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Linux 4.18.10
[linux/fpc-iii.git] / drivers / rtc / rtc-ac100.c
blob784b676284bff57d9bb675e0f0f1b7af3113f354
1 /*
2 * RTC Driver for X-Powers AC100
3 *
4 * Copyright (c) 2016 Chen-Yu Tsai
5 *
6 * Chen-Yu Tsai <wens@csie.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 */
17
18 #include <linux/bcd.h>
19 #include <linux/clk-provider.h>
20 #include <linux/device.h>
21 #include <linux/interrupt.h>
22 #include <linux/kernel.h>
23 #include <linux/mfd/ac100.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/of.h>
27 #include <linux/platform_device.h>
28 #include <linux/regmap.h>
29 #include <linux/rtc.h>
30 #include <linux/types.h>
31
32 /* Control register */
33 #define AC100_RTC_CTRL_24HOUR BIT(0)
34
35 /* Clock output register bits */
36 #define AC100_CLKOUT_PRE_DIV_SHIFT 5
37 #define AC100_CLKOUT_PRE_DIV_WIDTH 3
38 #define AC100_CLKOUT_MUX_SHIFT 4
39 #define AC100_CLKOUT_MUX_WIDTH 1
40 #define AC100_CLKOUT_DIV_SHIFT 1
41 #define AC100_CLKOUT_DIV_WIDTH 3
42 #define AC100_CLKOUT_EN BIT(0)
43
44 /* RTC */
45 #define AC100_RTC_SEC_MASK GENMASK(6, 0)
46 #define AC100_RTC_MIN_MASK GENMASK(6, 0)
47 #define AC100_RTC_HOU_MASK GENMASK(5, 0)
48 #define AC100_RTC_WEE_MASK GENMASK(2, 0)
49 #define AC100_RTC_DAY_MASK GENMASK(5, 0)
50 #define AC100_RTC_MON_MASK GENMASK(4, 0)
51 #define AC100_RTC_YEA_MASK GENMASK(7, 0)
52 #define AC100_RTC_YEA_LEAP BIT(15)
53 #define AC100_RTC_UPD_TRIGGER BIT(15)
54
55 /* Alarm (wall clock) */
56 #define AC100_ALM_INT_ENABLE BIT(0)
57
58 #define AC100_ALM_SEC_MASK GENMASK(6, 0)
59 #define AC100_ALM_MIN_MASK GENMASK(6, 0)
60 #define AC100_ALM_HOU_MASK GENMASK(5, 0)
61 #define AC100_ALM_WEE_MASK GENMASK(2, 0)
62 #define AC100_ALM_DAY_MASK GENMASK(5, 0)
63 #define AC100_ALM_MON_MASK GENMASK(4, 0)
64 #define AC100_ALM_YEA_MASK GENMASK(7, 0)
65 #define AC100_ALM_ENABLE_FLAG BIT(15)
66 #define AC100_ALM_UPD_TRIGGER BIT(15)
67
68 /*
69 * The year parameter passed to the driver is usually an offset relative to
70 * the year 1900. This macro is used to convert this offset to another one
71 * relative to the minimum year allowed by the hardware.
72 *
73 * The year range is 1970 - 2069. This range is selected to match Allwinner's
74 * driver.
