[linux-2.6-block.git] / drivers / rtc / rtc-coh901331.c

/*
 * Copyright (C) 2007-2009 ST-Ericsson AB
 * License terms: GNU General Public License (GPL) version 2
 * Real Time Clock interface for ST-Ericsson AB COH 901 331 RTC.
 * Author: Linus Walleij <linus.walleij@stericsson.com>
 * Based on rtc-pl031.c by Deepak Saxena <dsaxena@plexity.net>
 * Copyright 2006 (c) MontaVista Software, Inc.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>

/*
 * Registers in the COH 901 331
 */
/* Alarm value 32bit (R/W) */
#define COH901331_ALARM		0x00U
/* Used to set current time 32bit (R/W) */
#define COH901331_SET_TIME	0x04U
/* Indication if current time is valid 32bit (R/-) */
#define COH901331_VALID		0x08U
/* Read the current time 32bit (R/-) */
#define COH901331_CUR_TIME	0x0cU
/* Event register for the "alarm" interrupt */
#define COH901331_IRQ_EVENT	0x10U
/* Mask register for the "alarm" interrupt */
#define COH901331_IRQ_MASK	0x14U
/* Force register for the "alarm" interrupt */
#define COH901331_IRQ_FORCE	0x18U

/*
 * Reference to RTC block clock
 * Notice that the frequent clk_enable()/clk_disable() on this
 * clock is mainly to be able to turn on/off other clocks in the
 * hierarchy as needed, the RTC clock is always on anyway.
 */
struct coh901331_port {
	struct rtc_device *rtc;
	struct clk *clk;
	void __iomem *virtbase;
	int irq;
#ifdef CONFIG_PM_SLEEP
	u32 irqmaskstore;
#endif
};

static irqreturn_t coh901331_interrupt(int irq, void *data)
{
	struct coh901331_port *rtap = data;

	clk_enable(rtap->clk);
	/* Ack IRQ */
	writel(1, rtap->virtbase + COH901331_IRQ_EVENT);
	/*
	 * Disable the interrupt. This is necessary because
	 * the RTC lives on a lower-clocked line and will
	 * not release the IRQ line until after a few (slower)
	 * clock cycles. The interrupt will be re-enabled when
	 * a new alarm is set anyway.
	 */
	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
	clk_disable(rtap->clk);

	/* Set alarm flag */
	rtc_update_irq(rtap->rtc, 1, RTC_AF);

	return IRQ_HANDLED;
}

static int coh901331_read_time(struct device *dev, struct rtc_time *tm)
{
	struct coh901331_port *rtap = dev_get_drvdata(dev);

	clk_enable(rtap->clk);
	/* Check if the time is valid */
	if (readl(rtap->virtbase + COH901331_VALID)) {
		rtc_time_to_tm(readl(rtap->virtbase + COH901331_CUR_TIME), tm);
		clk_disable(rtap->clk);
		return rtc_valid_tm(tm);
	}
	clk_disable(rtap->clk);
	return -EINVAL;
}

static int coh901331_set_mmss(struct device *dev, unsigned long secs)
{
	struct coh901331_port *rtap = dev_get_drvdata(dev);

	clk_enable(rtap->clk);
	writel(secs, rtap->virtbase + COH901331_SET_TIME);
	clk_disable(rtap->clk);

	return 0;
}

static int coh901331_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct coh901331_port *rtap = dev_get_drvdata(dev);

	clk_enable(rtap->clk);
	rtc_time_to_tm(readl(rtap->virtbase + COH901331_ALARM), &alarm->time);
	alarm->pending = readl(rtap->virtbase + COH901331_IRQ_EVENT) & 1U;
	alarm->enabled = readl(rtap->virtbase + COH901331_IRQ_MASK) & 1U;
	clk_disable(rtap->clk);

	return 0;
}

static int coh901331_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct coh901331_port *rtap = dev_get_drvdata(dev);
	unsigned long time;

	rtc_tm_to_time(&alarm->time, &time);
	clk_enable(rtap->clk);
	writel(time, rtap->virtbase + COH901331_ALARM);
	writel(alarm->enabled, rtap->virtbase + COH901331_IRQ_MASK);
	clk_disable(rtap->clk);

