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

/*
 * rtc-st-lpc.c - ST's LPC RTC, powered by the Low Power Timer
 *
 * Copyright (C) 2014 STMicroelectronics Limited
 *
 * Author: David Paris <david.paris@st.com> for STMicroelectronics
 *         Lee Jones <lee.jones@linaro.org> for STMicroelectronics
 *
 * Based on the original driver written by Stuart Menefy.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>

#include <dt-bindings/mfd/st-lpc.h>

/* Low Power Timer */
#define LPC_LPT_LSB_OFF		0x400
#define LPC_LPT_MSB_OFF		0x404
#define LPC_LPT_START_OFF	0x408

/* Low Power Alarm */
#define LPC_LPA_LSB_OFF		0x410
#define LPC_LPA_MSB_OFF		0x414
#define LPC_LPA_START_OFF	0x418

/* LPC as WDT */
#define LPC_WDT_OFF		0x510
#define LPC_WDT_FLAG_OFF	0x514

struct st_rtc {
	struct rtc_device *rtc_dev;
	struct rtc_wkalrm alarm;
	struct resource *res;
	struct clk *clk;
	unsigned long clkrate;
	void __iomem *ioaddr;
	bool irq_enabled:1;
	spinlock_t lock;
	short irq;
};

static void st_rtc_set_hw_alarm(struct st_rtc *rtc,
				unsigned long msb, unsigned long  lsb)
{
	unsigned long flags;

	spin_lock_irqsave(&rtc->lock, flags);

	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);

	writel_relaxed(msb, rtc->ioaddr + LPC_LPA_MSB_OFF);
	writel_relaxed(lsb, rtc->ioaddr + LPC_LPA_LSB_OFF);
	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);

	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);

	spin_unlock_irqrestore(&rtc->lock, flags);
}

static irqreturn_t st_rtc_handler(int this_irq, void *data)
{
	struct st_rtc *rtc = (struct st_rtc *)data;

	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF);

	return IRQ_HANDLED;
}

static int st_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct st_rtc *rtc = dev_get_drvdata(dev);
	unsigned long lpt_lsb, lpt_msb;
	unsigned long long lpt;
	unsigned long flags;

	spin_lock_irqsave(&rtc->lock, flags);

	do {
		lpt_msb = readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF);
		lpt_lsb = readl_relaxed(rtc->ioaddr + LPC_LPT_LSB_OFF);
	} while (readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF) != lpt_msb);

	spin_unlock_irqrestore(&rtc->lock, flags);

	lpt = ((unsigned long long)lpt_msb << 32) | lpt_lsb;
	do_div(lpt, rtc->clkrate);
	rtc_time64_to_tm(lpt, tm);

	return 0;
}

static int st_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct st_rtc *rtc = dev_get_drvdata(dev);
	unsigned long long lpt, secs;
	unsigned long flags;

	secs = rtc_tm_to_time64(tm);

	lpt = (unsigned long long)secs * rtc->clkrate;

	spin_lock_irqsave(&rtc->lock, flags);

	writel_relaxed(lpt >> 32, rtc->ioaddr + LPC_LPT_MSB_OFF);
	writel_relaxed(lpt, rtc->ioaddr + LPC_LPT_LSB_OFF);
	writel_relaxed(1, rtc->ioaddr + LPC_LPT_START_OFF);

	spin_unlock_irqrestore(&rtc->lock, flags);

	return 0;
}

static int st_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
	struct st_rtc *rtc = dev_get_drvdata(dev);
	unsigned long flags;

	spin_lock_irqsave(&rtc->lock, flags);

	memcpy(wkalrm, &rtc->alarm, sizeof(struct rtc_wkalrm));

	spin_unlock_irqrestore(&rtc->lock, flags);

	return 0;
}

static int st_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct st_rtc *rtc = dev_get_drvdata(dev);

	if (enabled && !rtc->irq_enabled) {
		enable_irq(rtc->irq);
		rtc->irq_enabled = true;
	} else if (!enabled && rtc->irq_enabled) {
		disable_irq(rtc->irq);
		rtc->irq_enabled = false;
	}

	return 0;
}

static int st_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct st_rtc *rtc = dev_get_drvdata(dev);
	struct rtc_time now;
	unsigned long long now_secs;
	unsigned long long alarm_secs;
	unsigned long long lpa;

	st_rtc_read_time(dev, &now);
	now_secs = rtc_tm_to_time64(&now);
	alarm_secs = rtc_tm_to_time64(&t->time);