75 */
76 #define AC100_YEAR_MIN 1970
77 #define AC100_YEAR_MAX 2069
78 #define AC100_YEAR_OFF (AC100_YEAR_MIN - 1900)
79
80 struct ac100_clkout {
81 struct clk_hw hw;
82 struct regmap *regmap;
83 u8 offset;
84 };
85
86 #define to_ac100_clkout(_hw) container_of(_hw, struct ac100_clkout, hw)
87
88 #define AC100_RTC_32K_NAME "ac100-rtc-32k"
89 #define AC100_RTC_32K_RATE 32768
90 #define AC100_CLKOUT_NUM 3
91
92 static const char * const ac100_clkout_names[AC100_CLKOUT_NUM] = {
93 "ac100-cko1-rtc",
94 "ac100-cko2-rtc",
95 "ac100-cko3-rtc",
96 };
97
98 struct ac100_rtc_dev {
99 struct rtc_device *rtc;
100 struct device *dev;
101 struct regmap *regmap;
102 int irq;
103 unsigned long alarm;
104
105 struct clk_hw *rtc_32k_clk;
106 struct ac100_clkout clks[AC100_CLKOUT_NUM];
107 struct clk_hw_onecell_data *clk_data;
108 };
109
110 /**
111 * Clock controls for 3 clock output pins
112 */
113
114 static const struct clk_div_table ac100_clkout_prediv[] = {
115 { .val = 0, .div = 1 },
116 { .val = 1, .div = 2 },
117 { .val = 2, .div = 4 },
118 { .val = 3, .div = 8 },
119 { .val = 4, .div = 16 },
120 { .val = 5, .div = 32 },
121 { .val = 6, .div = 64 },
122 { .val = 7, .div = 122 },
123 { },
124 };
125
126 /* Abuse the fact that one parent is 32768 Hz, and the other is 4 MHz */
127 static unsigned long ac100_clkout_recalc_rate(struct clk_hw *hw,
128 unsigned long prate)
129 {
130 struct ac100_clkout *clk = to_ac100_clkout(hw);
131 unsigned int reg, div;
132
133 regmap_read(clk->regmap, clk->offset, &reg);
134
135 /* Handle pre-divider first */
136 if (prate != AC100_RTC_32K_RATE) {
137 div = (reg >> AC100_CLKOUT_PRE_DIV_SHIFT) &
138 ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1);
139 prate = divider_recalc_rate(hw, prate, div,
140 ac100_clkout_prediv, 0,
141 AC100_CLKOUT_PRE_DIV_WIDTH);
142 }
143
144 div = (reg >> AC100_CLKOUT_DIV_SHIFT) &
145 (BIT(AC100_CLKOUT_DIV_WIDTH) - 1);
146 return divider_recalc_rate(hw, prate, div, NULL,
147 CLK_DIVIDER_POWER_OF_TWO,
148 AC100_CLKOUT_DIV_WIDTH);
149 }
150
151 static long ac100_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
152 unsigned long prate)
153 {
154 unsigned long best_rate = 0, tmp_rate, tmp_prate;
155 int i;
156
157 if (prate == AC100_RTC_32K_RATE)
158 return divider_round_rate(hw, rate, &prate, NULL,
159 AC100_CLKOUT_DIV_WIDTH,
160 CLK_DIVIDER_POWER_OF_TWO);
161
162 for (i = 0; ac100_clkout_prediv[i].div; i++) {
163 tmp_prate = DIV_ROUND_UP(prate, ac100_clkout_prediv[i].val);
164 tmp_rate = divider_round_rate(hw, rate, &tmp_prate, NULL,
165 AC100_CLKOUT_DIV_WIDTH,
166 CLK_DIVIDER_POWER_OF_TWO);
167
168 if (tmp_rate > rate)
169 continue;
170 if (rate - tmp_rate < best_rate - tmp_rate)
171 best_rate = tmp_rate;
172 }
173
174 return best_rate;
175 }
176
177 static int ac100_clkout_determine_rate(struct clk_hw *hw,
178 struct clk_rate_request *req)
179 {
180 struct clk_hw *best_parent;
181 unsigned long best = 0;
182 int i, num_parents = clk_hw_get_num_parents(hw);
183
184 for (i = 0; i < num_parents; i++) {
185 struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
186 unsigned long tmp, prate;
187
188 /*
189 * The clock has two parents, one is a fixed clock which is
190 * internally registered by the ac100 driver. The other parent
191 * is a clock from the codec side of the chip, which we
192 * properly declare and reference in the devicetree and is
193 * not implemented in any driver right now.
194 * If the clock core looks for the parent of that second
195 * missing clock, it can't find one that is registered and
196 * returns NULL.
197 * So we end up in a situation where clk_hw_get_num_parents
198 * returns the amount of clocks we can be parented to, but
199 * clk_hw_get_parent_by_index will not return the orphan
200 * clocks.
201 * Thus we need to check if the parent exists before
202 * we get the parent rate, so we could use the RTC
203 * without waiting for the codec to be supported.
