[mirror_ubuntu-bionic-kernel.git] / drivers / rtc / rtc-snvs.c

/*
 * Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */

#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/clk.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#define SNVS_LPREGISTER_OFFSET	0x34

/* These register offsets are relative to LP (Low Power) range */
#define SNVS_LPCR		0x04
#define SNVS_LPSR		0x18
#define SNVS_LPSRTCMR		0x1c
#define SNVS_LPSRTCLR		0x20
#define SNVS_LPTAR		0x24
#define SNVS_LPPGDR		0x30

#define SNVS_LPCR_SRTC_ENV	(1 << 0)
#define SNVS_LPCR_LPTA_EN	(1 << 1)
#define SNVS_LPCR_LPWUI_EN	(1 << 3)
#define SNVS_LPSR_LPTA		(1 << 0)

#define SNVS_LPPGDR_INIT	0x41736166
#define CNTR_TO_SECS_SH		15

struct snvs_rtc_data {
	struct rtc_device *rtc;
	struct regmap *regmap;
	int offset;
	int irq;
	struct clk *clk;
};

/* Read 64 bit timer register, which could be in inconsistent state */
static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
{
	u32 msb, lsb;

	regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &msb);
	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &lsb);
	return (u64)msb << 32 | lsb;
}

/* Read the secure real time counter, taking care to deal with the cases of the
 * counter updating while being read.
 */
static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
{
	u64 read1, read2;
	unsigned int timeout = 100;

	/* As expected, the registers might update between the read of the LSB
	 * reg and the MSB reg.  It's also possible that one register might be
	 * in partially modified state as well.
	 */
	read1 = rtc_read_lpsrt(data);
	do {
		read2 = read1;
		read1 = rtc_read_lpsrt(data);
	} while (read1 != read2 && --timeout);
	if (!timeout)
		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");

	/* Convert 47-bit counter to 32-bit raw second count */
	return (u32) (read1 >> CNTR_TO_SECS_SH);
}

/* Just read the lsb from the counter, dealing with inconsistent state */
static int rtc_read_lp_counter_lsb(struct snvs_rtc_data *data, u32 *lsb)
{
	u32 count1, count2;
	unsigned int timeout = 100;

	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
	do {
		count2 = count1;
		regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
	} while (count1 != count2 && --timeout);
	if (!timeout) {
		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
		return -ETIMEDOUT;
	}

	*lsb = count1;
	return 0;
}

static int rtc_write_sync_lp(struct snvs_rtc_data *data)
{
	u32 count1, count2;
	u32 elapsed;
	unsigned int timeout = 1000;
	int ret;

	ret = rtc_read_lp_counter_lsb(data, &count1);
	if (ret)
		return ret;

	/* Wait for 3 CKIL cycles, about 61.0-91.5 µs */
	do {
		ret = rtc_read_lp_counter_lsb(data, &count2);
		if (ret)
			return ret;
		elapsed = count2 - count1; /* wrap around _is_ handled! */
	} while (elapsed < 3 && --timeout);
	if (!timeout) {
		dev_err(&data->rtc->dev, "Timeout waiting for LPSRT Counter to change\n");
		return -ETIMEDOUT;
	}
	return 0;
}

static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
{
	int timeout = 1000;
	u32 lpcr;

	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_SRTC_ENV,
			   enable ? SNVS_LPCR_SRTC_ENV : 0);

	while (--timeout) {
		regmap_read(data->regmap, data->offset + SNVS_LPCR, &lpcr);

		if (enable) {
			if (lpcr & SNVS_LPCR_SRTC_ENV)
				break;
		} else {
			if (!(lpcr & SNVS_LPCR_SRTC_ENV))
				break;
		}
	}

	if (!timeout)
		return -ETIMEDOUT;

	return 0;
}

static int snvs_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	unsigned long time = rtc_read_lp_counter(data);

	rtc_time_to_tm(time, tm);

	return 0;
}

static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	unsigned long time;
	int ret;

	rtc_tm_to_time(tm, &time);

	/* Disable RTC first */
	ret = snvs_rtc_enable(data, false);
	if (ret)
		return ret;

	/* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
	regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
	regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));

	/* Enable RTC again */
	ret = snvs_rtc_enable(data, true);

	return ret;
}

static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	u32 lptar, lpsr;

	regmap_read(data->regmap, data->offset + SNVS_LPTAR, &lptar);
	rtc_time_to_tm(lptar, &alrm->time);

	regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
	alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;

	return 0;
}

static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);

