[linux.git] / drivers / rtc / rtc-at32ap700x.c

/*
 * An RTC driver for the AVR32 AT32AP700x processor series.
 *
 * Copyright (C) 2007 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/io.h>

/*
 * This is a bare-bones RTC. It runs during most system sleep states, but has
 * no battery backup and gets reset during system restart.  It must be
 * initialized from an external clock (network, I2C, etc) before it can be of
 * much use.
 *
 * The alarm functionality is limited by the hardware, not supporting
 * periodic interrupts.
 */

#define RTC_CTRL		0x00
#define RTC_CTRL_EN		   0
#define RTC_CTRL_PCLR		   1
#define RTC_CTRL_TOPEN		   2
#define RTC_CTRL_PSEL		   8

#define RTC_VAL			0x04

#define RTC_TOP			0x08

#define RTC_IER			0x10
#define RTC_IER_TOPI		   0

#define RTC_IDR			0x14
#define RTC_IDR_TOPI		   0

#define RTC_IMR			0x18
#define RTC_IMR_TOPI		   0

#define RTC_ISR			0x1c
#define RTC_ISR_TOPI		   0

#define RTC_ICR			0x20
#define RTC_ICR_TOPI		   0

#define RTC_BIT(name)		(1 << RTC_##name)
#define RTC_BF(name, value)	((value) << RTC_##name)

#define rtc_readl(dev, reg)				\
	__raw_readl((dev)->regs + RTC_##reg)
#define rtc_writel(dev, reg, value)			\
	__raw_writel((value), (dev)->regs + RTC_##reg)

struct rtc_at32ap700x {
	struct rtc_device	*rtc;
	void __iomem		*regs;
	unsigned long		alarm_time;
	unsigned long		irq;
	/* Protect against concurrent register access. */
	spinlock_t		lock;
};

static int at32_rtc_readtime(struct device *dev, struct rtc_time *tm)
{
	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	unsigned long now;

	now = rtc_readl(rtc, VAL);
	rtc_time_to_tm(now, tm);

	return 0;
}

static int at32_rtc_settime(struct device *dev, struct rtc_time *tm)
{
	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	unsigned long now;
	int ret;

	ret = rtc_tm_to_time(tm, &now);
	if (ret == 0)
		rtc_writel(rtc, VAL, now);

	return ret;
}

static int at32_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);

	spin_lock_irq(&rtc->lock);
	rtc_time_to_tm(rtc->alarm_time, &alrm->time);
	alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
	alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0;
	spin_unlock_irq(&rtc->lock);

	return 0;
}

static int at32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	unsigned long rtc_unix_time;
	unsigned long alarm_unix_time;
	int ret;

	rtc_unix_time = rtc_readl(rtc, VAL);

	ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time);
	if (ret)
		return ret;

	if (alarm_unix_time < rtc_unix_time)
		return -EINVAL;

	spin_lock_irq(&rtc->lock);
	rtc->alarm_time = alarm_unix_time;
	rtc_writel(rtc, TOP, rtc->alarm_time);
	if (alrm->enabled)
		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
				| RTC_BIT(CTRL_TOPEN));
	else
		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
				& ~RTC_BIT(CTRL_TOPEN));
	spin_unlock_irq(&rtc->lock);

	return ret;
}

static int at32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	int ret = 0;

	spin_lock_irq(&rtc->lock);

	if(enabled) {
		if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
			ret = -EINVAL;
			goto out;
		}
		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
				| RTC_BIT(CTRL_TOPEN));
		rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
		rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
	} else {
		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
				& ~RTC_BIT(CTRL_TOPEN));
		rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
		rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
	}
out:
	spin_unlock_irq(&rtc->lock);

	return ret;
}

static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
{
	struct rtc_at32ap700x *rtc = (struct rtc_at32ap700x *)dev_id;
	unsigned long isr = rtc_readl(rtc, ISR);
	unsigned long events = 0;
	int ret = IRQ_NONE;

	spin_lock(&rtc->lock);

	if (isr & RTC_BIT(ISR_TOPI)) {
		rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
		rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
				& ~RTC_BIT(CTRL_TOPEN));
		rtc_writel(rtc, VAL, rtc->alarm_time);
		events = RTC_AF | RTC_IRQF;
		rtc_update_irq(rtc->rtc, 1, events);
		ret = IRQ_HANDLED;
	}

	spin_unlock(&rtc->lock);

	return ret;
}

static struct rtc_class_ops at32_rtc_ops = {
	.read_time	= at32_rtc_readtime,
	.set_time	= at32_rtc_settime,
	.read_alarm	= at32_rtc_readalarm,
	.set_alarm	= at32_rtc_setalarm,
	.alarm_irq_enable = at32_rtc_alarm_irq_enable,
};

static int __init at32_rtc_probe(struct platform_device *pdev)
{
	struct resource	*regs;
	struct rtc_at32ap700x *rtc;
	int irq;
	int ret;

	rtc = kzalloc(sizeof(struct rtc_at32ap700x), GFP_KERNEL);
	if (!rtc) {
		dev_dbg(&pdev->dev, "out of memory\n");
		return -ENOMEM;
	}