	return 0;
}

static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct coh901331_port *rtap = dev_get_drvdata(dev);

	clk_enable(rtap->clk);
	if (enabled)
		writel(1, rtap->virtbase + COH901331_IRQ_MASK);
	else
		writel(0, rtap->virtbase + COH901331_IRQ_MASK);
	clk_disable(rtap->clk);

	return 0;
}

static struct rtc_class_ops coh901331_ops = {
	.read_time = coh901331_read_time,
	.set_mmss = coh901331_set_mmss,
	.read_alarm = coh901331_read_alarm,
	.set_alarm = coh901331_set_alarm,
	.alarm_irq_enable = coh901331_alarm_irq_enable,
};

static int __exit coh901331_remove(struct platform_device *pdev)
{
	struct coh901331_port *rtap = platform_get_drvdata(pdev);

	if (rtap)
		clk_unprepare(rtap->clk);

	return 0;
}


static int __init coh901331_probe(struct platform_device *pdev)
{
	int ret;
	struct coh901331_port *rtap;
	struct resource *res;

	rtap = devm_kzalloc(&pdev->dev,
			    sizeof(struct coh901331_port), GFP_KERNEL);
	if (!rtap)
		return -ENOMEM;

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

	rtap->irq = platform_get_irq(pdev, 0);
	if (devm_request_irq(&pdev->dev, rtap->irq, coh901331_interrupt, 0,
			     "RTC COH 901 331 Alarm", rtap))
		return -EIO;

	rtap->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(rtap->clk)) {
		ret = PTR_ERR(rtap->clk);
		dev_err(&pdev->dev, "could not get clock\n");
		return ret;
	}

	/* We enable/disable the clock only to assure it works */
	ret = clk_prepare_enable(rtap->clk);
	if (ret) {
		dev_err(&pdev->dev, "could not enable clock\n");
		return ret;
	}
	clk_disable(rtap->clk);

	platform_set_drvdata(pdev, rtap);
	rtap->rtc = devm_rtc_device_register(&pdev->dev, "coh901331",
					&coh901331_ops, THIS_MODULE);
	if (IS_ERR(rtap->rtc)) {
		ret = PTR_ERR(rtap->rtc);
		goto out_no_rtc;
	}

	return 0;

 out_no_rtc:
	clk_unprepare(rtap->clk);
	return ret;
}

#ifdef CONFIG_PM_SLEEP
static int coh901331_suspend(struct device *dev)
{
	struct coh901331_port *rtap = dev_get_drvdata(dev);

	/*
	 * If this RTC alarm will be used for waking the system up,
	 * don't disable it of course. Else we just disable the alarm
	 * and await suspension.
	 */
	if (device_may_wakeup(dev)) {
		enable_irq_wake(rtap->irq);
	} else {
		clk_enable(rtap->clk);
		rtap->irqmaskstore = readl(rtap->virtbase + COH901331_IRQ_MASK);
		writel(0, rtap->virtbase + COH901331_IRQ_MASK);
		clk_disable(rtap->clk);
	}
	clk_unprepare(rtap->clk);
	return 0;
}

static int coh901331_resume(struct device *dev)
{
	struct coh901331_port *rtap = dev_get_drvdata(dev);

	clk_prepare(rtap->clk);
	if (device_may_wakeup(dev)) {
		disable_irq_wake(rtap->irq);
	} else {
		clk_enable(rtap->clk);
		writel(rtap->irqmaskstore, rtap->virtbase + COH901331_IRQ_MASK);
		clk_disable(rtap->clk);
	}
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(coh901331_pm_ops, coh901331_suspend, coh901331_resume);

static void coh901331_shutdown(struct platform_device *pdev)
{
	struct coh901331_port *rtap = platform_get_drvdata(pdev);

	clk_enable(rtap->clk);
	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
	clk_disable_unprepare(rtap->clk);
}

static const struct of_device_id coh901331_dt_match[] = {
	{ .compatible = "stericsson,coh901331" },
	{},
};
MODULE_DEVICE_TABLE(of, coh901331_dt_match);

static struct platform_driver coh901331_driver = {
	.driver = {
		.name = "rtc-coh901331",
		.pm = &coh901331_pm_ops,
		.of_match_table = coh901331_dt_match,
	},
	.remove = __exit_p(coh901331_remove),
	.shutdown = coh901331_shutdown,
};

module_platform_driver_probe(coh901331_driver, coh901331_probe);

MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("ST-Ericsson AB COH 901 331 RTC Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
aa958f57 LW	1	/*
	2	* Copyright (C) 2007-2009 ST-Ericsson AB
	3	* License terms: GNU General Public License (GPL) version 2
	4	* Real Time Clock interface for ST-Ericsson AB COH 901 331 RTC.
	5	* Author: Linus Walleij <linus.walleij@stericsson.com>
	6	* Based on rtc-pl031.c by Deepak Saxena <dsaxena@plexity.net>
	7	* Copyright 2006 (c) MontaVista Software, Inc.
	8	*/
	9	#include <linux/init.h>
	10	#include <linux/module.h>
	11	#include <linux/rtc.h>
	12	#include <linux/clk.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/pm.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/io.h>
5a0e3ad6	17	#include <linux/slab.h>
aa958f57 LW	18
	19	/*
	20	* Registers in the COH 901 331
	21	*/
	22	/* Alarm value 32bit (R/W) */
	23	#define COH901331_ALARM 0x00U
	24	/* Used to set current time 32bit (R/W) */
	25	#define COH901331_SET_TIME 0x04U
	26	/* Indication if current time is valid 32bit (R/-) */
	27	#define COH901331_VALID 0x08U
	28	/* Read the current time 32bit (R/-) */
	29	#define COH901331_CUR_TIME 0x0cU
	30	/* Event register for the "alarm" interrupt */
	31	#define COH901331_IRQ_EVENT 0x10U
	32	/* Mask register for the "alarm" interrupt */
	33	#define COH901331_IRQ_MASK 0x14U
	34	/* Force register for the "alarm" interrupt */
	35	#define COH901331_IRQ_FORCE 0x18U
	36
	37	/*
	38	* Reference to RTC block clock
	39	* Notice that the frequent clk_enable()/clk_disable() on this
	40	* clock is mainly to be able to turn on/off other clocks in the
	41	* hierarchy as needed, the RTC clock is always on anyway.
	42	*/
	43	struct coh901331_port {
	44	struct rtc_device *rtc;
	45	struct clk *clk;
aa958f57 LW	46	void __iomem *virtbase;
aa958f57 LW	47	int irq;
62068e2c	48	#ifdef CONFIG_PM_SLEEP
aa958f57 LW	49	u32 irqmaskstore;
	50	#endif
	51	};
	52
	53	static irqreturn_t coh901331_interrupt(int irq, void *data)
	54	{
	55	struct coh901331_port *rtap = data;
	56
	57	clk_enable(rtap->clk);
	58	/* Ack IRQ */
	59	writel(1, rtap->virtbase + COH901331_IRQ_EVENT);
378ce74b LW	60	/*
	61	* Disable the interrupt. This is necessary because
	62	* the RTC lives on a lower-clocked line and will
	63	* not release the IRQ line until after a few (slower)
	64	* clock cycles. The interrupt will be re-enabled when
	65	* a new alarm is set anyway.
	66	*/
	67	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
aa958f57	68	clk_disable(rtap->clk);
378ce74b	69
aa958f57 LW	70	/* Set alarm flag */
	71	rtc_update_irq(rtap->rtc, 1, RTC_AF);
	72
	73	return IRQ_HANDLED;
	74	}
	75
	76	static int coh901331_read_time(struct device dev, struct rtc_time tm)
	77	{
	78	struct coh901331_port *rtap = dev_get_drvdata(dev);
	79
	80	clk_enable(rtap->clk);
	81	/* Check if the time is valid */
	82	if (readl(rtap->virtbase + COH901331_VALID)) {
	83	rtc_time_to_tm(readl(rtap->virtbase + COH901331_CUR_TIME), tm);
	84	clk_disable(rtap->clk);
	85	return rtc_valid_tm(tm);
