Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/drivers/rtc/rtc-sunxi.c

  1 /*
  2  * An RTC driver for Allwinner A10/A20
  3  *
  4  * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License as published by
  8  * the Free Software Foundation; either version 2 of the License, or
  9  * (at your option) any later version.
 10  *
 11  * This program is distributed in the hope that it will be useful, but WITHOUT
 12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 14  * more details.
 15  *
 16  * You should have received a copy of the GNU General Public License along
 17  * with this program; if not, write to the Free Software Foundation, Inc.,
 18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 19  */
 20 
 21 #include <linux/delay.h>
 22 #include <linux/err.h>
 23 #include <linux/fs.h>
 24 #include <linux/init.h>
 25 #include <linux/interrupt.h>
 26 #include <linux/io.h>
 27 #include <linux/kernel.h>
 28 #include <linux/module.h>
 29 #include <linux/of.h>
 30 #include <linux/of_address.h>
 31 #include <linux/of_device.h>
 32 #include <linux/platform_device.h>
 33 #include <linux/rtc.h>
 34 #include <linux/types.h>
 35 
 36 #define SUNXI_LOSC_CTRL                         0x0000
 37 #define SUNXI_LOSC_CTRL_RTC_HMS_ACC             BIT(8)
 38 #define SUNXI_LOSC_CTRL_RTC_YMD_ACC             BIT(7)
 39 
 40 #define SUNXI_RTC_YMD                           0x0004
 41 
 42 #define SUNXI_RTC_HMS                           0x0008
 43 
 44 #define SUNXI_ALRM_DHMS                         0x000c
 45 
 46 #define SUNXI_ALRM_EN                           0x0014
 47 #define SUNXI_ALRM_EN_CNT_EN                    BIT(8)
 48 
 49 #define SUNXI_ALRM_IRQ_EN                       0x0018
 50 #define SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN            BIT(0)
 51 
 52 #define SUNXI_ALRM_IRQ_STA                      0x001c
 53 #define SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND         BIT(0)
 54 
 55 #define SUNXI_MASK_DH                           0x0000001f
 56 #define SUNXI_MASK_SM                           0x0000003f
 57 #define SUNXI_MASK_M                            0x0000000f
 58 #define SUNXI_MASK_LY                           0x00000001
 59 #define SUNXI_MASK_D                            0x00000ffe
 60 #define SUNXI_MASK_M                            0x0000000f
 61 
 62 #define SUNXI_GET(x, mask, shift)               (((x) & ((mask) << (shift))) \
 63                                                         >> (shift))
 64 
 65 #define SUNXI_SET(x, mask, shift)               (((x) & (mask)) << (shift))
 66 
 67 /*
 68  * Get date values
 69  */
 70 #define SUNXI_DATE_GET_DAY_VALUE(x)             SUNXI_GET(x, SUNXI_MASK_DH, 0)
 71 #define SUNXI_DATE_GET_MON_VALUE(x)             SUNXI_GET(x, SUNXI_MASK_M, 8)
 72 #define SUNXI_DATE_GET_YEAR_VALUE(x, mask)      SUNXI_GET(x, mask, 16)
 73 
 74 /*
 75  * Get time values
 76  */
 77 #define SUNXI_TIME_GET_SEC_VALUE(x)             SUNXI_GET(x, SUNXI_MASK_SM, 0)
 78 #define SUNXI_TIME_GET_MIN_VALUE(x)             SUNXI_GET(x, SUNXI_MASK_SM, 8)
 79 #define SUNXI_TIME_GET_HOUR_VALUE(x)            SUNXI_GET(x, SUNXI_MASK_DH, 16)
 80 
 81 /*
 82  * Get alarm values
 83  */
 84 #define SUNXI_ALRM_GET_SEC_VALUE(x)             SUNXI_GET(x, SUNXI_MASK_SM, 0)
 85 #define SUNXI_ALRM_GET_MIN_VALUE(x)             SUNXI_GET(x, SUNXI_MASK_SM, 8)
 86 #define SUNXI_ALRM_GET_HOUR_VALUE(x)            SUNXI_GET(x, SUNXI_MASK_DH, 16)
 87 
 88 /*
 89  * Set date values
 90  */
 91 #define SUNXI_DATE_SET_DAY_VALUE(x)             SUNXI_DATE_GET_DAY_VALUE(x)
 92 #define SUNXI_DATE_SET_MON_VALUE(x)             SUNXI_SET(x, SUNXI_MASK_M, 8)
 93 #define SUNXI_DATE_SET_YEAR_VALUE(x, mask)      SUNXI_SET(x, mask, 16)
 94 #define SUNXI_LEAP_SET_VALUE(x, shift)          SUNXI_SET(x, SUNXI_MASK_LY, shift)
 95 
 96 /*
 97  * Set time values
 98  */
 99 #define SUNXI_TIME_SET_SEC_VALUE(x)             SUNXI_TIME_GET_SEC_VALUE(x)
100 #define SUNXI_TIME_SET_MIN_VALUE(x)             SUNXI_SET(x, SUNXI_MASK_SM, 8)