	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR,
			   (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN),
			   enable ? (SNVS_LPCR_LPTA_EN | SNVS_LPCR_LPWUI_EN) : 0);

	return rtc_write_sync_lp(data);
}

static int snvs_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	struct rtc_time *alrm_tm = &alrm->time;
	unsigned long time;
	int ret;

	rtc_tm_to_time(alrm_tm, &time);

	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
	ret = rtc_write_sync_lp(data);
	if (ret)
		return ret;
	regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);

	/* Clear alarm interrupt status bit */
	regmap_write(data->regmap, data->offset + SNVS_LPSR, SNVS_LPSR_LPTA);

	return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
}

static const struct rtc_class_ops snvs_rtc_ops = {
	.read_time = snvs_rtc_read_time,
	.set_time = snvs_rtc_set_time,
	.read_alarm = snvs_rtc_read_alarm,
	.set_alarm = snvs_rtc_set_alarm,
	.alarm_irq_enable = snvs_rtc_alarm_irq_enable,
};

static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
{
	struct device *dev = dev_id;
	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	u32 lpsr;
	u32 events = 0;

	regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);

	if (lpsr & SNVS_LPSR_LPTA) {
		events |= (RTC_AF | RTC_IRQF);

		/* RTC alarm should be one-shot */
		snvs_rtc_alarm_irq_enable(dev, 0);

		rtc_update_irq(data->rtc, 1, events);
	}

	/* clear interrupt status */
	regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);

	return events ? IRQ_HANDLED : IRQ_NONE;
}

static const struct regmap_config snvs_rtc_config = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
};

static int snvs_rtc_probe(struct platform_device *pdev)
{
	struct snvs_rtc_data *data;
	struct resource *res;
	int ret;
	void __iomem *mmio;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(data->rtc))
		return PTR_ERR(data->rtc);

	data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");

	if (IS_ERR(data->regmap)) {
		dev_warn(&pdev->dev, "snvs rtc: you use old dts file, please update it\n");
		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

		mmio = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(mmio))
			return PTR_ERR(mmio);

		data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
	} else {
		data->offset = SNVS_LPREGISTER_OFFSET;
		of_property_read_u32(pdev->dev.of_node, "offset", &data->offset);
	}

	if (IS_ERR(data->regmap)) {
		dev_err(&pdev->dev, "Can't find snvs syscon\n");
		return -ENODEV;
	}

	data->irq = platform_get_irq(pdev, 0);
	if (data->irq < 0)
		return data->irq;

	data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
	if (IS_ERR(data->clk)) {
		data->clk = NULL;
	} else {
		ret = clk_prepare_enable(data->clk);
		if (ret) {
			dev_err(&pdev->dev,
				"Could not prepare or enable the snvs clock\n");
			return ret;
		}
	}

	platform_set_drvdata(pdev, data);

	/* Initialize glitch detect */
	regmap_write(data->regmap, data->offset + SNVS_LPPGDR, SNVS_LPPGDR_INIT);

	/* Clear interrupt status */
	regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);

	/* Enable RTC */
	ret = snvs_rtc_enable(data, true);
	if (ret) {
		dev_err(&pdev->dev, "failed to enable rtc %d\n", ret);
		goto error_rtc_device_register;
	}

	device_init_wakeup(&pdev->dev, true);

	ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
			       IRQF_SHARED, "rtc alarm", &pdev->dev);
	if (ret) {
		dev_err(&pdev->dev, "failed to request irq %d: %d\n",
			data->irq, ret);
		goto error_rtc_device_register;
	}

	data->rtc->ops = &snvs_rtc_ops;
	ret = rtc_register_device(data->rtc);
	if (ret) {
		dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
		goto error_rtc_device_register;
	}

	return 0;

error_rtc_device_register:
	if (data->clk)
		clk_disable_unprepare(data->clk);

	return ret;
}

#ifdef CONFIG_PM_SLEEP
static int snvs_rtc_suspend(struct device *dev)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		return enable_irq_wake(data->irq);

	return 0;
}

static int snvs_rtc_suspend_noirq(struct device *dev)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);

	if (data->clk)
		clk_disable_unprepare(data->clk);

	return 0;
}

static int snvs_rtc_resume(struct device *dev)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		return disable_irq_wake(data->irq);

	return 0;
}

static int snvs_rtc_resume_noirq(struct device *dev)
{
	struct snvs_rtc_data *data = dev_get_drvdata(dev);

	if (data->clk)
		return clk_prepare_enable(data->clk);

	return 0;
}

static const struct dev_pm_ops snvs_rtc_pm_ops = {
	.suspend = snvs_rtc_suspend,
	.suspend_noirq = snvs_rtc_suspend_noirq,
	.resume = snvs_rtc_resume,
	.resume_noirq = snvs_rtc_resume_noirq,
};