	/* Invalid alarm time */
	if (now_secs > alarm_secs)
		return -EINVAL;

	memcpy(&rtc->alarm, t, sizeof(struct rtc_wkalrm));

	/* Now many secs to fire */
	alarm_secs -= now_secs;
	lpa = (unsigned long long)alarm_secs * rtc->clkrate;

	st_rtc_set_hw_alarm(rtc, lpa >> 32, lpa);
	st_rtc_alarm_irq_enable(dev, t->enabled);

	return 0;
}

static struct rtc_class_ops st_rtc_ops = {
	.read_time		= st_rtc_read_time,
	.set_time		= st_rtc_set_time,
	.read_alarm		= st_rtc_read_alarm,
	.set_alarm		= st_rtc_set_alarm,
	.alarm_irq_enable	= st_rtc_alarm_irq_enable,
};

static int st_rtc_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct st_rtc *rtc;
	struct resource *res;
	struct rtc_time tm_check;
	uint32_t mode;
	int ret = 0;

	ret = of_property_read_u32(np, "st,lpc-mode", &mode);
	if (ret) {
		dev_err(&pdev->dev, "An LPC mode must be provided\n");
		return -EINVAL;
	}

	/* LPC can either run as a Clocksource or in RTC or WDT mode */
	if (mode != ST_LPC_MODE_RTC)
		return -ENODEV;

	rtc = devm_kzalloc(&pdev->dev, sizeof(struct st_rtc), GFP_KERNEL);
	if (!rtc)
		return -ENOMEM;

	spin_lock_init(&rtc->lock);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	rtc->ioaddr = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(rtc->ioaddr))
		return PTR_ERR(rtc->ioaddr);

	rtc->irq = irq_of_parse_and_map(np, 0);
	if (!rtc->irq) {
		dev_err(&pdev->dev, "IRQ missing or invalid\n");
		return -EINVAL;
	}

	ret = devm_request_irq(&pdev->dev, rtc->irq, st_rtc_handler, 0,
			       pdev->name, rtc);
	if (ret) {
		dev_err(&pdev->dev, "Failed to request irq %i\n", rtc->irq);
		return ret;
	}

	enable_irq_wake(rtc->irq);
	disable_irq(rtc->irq);

	rtc->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(rtc->clk)) {
		dev_err(&pdev->dev, "Unable to request clock\n");
		return PTR_ERR(rtc->clk);
	}

	clk_prepare_enable(rtc->clk);

	rtc->clkrate = clk_get_rate(rtc->clk);
	if (!rtc->clkrate) {
		dev_err(&pdev->dev, "Unable to fetch clock rate\n");
		return -EINVAL;
	}

	device_set_wakeup_capable(&pdev->dev, 1);

	platform_set_drvdata(pdev, rtc);

	/*
	 * The RTC-LPC is able to manage date.year > 2038
	 * but currently the kernel can not manage this date!
	 * If the RTC-LPC has a date.year > 2038 then
	 * it's set to the epoch "Jan 1st 2000"
	 */
	st_rtc_read_time(&pdev->dev, &tm_check);

	if (tm_check.tm_year >=  (2038 - 1900)) {
		memset(&tm_check, 0, sizeof(tm_check));
		tm_check.tm_year = 100;
		tm_check.tm_mday = 1;
		st_rtc_set_time(&pdev->dev, &tm_check);
	}

	rtc->rtc_dev = rtc_device_register("st-lpc-rtc", &pdev->dev,
					   &st_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc_dev)) {
		clk_disable_unprepare(rtc->clk);
		return PTR_ERR(rtc->rtc_dev);
	}

	return 0;
}

static int st_rtc_remove(struct platform_device *pdev)
{
	struct st_rtc *rtc = platform_get_drvdata(pdev);

	if (likely(rtc->rtc_dev))
		rtc_device_unregister(rtc->rtc_dev);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int st_rtc_suspend(struct device *dev)
{
	struct st_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		return 0;

