[mirror_ubuntu-bionic-kernel.git] / drivers / rtc / rtc-jz4740.c

/*
 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
 *  Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
 *	 JZ4740 SoC RTC driver
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under  the terms of  the GNU General Public License as published by the
 *  Free Software Foundation;  either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#define JZ_REG_RTC_CTRL		0x00
#define JZ_REG_RTC_SEC		0x04
#define JZ_REG_RTC_SEC_ALARM	0x08
#define JZ_REG_RTC_REGULATOR	0x0C
#define JZ_REG_RTC_HIBERNATE	0x20
#define JZ_REG_RTC_WAKEUP_FILTER	0x24
#define JZ_REG_RTC_RESET_COUNTER	0x28
#define JZ_REG_RTC_SCRATCHPAD	0x34

/* The following are present on the jz4780 */
#define JZ_REG_RTC_WENR	0x3C
#define JZ_RTC_WENR_WEN	BIT(31)

#define JZ_RTC_CTRL_WRDY	BIT(7)
#define JZ_RTC_CTRL_1HZ		BIT(6)
#define JZ_RTC_CTRL_1HZ_IRQ	BIT(5)
#define JZ_RTC_CTRL_AF		BIT(4)
#define JZ_RTC_CTRL_AF_IRQ	BIT(3)
#define JZ_RTC_CTRL_AE		BIT(2)
#define JZ_RTC_CTRL_ENABLE	BIT(0)

/* Magic value to enable writes on jz4780 */
#define JZ_RTC_WENR_MAGIC	0xA55A

#define JZ_RTC_WAKEUP_FILTER_MASK	0x0000FFE0
#define JZ_RTC_RESET_COUNTER_MASK	0x00000FE0

enum jz4740_rtc_type {
	ID_JZ4740,
	ID_JZ4780,
};

struct jz4740_rtc {
	void __iomem *base;
	enum jz4740_rtc_type type;

	struct rtc_device *rtc;
	struct clk *clk;

	int irq;

	spinlock_t lock;

	unsigned int min_wakeup_pin_assert_time;
	unsigned int reset_pin_assert_time;
};

static struct device *dev_for_power_off;

static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg)
{
	return readl(rtc->base + reg);
}

static int jz4740_rtc_wait_write_ready(struct jz4740_rtc *rtc)
{
	uint32_t ctrl;
	int timeout = 10000;

	do {
		ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
	} while (!(ctrl & JZ_RTC_CTRL_WRDY) && --timeout);

	return timeout ? 0 : -EIO;
}

static inline int jz4780_rtc_enable_write(struct jz4740_rtc *rtc)
{
	uint32_t ctrl;
	int ret, timeout = 10000;

	ret = jz4740_rtc_wait_write_ready(rtc);
	if (ret != 0)
		return ret;

	writel(JZ_RTC_WENR_MAGIC, rtc->base + JZ_REG_RTC_WENR);

	do {
		ctrl = readl(rtc->base + JZ_REG_RTC_WENR);
	} while (!(ctrl & JZ_RTC_WENR_WEN) && --timeout);

	return timeout ? 0 : -EIO;
}

static inline int jz4740_rtc_reg_write(struct jz4740_rtc *rtc, size_t reg,
	uint32_t val)
{
	int ret = 0;

	if (rtc->type >= ID_JZ4780)
		ret = jz4780_rtc_enable_write(rtc);
	if (ret == 0)
		ret = jz4740_rtc_wait_write_ready(rtc);
	if (ret == 0)
		writel(val, rtc->base + reg);

	return ret;
}

static int jz4740_rtc_ctrl_set_bits(struct jz4740_rtc *rtc, uint32_t mask,
	bool set)
{
	int ret;
	unsigned long flags;
	uint32_t ctrl;

	spin_lock_irqsave(&rtc->lock, flags);

	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);

	/* Don't clear interrupt flags by accident */
	ctrl |= JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF;

	if (set)
		ctrl |= mask;
	else
		ctrl &= ~mask;