101 #define SUNXI_TIME_SET_HOUR_VALUE(x)            SUNXI_SET(x, SUNXI_MASK_DH, 16)
102 
103 /*
104  * Set alarm values
105  */
106 #define SUNXI_ALRM_SET_SEC_VALUE(x)             SUNXI_ALRM_GET_SEC_VALUE(x)
107 #define SUNXI_ALRM_SET_MIN_VALUE(x)             SUNXI_SET(x, SUNXI_MASK_SM, 8)
108 #define SUNXI_ALRM_SET_HOUR_VALUE(x)            SUNXI_SET(x, SUNXI_MASK_DH, 16)
109 #define SUNXI_ALRM_SET_DAY_VALUE(x)             SUNXI_SET(x, SUNXI_MASK_D, 21)
110 
111 /*
112  * Time unit conversions
113  */
114 #define SEC_IN_MIN                              60
115 #define SEC_IN_HOUR                             (60 * SEC_IN_MIN)
116 #define SEC_IN_DAY                              (24 * SEC_IN_HOUR)
117 
118 /*
119  * The year parameter passed to the driver is usually an offset relative to
120  * the year 1900. This macro is used to convert this offset to another one
121  * relative to the minimum year allowed by the hardware.
122  */
123 #define SUNXI_YEAR_OFF(x)                       ((x)->min - 1900)
124 
125 /*
126  * min and max year are arbitrary set considering the limited range of the
127  * hardware register field
128  */
129 struct sunxi_rtc_data_year {
130         unsigned int min;               /* min year allowed */
131         unsigned int max;               /* max year allowed */
132         unsigned int mask;              /* mask for the year field */
133         unsigned char leap_shift;       /* bit shift to get the leap year */
134 };
135 
136 static struct sunxi_rtc_data_year data_year_param[] = {
137         [0] = {
138                 .min            = 2010,
139                 .max            = 2073,
140                 .mask           = 0x3f,
141                 .leap_shift     = 22,
142         },
143         [1] = {
144                 .min            = 1970,
145                 .max            = 2225,
146                 .mask           = 0xff,
147                 .leap_shift     = 24,
148         },
149 };
150 
151 struct sunxi_rtc_dev {
152         struct rtc_device *rtc;
153         struct device *dev;
154         struct sunxi_rtc_data_year *data_year;
155         void __iomem *base;
156         int irq;
157 };
158 
159 static irqreturn_t sunxi_rtc_alarmirq(int irq, void *id)
160 {
161         struct sunxi_rtc_dev *chip = (struct sunxi_rtc_dev *) id;
162         u32 val;
163 
164         val = readl(chip->base + SUNXI_ALRM_IRQ_STA);
165 
166         if (val & SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND) {
167                 val |= SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND;
168                 writel(val, chip->base + SUNXI_ALRM_IRQ_STA);
169 
170                 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
171 
172                 return IRQ_HANDLED;
173         }
174 
175         return IRQ_NONE;
176 }
177 
178 static void sunxi_rtc_setaie(int to, struct sunxi_rtc_dev *chip)
179 {
180         u32 alrm_val = 0;
181         u32 alrm_irq_val = 0;
182 
183         if (to) {
184                 alrm_val = readl(chip->base + SUNXI_ALRM_EN);
185                 alrm_val |= SUNXI_ALRM_EN_CNT_EN;
186 
187                 alrm_irq_val = readl(chip->base + SUNXI_ALRM_IRQ_EN);
188                 alrm_irq_val |= SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN;
189         } else {
190                 writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND,
191                                 chip->base + SUNXI_ALRM_IRQ_STA);
192         }
193 
194         writel(alrm_val, chip->base + SUNXI_ALRM_EN);
195         writel(alrm_irq_val, chip->base + SUNXI_ALRM_IRQ_EN);
196 }
197 
198 static int sunxi_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
199 {
200         struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);
201         struct rtc_time *alrm_tm = &wkalrm->time;
202         u32 alrm;
203         u32 alrm_en;
204         u32 date;
205 
206         alrm = readl(chip->base + SUNXI_ALRM_DHMS);