	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
	writel_relaxed(0, rtc->ioaddr + LPC_LPA_START_OFF);
	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);

	return 0;
}

static int st_rtc_resume(struct device *dev)
{
	struct st_rtc *rtc = dev_get_drvdata(dev);

	rtc_alarm_irq_enable(rtc->rtc_dev, 0);

	/*
	 * clean 'rtc->alarm' to allow a new
	 * .set_alarm to the upper RTC layer
	 */
	memset(&rtc->alarm, 0, sizeof(struct rtc_wkalrm));

	writel_relaxed(0, rtc->ioaddr + LPC_LPA_MSB_OFF);
	writel_relaxed(0, rtc->ioaddr + LPC_LPA_LSB_OFF);
	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);
	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(st_rtc_pm_ops, st_rtc_suspend, st_rtc_resume);

static const struct of_device_id st_rtc_match[] = {
	{ .compatible = "st,stih407-lpc" },
	{}
};
MODULE_DEVICE_TABLE(of, st_rtc_match);

static struct platform_driver st_rtc_platform_driver = {
	.driver = {
		.name = "st-lpc-rtc",
		.pm = &st_rtc_pm_ops,
		.of_match_table = st_rtc_match,
	},
	.probe = st_rtc_probe,
	.remove = st_rtc_remove,
};

module_platform_driver(st_rtc_platform_driver);