	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_CTRL, ctrl);

	spin_unlock_irqrestore(&rtc->lock, flags);

	return ret;
}

static int jz4740_rtc_read_time(struct device *dev, struct rtc_time *time)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	uint32_t secs, secs2;
	int timeout = 5;

	/* If the seconds register is read while it is updated, it can contain a
	 * bogus value. This can be avoided by making sure that two consecutive
	 * reads have the same value.
	 */
	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
	secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);

	while (secs != secs2 && --timeout) {
		secs = secs2;
		secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
	}

	if (timeout == 0)
		return -EIO;

	rtc_time_to_tm(secs, time);

	return rtc_valid_tm(time);
}

static int jz4740_rtc_set_mmss(struct device *dev, unsigned long secs)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);

	return jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, secs);
}

static int jz4740_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	uint32_t secs;
	uint32_t ctrl;

	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);

	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);

	alrm->enabled = !!(ctrl & JZ_RTC_CTRL_AE);
	alrm->pending = !!(ctrl & JZ_RTC_CTRL_AF);

	rtc_time_to_tm(secs, &alrm->time);

	return rtc_valid_tm(&alrm->time);
}

static int jz4740_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	int ret;
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	unsigned long secs;

	rtc_tm_to_time(&alrm->time, &secs);

	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC_ALARM, secs);
	if (!ret)
		ret = jz4740_rtc_ctrl_set_bits(rtc,
			JZ_RTC_CTRL_AE | JZ_RTC_CTRL_AF_IRQ, alrm->enabled);

	return ret;
}

static int jz4740_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	return jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AF_IRQ, enable);
}

static const struct rtc_class_ops jz4740_rtc_ops = {
	.read_time	= jz4740_rtc_read_time,
	.set_mmss	= jz4740_rtc_set_mmss,
	.read_alarm	= jz4740_rtc_read_alarm,
	.set_alarm	= jz4740_rtc_set_alarm,
	.alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
};

static irqreturn_t jz4740_rtc_irq(int irq, void *data)
{
	struct jz4740_rtc *rtc = data;
	uint32_t ctrl;
	unsigned long events = 0;

	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);

	if (ctrl & JZ_RTC_CTRL_1HZ)
		events |= (RTC_UF | RTC_IRQF);

	if (ctrl & JZ_RTC_CTRL_AF)
		events |= (RTC_AF | RTC_IRQF);

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

	jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ | JZ_RTC_CTRL_AF, false);

	return IRQ_HANDLED;
}

static void jz4740_rtc_poweroff(struct device *dev)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	jz4740_rtc_reg_write(rtc, JZ_REG_RTC_HIBERNATE, 1);
}

static void jz4740_rtc_power_off(void)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev_for_power_off);
	unsigned long rtc_rate;
	unsigned long wakeup_filter_ticks;
	unsigned long reset_counter_ticks;

	clk_prepare_enable(rtc->clk);

	rtc_rate = clk_get_rate(rtc->clk);

	/*
	 * Set minimum wakeup pin assertion time: 100 ms.
	 * Range is 0 to 2 sec if RTC is clocked at 32 kHz.
	 */
	wakeup_filter_ticks =
		(rtc->min_wakeup_pin_assert_time * rtc_rate) / 1000;
	if (wakeup_filter_ticks < JZ_RTC_WAKEUP_FILTER_MASK)
		wakeup_filter_ticks &= JZ_RTC_WAKEUP_FILTER_MASK;
	else
		wakeup_filter_ticks = JZ_RTC_WAKEUP_FILTER_MASK;
	jz4740_rtc_reg_write(rtc,
			     JZ_REG_RTC_WAKEUP_FILTER, wakeup_filter_ticks);