204 */
205 if (!parent)
206 continue;
207
208 prate = clk_hw_get_rate(parent);
209
210 tmp = ac100_clkout_round_rate(hw, req->rate, prate);
211
212 if (tmp > req->rate)
213 continue;
214 if (req->rate - tmp < req->rate - best) {
215 best = tmp;
216 best_parent = parent;
217 }
218 }
219
220 if (!best)
221 return -EINVAL;
222
223 req->best_parent_hw = best_parent;
224 req->best_parent_rate = best;
225 req->rate = best;
226
227 return 0;
228 }
229
230 static int ac100_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
231 unsigned long prate)
232 {
233 struct ac100_clkout *clk = to_ac100_clkout(hw);
234 int div = 0, pre_div = 0;
235
236 do {
237 div = divider_get_val(rate * ac100_clkout_prediv[pre_div].div,
238 prate, NULL, AC100_CLKOUT_DIV_WIDTH,
239 CLK_DIVIDER_POWER_OF_TWO);
240 if (div >= 0)
241 break;
242 } while (prate != AC100_RTC_32K_RATE &&
243 ac100_clkout_prediv[++pre_div].div);
244
245 if (div < 0)
246 return div;
247
248 pre_div = ac100_clkout_prediv[pre_div].val;
249
250 regmap_update_bits(clk->regmap, clk->offset,
251 ((1 << AC100_CLKOUT_DIV_WIDTH) - 1) << AC100_CLKOUT_DIV_SHIFT |
252 ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1) << AC100_CLKOUT_PRE_DIV_SHIFT,
253 (div - 1) << AC100_CLKOUT_DIV_SHIFT |
254 (pre_div - 1) << AC100_CLKOUT_PRE_DIV_SHIFT);
255
256 return 0;
257 }
258
259 static int ac100_clkout_prepare(struct clk_hw *hw)
260 {
261 struct ac100_clkout *clk = to_ac100_clkout(hw);
262
263 return regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN,
264 AC100_CLKOUT_EN);
265 }
266
267 static void ac100_clkout_unprepare(struct clk_hw *hw)
268 {
269 struct ac100_clkout *clk = to_ac100_clkout(hw);
270
271 regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN, 0);
272 }
273
274 static int ac100_clkout_is_prepared(struct clk_hw *hw)
275 {
276 struct ac100_clkout *clk = to_ac100_clkout(hw);
277 unsigned int reg;
278
279 regmap_read(clk->regmap, clk->offset, &reg);
280
281 return reg & AC100_CLKOUT_EN;
282 }
283
284 static u8 ac100_clkout_get_parent(struct clk_hw *hw)
285 {
286 struct ac100_clkout *clk = to_ac100_clkout(hw);
287 unsigned int reg;
288
289 regmap_read(clk->regmap, clk->offset, &reg);
290
291 return (reg >> AC100_CLKOUT_MUX_SHIFT) & 0x1;
292 }
293
294 static int ac100_clkout_set_parent(struct clk_hw *hw, u8 index)
295 {
296 struct ac100_clkout *clk = to_ac100_clkout(hw);
297
298 return regmap_update_bits(clk->regmap, clk->offset,
299 BIT(AC100_CLKOUT_MUX_SHIFT),
300 index ? BIT(AC100_CLKOUT_MUX_SHIFT) : 0);
301 }
302
303 static const struct clk_ops ac100_clkout_ops = {
304 .prepare = ac100_clkout_prepare,
305 .unprepare = ac100_clkout_unprepare,
306 .is_prepared = ac100_clkout_is_prepared,
307 .recalc_rate = ac100_clkout_recalc_rate,
308 .determine_rate = ac100_clkout_determine_rate,
309 .get_parent = ac100_clkout_get_parent,
310 .set_parent = ac100_clkout_set_parent,
311 .set_rate = ac100_clkout_set_rate,
312 };
313
314 static int ac100_rtc_register_clks(struct ac100_rtc_dev *chip)
315 {
316 struct device_node *np = chip->dev->of_node;
317 const char *parents[2] = {AC100_RTC_32K_NAME};
318 int i, ret;
319
320 chip->clk_data = devm_kzalloc(chip->dev,
321 struct_size(chip->clk_data, hws,
322 AC100_CLKOUT_NUM),
323 GFP_KERNEL);
324 if (!chip->clk_data)
325 return -ENOMEM;
326