	86	}
	87	clk_disable(rtap->clk);
	88	return -EINVAL;
	89	}
	90
	91	static int coh901331_set_mmss(struct device *dev, unsigned long secs)
	92	{
	93	struct coh901331_port *rtap = dev_get_drvdata(dev);
	94
	95	clk_enable(rtap->clk);
	96	writel(secs, rtap->virtbase + COH901331_SET_TIME);
	97	clk_disable(rtap->clk);
	98
	99	return 0;
	100	}
	101
	102	static int coh901331_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	103	{
	104	struct coh901331_port *rtap = dev_get_drvdata(dev);
	105
	106	clk_enable(rtap->clk);
	107	rtc_time_to_tm(readl(rtap->virtbase + COH901331_ALARM), &alarm->time);
	108	alarm->pending = readl(rtap->virtbase + COH901331_IRQ_EVENT) & 1U;
	109	alarm->enabled = readl(rtap->virtbase + COH901331_IRQ_MASK) & 1U;
	110	clk_disable(rtap->clk);
	111
	112	return 0;
	113	}
	114
	115	static int coh901331_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	116	{
	117	struct coh901331_port *rtap = dev_get_drvdata(dev);
	118	unsigned long time;
	119
	120	rtc_tm_to_time(&alarm->time, &time);
	121	clk_enable(rtap->clk);
	122	writel(time, rtap->virtbase + COH901331_ALARM);
	123	writel(alarm->enabled, rtap->virtbase + COH901331_IRQ_MASK);
	124	clk_disable(rtap->clk);
	125
	126	return 0;
	127	}
	128
	129	static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled)
	130	{
	131	struct coh901331_port *rtap = dev_get_drvdata(dev);
	132
	133	clk_enable(rtap->clk);
134	if (enabled)
135	writel(1, rtap->virtbase + COH901331_IRQ_MASK);
136	else
137	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
138	clk_disable(rtap->clk);
378ce74b LW	139
378ce74b LW	140	return 0;
aa958f57 LW	141	}
	142
	143	static struct rtc_class_ops coh901331_ops = {
	144	.read_time = coh901331_read_time,
	145	.set_mmss = coh901331_set_mmss,
	146	.read_alarm = coh901331_read_alarm,
	147	.set_alarm = coh901331_set_alarm,
	148	.alarm_irq_enable = coh901331_alarm_irq_enable,
	149	};
	150
	151	static int __exit coh901331_remove(struct platform_device *pdev)
	152	{
3a02893f	153	struct coh901331_port *rtap = platform_get_drvdata(pdev);
aa958f57	154
7fcbf5fd	155	if (rtap)
8384dfeb	156	clk_unprepare(rtap->clk);
aa958f57 LW	157
	158	return 0;
	159	}
	160
	161
	162	static int __init coh901331_probe(struct platform_device *pdev)
	163	{
	164	int ret;
	165	struct coh901331_port *rtap;
	166	struct resource *res;
	167
36ac1d24 LW	168	rtap = devm_kzalloc(&pdev->dev,
36ac1d24 LW	169	sizeof(struct coh901331_port), GFP_KERNEL);
aa958f57 LW	170	if (!rtap)
	171	return -ENOMEM;
	172
	173	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
daaf90f0 JH	174	rtap->virtbase = devm_ioremap_resource(&pdev->dev, res);
	175	if (IS_ERR(rtap->virtbase))
	176	return PTR_ERR(rtap->virtbase);
aa958f57 LW	177
aa958f57 LW	178	rtap->irq = platform_get_irq(pdev, 0);
36ac1d24 LW	179	if (devm_request_irq(&pdev->dev, rtap->irq, coh901331_interrupt, 0,
	180	"RTC COH 901 331 Alarm", rtap))
	181	return -EIO;
aa958f57	182
3b759d7f	183	rtap->clk = devm_clk_get(&pdev->dev, NULL);