207         date = readl(chip->base + SUNXI_RTC_YMD);
208 
209         alrm_tm->tm_sec = SUNXI_ALRM_GET_SEC_VALUE(alrm);
210         alrm_tm->tm_min = SUNXI_ALRM_GET_MIN_VALUE(alrm);
211         alrm_tm->tm_hour = SUNXI_ALRM_GET_HOUR_VALUE(alrm);
212 
213         alrm_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date);
214         alrm_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date);
215         alrm_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date,
216                         chip->data_year->mask);
217 
218         alrm_tm->tm_mon -= 1;
219 
220         /*
221          * switch from (data_year->min)-relative offset to
222          * a (1900)-relative one
223          */
224         alrm_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year);
225 
226         alrm_en = readl(chip->base + SUNXI_ALRM_IRQ_EN);
227         if (alrm_en & SUNXI_ALRM_EN_CNT_EN)
228                 wkalrm->enabled = 1;
229 
230         return 0;
231 }
232 
233 static int sunxi_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
234 {
235         struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);
236         u32 date, time;
237 
238         /*
239          * read again in case it changes
240          */
241         do {
242                 date = readl(chip->base + SUNXI_RTC_YMD);
243                 time = readl(chip->base + SUNXI_RTC_HMS);
244         } while ((date != readl(chip->base + SUNXI_RTC_YMD)) ||
245                  (time != readl(chip->base + SUNXI_RTC_HMS)));
246 
247         rtc_tm->tm_sec  = SUNXI_TIME_GET_SEC_VALUE(time);
248         rtc_tm->tm_min  = SUNXI_TIME_GET_MIN_VALUE(time);
249         rtc_tm->tm_hour = SUNXI_TIME_GET_HOUR_VALUE(time);
250 
251         rtc_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date);
252         rtc_tm->tm_mon  = SUNXI_DATE_GET_MON_VALUE(date);
253         rtc_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date,
254                                         chip->data_year->mask);
255 
256         rtc_tm->tm_mon  -= 1;
257 
258         /*
259          * switch from (data_year->min)-relative offset to
260          * a (1900)-relative one
261          */
262         rtc_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year);
263 
264         return rtc_valid_tm(rtc_tm);
265 }
266 
267 static int sunxi_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
268 {
269         struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);
270         struct rtc_time *alrm_tm = &wkalrm->time;
271         struct rtc_time tm_now;
272         u32 alrm = 0;
273         unsigned long time_now = 0;
274         unsigned long time_set = 0;
275         unsigned long time_gap = 0;
276         unsigned long time_gap_day = 0;
277         unsigned long time_gap_hour = 0;
278         unsigned long time_gap_min = 0;
279         int ret = 0;
280 
281         ret = sunxi_rtc_gettime(dev, &tm_now);
282         if (ret < 0) {
283                 dev_err(dev, "Error in getting time\n");
284                 return -EINVAL;
285         }
286 
287         rtc_tm_to_time(alrm_tm, &time_set);
288         rtc_tm_to_time(&tm_now, &time_now);
289         if (time_set <= time_now) {
290                 dev_err(dev, "Date to set in the past\n");
291                 return -EINVAL;
292         }
293 
294         time_gap = time_set - time_now;
295         time_gap_day = time_gap / SEC_IN_DAY;
296         time_gap -= time_gap_day * SEC_IN_DAY;
297         time_gap_hour = time_gap / SEC_IN_HOUR;
298         time_gap -= time_gap_hour * SEC_IN_HOUR;
299         time_gap_min = time_gap / SEC_IN_MIN;
300         time_gap -= time_gap_min * SEC_IN_MIN;
301 
302         if (time_gap_day > 255) {
303                 dev_err(dev, "Day must be in the range 0 - 255\n");
304                 return -EINVAL;
305         }
306 
307         sunxi_rtc_setaie(0, chip);
308         writel(0, chip->base + SUNXI_ALRM_DHMS);
309         usleep_range(100, 300);
310 
311         alrm = SUNXI_ALRM_SET_SEC_VALUE(time_gap) |