#define SNVS_RTC_PM_OPS	(&snvs_rtc_pm_ops)

#else

#define SNVS_RTC_PM_OPS	NULL

#endif

static const struct of_device_id snvs_dt_ids[] = {
	{ .compatible = "fsl,sec-v4.0-mon-rtc-lp", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, snvs_dt_ids);

static struct platform_driver snvs_rtc_driver = {
	.driver = {
		.name	= "snvs_rtc",
		.pm	= SNVS_RTC_PM_OPS,
		.of_match_table = snvs_dt_ids,
	},
	.probe		= snvs_rtc_probe,
};
module_platform_driver(snvs_rtc_driver);

MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
179a502f SG	1	/*
	2	* Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
	3	*
	4	* The code contained herein is licensed under the GNU General Public
	5	* License. You may obtain a copy of the GNU General Public License
	6	* Version 2 or later at the following locations:
	7	*
	8	* http://www.opensource.org/licenses/gpl-license.html
	9	* http://www.gnu.org/copyleft/gpl.html
	10	*/
	11
	12	#include <linux/init.h>
	13	#include <linux/io.h>
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
	16	#include <linux/of.h>
	17	#include <linux/of_device.h>
	18	#include <linux/platform_device.h>
	19	#include <linux/rtc.h>
7f899399	20	#include <linux/clk.h>
d482893b FL	21	#include <linux/mfd/syscon.h>
	22	#include <linux/regmap.h>
	23
	24	#define SNVS_LPREGISTER_OFFSET 0x34
179a502f SG	25
	26	/* These register offsets are relative to LP (Low Power) range */
	27	#define SNVS_LPCR 0x04
	28	#define SNVS_LPSR 0x18
	29	#define SNVS_LPSRTCMR 0x1c
	30	#define SNVS_LPSRTCLR 0x20
	31	#define SNVS_LPTAR 0x24
	32	#define SNVS_LPPGDR 0x30
	33
	34	#define SNVS_LPCR_SRTC_ENV (1 << 0)
	35	#define SNVS_LPCR_LPTA_EN (1 << 1)
	36	#define SNVS_LPCR_LPWUI_EN (1 << 3)
	37	#define SNVS_LPSR_LPTA (1 << 0)
	38
	39	#define SNVS_LPPGDR_INIT 0x41736166
	40	#define CNTR_TO_SECS_SH 15
	41
	42	struct snvs_rtc_data {
	43	struct rtc_device *rtc;
d482893b FL	44	struct regmap *regmap;
d482893b FL	45	int offset;
179a502f	46	int irq;
7f899399	47	struct clk *clk;
179a502f SG	48	};
179a502f SG	49
d9c508be TP	50	/* Read 64 bit timer register, which could be in inconsistent state */
	51	static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
	52	{
	53	u32 msb, lsb;
	54
	55	regmap_read(data->regmap, data->offset + SNVS_LPSRTCMR, &msb);
	56	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &lsb);
	57	return (u64)msb << 32 \| lsb;
	58	}
	59
	60	/* Read the secure real time counter, taking care to deal with the cases of the
	61	* counter updating while being read.
	62	*/
d482893b	63	static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
179a502f SG	64	{
179a502f SG	65	u64 read1, read2;
d9c508be	66	unsigned int timeout = 100;
179a502f	67
d9c508be TP	68	/* As expected, the registers might update between the read of the LSB
	69	* reg and the MSB reg. It's also possible that one register might be
	70	* in partially modified state as well.
	71	*/
	72	read1 = rtc_read_lpsrt(data);
179a502f	73	do {
d9c508be TP	74	read2 = read1;
	75	read1 = rtc_read_lpsrt(data);
	76	} while (read1 != read2 && --timeout);
	77	if (!timeout)
	78	dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
179a502f SG	79
	80	/* Convert 47-bit counter to 32-bit raw second count */
	81	return (u32) (read1 >> CNTR_TO_SECS_SH);
	82	}
	83
d9c508be TP	84	/* Just read the lsb from the counter, dealing with inconsistent state */
	85	static int rtc_read_lp_counter_lsb(struct snvs_rtc_data data, u32 lsb)
	86	{
	87	u32 count1, count2;
	88	unsigned int timeout = 100;
	89