	/*
	 * Set reset pin low-level assertion time after wakeup: 60 ms.
	 * Range is 0 to 125 ms if RTC is clocked at 32 kHz.
	 */
	reset_counter_ticks = (rtc->reset_pin_assert_time * rtc_rate) / 1000;
	if (reset_counter_ticks < JZ_RTC_RESET_COUNTER_MASK)
		reset_counter_ticks &= JZ_RTC_RESET_COUNTER_MASK;
	else
		reset_counter_ticks = JZ_RTC_RESET_COUNTER_MASK;
	jz4740_rtc_reg_write(rtc,
			     JZ_REG_RTC_RESET_COUNTER, reset_counter_ticks);

	jz4740_rtc_poweroff(dev_for_power_off);
	kernel_halt();
}

static const struct of_device_id jz4740_rtc_of_match[] = {
	{ .compatible = "ingenic,jz4740-rtc", .data = (void *)ID_JZ4740 },
	{ .compatible = "ingenic,jz4780-rtc", .data = (void *)ID_JZ4780 },
	{},
};
MODULE_DEVICE_TABLE(of, jz4740_rtc_of_match);

static int jz4740_rtc_probe(struct platform_device *pdev)
{
	int ret;
	struct jz4740_rtc *rtc;
	uint32_t scratchpad;
	struct resource *mem;
	const struct platform_device_id *id = platform_get_device_id(pdev);
	const struct of_device_id *of_id = of_match_device(
			jz4740_rtc_of_match, &pdev->dev);
	struct device_node *np = pdev->dev.of_node;

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

	if (of_id)
		rtc->type = (enum jz4740_rtc_type)of_id->data;
	else
		rtc->type = id->driver_data;

	rtc->irq = platform_get_irq(pdev, 0);
	if (rtc->irq < 0) {
		dev_err(&pdev->dev, "Failed to get platform irq\n");
		return -ENOENT;
	}

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

	rtc->clk = devm_clk_get(&pdev->dev, "rtc");
	if (IS_ERR(rtc->clk)) {
		dev_err(&pdev->dev, "Failed to get RTC clock\n");
		return PTR_ERR(rtc->clk);
	}

	spin_lock_init(&rtc->lock);

	platform_set_drvdata(pdev, rtc);

	device_init_wakeup(&pdev->dev, 1);

	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
					&jz4740_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc)) {
		ret = PTR_ERR(rtc->rtc);
		dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
		return ret;
	}

	ret = devm_request_irq(&pdev->dev, rtc->irq, jz4740_rtc_irq, 0,
				pdev->name, rtc);
	if (ret) {
		dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
		return ret;
	}

	scratchpad = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SCRATCHPAD);
	if (scratchpad != 0x12345678) {
		ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SCRATCHPAD, 0x12345678);
		ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, 0);
		if (ret) {
			dev_err(&pdev->dev, "Could not write to RTC registers\n");
			return ret;
		}
	}

	if (np && of_device_is_system_power_controller(np)) {
		if (!pm_power_off) {
			/* Default: 60ms */
			rtc->reset_pin_assert_time = 60;
			of_property_read_u32(np, "reset-pin-assert-time-ms",
					     &rtc->reset_pin_assert_time);

			/* Default: 100ms */
			rtc->min_wakeup_pin_assert_time = 100;
			of_property_read_u32(np,
					     "min-wakeup-pin-assert-time-ms",
					     &rtc->min_wakeup_pin_assert_time);

			dev_for_power_off = &pdev->dev;
			pm_power_off = jz4740_rtc_power_off;
		} else {
			dev_warn(&pdev->dev,
				 "Poweroff handler already present!\n");
		}
	}

	return 0;
}

#ifdef CONFIG_PM
static int jz4740_rtc_suspend(struct device *dev)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		enable_irq_wake(rtc->irq);
	return 0;
}

static int jz4740_rtc_resume(struct device *dev)
{
	struct jz4740_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		disable_irq_wake(rtc->irq);
	return 0;
}

static const struct dev_pm_ops jz4740_pm_ops = {
	.suspend = jz4740_rtc_suspend,
	.resume  = jz4740_rtc_resume,
};
#define JZ4740_RTC_PM_OPS (&jz4740_pm_ops)