MODULE_DESCRIPTION("STMicroelectronics LPC RTC driver");
MODULE_AUTHOR("David Paris <david.paris@st.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
b5b2bdfc LJ	1	/*
	2	* rtc-st-lpc.c - ST's LPC RTC, powered by the Low Power Timer
	3	*
	4	* Copyright (C) 2014 STMicroelectronics Limited
	5	*
	6	* Author: David Paris <david.paris@st.com> for STMicroelectronics
	7	* Lee Jones <lee.jones@linaro.org> for STMicroelectronics
	8	*
	9	* Based on the original driver written by Stuart Menefy.
	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public Licence
	13	* as published by the Free Software Foundation; either version
	14	* 2 of the Licence, or (at your option) any later version.
	15	*/
	16
	17	#include <linux/clk.h>
	18	#include <linux/delay.h>
	19	#include <linux/init.h>
	20	#include <linux/io.h>
	21	#include <linux/irq.h>
	22	#include <linux/kernel.h>
	23	#include <linux/module.h>
	24	#include <linux/of.h>
	25	#include <linux/of_irq.h>
	26	#include <linux/platform_device.h>
	27	#include <linux/rtc.h>
	28
	29	#include <dt-bindings/mfd/st-lpc.h>
	30
	31	/* Low Power Timer */
	32	#define LPC_LPT_LSB_OFF 0x400
	33	#define LPC_LPT_MSB_OFF 0x404
	34	#define LPC_LPT_START_OFF 0x408
	35
	36	/* Low Power Alarm */
	37	#define LPC_LPA_LSB_OFF 0x410
	38	#define LPC_LPA_MSB_OFF 0x414
	39	#define LPC_LPA_START_OFF 0x418
	40
	41	/* LPC as WDT */
	42	#define LPC_WDT_OFF 0x510
	43	#define LPC_WDT_FLAG_OFF 0x514
	44
	45	struct st_rtc {
	46	struct rtc_device *rtc_dev;
	47	struct rtc_wkalrm alarm;
	48	struct resource *res;
	49	struct clk *clk;
	50	unsigned long clkrate;
	51	void __iomem *ioaddr;
	52	bool irq_enabled:1;
	53	spinlock_t lock;
	54	short irq;
	55	};
	56
	57	static void st_rtc_set_hw_alarm(struct st_rtc *rtc,
	58	unsigned long msb, unsigned long lsb)
	59	{
	60	unsigned long flags;
	61
	62	spin_lock_irqsave(&rtc->lock, flags);
	63
	64	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
65
66	writel_relaxed(msb, rtc->ioaddr + LPC_LPA_MSB_OFF);
67	writel_relaxed(lsb, rtc->ioaddr + LPC_LPA_LSB_OFF);
68	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);
69
70	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);
71
72	spin_unlock_irqrestore(&rtc->lock, flags);
73	}
74
75	static irqreturn_t st_rtc_handler(int this_irq, void *data)
76	{
77	struct st_rtc rtc = (struct st_rtc )data;
78
79	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF);
80
81	return IRQ_HANDLED;
82	}
83
84	static int st_rtc_read_time(struct device dev, struct rtc_time tm)
85	{
86	struct st_rtc *rtc = dev_get_drvdata(dev);
87	unsigned long lpt_lsb, lpt_msb;
88	unsigned long long lpt;
89	unsigned long flags;
90
91	spin_lock_irqsave(&rtc->lock, flags);
92
93	do {
94	lpt_msb = readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF);
95	lpt_lsb = readl_relaxed(rtc->ioaddr + LPC_LPT_LSB_OFF);
96	} while (readl_relaxed(rtc->ioaddr + LPC_LPT_MSB_OFF) != lpt_msb);
97
98	spin_unlock_irqrestore(&rtc->lock, flags);
99
100	lpt = ((unsigned long long)lpt_msb << 32) \| lpt_lsb;
101	do_div(lpt, rtc->clkrate);
f4b82d39	102	rtc_time64_to_tm(lpt, tm);
b5b2bdfc LJ	103
	104	return 0;
	105	}
	106
	107	static int st_rtc_set_time(struct device dev, struct rtc_time tm)
	108	{
	109	struct st_rtc *rtc = dev_get_drvdata(dev);
f4b82d39 BG	110	unsigned long long lpt, secs;
f4b82d39 BG	111	unsigned long flags;
b5b2bdfc	112