	90	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
	91	do {
	92	count2 = count1;
	93	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
	94	} while (count1 != count2 && --timeout);
	95	if (!timeout) {
	96	dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
	97	return -ETIMEDOUT;
	98	}
	99
	100	*lsb = count1;
	101	return 0;
	102	}
	103
	104	static int rtc_write_sync_lp(struct snvs_rtc_data *data)
179a502f	105	{
d9c508be TP	106	u32 count1, count2;
	107	u32 elapsed;
	108	unsigned int timeout = 1000;
	109	int ret;
	110
	111	ret = rtc_read_lp_counter_lsb(data, &count1);
	112	if (ret)
	113	return ret;
	114
	115	/* Wait for 3 CKIL cycles, about 61.0-91.5 µs */
	116	do {
	117	ret = rtc_read_lp_counter_lsb(data, &count2);
	118	if (ret)
	119	return ret;
	120	elapsed = count2 - count1; /* wrap around _is_ handled! */
	121	} while (elapsed < 3 && --timeout);
	122	if (!timeout) {
	123	dev_err(&data->rtc->dev, "Timeout waiting for LPSRT Counter to change\n");
	124	return -ETIMEDOUT;
179a502f	125	}
d9c508be	126	return 0;
179a502f SG	127	}
	128
	129	static int snvs_rtc_enable(struct snvs_rtc_data *data, bool enable)
	130	{
179a502f SG	131	int timeout = 1000;
	132	u32 lpcr;
	133
d482893b FL	134	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_SRTC_ENV,
d482893b FL	135	enable ? SNVS_LPCR_SRTC_ENV : 0);
179a502f SG	136
179a502f SG	137	while (--timeout) {
d482893b	138	regmap_read(data->regmap, data->offset + SNVS_LPCR, &lpcr);
179a502f SG	139
	140	if (enable) {
	141	if (lpcr & SNVS_LPCR_SRTC_ENV)
	142	break;
	143	} else {
	144	if (!(lpcr & SNVS_LPCR_SRTC_ENV))
	145	break;
	146	}
	147	}
	148
	149	if (!timeout)
	150	return -ETIMEDOUT;
	151
	152	return 0;
	153	}
	154
	155	static int snvs_rtc_read_time(struct device dev, struct rtc_time tm)
	156	{
	157	struct snvs_rtc_data *data = dev_get_drvdata(dev);
d482893b	158	unsigned long time = rtc_read_lp_counter(data);
179a502f SG	159
	160	rtc_time_to_tm(time, tm);
	161
	162	return 0;
	163	}
	164
	165	static int snvs_rtc_set_time(struct device dev, struct rtc_time tm)
	166	{
	167	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	168	unsigned long time;
3f129bd8	169	int ret;
179a502f SG	170
	171	rtc_tm_to_time(tm, &time);
	172
	173	/* Disable RTC first */
3f129bd8 BD	174	ret = snvs_rtc_enable(data, false);
	175	if (ret)
	176	return ret;
179a502f SG	177
179a502f SG	178	/* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */
d482893b FL	179	regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH);
d482893b FL	180	regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH));
179a502f SG	181
179a502f SG	182	/* Enable RTC again */
3f129bd8	183	ret = snvs_rtc_enable(data, true);
179a502f	184
3f129bd8	185	return ret;
179a502f SG	186	}
	187
	188	static int snvs_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	189	{
	190	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	191	u32 lptar, lpsr;
	192
d482893b	193	regmap_read(data->regmap, data->offset + SNVS_LPTAR, &lptar);
179a502f SG	194	rtc_time_to_tm(lptar, &alrm->time);
179a502f SG	195
d482893b	196	regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
179a502f SG	197	alrm->pending = (lpsr & SNVS_LPSR_LPTA) ? 1 : 0;
	198
	199	return 0;
	200	}
	201
	202	static int snvs_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
	203	{
	204	struct snvs_rtc_data *data = dev_get_drvdata(dev);
179a502f	205
d482893b FL	206	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR,
	207	(SNVS_LPCR_LPTA_EN \| SNVS_LPCR_LPWUI_EN),
	208	enable ? (SNVS_LPCR_LPTA_EN \| SNVS_LPCR_LPWUI_EN) : 0);