#else
#define JZ4740_RTC_PM_OPS NULL
#endif  /* CONFIG_PM */

static const struct platform_device_id jz4740_rtc_ids[] = {
	{ "jz4740-rtc", ID_JZ4740 },
	{ "jz4780-rtc", ID_JZ4780 },
	{}
};
MODULE_DEVICE_TABLE(platform, jz4740_rtc_ids);

static struct platform_driver jz4740_rtc_driver = {
	.probe	 = jz4740_rtc_probe,
	.driver	 = {
		.name  = "jz4740-rtc",
		.pm    = JZ4740_RTC_PM_OPS,
		.of_match_table = of_match_ptr(jz4740_rtc_of_match),
	},
	.id_table = jz4740_rtc_ids,
};

module_platform_driver(jz4740_rtc_driver);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RTC driver for the JZ4740 SoC\n");
MODULE_ALIAS("platform:jz4740-rtc");
Commit	Line	Data
3bf0eea8 LPC	1	/*
3bf0eea8 LPC	2	* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
d0f744c8	3	* Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
3bf0eea8 LPC	4	* JZ4740 SoC RTC driver
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the
	8	* Free Software Foundation; either version 2 of the License, or (at your
	9	* option) any later version.
	10	*
	11	* You should have received a copy of the GNU General Public License along
	12	* with this program; if not, write to the Free Software Foundation, Inc.,
	13	* 675 Mass Ave, Cambridge, MA 02139, USA.
	14	*
	15	*/
	16
f9eb69d1	17	#include <linux/clk.h>
c08ac489	18	#include <linux/io.h>
3bf0eea8	19	#include <linux/kernel.h>
586655d2	20	#include <linux/module.h>
c05229a8	21	#include <linux/of_device.h>
3bf0eea8	22	#include <linux/platform_device.h>
f9eb69d1	23	#include <linux/reboot.h>
3bf0eea8 LPC	24	#include <linux/rtc.h>
	25	#include <linux/slab.h>
	26	#include <linux/spinlock.h>
	27
	28	#define JZ_REG_RTC_CTRL 0x00
	29	#define JZ_REG_RTC_SEC 0x04
	30	#define JZ_REG_RTC_SEC_ALARM 0x08
	31	#define JZ_REG_RTC_REGULATOR 0x0C
	32	#define JZ_REG_RTC_HIBERNATE 0x20
f9eb69d1 PC	33	#define JZ_REG_RTC_WAKEUP_FILTER 0x24
f9eb69d1 PC	34	#define JZ_REG_RTC_RESET_COUNTER 0x28
3bf0eea8 LPC	35	#define JZ_REG_RTC_SCRATCHPAD 0x34
3bf0eea8 LPC	36
cd563200 PC	37	/* The following are present on the jz4780 */
	38	#define JZ_REG_RTC_WENR 0x3C
	39	#define JZ_RTC_WENR_WEN BIT(31)
	40
3bf0eea8 LPC	41	#define JZ_RTC_CTRL_WRDY BIT(7)
	42	#define JZ_RTC_CTRL_1HZ BIT(6)
	43	#define JZ_RTC_CTRL_1HZ_IRQ BIT(5)
	44	#define JZ_RTC_CTRL_AF BIT(4)
	45	#define JZ_RTC_CTRL_AF_IRQ BIT(3)
	46	#define JZ_RTC_CTRL_AE BIT(2)
	47	#define JZ_RTC_CTRL_ENABLE BIT(0)
	48
cd563200 PC	49	/* Magic value to enable writes on jz4780 */
	50	#define JZ_RTC_WENR_MAGIC 0xA55A
	51
f9eb69d1 PC	52	#define JZ_RTC_WAKEUP_FILTER_MASK 0x0000FFE0
	53	#define JZ_RTC_RESET_COUNTER_MASK 0x00000FE0
	54
cd563200 PC	55	enum jz4740_rtc_type {
	56	ID_JZ4740,
	57	ID_JZ4780,
	58	};
	59
3bf0eea8	60	struct jz4740_rtc {
3bf0eea8	61	void __iomem *base;
cd563200	62	enum jz4740_rtc_type type;
3bf0eea8 LPC	63
3bf0eea8 LPC	64	struct rtc_device *rtc;
f9eb69d1	65	struct clk *clk;
3bf0eea8	66
7c6a52a0	67	int irq;
3bf0eea8 LPC	68
3bf0eea8 LPC	69	spinlock_t lock;
f9eb69d1 PC	70
