[deliverable/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/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_ioctl(struct device *dev, unsigned int cmd,
			unsigned long arg)
{
	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	int ret = 0;

	spin_lock_irq(&rtc->lock);

	switch (cmd) {
	case RTC_AIE_ON:
		if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
			ret = -EINVAL;
			break;
		}
		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));
		break;
	case RTC_AIE_OFF:
		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));
		break;
	default:
		ret = -ENOIOCTLCMD;
		break;
	}

	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 = {
	.ioctl		= at32_rtc_ioctl,
	.read_time	= at32_rtc_readtime,
	.set_time	= at32_rtc_settime,
	.read_alarm	= at32_rtc_readalarm,
	.set_alarm	= at32_rtc_setalarm,
};

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, regs->end - regs->start + 1);
	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 <hcegtvedt@atmel.com>");
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>
	14	#include <linux/rtc.h>
	15	#include <linux/io.h>
	16
	17	/*
	18	* This is a bare-bones RTC. It runs during most system sleep states, but has
	19	* no battery backup and gets reset during system restart. It must be
	20	* initialized from an external clock (network, I2C, etc) before it can be of
	21	* much use.
	22	*
	23	* The alarm functionality is limited by the hardware, not supporting
	24	* periodic interrupts.
	25	*/
	26
	27	#define RTC_CTRL 0x00
	28	#define RTC_CTRL_EN 0
	29	#define RTC_CTRL_PCLR 1
	30	#define RTC_CTRL_TOPEN 2
	31	#define RTC_CTRL_PSEL 8
	32
	33	#define RTC_VAL 0x04
	34
	35	#define RTC_TOP 0x08
	36
	37	#define RTC_IER 0x10
	38	#define RTC_IER_TOPI 0
	39
	40	#define RTC_IDR 0x14
	41	#define RTC_IDR_TOPI 0
	42
	43	#define RTC_IMR 0x18
	44	#define RTC_IMR_TOPI 0
	45
	46	#define RTC_ISR 0x1c
	47	#define RTC_ISR_TOPI 0
	48
	49	#define RTC_ICR 0x20
	50	#define RTC_ICR_TOPI 0
	51
	52	#define RTC_BIT(name) (1 << RTC_##name)
	53	#define RTC_BF(name, value) ((value) << RTC_##name)
	54
	55	#define rtc_readl(dev, reg) \
	56	__raw_readl((dev)->regs + RTC_##reg)
	57	#define rtc_writel(dev, reg, value) \
	58	__raw_writel((value), (dev)->regs + RTC_##reg)
	59
	60	struct rtc_at32ap700x {
	61	struct rtc_device *rtc;
	62	void __iomem *regs;
	63	unsigned long alarm_time;
	64	unsigned long irq;
65	/* Protect against concurrent register access. */
66	spinlock_t lock;
67	};
68
69	static int at32_rtc_readtime(struct device dev, struct rtc_time tm)
70	{
71	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
72	unsigned long now;
73
74	now = rtc_readl(rtc, VAL);
75	rtc_time_to_tm(now, tm);
76
77	return 0;
78	}
79
80	static int at32_rtc_settime(struct device dev, struct rtc_time tm)
81	{
82	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
83	unsigned long now;
84	int ret;
85
86	ret = rtc_tm_to_time(tm, &now);
87	if (ret == 0)
88	rtc_writel(rtc, VAL, now);
89
90	return ret;
91	}
92
93	static int at32_rtc_readalarm(struct device dev, struct rtc_wkalrm alrm)
94	{
95	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
96
529a4f4e	97	spin_lock_irq(&rtc->lock);
fa04e78b	98	rtc_time_to_tm(rtc->alarm_time, &alrm->time);
529a4f4e HS	99	alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
	100	alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0;
	101	spin_unlock_irq(&rtc->lock);
fa04e78b HCE	102
	103	return 0;
	104	}
	105
	106	static int at32_rtc_setalarm(struct device dev, struct rtc_wkalrm alrm)
	107	{
	108	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	109	unsigned long rtc_unix_time;
