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  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
 80struct 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
 92static const char * const ac100_clkout_names[AC100_CLKOUT_NUM] = {
 93	"ac100-cko1-rtc",
 94	"ac100-cko2-rtc",
 95	"ac100-cko3-rtc",
 96};
 97
 98struct 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
114static 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 */
127static 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	}
142
143	div = (reg >> AC100_CLKOUT_DIV_SHIFT) &
144		(BIT(AC100_CLKOUT_DIV_WIDTH) - 1);
145	return divider_recalc_rate(hw, prate, div, NULL,
146				   CLK_DIVIDER_POWER_OF_TWO);
147}
148
149static long ac100_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
150				    unsigned long prate)
151{
152	unsigned long best_rate = 0, tmp_rate, tmp_prate;
153	int i;
154
155	if (prate == AC100_RTC_32K_RATE)
156		return divider_round_rate(hw, rate, &prate, NULL,
157					  AC100_CLKOUT_DIV_WIDTH,
158					  CLK_DIVIDER_POWER_OF_TWO);
159
160	for (i = 0; ac100_clkout_prediv[i].div; i++) {
161		tmp_prate = DIV_ROUND_UP(prate, ac100_clkout_prediv[i].val);
162		tmp_rate = divider_round_rate(hw, rate, &tmp_prate, NULL,
163					      AC100_CLKOUT_DIV_WIDTH,
164					      CLK_DIVIDER_POWER_OF_TWO);
165
166		if (tmp_rate > rate)
167			continue;
168		if (rate - tmp_rate < best_rate - tmp_rate)
169			best_rate = tmp_rate;
170	}
171
172	return best_rate;
173}
174
175static int ac100_clkout_determine_rate(struct clk_hw *hw,
176				       struct clk_rate_request *req)
177{
178	struct clk_hw *best_parent;
179	unsigned long best = 0;
180	int i, num_parents = clk_hw_get_num_parents(hw);
181
182	for (i = 0; i < num_parents; i++) {
183		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
184		unsigned long tmp, prate = clk_hw_get_rate(parent);
185
186		tmp = ac100_clkout_round_rate(hw, req->rate, prate);
187
188		if (tmp > req->rate)
189			continue;
190		if (req->rate - tmp < req->rate - best) {
191			best = tmp;
192			best_parent = parent;
193		}
194	}
195
196	if (!best)
197		return -EINVAL;
198
199	req->best_parent_hw = best_parent;
200	req->best_parent_rate = best;
201	req->rate = best;
202
203	return 0;
204}
205
206static int ac100_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
207				 unsigned long prate)
208{
209	struct ac100_clkout *clk = to_ac100_clkout(hw);
210	int div = 0, pre_div = 0;
211
212	do {
213		div = divider_get_val(rate * ac100_clkout_prediv[pre_div].div,
214				      prate, NULL, AC100_CLKOUT_DIV_WIDTH,
215				      CLK_DIVIDER_POWER_OF_TWO);
216		if (div >= 0)
217			break;
218	} while (prate != AC100_RTC_32K_RATE &&
219		 ac100_clkout_prediv[++pre_div].div);
220
221	if (div < 0)
222		return div;
223
224	pre_div = ac100_clkout_prediv[pre_div].val;
225
226	regmap_update_bits(clk->regmap, clk->offset,
227			   ((1 << AC100_CLKOUT_DIV_WIDTH) - 1) << AC100_CLKOUT_DIV_SHIFT |
228			   ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1) << AC100_CLKOUT_PRE_DIV_SHIFT,
229			   (div - 1) << AC100_CLKOUT_DIV_SHIFT |
230			   (pre_div - 1) << AC100_CLKOUT_PRE_DIV_SHIFT);
231
232	return 0;
233}
234
235static int ac100_clkout_prepare(struct clk_hw *hw)
236{
237	struct ac100_clkout *clk = to_ac100_clkout(hw);
238
239	return regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN,
240				  AC100_CLKOUT_EN);
241}
242
243static void ac100_clkout_unprepare(struct clk_hw *hw)
244{
245	struct ac100_clkout *clk = to_ac100_clkout(hw);
246
247	regmap_update_bits(clk->regmap, clk->offset, AC100_CLKOUT_EN, 0);
248}
249
250static int ac100_clkout_is_prepared(struct clk_hw *hw)
251{
252	struct ac100_clkout *clk = to_ac100_clkout(hw);
253	unsigned int reg;
254
255	regmap_read(clk->regmap, clk->offset, &reg);