	71	unsigned int min_wakeup_pin_assert_time;
	72	unsigned int reset_pin_assert_time;
3bf0eea8 LPC	73	};
3bf0eea8 LPC	74
f9eb69d1 PC	75	static struct device *dev_for_power_off;
f9eb69d1 PC	76
3bf0eea8 LPC	77	static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg)
	78	{
	79	return readl(rtc->base + reg);
	80	}
	81
	82	static int jz4740_rtc_wait_write_ready(struct jz4740_rtc *rtc)
	83	{
	84	uint32_t ctrl;
695e38d8	85	int timeout = 10000;
3bf0eea8 LPC	86
	87	do {
	88	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
	89	} while (!(ctrl & JZ_RTC_CTRL_WRDY) && --timeout);
	90
	91	return timeout ? 0 : -EIO;
	92	}
	93
cd563200 PC	94	static inline int jz4780_rtc_enable_write(struct jz4740_rtc *rtc)
	95	{
	96	uint32_t ctrl;
695e38d8	97	int ret, timeout = 10000;
cd563200 PC	98
	99	ret = jz4740_rtc_wait_write_ready(rtc);
	100	if (ret != 0)
	101	return ret;
	102
	103	writel(JZ_RTC_WENR_MAGIC, rtc->base + JZ_REG_RTC_WENR);
	104
	105	do {
	106	ctrl = readl(rtc->base + JZ_REG_RTC_WENR);
	107	} while (!(ctrl & JZ_RTC_WENR_WEN) && --timeout);
	108
	109	return timeout ? 0 : -EIO;
	110	}
	111
3bf0eea8 LPC	112	static inline int jz4740_rtc_reg_write(struct jz4740_rtc *rtc, size_t reg,
	113	uint32_t val)
	114	{
cd563200 PC	115	int ret = 0;
	116
	117	if (rtc->type >= ID_JZ4780)
	118	ret = jz4780_rtc_enable_write(rtc);
	119	if (ret == 0)
	120	ret = jz4740_rtc_wait_write_ready(rtc);
3bf0eea8 LPC	121	if (ret == 0)
	122	writel(val, rtc->base + reg);
	123
	124	return ret;
	125	}
	126
	127	static int jz4740_rtc_ctrl_set_bits(struct jz4740_rtc *rtc, uint32_t mask,
	128	bool set)
	129	{
	130	int ret;
	131	unsigned long flags;
	132	uint32_t ctrl;
	133
	134	spin_lock_irqsave(&rtc->lock, flags);
	135
	136	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
	137
	138	/* Don't clear interrupt flags by accident */
	139	ctrl \|= JZ_RTC_CTRL_1HZ \| JZ_RTC_CTRL_AF;
	140
	141	if (set)
	142	ctrl \|= mask;
	143	else
	144	ctrl &= ~mask;
	145
	146	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_CTRL, ctrl);
	147
	148	spin_unlock_irqrestore(&rtc->lock, flags);
	149
	150	return ret;
	151	}
	152
	153	static int jz4740_rtc_read_time(struct device dev, struct rtc_time time)
	154	{
	155	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	156	uint32_t secs, secs2;
	157	int timeout = 5;
	158
	159	/* If the seconds register is read while it is updated, it can contain a
	160	* bogus value. This can be avoided by making sure that two consecutive
	161	* reads have the same value.
	162	*/
	163	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
	164	secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
	165
	166	while (secs != secs2 && --timeout) {
	167	secs = secs2;
	168	secs2 = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC);
	169	}
	170
	171	if (timeout == 0)
	172	return -EIO;
	173
	174	rtc_time_to_tm(secs, time);
	175
	176	return rtc_valid_tm(time);
	177	}
	178
	179	static int jz4740_rtc_set_mmss(struct device *dev, unsigned long secs)
	180	{