179a502f	209
d9c508be	210	return rtc_write_sync_lp(data);
179a502f SG	211	}
	212
	213	static int snvs_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	214	{
	215	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	216	struct rtc_time *alrm_tm = &alrm->time;
	217	unsigned long time;
d9c508be	218	int ret;
179a502f SG	219
	220	rtc_tm_to_time(alrm_tm, &time);
	221
d482893b	222	regmap_update_bits(data->regmap, data->offset + SNVS_LPCR, SNVS_LPCR_LPTA_EN, 0);
d9c508be TP	223	ret = rtc_write_sync_lp(data);
	224	if (ret)
	225	return ret;
d482893b	226	regmap_write(data->regmap, data->offset + SNVS_LPTAR, time);
179a502f SG	227
179a502f SG	228	/* Clear alarm interrupt status bit */
d482893b	229	regmap_write(data->regmap, data->offset + SNVS_LPSR, SNVS_LPSR_LPTA);
179a502f SG	230
	231	return snvs_rtc_alarm_irq_enable(dev, alrm->enabled);
	232	}
	233
	234	static const struct rtc_class_ops snvs_rtc_ops = {
	235	.read_time = snvs_rtc_read_time,
	236	.set_time = snvs_rtc_set_time,
	237	.read_alarm = snvs_rtc_read_alarm,
	238	.set_alarm = snvs_rtc_set_alarm,
	239	.alarm_irq_enable = snvs_rtc_alarm_irq_enable,
	240	};
	241
	242	static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
	243	{
	244	struct device *dev = dev_id;
	245	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	246	u32 lpsr;
	247	u32 events = 0;
	248
d482893b	249	regmap_read(data->regmap, data->offset + SNVS_LPSR, &lpsr);
179a502f SG	250
	251	if (lpsr & SNVS_LPSR_LPTA) {
	252	events \|= (RTC_AF \| RTC_IRQF);
	253
	254	/* RTC alarm should be one-shot */
	255	snvs_rtc_alarm_irq_enable(dev, 0);
	256
	257	rtc_update_irq(data->rtc, 1, events);
	258	}
	259
	260	/* clear interrupt status */
d482893b	261	regmap_write(data->regmap, data->offset + SNVS_LPSR, lpsr);
179a502f SG	262
	263	return events ? IRQ_HANDLED : IRQ_NONE;
	264	}
	265
d482893b FL	266	static const struct regmap_config snvs_rtc_config = {
	267	.reg_bits = 32,
	268	.val_bits = 32,
	269	.reg_stride = 4,
	270	};
	271
5a167f45	272	static int snvs_rtc_probe(struct platform_device *pdev)
179a502f SG	273	{
	274	struct snvs_rtc_data *data;
	275	struct resource *res;
	276	int ret;
d482893b	277	void __iomem *mmio;
179a502f SG	278
	279	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	280	if (!data)
	281	return -ENOMEM;
	282
1a13e648 AH	283	data->rtc = devm_rtc_allocate_device(&pdev->dev);
	284	if (IS_ERR(data->rtc))
	285	return PTR_ERR(data->rtc);
	286
d482893b FL	287	data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
	288
	289	if (IS_ERR(data->regmap)) {
	290	dev_warn(&pdev->dev, "snvs rtc: you use old dts file, please update it\n");
	291	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	292
	293	mmio = devm_ioremap_resource(&pdev->dev, res);
	294	if (IS_ERR(mmio))
	295	return PTR_ERR(mmio);
	296
	297	data->regmap = devm_regmap_init_mmio(&pdev->dev, mmio, &snvs_rtc_config);
	298	} else {
	299	data->offset = SNVS_LPREGISTER_OFFSET;
	300	of_property_read_u32(pdev->dev.of_node, "offset", &data->offset);
	301	}
	302
75892900	303	if (IS_ERR(data->regmap)) {
d482893b FL	304	dev_err(&pdev->dev, "Can't find snvs syscon\n");
	305	return -ENODEV;
	306	}
179a502f SG	307
	308	data->irq = platform_get_irq(pdev, 0);
	309	if (data->irq < 0)
	310	return data->irq;
	311
7f899399 SM	312	data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
	313	if (IS_ERR(data->clk)) {
	314	data->clk = NULL;
	315	} else {
	316	ret = clk_prepare_enable(data->clk);
	317	if (ret) {
	318	dev_err(&pdev->dev,
