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9765d2d9 CYT |
1 | /* |
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 | ||
111 | struct 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 | ||
119 | static 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 | ||
138 | static 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 | ||
158 | static 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 | ||
191 | static 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 | ||
206 | static 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 | ||
248 | static 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 | ||
266 | static 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 | ||
332 | static 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 | ||
342 | static 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 | ||
350 | static 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 | ||
419 | static 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 | ||
428 | static const struct of_device_id sun6i_rtc_dt_ids[] = { | |
429 | { .compatible = "allwinner,sun6i-a31-rtc" }, | |
430 | { /* sentinel */ }, | |
431 | }; | |
432 | MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids); | |
433 | ||
434 | static 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 | ||
443 | module_platform_driver(sun6i_rtc_driver); | |
444 | ||
445 | MODULE_DESCRIPTION("sun6i RTC driver"); | |
446 | MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>"); | |
447 | MODULE_LICENSE("GPL"); |