	181	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	182
	183	return jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, secs);
	184	}
185
186	static int jz4740_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
187	{
188	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
189	uint32_t secs;
190	uint32_t ctrl;
191
192	secs = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SEC_ALARM);
193
194	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
195
196	alrm->enabled = !!(ctrl & JZ_RTC_CTRL_AE);
197	alrm->pending = !!(ctrl & JZ_RTC_CTRL_AF);
198
199	rtc_time_to_tm(secs, &alrm->time);
200
201	return rtc_valid_tm(&alrm->time);
202	}
203
204	static int jz4740_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
205	{
206	int ret;
207	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
208	unsigned long secs;
209
210	rtc_tm_to_time(&alrm->time, &secs);
211
212	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC_ALARM, secs);
213	if (!ret)
d0f744c8 PC	214	ret = jz4740_rtc_ctrl_set_bits(rtc,
d0f744c8 PC	215	JZ_RTC_CTRL_AE \| JZ_RTC_CTRL_AF_IRQ, alrm->enabled);
3bf0eea8 LPC	216
	217	return ret;
	218	}
	219
3bf0eea8 LPC	220	static int jz4740_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
	221	{
	222	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	223	return jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_AF_IRQ, enable);
	224	}
	225
34c7b3ac	226	static const struct rtc_class_ops jz4740_rtc_ops = {
3bf0eea8 LPC	227	.read_time = jz4740_rtc_read_time,
	228	.set_mmss = jz4740_rtc_set_mmss,
	229	.read_alarm = jz4740_rtc_read_alarm,
	230	.set_alarm = jz4740_rtc_set_alarm,
3bf0eea8 LPC	231	.alarm_irq_enable = jz4740_rtc_alarm_irq_enable,
	232	};
	233
	234	static irqreturn_t jz4740_rtc_irq(int irq, void *data)
	235	{
	236	struct jz4740_rtc *rtc = data;
	237	uint32_t ctrl;
	238	unsigned long events = 0;
	239
	240	ctrl = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_CTRL);
	241
	242	if (ctrl & JZ_RTC_CTRL_1HZ)
	243	events \|= (RTC_UF \| RTC_IRQF);
	244
	245	if (ctrl & JZ_RTC_CTRL_AF)
	246	events \|= (RTC_AF \| RTC_IRQF);
	247
	248	rtc_update_irq(rtc->rtc, 1, events);
	249
	250	jz4740_rtc_ctrl_set_bits(rtc, JZ_RTC_CTRL_1HZ \| JZ_RTC_CTRL_AF, false);
	251
	252	return IRQ_HANDLED;
	253	}
	254
819c2178	255	static void jz4740_rtc_poweroff(struct device *dev)
3bf0eea8 LPC	256	{
	257	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	258	jz4740_rtc_reg_write(rtc, JZ_REG_RTC_HIBERNATE, 1);
	259	}
3bf0eea8	260
f9eb69d1 PC	261	static void jz4740_rtc_power_off(void)
	262	{
	263	struct jz4740_rtc *rtc = dev_get_drvdata(dev_for_power_off);
	264	unsigned long rtc_rate;
	265	unsigned long wakeup_filter_ticks;
	266	unsigned long reset_counter_ticks;
	267
	268	clk_prepare_enable(rtc->clk);
	269
	270	rtc_rate = clk_get_rate(rtc->clk);
	271
	272	/*
	273	* Set minimum wakeup pin assertion time: 100 ms.
	274	* Range is 0 to 2 sec if RTC is clocked at 32 kHz.
	275	*/
	276	wakeup_filter_ticks =