327 chip->rtc_32k_clk = clk_hw_register_fixed_rate(chip->dev,
328 AC100_RTC_32K_NAME,
329 NULL, 0,
330 AC100_RTC_32K_RATE);
331 if (IS_ERR(chip->rtc_32k_clk)) {
332 ret = PTR_ERR(chip->rtc_32k_clk);
333 dev_err(chip->dev, "Failed to register RTC-32k clock: %d\n",
334 ret);
335 return ret;
336 }
337
338 parents[1] = of_clk_get_parent_name(np, 0);
339 if (!parents[1]) {
340 dev_err(chip->dev, "Failed to get ADDA 4M clock\n");
341 return -EINVAL;
342 }
343
344 for (i = 0; i < AC100_CLKOUT_NUM; i++) {
345 struct ac100_clkout *clk = &chip->clks[i];
346 struct clk_init_data init = {
347 .name = ac100_clkout_names[i],
348 .ops = &ac100_clkout_ops,
349 .parent_names = parents,
350 .num_parents = ARRAY_SIZE(parents),
351 .flags = 0,
352 };
353
354 of_property_read_string_index(np, "clock-output-names",
355 i, &init.name);
356 clk->regmap = chip->regmap;
357 clk->offset = AC100_CLKOUT_CTRL1 + i;
358 clk->hw.init = &init;
359
360 ret = devm_clk_hw_register(chip->dev, &clk->hw);
361 if (ret) {
362 dev_err(chip->dev, "Failed to register clk '%s': %d\n",
363 init.name, ret);
364 goto err_unregister_rtc_32k;
365 }
366
367 chip->clk_data->hws[i] = &clk->hw;
368 }
369
370 chip->clk_data->num = i;
371 ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, chip->clk_data);
372 if (ret)
373 goto err_unregister_rtc_32k;
374
375 return 0;
376
377 err_unregister_rtc_32k:
378 clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
379
380 return ret;
381 }
382
383 static void ac100_rtc_unregister_clks(struct ac100_rtc_dev *chip)
384 {
385 of_clk_del_provider(chip->dev->of_node);
386 clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
387 }
388
389 /**
390 * RTC related bits
391 */
392 static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm)
393 {
394 struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
395 struct regmap *regmap = chip->regmap;
396 u16 reg[7];
397 int ret;
398
399 ret = regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7);
400 if (ret)
401 return ret;
402
403 rtc_tm->tm_sec = bcd2bin(reg[0] & AC100_RTC_SEC_MASK);
404 rtc_tm->tm_min = bcd2bin(reg[1] & AC100_RTC_MIN_MASK);
405 rtc_tm->tm_hour = bcd2bin(reg[2] & AC100_RTC_HOU_MASK);
406 rtc_tm->tm_wday = bcd2bin(reg[3] & AC100_RTC_WEE_MASK);
407 rtc_tm->tm_mday = bcd2bin(reg[4] & AC100_RTC_DAY_MASK);
408 rtc_tm->tm_mon = bcd2bin(reg[5] & AC100_RTC_MON_MASK) - 1;
409 rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK) +
410 AC100_YEAR_OFF;
411
412 return 0;
413 }
414
415 static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
416 {
417 struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
418 struct regmap *regmap = chip->regmap;
419 int year;
420 u16 reg[8];
421
422 /* our RTC has a limited year range... */
423 year = rtc_tm->tm_year - AC100_YEAR_OFF;
424 if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
425 dev_err(dev, "rtc only supports year in range %d - %d\n",
426 AC100_YEAR_MIN, AC100_YEAR_MAX);
427 return -EINVAL;
428 }
429
430 /* convert to BCD */
431 reg[0] = bin2bcd(rtc_tm->tm_sec) & AC100_RTC_SEC_MASK;
432 reg[1] = bin2bcd(rtc_tm->tm_min) & AC100_RTC_MIN_MASK;
433 reg[2] = bin2bcd(rtc_tm->tm_hour) & AC100_RTC_HOU_MASK;
434 reg[3] = bin2bcd(rtc_tm->tm_wday) & AC100_RTC_WEE_MASK;
435 reg[4] = bin2bcd(rtc_tm->tm_mday) & AC100_RTC_DAY_MASK;