256
257	return reg & AC100_CLKOUT_EN;
258}
259
260static u8 ac100_clkout_get_parent(struct clk_hw *hw)
261{
262	struct ac100_clkout *clk = to_ac100_clkout(hw);
263	unsigned int reg;
264
265	regmap_read(clk->regmap, clk->offset, &reg);
266
267	return (reg >> AC100_CLKOUT_MUX_SHIFT) & 0x1;
268}
269
270static int ac100_clkout_set_parent(struct clk_hw *hw, u8 index)
271{
272	struct ac100_clkout *clk = to_ac100_clkout(hw);
273
274	return regmap_update_bits(clk->regmap, clk->offset,
275				  BIT(AC100_CLKOUT_MUX_SHIFT),
276				  index ? BIT(AC100_CLKOUT_MUX_SHIFT) : 0);
277}
278
279static const struct clk_ops ac100_clkout_ops = {
280	.prepare	= ac100_clkout_prepare,
281	.unprepare	= ac100_clkout_unprepare,
282	.is_prepared	= ac100_clkout_is_prepared,
283	.recalc_rate	= ac100_clkout_recalc_rate,
284	.determine_rate	= ac100_clkout_determine_rate,
285	.get_parent	= ac100_clkout_get_parent,
286	.set_parent	= ac100_clkout_set_parent,
287	.set_rate	= ac100_clkout_set_rate,
288};
289
290static int ac100_rtc_register_clks(struct ac100_rtc_dev *chip)
291{
292	struct device_node *np = chip->dev->of_node;
293	const char *parents[2] = {AC100_RTC_32K_NAME};
294	int i, ret;
295
296	chip->clk_data = devm_kzalloc(chip->dev, sizeof(*chip->clk_data) +
297						 sizeof(*chip->clk_data->hws) *
298						 AC100_CLKOUT_NUM,
299						 GFP_KERNEL);
300	if (!chip->clk_data)
301		return -ENOMEM;
302
303	chip->rtc_32k_clk = clk_hw_register_fixed_rate(chip->dev,
304						       AC100_RTC_32K_NAME,
305						       NULL, 0,
306						       AC100_RTC_32K_RATE);
307	if (IS_ERR(chip->rtc_32k_clk)) {
308		ret = PTR_ERR(chip->rtc_32k_clk);
309		dev_err(chip->dev, "Failed to register RTC-32k clock: %d\n",
310			ret);
311		return ret;
312	}
313
314	parents[1] = of_clk_get_parent_name(np, 0);
315	if (!parents[1]) {
316		dev_err(chip->dev, "Failed to get ADDA 4M clock\n");
317		return -EINVAL;
318	}
319
320	for (i = 0; i < AC100_CLKOUT_NUM; i++) {
321		struct ac100_clkout *clk = &chip->clks[i];
322		struct clk_init_data init = {
323			.name = ac100_clkout_names[i],
324			.ops = &ac100_clkout_ops,
325			.parent_names = parents,
326			.num_parents = ARRAY_SIZE(parents),
327			.flags = 0,
328		};
329
330		of_property_read_string_index(np, "clock-output-names",
331					      i, &init.name);
332		clk->regmap = chip->regmap;
333		clk->offset = AC100_CLKOUT_CTRL1 + i;
334		clk->hw.init = &init;
335
336		ret = devm_clk_hw_register(chip->dev, &clk->hw);
337		if (ret) {
338			dev_err(chip->dev, "Failed to register clk '%s': %d\n",
339				init.name, ret);
340			goto err_unregister_rtc_32k;
341		}
342
343		chip->clk_data->hws[i] = &clk->hw;
344	}
345
346	chip->clk_data->num = i;
347	ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, chip->clk_data);
348	if (ret)
349		goto err_unregister_rtc_32k;
350
351	return 0;
352
353err_unregister_rtc_32k:
354	clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
355
356	return ret;
357}
358
359static void ac100_rtc_unregister_clks(struct ac100_rtc_dev *chip)
360{
361	of_clk_del_provider(chip->dev->of_node);
362	clk_unregister_fixed_rate(chip->rtc_32k_clk->clk);
363}
364
365/**
366 * RTC related bits
367 */
368static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm)
369{
370	struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
371	struct regmap *regmap = chip->regmap;
372	u16 reg[7];
373	int ret;
374
375	ret = regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7);
376	if (ret)
377		return ret;
378
379	rtc_tm->tm_sec  = bcd2bin(reg[0] & AC100_RTC_SEC_MASK);
380	rtc_tm->tm_min  = bcd2bin(reg[1] & AC100_RTC_MIN_MASK);
381	rtc_tm->tm_hour = bcd2bin(reg[2] & AC100_RTC_HOU_MASK);
382	rtc_tm->tm_wday = bcd2bin(reg[3] & AC100_RTC_WEE_MASK);
383	rtc_tm->tm_mday = bcd2bin(reg[4] & AC100_RTC_DAY_MASK);