	277	(rtc->min_wakeup_pin_assert_time * rtc_rate) / 1000;
	278	if (wakeup_filter_ticks < JZ_RTC_WAKEUP_FILTER_MASK)
	279	wakeup_filter_ticks &= JZ_RTC_WAKEUP_FILTER_MASK;
	280	else
	281	wakeup_filter_ticks = JZ_RTC_WAKEUP_FILTER_MASK;
	282	jz4740_rtc_reg_write(rtc,
	283	JZ_REG_RTC_WAKEUP_FILTER, wakeup_filter_ticks);
	284
	285	/*
	286	* Set reset pin low-level assertion time after wakeup: 60 ms.
	287	* Range is 0 to 125 ms if RTC is clocked at 32 kHz.
	288	*/
	289	reset_counter_ticks = (rtc->reset_pin_assert_time * rtc_rate) / 1000;
	290	if (reset_counter_ticks < JZ_RTC_RESET_COUNTER_MASK)
	291	reset_counter_ticks &= JZ_RTC_RESET_COUNTER_MASK;
	292	else
	293	reset_counter_ticks = JZ_RTC_RESET_COUNTER_MASK;
	294	jz4740_rtc_reg_write(rtc,
	295	JZ_REG_RTC_RESET_COUNTER, reset_counter_ticks);
	296
	297	jz4740_rtc_poweroff(dev_for_power_off);
586655d2	298	kernel_halt();
f9eb69d1 PC	299	}
f9eb69d1 PC	300
c05229a8 PC	301	static const struct of_device_id jz4740_rtc_of_match[] = {
	302	{ .compatible = "ingenic,jz4740-rtc", .data = (void *)ID_JZ4740 },
	303	{ .compatible = "ingenic,jz4780-rtc", .data = (void *)ID_JZ4780 },
	304	{},
	305	};
586655d2	306	MODULE_DEVICE_TABLE(of, jz4740_rtc_of_match);
c05229a8	307
5a167f45	308	static int jz4740_rtc_probe(struct platform_device *pdev)
3bf0eea8 LPC	309	{
	310	int ret;
	311	struct jz4740_rtc *rtc;
	312	uint32_t scratchpad;
3b6aa907	313	struct resource *mem;
cd563200	314	const struct platform_device_id *id = platform_get_device_id(pdev);
c05229a8 PC	315	const struct of_device_id *of_id = of_match_device(
c05229a8 PC	316	jz4740_rtc_of_match, &pdev->dev);
f9eb69d1	317	struct device_node *np = pdev->dev.of_node;
3bf0eea8	318
c08ac489	319	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
3bf0eea8 LPC	320	if (!rtc)
	321	return -ENOMEM;
	322
c05229a8 PC	323	if (of_id)
	324	rtc->type = (enum jz4740_rtc_type)of_id->data;
	325	else
	326	rtc->type = id->driver_data;
cd563200	327
3bf0eea8 LPC	328	rtc->irq = platform_get_irq(pdev, 0);
3bf0eea8 LPC	329	if (rtc->irq < 0) {
3bf0eea8	330	dev_err(&pdev->dev, "Failed to get platform irq\n");
c08ac489	331	return -ENOENT;
3bf0eea8 LPC	332	}
3bf0eea8 LPC	333
3b6aa907 JH	334	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	335	rtc->base = devm_ioremap_resource(&pdev->dev, mem);
	336	if (IS_ERR(rtc->base))
	337	return PTR_ERR(rtc->base);
3bf0eea8	338
f9eb69d1 PC	339	rtc->clk = devm_clk_get(&pdev->dev, "rtc");
	340	if (IS_ERR(rtc->clk)) {
	341	dev_err(&pdev->dev, "Failed to get RTC clock\n");
	342	return PTR_ERR(rtc->clk);
	343	}
	344
3bf0eea8 LPC	345	spin_lock_init(&rtc->lock);
	346
	347	platform_set_drvdata(pdev, rtc);
	348
d0f744c8 PC	349	device_init_wakeup(&pdev->dev, 1);
d0f744c8 PC	350
c08ac489 JH	351	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
c08ac489 JH	352	&jz4740_rtc_ops, THIS_MODULE);
3bf0eea8 LPC	353	if (IS_ERR(rtc->rtc)) {
	354	ret = PTR_ERR(rtc->rtc);
	355	dev_err(&pdev->dev, "Failed to register rtc device: %d\n", ret);