	110	unsigned long alarm_unix_time;
	111	int ret;
	112
	113	rtc_unix_time = rtc_readl(rtc, VAL);
	114
	115	ret = rtc_tm_to_time(&alrm->time, &alarm_unix_time);
	116	if (ret)
	117	return ret;
	118
	119	if (alarm_unix_time < rtc_unix_time)
	120	return -EINVAL;
	121
	122	spin_lock_irq(&rtc->lock);
	123	rtc->alarm_time = alarm_unix_time;
	124	rtc_writel(rtc, TOP, rtc->alarm_time);
529a4f4e	125	if (alrm->enabled)
fa04e78b HCE	126	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	127	\| RTC_BIT(CTRL_TOPEN));
	128	else
	129	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	130	& ~RTC_BIT(CTRL_TOPEN));
	131	spin_unlock_irq(&rtc->lock);
	132
	133	return ret;
	134	}
	135
	136	static int at32_rtc_ioctl(struct device *dev, unsigned int cmd,
	137	unsigned long arg)
	138	{
	139	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
	140	int ret = 0;
	141
	142	spin_lock_irq(&rtc->lock);
	143
	144	switch (cmd) {
	145	case RTC_AIE_ON:
	146	if (rtc_readl(rtc, VAL) > rtc->alarm_time) {
	147	ret = -EINVAL;
	148	break;
	149	}
	150	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	151	\| RTC_BIT(CTRL_TOPEN));
	152	rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
	153	rtc_writel(rtc, IER, RTC_BIT(IER_TOPI));
	154	break;
	155	case RTC_AIE_OFF:
	156	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	157	& ~RTC_BIT(CTRL_TOPEN));
	158	rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
	159	rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
	160	break;
	161	default:
	162	ret = -ENOIOCTLCMD;
	163	break;
	164	}
	165
	166	spin_unlock_irq(&rtc->lock);
	167
	168	return ret;
	169	}
	170
	171	static irqreturn_t at32_rtc_interrupt(int irq, void *dev_id)
	172	{
	173	struct rtc_at32ap700x rtc = (struct rtc_at32ap700x )dev_id;
	174	unsigned long isr = rtc_readl(rtc, ISR);
	175	unsigned long events = 0;
	176	int ret = IRQ_NONE;
	177
	178	spin_lock(&rtc->lock);
	179
	180	if (isr & RTC_BIT(ISR_TOPI)) {
	181	rtc_writel(rtc, ICR, RTC_BIT(ICR_TOPI));
	182	rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
	183	rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
	184	& ~RTC_BIT(CTRL_TOPEN));
	185	rtc_writel(rtc, VAL, rtc->alarm_time);
	186	events = RTC_AF \| RTC_IRQF;
	187	rtc_update_irq(rtc->rtc, 1, events);
	188	ret = IRQ_HANDLED;
	189	}
190
191	spin_unlock(&rtc->lock);
192
193	return ret;
194	}
195
196	static struct rtc_class_ops at32_rtc_ops = {
197	.ioctl = at32_rtc_ioctl,
198	.read_time = at32_rtc_readtime,
199	.set_time = at32_rtc_settime,
200	.read_alarm = at32_rtc_readalarm,
201	.set_alarm = at32_rtc_setalarm,
202	};
203
204	static int __init at32_rtc_probe(struct platform_device *pdev)
205	{
206	struct resource *regs;
207	struct rtc_at32ap700x *rtc;
2fac6674	208	int irq;
fa04e78b HCE	209	int ret;
	210
	211	rtc = kzalloc(sizeof(struct rtc_at32ap700x), GFP_KERNEL);
	212	if (!rtc) {
	213	dev_dbg(&pdev->dev, "out of memory\n");
	214	return -ENOMEM;
	215	}
	216
	217	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	218	if (!regs) {
	219	dev_dbg(&pdev->dev, "no mmio resource defined\n");
	220	ret = -ENXIO;
	221	goto out;
	222	}
	223
	224	irq = platform_get_irq(pdev, 0);
2fac6674	225	if (irq <= 0) {
fa04e78b HCE	226	dev_dbg(&pdev->dev, "could not get irq\n");
	227	ret = -ENXIO;
	228	goto out;
	229	}
	230
fa04e78b HCE	231	rtc->irq = irq;
	232	rtc->regs = ioremap(regs->start, regs->end - regs->start + 1);
	233	if (!rtc->regs) {
	234	ret = -ENOMEM;
	235	dev_dbg(&pdev->dev, "could not map I/O memory\n");
8d431dbe	236	goto out;
fa04e78b HCE	237	}
	238	spin_lock_init(&rtc->lock);
	239
	240	/*
	241	* Maybe init RTC: count from zero at 1 Hz, disable wrap irq.