	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!regs) {
		dev_dbg(&pdev->dev, "no mmio resource defined\n");
		ret = -ENXIO;
		goto out;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq <= 0) {
		dev_dbg(&pdev->dev, "could not get irq\n");
		ret = -ENXIO;
		goto out;
	}

	rtc->irq = irq;
	rtc->regs = ioremap(regs->start, resource_size(regs));
	if (!rtc->regs) {
		ret = -ENOMEM;
		dev_dbg(&pdev->dev, "could not map I/O memory\n");
		goto out;
	}
	spin_lock_init(&rtc->lock);

	/*
	 * Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
	 *
	 * Do not reset VAL register, as it can hold an old time
	 * from last JTAG reset.
	 */
	if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
		rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
		rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
		rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
				| RTC_BIT(CTRL_EN));
	}

	ret = request_irq(irq, at32_rtc_interrupt, IRQF_SHARED, "rtc", rtc);
	if (ret) {
		dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
		goto out_iounmap;
	}

	platform_set_drvdata(pdev, rtc);

	rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
				&at32_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc)) {
		dev_dbg(&pdev->dev, "could not register rtc device\n");
		ret = PTR_ERR(rtc->rtc);
		goto out_free_irq;
	}

	device_init_wakeup(&pdev->dev, 1);

	dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
			(unsigned long)rtc->regs, rtc->irq);

	return 0;

out_free_irq:
	platform_set_drvdata(pdev, NULL);
	free_irq(irq, rtc);
out_iounmap:
	iounmap(rtc->regs);
out:
	kfree(rtc);
	return ret;
}

static int __exit at32_rtc_remove(struct platform_device *pdev)
{
	struct rtc_at32ap700x *rtc = platform_get_drvdata(pdev);

	device_init_wakeup(&pdev->dev, 0);

	free_irq(rtc->irq, rtc);
	iounmap(rtc->regs);
	rtc_device_unregister(rtc->rtc);
	kfree(rtc);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

MODULE_ALIAS("platform:at32ap700x_rtc");

static struct platform_driver at32_rtc_driver = {
	.remove		= __exit_p(at32_rtc_remove),
	.driver		= {
		.name	= "at32ap700x_rtc",
		.owner	= THIS_MODULE,
	},
};

static int __init at32_rtc_init(void)
{
	return platform_driver_probe(&at32_rtc_driver, at32_rtc_probe);
}
module_init(at32_rtc_init);

static void __exit at32_rtc_exit(void)
{
	platform_driver_unregister(&at32_rtc_driver);
}
module_exit(at32_rtc_exit);