	319	"Could not prepare or enable the snvs clock\n");
	320	return ret;
	321	}
	322	}
	323
179a502f SG	324	platform_set_drvdata(pdev, data);
179a502f SG	325
179a502f	326	/* Initialize glitch detect */
d482893b	327	regmap_write(data->regmap, data->offset + SNVS_LPPGDR, SNVS_LPPGDR_INIT);
179a502f SG	328
179a502f SG	329	/* Clear interrupt status */
d482893b	330	regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff);
179a502f SG	331
179a502f SG	332	/* Enable RTC */
3f129bd8 BD	333	ret = snvs_rtc_enable(data, true);
	334	if (ret) {
	335	dev_err(&pdev->dev, "failed to enable rtc %d\n", ret);
	336	goto error_rtc_device_register;
	337	}
179a502f SG	338
	339	device_init_wakeup(&pdev->dev, true);
	340
	341	ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
	342	IRQF_SHARED, "rtc alarm", &pdev->dev);
	343	if (ret) {
	344	dev_err(&pdev->dev, "failed to request irq %d: %d\n",
	345	data->irq, ret);
7f899399	346	goto error_rtc_device_register;
179a502f SG	347	}
179a502f SG	348
1a13e648 AH	349	data->rtc->ops = &snvs_rtc_ops;
	350	ret = rtc_register_device(data->rtc);
	351	if (ret) {
179a502f	352	dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
7f899399	353	goto error_rtc_device_register;
179a502f SG	354	}
	355
	356	return 0;
7f899399 SM	357
	358	error_rtc_device_register:
	359	if (data->clk)
	360	clk_disable_unprepare(data->clk);
	361
	362	return ret;
179a502f SG	363	}
179a502f SG	364
179a502f SG	365	#ifdef CONFIG_PM_SLEEP
	366	static int snvs_rtc_suspend(struct device *dev)
	367	{
	368	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	369
	370	if (device_may_wakeup(dev))
a350259d	371	return enable_irq_wake(data->irq);
179a502f	372
119434f4 SA	373	return 0;
	374	}
	375
	376	static int snvs_rtc_suspend_noirq(struct device *dev)
	377	{
	378	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	379
7f899399 SM	380	if (data->clk)
	381	clk_disable_unprepare(data->clk);
	382
179a502f SG	383	return 0;
	384	}
	385
	386	static int snvs_rtc_resume(struct device *dev)
	387	{
	388	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	389
	390	if (device_may_wakeup(dev))
119434f4	391	return disable_irq_wake(data->irq);
179a502f	392
119434f4 SA	393	return 0;
	394	}
	395
	396	static int snvs_rtc_resume_noirq(struct device *dev)
	397	{
	398	struct snvs_rtc_data *data = dev_get_drvdata(dev);
	399
	400	if (data->clk)
	401	return clk_prepare_enable(data->clk);
7f899399	402
179a502f SG	403	return 0;
179a502f SG	404	}
179a502f	405
7654e9d4	406	static const struct dev_pm_ops snvs_rtc_pm_ops = {
119434f4 SA	407	.suspend = snvs_rtc_suspend,
	408	.suspend_noirq = snvs_rtc_suspend_noirq,
	409	.resume = snvs_rtc_resume,
	410	.resume_noirq = snvs_rtc_resume_noirq,
7654e9d4	411	};
179a502f	412
88221c32 GR	413	#define SNVS_RTC_PM_OPS (&snvs_rtc_pm_ops)
	414
	415	#else
	416
	417	#define SNVS_RTC_PM_OPS NULL
	418
	419	#endif
	420
5a167f45	421	static const struct of_device_id snvs_dt_ids[] = {
179a502f SG	422	{ .compatible = "fsl,sec-v4.0-mon-rtc-lp", },
	423	{ /* sentinel */ }
	424	};
	425	MODULE_DEVICE_TABLE(of, snvs_dt_ids);
	426
	427	static struct platform_driver snvs_rtc_driver = {
	428	.driver = {
	429	.name = "snvs_rtc",
88221c32	430	.pm = SNVS_RTC_PM_OPS,
c39b3717	431	.of_match_table = snvs_dt_ids,
179a502f SG	432	},
179a502f SG	433	.probe = snvs_rtc_probe,
179a502f SG	434	};
	435	module_platform_driver(snvs_rtc_driver);
	436
	437	MODULE_AUTHOR("Freescale Semiconductor, Inc.");
	438	MODULE_DESCRIPTION("Freescale SNVS RTC Driver");
	439	MODULE_LICENSE("GPL");