
78 * Get time values
79 */
80#define SUN6I_TIME_GET_SEC_VALUE(x) ((x) & 0x0000003f)
81#define SUN6I_TIME_GET_MIN_VALUE(x) (((x) & 0x00003f00) >> 8)
82#define SUN6I_TIME_GET_HOUR_VALUE(x) (((x) & 0x001f0000) >> 16)
83
84/*
85 * Set date values
86 */
87#define SUN6I_DATE_SET_DAY_VALUE(x) ((x) & 0x0000001f)
88#define SUN6I_DATE_SET_MON_VALUE(x) ((x) << 8 & 0x00000f00)
89#define SUN6I_DATE_SET_YEAR_VALUE(x) ((x) << 16 & 0x003f0000)
90#define SUN6I_LEAP_SET_VALUE(x) ((x) << 22 & 0x00400000)
91
92/*
93 * Set time values
94 */
95#define SUN6I_TIME_SET_SEC_VALUE(x) ((x) & 0x0000003f)
96#define SUN6I_TIME_SET_MIN_VALUE(x) ((x) << 8 & 0x00003f00)
97#define SUN6I_TIME_SET_HOUR_VALUE(x) ((x) << 16 & 0x001f0000)
98
99/*
100 * The year parameter passed to the driver is usually an offset relative to
101 * the year 1900. This macro is used to convert this offset to another one
102 * relative to the minimum year allowed by the hardware.
103 *
104 * The year range is 1970 - 2033. This range is selected to match Allwinner's
105 * driver, even though it is somewhat limited.
106 */
107#define SUN6I_YEAR_MIN 1970
108#define SUN6I_YEAR_MAX 2033
109#define SUN6I_YEAR_OFF (SUN6I_YEAR_MIN - 1900)
110
111struct sun6i_rtc_dev {
112 struct rtc_device *rtc;
113 struct device *dev;
114 void __iomem *base;
115 int irq;
116 unsigned long alarm;
117};
118
119static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
120{
121 struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;
122 u32 val;
123
124 val = readl(chip->base + SUN6I_ALRM_IRQ_STA);
125
126 if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
127 val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;
128 writel(val, chip->base + SUN6I_ALRM_IRQ_STA);
129
130 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
131
132 return IRQ_HANDLED;
133 }
134
135 return IRQ_NONE;
136}
137
138static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
139{
140 u32 alrm_val = 0;
141 u32 alrm_irq_val = 0;
142 u32 alrm_wake_val = 0;
143
144 if (to) {
145 alrm_val = SUN6I_ALRM_EN_CNT_EN;
146 alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;
147 alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;
148 } else {
149 writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
150 chip->base + SUN6I_ALRM_IRQ_STA);
151 }
152
153 writel(alrm_val, chip->base + SUN6I_ALRM_EN);
154 writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
155 writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
156}
157
158static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
159{
160 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
161 u32 date, time;
162
163 /*
164 * read again in case it changes
165 */
166 do {
167 date = readl(chip->base + SUN6I_RTC_YMD);
168 time = readl(chip->base + SUN6I_RTC_HMS);
169 } while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
170 (time != readl(chip->base + SUN6I_RTC_HMS)));
171
172 rtc_tm->tm_sec = SUN6I_TIME_GET_SEC_VALUE(time);
173 rtc_tm->tm_min = SUN6I_TIME_GET_MIN_VALUE(time);
174 rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
175
176 rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
177 rtc_tm->tm_mon = SUN6I_DATE_GET_MON_VALUE(date);
178 rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
179
180 rtc_tm->tm_mon -= 1;
181
182 /*
183 * switch from (data_year->min)-relative offset to
184 * a (1900)-relative one
185 */
186 rtc_tm->tm_year += SUN6I_YEAR_OFF;
187
188 return rtc_valid_tm(rtc_tm);
189}
190
191static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
192{
193 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
194 u32 alrm_st;
195 u32 alrm_en;
196
197 alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
198 alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
199 wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
200 wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
201 rtc_time_to_tm(chip->alarm, &wkalrm->time);
202
203 return 0;
204}
205
206static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
207{
208 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
209 struct rtc_time *alrm_tm = &wkalrm->time;
210 struct rtc_time tm_now;
211 unsigned long time_now = 0;
212 unsigned long time_set = 0;
213 unsigned long time_gap = 0;
214 int ret = 0;
215
216 ret = sun6i_rtc_gettime(dev, &tm_now);
217 if (ret < 0) {
218 dev_err(dev, "Error in getting time\n");
219 return -EINVAL;
220 }
221
222 rtc_tm_to_time(alrm_tm, &time_set);
223 rtc_tm_to_time(&tm_now, &time_now);
224 if (time_set <= time_now) {
225 dev_err(dev, "Date to set in the past\n");
226 return -EINVAL;
227 }
228
229 time_gap = time_set - time_now;
230
231 if (time_gap > U32_MAX) {
232 dev_err(dev, "Date too far in the future\n");
233 return -EINVAL;
234 }
235
236 sun6i_rtc_setaie(0, chip);
237 writel(0, chip->base + SUN6I_ALRM_COUNTER);
238 usleep_range(100, 300);
239
240 writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
241 chip->alarm = time_set;
242
243 sun6i_rtc_setaie(wkalrm->enabled, chip);
244
245 return 0;
246}
247
248static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,
249 unsigned int mask, unsigned int ms_timeout)
250{
251 const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
252 u32 reg;
253
254 do {
255 reg = readl(chip->base + offset);
256 reg &= mask;
257
258 if (!reg)
259 return 0;
260
261 } while (time_before(jiffies, timeout));