312                 SUNXI_ALRM_SET_MIN_VALUE(time_gap_min) |
313                 SUNXI_ALRM_SET_HOUR_VALUE(time_gap_hour) |
314                 SUNXI_ALRM_SET_DAY_VALUE(time_gap_day);
315         writel(alrm, chip->base + SUNXI_ALRM_DHMS);
316 
317         writel(0, chip->base + SUNXI_ALRM_IRQ_EN);
318         writel(SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN, chip->base + SUNXI_ALRM_IRQ_EN);
319 
320         sunxi_rtc_setaie(wkalrm->enabled, chip);
321 
322         return 0;
323 }
324 
325 static int sunxi_rtc_wait(struct sunxi_rtc_dev *chip, int offset,
326                           unsigned int mask, unsigned int ms_timeout)
327 {
328         const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
329         u32 reg;
330 
331         do {
332                 reg = readl(chip->base + offset);
333                 reg &= mask;
334 
335                 if (reg == mask)
336                         return 0;
337 
338         } while (time_before(jiffies, timeout));
339 
340         return -ETIMEDOUT;
341 }
342 
343 static int sunxi_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
344 {
345         struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);
346         u32 date = 0;
347         u32 time = 0;
348         int year;
349 
350         /*
351          * the input rtc_tm->tm_year is the offset relative to 1900. We use
352          * the SUNXI_YEAR_OFF macro to rebase it with respect to the min year
353          * allowed by the hardware
354          */
355 
356         year = rtc_tm->tm_year + 1900;
357         if (year < chip->data_year->min || year > chip->data_year->max) {
358                 dev_err(dev, "rtc only supports year in range %d - %d\n",
359                                 chip->data_year->min, chip->data_year->max);
360                 return -EINVAL;
361         }
362 
363         rtc_tm->tm_year -= SUNXI_YEAR_OFF(chip->data_year);
364         rtc_tm->tm_mon += 1;
365 
366         date = SUNXI_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
367                 SUNXI_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |
368                 SUNXI_DATE_SET_YEAR_VALUE(rtc_tm->tm_year,
369                                 chip->data_year->mask);
370 
371         if (is_leap_year(year))
372                 date |= SUNXI_LEAP_SET_VALUE(1, chip->data_year->leap_shift);
373 
374         time = SUNXI_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |
375                 SUNXI_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |
376                 SUNXI_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
377 
378         writel(0, chip->base + SUNXI_RTC_HMS);
379         writel(0, chip->base + SUNXI_RTC_YMD);
380 
381         writel(time, chip->base + SUNXI_RTC_HMS);
382 
383         /*
384          * After writing the RTC HH-MM-SS register, the
385          * SUNXI_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
386          * be cleared until the real writing operation is finished
387          */
388 
389         if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL,
390                                 SUNXI_LOSC_CTRL_RTC_HMS_ACC, 50)) {
391                 dev_err(dev, "Failed to set rtc time.\n");
392                 return -1;
393         }
394 
395         writel(date, chip->base + SUNXI_RTC_YMD);
396 
397         /*
398          * After writing the RTC YY-MM-DD register, the
399          * SUNXI_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
400          * be cleared until the real writing operation is finished
401          */
402 
403         if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL,
404                                 SUNXI_LOSC_CTRL_RTC_YMD_ACC, 50)) {
405                 dev_err(dev, "Failed to set rtc time.\n");
406                 return -1;
407         }
408 
409         return 0;
410 }
411 
412 static int sunxi_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
413 {
414         struct sunxi_rtc_dev *chip = dev_get_drvdata(dev);