c08ac489	356	return ret;
3bf0eea8 LPC	357	}
3bf0eea8 LPC	358
c08ac489	359	ret = devm_request_irq(&pdev->dev, rtc->irq, jz4740_rtc_irq, 0,
3bf0eea8 LPC	360	pdev->name, rtc);
	361	if (ret) {
	362	dev_err(&pdev->dev, "Failed to request rtc irq: %d\n", ret);
c08ac489	363	return ret;
3bf0eea8 LPC	364	}
	365
	366	scratchpad = jz4740_rtc_reg_read(rtc, JZ_REG_RTC_SCRATCHPAD);
	367	if (scratchpad != 0x12345678) {
	368	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SCRATCHPAD, 0x12345678);
	369	ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_SEC, 0);
	370	if (ret) {
49de9828	371	dev_err(&pdev->dev, "Could not write to RTC registers\n");
c08ac489	372	return ret;
3bf0eea8 LPC	373	}
	374	}
	375
f9eb69d1 PC	376	if (np && of_device_is_system_power_controller(np)) {
	377	if (!pm_power_off) {
	378	/* Default: 60ms */
	379	rtc->reset_pin_assert_time = 60;
	380	of_property_read_u32(np, "reset-pin-assert-time-ms",
	381	&rtc->reset_pin_assert_time);
	382
	383	/* Default: 100ms */
	384	rtc->min_wakeup_pin_assert_time = 100;
	385	of_property_read_u32(np,
	386	"min-wakeup-pin-assert-time-ms",
	387	&rtc->min_wakeup_pin_assert_time);
	388
	389	dev_for_power_off = &pdev->dev;
	390	pm_power_off = jz4740_rtc_power_off;
	391	} else {
	392	dev_warn(&pdev->dev,
	393	"Poweroff handler already present!\n");
	394	}
	395	}
	396
3bf0eea8	397	return 0;
3bf0eea8 LPC	398	}
3bf0eea8 LPC	399
d0f744c8 PC	400	#ifdef CONFIG_PM
	401	static int jz4740_rtc_suspend(struct device *dev)
	402	{
	403	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	404
	405	if (device_may_wakeup(dev))
	406	enable_irq_wake(rtc->irq);
	407	return 0;
	408	}
	409
	410	static int jz4740_rtc_resume(struct device *dev)
	411	{
	412	struct jz4740_rtc *rtc = dev_get_drvdata(dev);
	413
	414	if (device_may_wakeup(dev))
	415	disable_irq_wake(rtc->irq);
	416	return 0;
	417	}
	418
	419	static const struct dev_pm_ops jz4740_pm_ops = {
	420	.suspend = jz4740_rtc_suspend,
	421	.resume = jz4740_rtc_resume,
	422	};
	423	#define JZ4740_RTC_PM_OPS (&jz4740_pm_ops)
	424
	425	#else
	426	#define JZ4740_RTC_PM_OPS NULL
	427	#endif /* CONFIG_PM */
	428
cd563200 PC	429	static const struct platform_device_id jz4740_rtc_ids[] = {
	430	{ "jz4740-rtc", ID_JZ4740 },
	431	{ "jz4780-rtc", ID_JZ4780 },
	432	{}
	433	};
586655d2	434	MODULE_DEVICE_TABLE(platform, jz4740_rtc_ids);
cd563200	435
681d0378	436	static struct platform_driver jz4740_rtc_driver = {
d0f744c8	437	.probe = jz4740_rtc_probe,
d0f744c8 PC	438	.driver = {
d0f744c8 PC	439	.name = "jz4740-rtc",
d0f744c8	440	.pm = JZ4740_RTC_PM_OPS,
c05229a8	441	.of_match_table = of_match_ptr(jz4740_rtc_of_match),
3bf0eea8	442	},
cd563200	443	.id_table = jz4740_rtc_ids,
3bf0eea8 LPC	444	};
3bf0eea8 LPC	445
586655d2 AB	446	module_platform_driver(jz4740_rtc_driver);
	447
	448	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
	449	MODULE_LICENSE("GPL");
	450	MODULE_DESCRIPTION("RTC driver for the JZ4740 SoC\n");
	451	MODULE_ALIAS("platform:jz4740-rtc");