f4b82d39	113	secs = rtc_tm_to_time64(tm);
b5b2bdfc LJ	114
	115	lpt = (unsigned long long)secs * rtc->clkrate;
	116
	117	spin_lock_irqsave(&rtc->lock, flags);
	118
	119	writel_relaxed(lpt >> 32, rtc->ioaddr + LPC_LPT_MSB_OFF);
	120	writel_relaxed(lpt, rtc->ioaddr + LPC_LPT_LSB_OFF);
	121	writel_relaxed(1, rtc->ioaddr + LPC_LPT_START_OFF);
	122
	123	spin_unlock_irqrestore(&rtc->lock, flags);
	124
	125	return 0;
	126	}
	127
	128	static int st_rtc_read_alarm(struct device dev, struct rtc_wkalrm wkalrm)
	129	{
	130	struct st_rtc *rtc = dev_get_drvdata(dev);
	131	unsigned long flags;
	132
	133	spin_lock_irqsave(&rtc->lock, flags);
	134
	135	memcpy(wkalrm, &rtc->alarm, sizeof(struct rtc_wkalrm));
	136
	137	spin_unlock_irqrestore(&rtc->lock, flags);
	138
	139	return 0;
	140	}
	141
	142	static int st_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
	143	{
	144	struct st_rtc *rtc = dev_get_drvdata(dev);
	145
	146	if (enabled && !rtc->irq_enabled) {
	147	enable_irq(rtc->irq);
	148	rtc->irq_enabled = true;
	149	} else if (!enabled && rtc->irq_enabled) {
	150	disable_irq(rtc->irq);
	151	rtc->irq_enabled = false;
	152	}
	153
	154	return 0;
	155	}
	156
	157	static int st_rtc_set_alarm(struct device dev, struct rtc_wkalrm t)
	158	{
	159	struct st_rtc *rtc = dev_get_drvdata(dev);
	160	struct rtc_time now;
f4b82d39 BG	161	unsigned long long now_secs;
f4b82d39 BG	162	unsigned long long alarm_secs;
b5b2bdfc LJ	163	unsigned long long lpa;
	164
	165	st_rtc_read_time(dev, &now);
f4b82d39 BG	166	now_secs = rtc_tm_to_time64(&now);
f4b82d39 BG	167	alarm_secs = rtc_tm_to_time64(&t->time);
b5b2bdfc LJ	168
	169	/* Invalid alarm time */
	170	if (now_secs > alarm_secs)
	171	return -EINVAL;
	172
	173	memcpy(&rtc->alarm, t, sizeof(struct rtc_wkalrm));
	174
	175	/* Now many secs to fire */
	176	alarm_secs -= now_secs;
	177	lpa = (unsigned long long)alarm_secs * rtc->clkrate;
	178
	179	st_rtc_set_hw_alarm(rtc, lpa >> 32, lpa);
	180	st_rtc_alarm_irq_enable(dev, t->enabled);
	181
	182	return 0;
	183	}
	184
	185	static struct rtc_class_ops st_rtc_ops = {
	186	.read_time = st_rtc_read_time,
	187	.set_time = st_rtc_set_time,
	188	.read_alarm = st_rtc_read_alarm,
	189	.set_alarm = st_rtc_set_alarm,
	190	.alarm_irq_enable = st_rtc_alarm_irq_enable,
	191	};
	192
	193	static int st_rtc_probe(struct platform_device *pdev)
	194	{
	195	struct device_node *np = pdev->dev.of_node;
	196	struct st_rtc *rtc;
	197	struct resource *res;
	198	struct rtc_time tm_check;
	199	uint32_t mode;
	200	int ret = 0;
	201
	202	ret = of_property_read_u32(np, "st,lpc-mode", &mode);
	203	if (ret) {
	204	dev_err(&pdev->dev, "An LPC mode must be provided\n");
	205	return -EINVAL;
	206	}
	207
742e4097	208	/* LPC can either run as a Clocksource or in RTC or WDT mode */
b5b2bdfc LJ	209	if (mode != ST_LPC_MODE_RTC)
	210	return -ENODEV;
	211
	212	rtc = devm_kzalloc(&pdev->dev, sizeof(struct st_rtc), GFP_KERNEL);
	213	if (!rtc)
	214	return -ENOMEM;
	215
	216	spin_lock_init(&rtc->lock);
	217
	218	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	219	rtc->ioaddr = devm_ioremap_resource(&pdev->dev, res);
	220	if (IS_ERR(rtc->ioaddr))
	221	return PTR_ERR(rtc->ioaddr);
	222
	223	rtc->irq = irq_of_parse_and_map(np, 0);
	224	if (!rtc->irq) {
	225	dev_err(&pdev->dev, "IRQ missing or invalid\n");
	226	return -EINVAL;
	227	}
	228