415 
416         if (!enabled)
417                 sunxi_rtc_setaie(enabled, chip);
418 
419         return 0;
420 }
421 
422 static const struct rtc_class_ops sunxi_rtc_ops = {
423         .read_time              = sunxi_rtc_gettime,
424         .set_time               = sunxi_rtc_settime,
425         .read_alarm             = sunxi_rtc_getalarm,
426         .set_alarm              = sunxi_rtc_setalarm,
427         .alarm_irq_enable       = sunxi_rtc_alarm_irq_enable
428 };
429 
430 static const struct of_device_id sunxi_rtc_dt_ids[] = {
431         { .compatible = "allwinner,sun4i-a10-rtc", .data = &data_year_param[0] },
432         { .compatible = "allwinner,sun7i-a20-rtc", .data = &data_year_param[1] },
433         { /* sentinel */ },
434 };
435 MODULE_DEVICE_TABLE(of, sunxi_rtc_dt_ids);
436 
437 static int sunxi_rtc_probe(struct platform_device *pdev)
438 {
439         struct sunxi_rtc_dev *chip;
440         struct resource *res;
441         const struct of_device_id *of_id;
442         int ret;
443 
444         chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
445         if (!chip)
446                 return -ENOMEM;
447 
448         platform_set_drvdata(pdev, chip);
449         chip->dev = &pdev->dev;
450 
451         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
452         chip->base = devm_ioremap_resource(&pdev->dev, res);
453         if (IS_ERR(chip->base))
454                 return PTR_ERR(chip->base);
455 
456         chip->irq = platform_get_irq(pdev, 0);
457         if (chip->irq < 0) {
458                 dev_err(&pdev->dev, "No IRQ resource\n");
459                 return chip->irq;
460         }
461         ret = devm_request_irq(&pdev->dev, chip->irq, sunxi_rtc_alarmirq,
462                         0, dev_name(&pdev->dev), chip);
463         if (ret) {
464                 dev_err(&pdev->dev, "Could not request IRQ\n");
465                 return ret;
466         }
467 
468         of_id = of_match_device(sunxi_rtc_dt_ids, &pdev->dev);
469         if (!of_id) {
470                 dev_err(&pdev->dev, "Unable to setup RTC data\n");
471                 return -ENODEV;
472         }
473         chip->data_year = (struct sunxi_rtc_data_year *) of_id->data;
474 
475         /* clear the alarm count value */
476         writel(0, chip->base + SUNXI_ALRM_DHMS);
477 
478         /* disable alarm, not generate irq pending */
479         writel(0, chip->base + SUNXI_ALRM_EN);
480 
481         /* disable alarm week/cnt irq, unset to cpu */
482         writel(0, chip->base + SUNXI_ALRM_IRQ_EN);
483 
484         /* clear alarm week/cnt irq pending */
485         writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +
486                         SUNXI_ALRM_IRQ_STA);
487 
488         chip->rtc = rtc_device_register("rtc-sunxi", &pdev->dev,
489                         &sunxi_rtc_ops, THIS_MODULE);
490         if (IS_ERR(chip->rtc)) {
491                 dev_err(&pdev->dev, "unable to register device\n");
492                 return PTR_ERR(chip->rtc);
493         }
494 
495         dev_info(&pdev->dev, "RTC enabled\n");
496 
497         return 0;
498 }
499 
500 static int sunxi_rtc_remove(struct platform_device *pdev)
501 {
502         struct sunxi_rtc_dev *chip = platform_get_drvdata(pdev);
503 
504         rtc_device_unregister(chip->rtc);
505 
506         return 0;
507 }
508 
509 static struct platform_driver sunxi_rtc_driver = {
510         .probe          = sunxi_rtc_probe,
511         .remove         = sunxi_rtc_remove,
512         .driver         = {
513                 .name           = "sunxi-rtc",
514                 .owner          = THIS_MODULE,
515                 .of_match_table = sunxi_rtc_dt_ids,
516         },
517 };
518 
519 module_platform_driver(sunxi_rtc_driver);
520 
521 MODULE_DESCRIPTION("sunxi RTC driver");
522 MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
523 MODULE_LICENSE("GPL");
524 

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