384	rtc_tm->tm_mon  = bcd2bin(reg[5] & AC100_RTC_MON_MASK) - 1;
385	rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK) +
386			  AC100_YEAR_OFF;
387
388	return rtc_valid_tm(rtc_tm);
389}
390
391static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
392{
393	struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
394	struct regmap *regmap = chip->regmap;
395	int year;
396	u16 reg[8];
397
398	/* our RTC has a limited year range... */
399	year = rtc_tm->tm_year - AC100_YEAR_OFF;
400	if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
401		dev_err(dev, "rtc only supports year in range %d - %d\n",
402			AC100_YEAR_MIN, AC100_YEAR_MAX);
403		return -EINVAL;
404	}
405
406	/* convert to BCD */
407	reg[0] = bin2bcd(rtc_tm->tm_sec)     & AC100_RTC_SEC_MASK;
408	reg[1] = bin2bcd(rtc_tm->tm_min)     & AC100_RTC_MIN_MASK;
409	reg[2] = bin2bcd(rtc_tm->tm_hour)    & AC100_RTC_HOU_MASK;
410	reg[3] = bin2bcd(rtc_tm->tm_wday)    & AC100_RTC_WEE_MASK;
411	reg[4] = bin2bcd(rtc_tm->tm_mday)    & AC100_RTC_DAY_MASK;
412	reg[5] = bin2bcd(rtc_tm->tm_mon + 1) & AC100_RTC_MON_MASK;
413	reg[6] = bin2bcd(year)		     & AC100_RTC_YEA_MASK;
414	/* trigger write */
415	reg[7] = AC100_RTC_UPD_TRIGGER;
416
417	/* Is it a leap year? */
418	if (is_leap_year(year + AC100_YEAR_OFF + 1900))
419		reg[6] |= AC100_RTC_YEA_LEAP;
420
421	return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8);
422}
423
424static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
425{
426	struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
427	struct regmap *regmap = chip->regmap;
428	unsigned int val;
429
430	val = en ? AC100_ALM_INT_ENABLE : 0;
431
432	return regmap_write(regmap, AC100_ALM_INT_ENA, val);
433}
434
435static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
436{
437	struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
438	struct regmap *regmap = chip->regmap;
439	struct rtc_time *alrm_tm = &alrm->time;
440	u16 reg[7];
441	unsigned int val;
442	int ret;
443
444	ret = regmap_read(regmap, AC100_ALM_INT_ENA, &val);
445	if (ret)
446		return ret;
447
448	alrm->enabled = !!(val & AC100_ALM_INT_ENABLE);
449
450	ret = regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7);
451	if (ret)
452		return ret;
453
454	alrm_tm->tm_sec  = bcd2bin(reg[0] & AC100_ALM_SEC_MASK);
455	alrm_tm->tm_min  = bcd2bin(reg[1] & AC100_ALM_MIN_MASK);
456	alrm_tm->tm_hour = bcd2bin(reg[2] & AC100_ALM_HOU_MASK);
457	alrm_tm->tm_wday = bcd2bin(reg[3] & AC100_ALM_WEE_MASK);
458	alrm_tm->tm_mday = bcd2bin(reg[4] & AC100_ALM_DAY_MASK);
459	alrm_tm->tm_mon  = bcd2bin(reg[5] & AC100_ALM_MON_MASK) - 1;
460	alrm_tm->tm_year = bcd2bin(reg[6] & AC100_ALM_YEA_MASK) +
461			   AC100_YEAR_OFF;
462
463	return 0;
464}
465
466static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
467{
468	struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
469	struct regmap *regmap = chip->regmap;
470	struct rtc_time *alrm_tm = &alrm->time;
471	u16 reg[8];
472	int year;
473	int ret;
474
475	/* our alarm has a limited year range... */
476	year = alrm_tm->tm_year - AC100_YEAR_OFF;
477	if (year < 0 || year > (AC100_YEAR_MAX - 1900)) {
478		dev_err(dev, "alarm only supports year in range %d - %d\n",
479			AC100_YEAR_MIN, AC100_YEAR_MAX);
480		return -EINVAL;
481	}
482
483	/* convert to BCD */
484	reg[0] = (bin2bcd(alrm_tm->tm_sec)  & AC100_ALM_SEC_MASK) |
485			AC100_ALM_ENABLE_FLAG;
486	reg[1] = (bin2bcd(alrm_tm->tm_min)  & AC100_ALM_MIN_MASK) |
487			AC100_ALM_ENABLE_FLAG;
488	reg[2] = (bin2bcd(alrm_tm->tm_hour) & AC100_ALM_HOU_MASK) |
489			AC100_ALM_ENABLE_FLAG;
490	/* Do not enable weekday alarm */
491	reg[3] = bin2bcd(alrm_tm->tm_wday) & AC100_ALM_WEE_MASK;
492	reg[4] = (bin2bcd(alrm_tm->tm_mday) & AC100_ALM_DAY_MASK) |
493			AC100_ALM_ENABLE_FLAG;