436 reg[5] = bin2bcd(rtc_tm->tm_mon + 1) & AC100_RTC_MON_MASK;
437 reg[6] = bin2bcd(year) & AC100_RTC_YEA_MASK;
438 /* trigger write */
439 reg[7] = AC100_RTC_UPD_TRIGGER;
440
441 /* Is it a leap year? */
442 if (is_leap_year(year + AC100_YEAR_OFF + 1900))
443 reg[6] |= AC100_RTC_YEA_LEAP;
444
445 return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8);
446 }
447
448 static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
449 {
450 struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
451 struct regmap *regmap = chip->regmap;
452 unsigned int val;
453
454 val = en ? AC100_ALM_INT_ENABLE : 0;
455
456 return regmap_write(regmap, AC100_ALM_INT_ENA, val);
457 }
458
459 static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
460 {
461 struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
462 struct regmap *regmap = chip->regmap;
463 struct rtc_time *alrm_tm = &alrm->time;
464 u16 reg[7];
465 unsigned int val;
466 int ret;
467
468 ret = regmap_read(regmap, AC100_ALM_INT_ENA, &val);
469 if (ret)
470 return ret;
471
472 alrm->enabled = !!(val & AC100_ALM_INT_ENABLE);
473
474 ret = regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7);
475 if (ret)
476 return ret;
477
478 alrm_tm->tm_sec = bcd2bin(reg[0] & AC100_ALM_SEC_MASK);
479 alrm_tm->tm_min = bcd2bin(reg[1] & AC100_ALM_MIN_MASK);
480 alrm_tm->tm_hour = bcd2bin(reg[2] & AC100_ALM_HOU_MASK);
481 alrm_tm->tm_wday = bcd2bin(reg[3] & AC100_ALM_WEE_MASK);
482 alrm_tm->tm_mday = bcd2bin(reg[4] & AC100_ALM_DAY_MASK);
483 alrm_tm->tm_mon = bcd2bin(reg[5] & AC100_ALM_MON_MASK) - 1;
484 alrm_tm->tm_year = bcd2bin(reg[6] & AC100_ALM_YEA_MASK) +
485 AC100_YEAR_OFF;
486
487 return 0;
488 }
489
490 static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
491 {
492 struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
493 struct regmap *regmap = chip->regmap;
494 struct rtc_time *alrm_tm = &alrm->time;
495 u16 reg[8];
496 int year;
497 int ret;
498
499 /* our alarm has a limited year range... */
500 year = alrm_tm->tm_year - AC100_YEAR_OFF;
501 if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
502 dev_err(dev, "alarm only supports year in range %d - %d\n",
503 AC100_YEAR_MIN, AC100_YEAR_MAX);
504 return -EINVAL;
505 }
506
507 /* convert to BCD */
508 reg[0] = (bin2bcd(alrm_tm->tm_sec) & AC100_ALM_SEC_MASK) |
509 AC100_ALM_ENABLE_FLAG;
510 reg[1] = (bin2bcd(alrm_tm->tm_min) & AC100_ALM_MIN_MASK) |
511 AC100_ALM_ENABLE_FLAG;
512 reg[2] = (bin2bcd(alrm_tm->tm_hour) & AC100_ALM_HOU_MASK) |
513 AC100_ALM_ENABLE_FLAG;
514 /* Do not enable weekday alarm */
515 reg[3] = bin2bcd(alrm_tm->tm_wday) & AC100_ALM_WEE_MASK;
516 reg[4] = (bin2bcd(alrm_tm->tm_mday) & AC100_ALM_DAY_MASK) |
517 AC100_ALM_ENABLE_FLAG;
518 reg[5] = (bin2bcd(alrm_tm->tm_mon + 1) & AC100_ALM_MON_MASK) |
519 AC100_ALM_ENABLE_FLAG;
520 reg[6] = (bin2bcd(year) & AC100_ALM_YEA_MASK) |
521 AC100_ALM_ENABLE_FLAG;
522 /* trigger write */
523 reg[7] = AC100_ALM_UPD_TRIGGER;
524
525 ret = regmap_bulk_write(regmap, AC100_ALM_SEC, reg, 8);
526 if (ret)
527 return ret;
528
529 return ac100_rtc_alarm_irq_enable(dev, alrm->enabled);
530 }
531
532 static irqreturn_t ac100_rtc_irq(int irq, void *data)
533 {
534 struct ac100_rtc_dev *chip = data;
535 struct regmap *regmap = chip->regmap;