	242	*
	243	* Do not reset VAL register, as it can hold an old time
	244	* from last JTAG reset.
	245	*/
	246	if (!(rtc_readl(rtc, CTRL) & RTC_BIT(CTRL_EN))) {
	247	rtc_writel(rtc, CTRL, RTC_BIT(CTRL_PCLR));
	248	rtc_writel(rtc, IDR, RTC_BIT(IDR_TOPI));
	249	rtc_writel(rtc, CTRL, RTC_BF(CTRL_PSEL, 0xe)
	250	\| RTC_BIT(CTRL_EN));
	251	}
	252
8d431dbe DB	253	ret = request_irq(irq, at32_rtc_interrupt, IRQF_SHARED, "rtc", rtc);
	254	if (ret) {
	255	dev_dbg(&pdev->dev, "could not request irq %d\n", irq);
	256	goto out_iounmap;
	257	}
	258
b74d2caa AZ	259	platform_set_drvdata(pdev, rtc);
b74d2caa AZ	260
fa04e78b HCE	261	rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
	262	&at32_rtc_ops, THIS_MODULE);
	263	if (IS_ERR(rtc->rtc)) {
	264	dev_dbg(&pdev->dev, "could not register rtc device\n");
	265	ret = PTR_ERR(rtc->rtc);
8d431dbe	266	goto out_free_irq;
fa04e78b HCE	267	}
fa04e78b HCE	268
f3a24e1e	269	device_init_wakeup(&pdev->dev, 1);
fa04e78b HCE	270
	271	dev_info(&pdev->dev, "Atmel RTC for AT32AP700x at %08lx irq %ld\n",
	272	(unsigned long)rtc->regs, rtc->irq);
	273
	274	return 0;
	275
fa04e78b	276	out_free_irq:
b74d2caa	277	platform_set_drvdata(pdev, NULL);
fa04e78b	278	free_irq(irq, rtc);
8d431dbe DB	279	out_iounmap:
8d431dbe DB	280	iounmap(rtc->regs);
fa04e78b HCE	281	out:
	282	kfree(rtc);
	283	return ret;
	284	}
	285
	286	static int __exit at32_rtc_remove(struct platform_device *pdev)
	287	{
	288	struct rtc_at32ap700x *rtc = platform_get_drvdata(pdev);
	289
f3a24e1e HS	290	device_init_wakeup(&pdev->dev, 0);
f3a24e1e HS	291
fa04e78b HCE	292	free_irq(rtc->irq, rtc);
	293	iounmap(rtc->regs);
	294	rtc_device_unregister(rtc->rtc);
	295	kfree(rtc);
	296	platform_set_drvdata(pdev, NULL);
	297
	298	return 0;
	299	}
	300
ad28a07b	301	MODULE_ALIAS("platform:at32ap700x_rtc");
fa04e78b HCE	302
	303	static struct platform_driver at32_rtc_driver = {
	304	.remove = __exit_p(at32_rtc_remove),
	305	.driver = {
	306	.name = "at32ap700x_rtc",
	307	.owner = THIS_MODULE,
	308	},
	309	};
	310
	311	static int __init at32_rtc_init(void)
	312	{
	313	return platform_driver_probe(&at32_rtc_driver, at32_rtc_probe);
	314	}
	315	module_init(at32_rtc_init);
	316
	317	static void __exit at32_rtc_exit(void)
	318	{
	319	platform_driver_unregister(&at32_rtc_driver);
	320	}
	321	module_exit(at32_rtc_exit);
	322
	323	MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
	324	MODULE_DESCRIPTION("Real time clock for AVR32 AT32AP700x");
	325	MODULE_LICENSE("GPL");