494	reg[5] = (bin2bcd(alrm_tm->tm_mon + 1)  & AC100_ALM_MON_MASK) |
495			AC100_ALM_ENABLE_FLAG;
496	reg[6] = (bin2bcd(year) & AC100_ALM_YEA_MASK) |
497			AC100_ALM_ENABLE_FLAG;
498	/* trigger write */
499	reg[7] = AC100_ALM_UPD_TRIGGER;
500
501	ret = regmap_bulk_write(regmap, AC100_ALM_SEC, reg, 8);
502	if (ret)
503		return ret;
504
505	return ac100_rtc_alarm_irq_enable(dev, alrm->enabled);
506}
507
508static irqreturn_t ac100_rtc_irq(int irq, void *data)
509{
510	struct ac100_rtc_dev *chip = data;
511	struct regmap *regmap = chip->regmap;
512	unsigned int val = 0;
513	int ret;
514
515	mutex_lock(&chip->rtc->ops_lock);
516
517	/* read status */
518	ret = regmap_read(regmap, AC100_ALM_INT_STA, &val);
519	if (ret)
520		goto out;
521
522	if (val & AC100_ALM_INT_ENABLE) {
523		/* signal rtc framework */
524		rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
525
526		/* clear status */
527		ret = regmap_write(regmap, AC100_ALM_INT_STA, val);
528		if (ret)
529			goto out;
530
531		/* disable interrupt */
532		ret = ac100_rtc_alarm_irq_enable(chip->dev, 0);
533		if (ret)
534			goto out;
535	}
536
537out:
538	mutex_unlock(&chip->rtc->ops_lock);
539	return IRQ_HANDLED;
540}
541
542static const struct rtc_class_ops ac100_rtc_ops = {
543	.read_time	  = ac100_rtc_get_time,
544	.set_time	  = ac100_rtc_set_time,
545	.read_alarm	  = ac100_rtc_get_alarm,
546	.set_alarm	  = ac100_rtc_set_alarm,
547	.alarm_irq_enable = ac100_rtc_alarm_irq_enable,
548};
549
550static int ac100_rtc_probe(struct platform_device *pdev)
551{
552	struct ac100_dev *ac100 = dev_get_drvdata(pdev->dev.parent);
553	struct ac100_rtc_dev *chip;
554	int ret;
555
556	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
557	if (!chip)
558		return -ENOMEM;
559
560	platform_set_drvdata(pdev, chip);
561	chip->dev = &pdev->dev;
562	chip->regmap = ac100->regmap;
563
564	chip->irq = platform_get_irq(pdev, 0);
565	if (chip->irq < 0) {
566		dev_err(&pdev->dev, "No IRQ resource\n");
567		return chip->irq;
568	}
569
570	ret = devm_request_threaded_irq(&pdev->dev, chip->irq, NULL,
571					ac100_rtc_irq,
572					IRQF_SHARED | IRQF_ONESHOT,
573					dev_name(&pdev->dev), chip);
574	if (ret) {
575		dev_err(&pdev->dev, "Could not request IRQ\n");
576		return ret;
577	}
578
579	/* always use 24 hour mode */
580	regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR,
581			  AC100_RTC_CTRL_24HOUR);
582
583	/* disable counter alarm interrupt */
584	regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0);
585
586	/* clear counter alarm pending interrupts */
587	regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE);
588
589	chip->rtc = devm_rtc_device_register(&pdev->dev, "rtc-ac100",
590					     &ac100_rtc_ops, THIS_MODULE);
591	if (IS_ERR(chip->rtc)) {
592		dev_err(&pdev->dev, "unable to register device\n");
593		return PTR_ERR(chip->rtc);
594	}
595
596	ret = ac100_rtc_register_clks(chip);
597	if (ret)
598		return ret;
599
600	dev_info(&pdev->dev, "RTC enabled\n");
601
602	return 0;
603}
604
605static int ac100_rtc_remove(struct platform_device *pdev)
606{
607	struct ac100_rtc_dev *chip = platform_get_drvdata(pdev);
608
609	ac100_rtc_unregister_clks(chip);
610
611	return 0;
612}
613
614static const struct of_device_id ac100_rtc_match[] = {
615	{ .compatible = "x-powers,ac100-rtc" },
616	{ },
617};
618MODULE_DEVICE_TABLE(of, ac100_rtc_match);
619
620static struct platform_driver ac100_rtc_driver = {
621	.probe		= ac100_rtc_probe,
622	.remove		= ac100_rtc_remove,
623	.driver		= {
624		.name		= "ac100-rtc",
625		.of_match_table	= of_match_ptr(ac100_rtc_match),
626	},
627};
628module_platform_driver(ac100_rtc_driver);
629
630MODULE_DESCRIPTION("X-Powers AC100 RTC driver");
631MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
632MODULE_LICENSE("GPL v2");