MODULE_AUTHOR("Hans-Christian Egtvedt <[email protected]>");
MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
MODULE_LICENSE("GPL");
Commit	Line	Data
fa04e78b HCE	1	/*
	2	* An RTC driver for the AVR32 AT32AP700x processor series.
	3	*
	4	* Copyright (C) 2007 Atmel Corporation
	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 version 2 as published
	8	* by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/kernel.h>
	13	#include <linux/platform_device.h>
5a0e3ad6	14	#include <linux/slab.h>
fa04e78b HCE	15	#include <linux/rtc.h>
	16	#include <linux/io.h>
	17
	18	/*
	19	* This is a bare-bones RTC. It runs during most system sleep states, but has
	20	* no battery backup and gets reset during system restart. It must be
	21	* initialized from an external clock (network, I2C, etc) before it can be of
	22	* much use.
	23	*
	24	* The alarm functionality is limited by the hardware, not supporting
	25	* periodic interrupts.
	26	*/
	27
	28	#define RTC_CTRL 0x00
	29	#define RTC_CTRL_EN 0
	30	#define RTC_CTRL_PCLR 1
	31	#define RTC_CTRL_TOPEN 2
	32	#define RTC_CTRL_PSEL 8
	33
	34	#define RTC_VAL 0x04
	35
	36	#define RTC_TOP 0x08
	37
	38	#define RTC_IER 0x10
	39	#define RTC_IER_TOPI 0
	40
	41	#define RTC_IDR 0x14
	42	#define RTC_IDR_TOPI 0
	43
	44	#define RTC_IMR 0x18
	45	#define RTC_IMR_TOPI 0
	46
	47	#define RTC_ISR 0x1c
	48	#define RTC_ISR_TOPI 0
	49
	50	#define RTC_ICR 0x20
	51	#define RTC_ICR_TOPI 0
	52
	53	#define RTC_BIT(name) (1 << RTC_##name)
	54	#define RTC_BF(name, value) ((value) << RTC_##name)
	55
	56	#define rtc_readl(dev, reg) \
	57	__raw_readl((dev)->regs + RTC_##reg)
	58	#define rtc_writel(dev, reg, value) \
	59	__raw_writel((value), (dev)->regs + RTC_##reg)
	60
	61	struct rtc_at32ap700x {
	62	struct rtc_device *rtc;
	63	void __iomem *regs;
	64	unsigned long alarm_time;
	65	unsigned long irq;
	66	/* Protect against concurrent register access. */
	67	spinlock_t lock;
	68	};
	69
	70	static int at32_rtc_readtime(struct device dev, struct rtc_time tm)
	71	{
	72	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	73	unsigned long now;
	74
	75	now = rtc_readl(rtc, VAL);
	76	rtc_time_to_tm(now, tm);
	77
	78	return 0;
79	}
80
81	static int at32_rtc_settime(struct device dev, struct rtc_time tm)
82	{
83	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
84	unsigned long now;
85	int ret;
86
87	ret = rtc_tm_to_time(tm, &now);
88	if (ret == 0)
89	rtc_writel(rtc, VAL, now);
90
91	return ret;
92	}
93
94	static int at32_rtc_readalarm(struct device dev, struct rtc_wkalrm alrm)
95	{
96	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
97
529a4f4e	98	spin_lock_irq(&rtc->lock);
fa04e78b	99	rtc_time_to_tm(rtc->alarm_time, &alrm->time);
529a4f4e HS	100	alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
	101	alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0;
	102	spin_unlock_irq(&rtc->lock);
fa04e78b HCE	103
	104	return 0;
	105	}
	106
	107	static int at32_rtc_setalarm(struct device dev, struct rtc_wkalrm alrm)
	108	{
	109	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	110	unsigned long rtc_unix_time;
	111	unsigned long alarm_unix_time;
	112	int ret;
	113
	114	rtc_unix_time = rtc_readl(rtc, VAL);
	115
	116	ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time);
	117	if (ret)
	118	return ret;
	119
	120	if (alarm_unix_time < rtc_unix_time)
	121	return -EINVAL;
	122
	123	spin_lock_irq(&rtc->lock);
	124	rtc->alarm_time = alarm_unix_time;
	125	rtc_writel(rtc, TOP, rtc->alarm_time);
529a4f4e	126	if (alrm->enabled)
fa04e78b HCE	127	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	128	\| RTC_BIT(CTRL_TOPEN));
	129	else
	130	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	131	& ~RTC_BIT(CTRL_TOPEN));
	132	spin_unlock_irq(&rtc->lock);
	133
	134	return ret;
	135	}
	136
16380c15	137	static int at32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
fa04e78b HCE	138	{
	139	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	140	int ret = 0;
	141
	142	spin_lock_irq(&rtc->lock);
	143
16380c15	144	if(enabled) {
fa04e78b HCE	145	if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
fa04e78b HCE	146	ret = -EINVAL;
16380c15	147	goto out;
fa04e78b HCE	148	}
	149	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	150	\| RTC_BIT(CTRL_TOPEN));
	151	rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
	152	rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
16380c15	153	} else {
fa04e78b HCE	154	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	155	& ~RTC_BIT(CTRL_TOPEN));
	156	rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
	157	rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
fa04e78b	158	}
16380c15	159	out:
fa04e78b HCE	160	spin_unlock_irq(&rtc->lock);
	161
	162	return ret;
	163	}
	164
	165	static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
	166	{
	167	struct rtc_at32ap700x rtc = (struct rtc_at32ap700x )dev_id;
	168	unsigned long isr = rtc_readl(rtc, ISR);
	169	unsigned long events = 0;
	170	int ret = IRQ_NONE;
	171
	172	spin_lock(&rtc->lock);
	173
	174	if (isr & RTC_BIT(ISR_TOPI)) {
	175	rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
	176	rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
	177	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	178	& ~RTC_BIT(CTRL_TOPEN));
	179	rtc_writel(rtc, VAL, rtc->alarm_time);
	180	events = RTC_AF \| RTC_IRQF;
	181	rtc_update_irq(rtc->rtc, 1, events);
	182	ret = IRQ_HANDLED;
	183	}
	184
	185	spin_unlock(&rtc->lock);
	186
	187	return ret;
	188	}
	189
	190	static struct rtc_class_ops at32_rtc_ops = {
fa04e78b HCE	191	.read_time = at32_rtc_readtime,
	192	.set_time = at32_rtc_settime,
	193	.read_alarm = at32_rtc_readalarm,
	194	.set_alarm = at32_rtc_setalarm,
16380c15	195	.alarm_irq_enable = at32_rtc_alarm_irq_enable,
fa04e78b HCE	196	};
	197
	198	static int __init at32_rtc_probe(struct platform_device *pdev)
	199	{
	200	struct resource *regs;
	201	struct rtc_at32ap700x *rtc;
2fac6674	202	int irq;
fa04e78b HCE	203	int ret;
	204
	205	rtc = kzalloc(sizeof(struct rtc_at32ap700x), GFP_KERNEL);
	206	if (!rtc) {
	207	dev_dbg(&pdev->dev, "out of memory\n");
	208	return -ENOMEM;
	209	}
	210
	211	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	212	if (!regs) {
	213	dev_dbg(&pdev->dev, "no mmio resource defined\n");
	214	ret = -ENXIO;
	215	goto out;
	216	}
	217
	218	irq = platform_get_irq(pdev, 0);
2fac6674	219	if (irq <= 0) {
fa04e78b HCE	220	dev_dbg(&pdev->dev, "could not get irq\n");
	221	ret = -ENXIO;
	222	goto out;
	223	}
	224
fa04e78b	225	rtc->irq = irq;
28f65c11	226	rtc->regs = ioremap(regs->start, resource_size(regs));
fa04e78b HCE	227	if (!rtc->regs) {
	228	ret = -ENOMEM;
	229	dev_dbg(&pdev->dev, "could not map I/O memory\n");
8d431dbe	230	goto out;
fa04e78b HCE	231	}
	232	spin_lock_init(&rtc->lock);
	233
	234	/*
	235	* Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
	236	*
	237	* Do not reset VAL register, as it can hold an old time
	238	* from last JTAG reset.
	239	*/
	240	if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
	241	rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
	242	rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
	243	rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
	244	\| RTC_BIT(CTRL_EN));
	245	}
	246
8d431dbe DB	247	ret = request_irq(irq, at32_rtc_interrupt, IRQF_SHARED, "rtc", rtc);
	248	if (ret) {
	249	dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
	250	goto out_iounmap;
	251	}
	252
b74d2caa AZ	253	platform_set_drvdata(pdev, rtc);
b74d2caa AZ	254
fa04e78b HCE	255	rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
	256	&at32_rtc_ops, THIS_MODULE);
	257	if (IS_ERR(rtc->rtc)) {
	258	dev_dbg(&pdev->dev, "could not register rtc device\n");
	259	ret = PTR_ERR(rtc->rtc);
8d431dbe	260	goto out_free_irq;
fa04e78b HCE	261	}
fa04e78b HCE	262
f3a24e1e	263	device_init_wakeup(&pdev->dev, 1);
fa04e78b HCE	264
	265	dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
	266	(unsigned long)rtc->regs, rtc->irq);
	267
	268	return 0;
	269
fa04e78b	270	out_free_irq:
b74d2caa	271	platform_set_drvdata(pdev, NULL);
fa04e78b	272	free_irq(irq, rtc);
8d431dbe DB	273	out_iounmap:
8d431dbe DB	274	iounmap(rtc->regs);
fa04e78b HCE	275	out:
	276	kfree(rtc);
	277	return ret;
	278	}
	279
	280	static int __exit at32_rtc_remove(struct platform_device *pdev)
	281	{
	282	struct rtc_at32ap700x *rtc = platform_get_drvdata(pdev);
	283
f3a24e1e HS	284	device_init_wakeup(&pdev->dev, 0);
f3a24e1e HS	285
fa04e78b HCE	286	free_irq(rtc->irq, rtc);
	287	iounmap(rtc->regs);
	288	rtc_device_unregister(rtc->rtc);
	289	kfree(rtc);
	290	platform_set_drvdata(pdev, NULL);
	291
	292	return 0;
	293	}
	294
ad28a07b	295	MODULE_ALIAS("platform:at32ap700x_rtc");
fa04e78b HCE	296
	297	static struct platform_driver at32_rtc_driver = {
	298	.remove = __exit_p(at32_rtc_remove),
	299	.driver = {
	300	.name = "at32ap700x_rtc",
	301	.owner = THIS_MODULE,
	302	},
	303	};
	304
	305	static int __init at32_rtc_init(void)
	306	{
	307	return platform_driver_probe(&at32_rtc_driver, at32_rtc_probe);
	308	}
	309	module_init(at32_rtc_init);
	310
	311	static void __exit at32_rtc_exit(void)
	312	{
	313	platform_driver_unregister(&at32_rtc_driver);
	314	}
	315	module_exit(at32_rtc_exit);
	316
	317	MODULE_AUTHOR("Hans-Christian Egtvedt <[email protected]>");
	318	MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
	319	MODULE_LICENSE("GPL");