	229	ret = devm_request_irq(&pdev->dev, rtc->irq, st_rtc_handler, 0,
	230	pdev->name, rtc);
	231	if (ret) {
	232	dev_err(&pdev->dev, "Failed to request irq %i\n", rtc->irq);
	233	return ret;
	234	}
	235
	236	enable_irq_wake(rtc->irq);
	237	disable_irq(rtc->irq);
	238
	239	rtc->clk = clk_get(&pdev->dev, NULL);
	240	if (IS_ERR(rtc->clk)) {
	241	dev_err(&pdev->dev, "Unable to request clock\n");
	242	return PTR_ERR(rtc->clk);
	243	}
	244
	245	clk_prepare_enable(rtc->clk);
	246
	247	rtc->clkrate = clk_get_rate(rtc->clk);
	248	if (!rtc->clkrate) {
	249	dev_err(&pdev->dev, "Unable to fetch clock rate\n");
	250	return -EINVAL;
	251	}
	252
	253	device_set_wakeup_capable(&pdev->dev, 1);
	254
	255	platform_set_drvdata(pdev, rtc);
	256
	257	/*
	258	* The RTC-LPC is able to manage date.year > 2038
	259	* but currently the kernel can not manage this date!
	260	* If the RTC-LPC has a date.year > 2038 then
	261	* it's set to the epoch "Jan 1st 2000"
	262	*/
	263	st_rtc_read_time(&pdev->dev, &tm_check);
	264
	265	if (tm_check.tm_year >= (2038 - 1900)) {
	266	memset(&tm_check, 0, sizeof(tm_check));
	267	tm_check.tm_year = 100;
	268	tm_check.tm_mday = 1;
	269	st_rtc_set_time(&pdev->dev, &tm_check);
	270	}
	271
	272	rtc->rtc_dev = rtc_device_register("st-lpc-rtc", &pdev->dev,
273	&st_rtc_ops, THIS_MODULE);
274	if (IS_ERR(rtc->rtc_dev)) {
275	clk_disable_unprepare(rtc->clk);
276	return PTR_ERR(rtc->rtc_dev);
277	}
278
279	return 0;
280	}
281
282	static int st_rtc_remove(struct platform_device *pdev)
283	{
284	struct st_rtc *rtc = platform_get_drvdata(pdev);
285
286	if (likely(rtc->rtc_dev))
287	rtc_device_unregister(rtc->rtc_dev);
288
289	return 0;
290	}
291
292	#ifdef CONFIG_PM_SLEEP
293	static int st_rtc_suspend(struct device *dev)
294	{
295	struct st_rtc *rtc = dev_get_drvdata(dev);
296
297	if (device_may_wakeup(dev))
298	return 0;
299
300	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
301	writel_relaxed(0, rtc->ioaddr + LPC_LPA_START_OFF);
302	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);
303
304	return 0;
305	}
306
307	static int st_rtc_resume(struct device *dev)
308	{
309	struct st_rtc *rtc = dev_get_drvdata(dev);
310
311	rtc_alarm_irq_enable(rtc->rtc_dev, 0);
312
313	/*
314	* clean 'rtc->alarm' to allow a new
315	* .set_alarm to the upper RTC layer
316	*/
317	memset(&rtc->alarm, 0, sizeof(struct rtc_wkalrm));
318
319	writel_relaxed(0, rtc->ioaddr + LPC_LPA_MSB_OFF);
320	writel_relaxed(0, rtc->ioaddr + LPC_LPA_LSB_OFF);
321	writel_relaxed(1, rtc->ioaddr + LPC_WDT_OFF);
322	writel_relaxed(1, rtc->ioaddr + LPC_LPA_START_OFF);
323	writel_relaxed(0, rtc->ioaddr + LPC_WDT_OFF);
324
325	return 0;
326	}
327	#endif
328
329	static SIMPLE_DEV_PM_OPS(st_rtc_pm_ops, st_rtc_suspend, st_rtc_resume);
330
331	static const struct of_device_id st_rtc_match[] = {
332	{ .compatible = "st,stih407-lpc" },
333	{}
334	};
335	MODULE_DEVICE_TABLE(of, st_rtc_match);
336
337	static struct platform_driver st_rtc_platform_driver = {
338	.driver = {
339	.name = "st-lpc-rtc",
340	.pm = &st_rtc_pm_ops,
341	.of_match_table = st_rtc_match,
342	},
343	.probe = st_rtc_probe,
344	.remove = st_rtc_remove,
345	};
346
347	module_platform_driver(st_rtc_platform_driver);
348
349	MODULE_DESCRIPTION("STMicroelectronics LPC RTC driver");
350	MODULE_AUTHOR("David Paris <david.paris@st.com>");
351	MODULE_LICENSE("GPL");