262
263 return -ETIMEDOUT;
264}
265
266static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
267{
268 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
269 u32 date = 0;
270 u32 time = 0;
271 int year;
272
273 year = rtc_tm->tm_year + 1900;
274 if (year < SUN6I_YEAR_MIN || year > SUN6I_YEAR_MAX) {
275 dev_err(dev, "rtc only supports year in range %d - %d\n",
276 SUN6I_YEAR_MIN, SUN6I_YEAR_MAX);
277 return -EINVAL;
278 }
279
280 rtc_tm->tm_year -= SUN6I_YEAR_OFF;
281 rtc_tm->tm_mon += 1;
282
283 date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
284 SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon) |
285 SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
286
287 if (is_leap_year(year))
288 date |= SUN6I_LEAP_SET_VALUE(1);
289
290 time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) |
291 SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min) |
292 SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
293
294 /* Check whether registers are writable */
295 if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
296 SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
297 dev_err(dev, "rtc is still busy.\n");
298 return -EBUSY;
299 }
300
301 writel(time, chip->base + SUN6I_RTC_HMS);
302
303 /*
304 * After writing the RTC HH-MM-SS register, the
305 * SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
306 * be cleared until the real writing operation is finished
307 */
308
309 if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
310 SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {
311 dev_err(dev, "Failed to set rtc time.\n");
312 return -ETIMEDOUT;
313 }
314
315 writel(date, chip->base + SUN6I_RTC_YMD);
316
317 /*
318 * After writing the RTC YY-MM-DD register, the
319 * SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
320 * be cleared until the real writing operation is finished
321 */
322
323 if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
324 SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {
325 dev_err(dev, "Failed to set rtc time.\n");
326 return -ETIMEDOUT;
327 }
328
329 return 0;
330}
331
332static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
333{
334 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
335
336 if (!enabled)
337 sun6i_rtc_setaie(enabled, chip);
338
339 return 0;
340}
341
342static const struct rtc_class_ops sun6i_rtc_ops = {
343 .read_time = sun6i_rtc_gettime,
344 .set_time = sun6i_rtc_settime,
345 .read_alarm = sun6i_rtc_getalarm,
346 .set_alarm = sun6i_rtc_setalarm,
347 .alarm_irq_enable = sun6i_rtc_alarm_irq_enable
348};
349
350static int sun6i_rtc_probe(struct platform_device *pdev)
351{
352 struct sun6i_rtc_dev *chip;
353 struct resource *res;
354 int ret;
355
356 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
357 if (!chip)
358 return -ENOMEM;
359
360 platform_set_drvdata(pdev, chip);
361 chip->dev = &pdev->dev;
362
363 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
364 chip->base = devm_ioremap_resource(&pdev->dev, res);
365 if (IS_ERR(chip->base))
366 return PTR_ERR(chip->base);
367
368 chip->irq = platform_get_irq(pdev, 0);
369 if (chip->irq < 0) {
370 dev_err(&pdev->dev, "No IRQ resource\n");
371 return chip->irq;
372 }
373
374 ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,
375 0, dev_name(&pdev->dev), chip);
376 if (ret) {
377 dev_err(&pdev->dev, "Could not request IRQ\n");
378 return ret;
379 }
380
381 /* clear the alarm counter value */
382 writel(0, chip->base + SUN6I_ALRM_COUNTER);
383
384 /* disable counter alarm */
385 writel(0, chip->base + SUN6I_ALRM_EN);
386
387 /* disable counter alarm interrupt */
388 writel(0, chip->base + SUN6I_ALRM_IRQ_EN);
389
390 /* disable week alarm */
391 writel(0, chip->base + SUN6I_ALRM1_EN);
392
393 /* disable week alarm interrupt */
394 writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);
395
396 /* clear counter alarm pending interrupts */
397 writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
398 chip->base + SUN6I_ALRM_IRQ_STA);
399
400 /* clear week alarm pending interrupts */
401 writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND,
402 chip->base + SUN6I_ALRM1_IRQ_STA);
403
404 /* disable alarm wakeup */
405 writel(0, chip->base + SUN6I_ALARM_CONFIG);
406
407 chip->rtc = rtc_device_register("rtc-sun6i", &pdev->dev,
408 &sun6i_rtc_ops, THIS_MODULE);
409 if (IS_ERR(chip->rtc)) {
410 dev_err(&pdev->dev, "unable to register device\n");
411 return PTR_ERR(chip->rtc);
412 }
413
414 dev_info(&pdev->dev, "RTC enabled\n");
415
416 return 0;
417}
418
419static int sun6i_rtc_remove(struct platform_device *pdev)
420{
421 struct sun6i_rtc_dev *chip = platform_get_drvdata(pdev);
422
423 rtc_device_unregister(chip->rtc);
424
425 return 0;
426}
427
428static const struct of_device_id sun6i_rtc_dt_ids[] = {
429 { .compatible = "allwinner,sun6i-a31-rtc" },
430 { /* sentinel */ },
431};
432MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
433
434static struct platform_driver sun6i_rtc_driver = {
435 .probe = sun6i_rtc_probe,
436 .remove = sun6i_rtc_remove,
437 .driver = {
438 .name = "sun6i-rtc",
439 .of_match_table = sun6i_rtc_dt_ids,
440 },
441};
442
443module_platform_driver(sun6i_rtc_driver);
444
445MODULE_DESCRIPTION("sun6i RTC driver");
446MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
447MODULE_LICENSE("GPL");