536 unsigned int val = 0;
537 int ret;
538
539 mutex_lock(&chip->rtc->ops_lock);
540
541 /* read status */
542 ret = regmap_read(regmap, AC100_ALM_INT_STA, &val);
543 if (ret)
544 goto out;
545
546 if (val & AC100_ALM_INT_ENABLE) {
547 /* signal rtc framework */
548 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
549
550 /* clear status */
551 ret = regmap_write(regmap, AC100_ALM_INT_STA, val);
552 if (ret)
553 goto out;
554
555 /* disable interrupt */
556 ret = ac100_rtc_alarm_irq_enable(chip->dev, 0);
557 if (ret)
558 goto out;
559 }
560
561 out:
562 mutex_unlock(&chip->rtc->ops_lock);
563 return IRQ_HANDLED;
564 }
565
566 static const struct rtc_class_ops ac100_rtc_ops = {
567 .read_time = ac100_rtc_get_time,
568 .set_time = ac100_rtc_set_time,
569 .read_alarm = ac100_rtc_get_alarm,
570 .set_alarm = ac100_rtc_set_alarm,
571 .alarm_irq_enable = ac100_rtc_alarm_irq_enable,
572 };
573
574 static int ac100_rtc_probe(struct platform_device *pdev)
575 {
576 struct ac100_dev *ac100 = dev_get_drvdata(pdev->dev.parent);
577 struct ac100_rtc_dev *chip;
578 int ret;
579
580 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
581 if (!chip)
582 return -ENOMEM;
583
584 platform_set_drvdata(pdev, chip);
585 chip->dev = &pdev->dev;
586 chip->regmap = ac100->regmap;
587
588 chip->irq = platform_get_irq(pdev, 0);
589 if (chip->irq < 0) {
590 dev_err(&pdev->dev, "No IRQ resource\n");
591 return chip->irq;
592 }
593
594 chip->rtc = devm_rtc_allocate_device(&pdev->dev);
595 if (IS_ERR(chip->rtc))
596 return PTR_ERR(chip->rtc);
597
598 chip->rtc->ops = &ac100_rtc_ops;
599
600 ret = devm_request_threaded_irq(&pdev->dev, chip->irq, NULL,
601 ac100_rtc_irq,
602 IRQF_SHARED | IRQF_ONESHOT,
603 dev_name(&pdev->dev), chip);
604 if (ret) {
605 dev_err(&pdev->dev, "Could not request IRQ\n");
606 return ret;
607 }
608
609 /* always use 24 hour mode */
610 regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR,
611 AC100_RTC_CTRL_24HOUR);
612
613 /* disable counter alarm interrupt */
614 regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0);
615
616 /* clear counter alarm pending interrupts */
617 regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE);
618
619 ret = ac100_rtc_register_clks(chip);
620 if (ret)
621 return ret;
622
623 ret = rtc_register_device(chip->rtc);
624 if (ret) {
625 dev_err(&pdev->dev, "unable to register device\n");
626 return ret;
627 }
628
629 dev_info(&pdev->dev, "RTC enabled\n");
630
631 return 0;
632 }
633
634 static int ac100_rtc_remove(struct platform_device *pdev)
635 {
636 struct ac100_rtc_dev *chip = platform_get_drvdata(pdev);
637
638 ac100_rtc_unregister_clks(chip);
639
640 return 0;
641 }
642
643 static const struct of_device_id ac100_rtc_match[] = {
644 { .compatible = "x-powers,ac100-rtc" },
645 { },
646 };
647 MODULE_DEVICE_TABLE(of, ac100_rtc_match);
648
649 static struct platform_driver ac100_rtc_driver = {
650 .probe = ac100_rtc_probe,
651 .remove = ac100_rtc_remove,
652 .driver = {
653 .name = "ac100-rtc",
654 .of_match_table = of_match_ptr(ac100_rtc_match),
655 },
656 };
657 module_platform_driver(ac100_rtc_driver);
658
659 MODULE_DESCRIPTION("X-Powers AC100 RTC driver");
660 MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
661 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support