aa958f57 LW	184	if (IS_ERR(rtap->clk)) {
	185	ret = PTR_ERR(rtap->clk);
	186	dev_err(&pdev->dev, "could not get clock\n");
36ac1d24	187	return ret;
aa958f57 LW	188	}
	189
	190	/* We enable/disable the clock only to assure it works */
8384dfeb	191	ret = clk_prepare_enable(rtap->clk);
aa958f57 LW	192	if (ret) {
aa958f57 LW	193	dev_err(&pdev->dev, "could not enable clock\n");
3b759d7f	194	return ret;
aa958f57 LW	195	}
	196	clk_disable(rtap->clk);
	197
9cf3b5fa	198	platform_set_drvdata(pdev, rtap);
94b60dba JH	199	rtap->rtc = devm_rtc_device_register(&pdev->dev, "coh901331",
94b60dba JH	200	&coh901331_ops, THIS_MODULE);
aa958f57 LW	201	if (IS_ERR(rtap->rtc)) {
	202	ret = PTR_ERR(rtap->rtc);
	203	goto out_no_rtc;
	204	}
	205
aa958f57 LW	206	return 0;
	207
	208	out_no_rtc:
8384dfeb	209	clk_unprepare(rtap->clk);
aa958f57 LW	210	return ret;
	211	}
	212
62068e2c JH	213	#ifdef CONFIG_PM_SLEEP
62068e2c JH	214	static int coh901331_suspend(struct device *dev)
aa958f57	215	{
62068e2c	216	struct coh901331_port *rtap = dev_get_drvdata(dev);
aa958f57 LW	217
	218	/*
	219	* If this RTC alarm will be used for waking the system up,
	220	* don't disable it of course. Else we just disable the alarm
	221	* and await suspension.
	222	*/
62068e2c	223	if (device_may_wakeup(dev)) {
aa958f57 LW	224	enable_irq_wake(rtap->irq);
	225	} else {
	226	clk_enable(rtap->clk);
	227	rtap->irqmaskstore = readl(rtap->virtbase + COH901331_IRQ_MASK);
	228	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
	229	clk_disable(rtap->clk);
	230	}
8384dfeb	231	clk_unprepare(rtap->clk);
aa958f57 LW	232	return 0;
	233	}
	234
62068e2c	235	static int coh901331_resume(struct device *dev)
aa958f57	236	{
62068e2c	237	struct coh901331_port *rtap = dev_get_drvdata(dev);
aa958f57	238
8384dfeb	239	clk_prepare(rtap->clk);
62068e2c	240	if (device_may_wakeup(dev)) {
aa958f57	241	disable_irq_wake(rtap->irq);
5a98c04d	242	} else {
aa958f57 LW	243	clk_enable(rtap->clk);
	244	writel(rtap->irqmaskstore, rtap->virtbase + COH901331_IRQ_MASK);
	245	clk_disable(rtap->clk);
5a98c04d	246	}
aa958f57 LW	247	return 0;
aa958f57 LW	248	}
aa958f57 LW	249	#endif
aa958f57 LW	250
62068e2c JH	251	static SIMPLE_DEV_PM_OPS(coh901331_pm_ops, coh901331_suspend, coh901331_resume);
62068e2c JH	252
aa958f57 LW	253	static void coh901331_shutdown(struct platform_device *pdev)
aa958f57 LW	254	{
3a02893f	255	struct coh901331_port *rtap = platform_get_drvdata(pdev);
aa958f57 LW	256
	257	clk_enable(rtap->clk);
	258	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
828296de	259	clk_disable_unprepare(rtap->clk);
aa958f57 LW	260	}
aa958f57 LW	261
a16b6c63 LW	262	static const struct of_device_id coh901331_dt_match[] = {
	263	{ .compatible = "stericsson,coh901331" },
	264	{},
	265	};
73798d5c	266	MODULE_DEVICE_TABLE(of, coh901331_dt_match);
a16b6c63	267
aa958f57 LW	268	static struct platform_driver coh901331_driver = {
	269	.driver = {
	270	.name = "rtc-coh901331",
62068e2c	271	.pm = &coh901331_pm_ops,
a16b6c63	272	.of_match_table = coh901331_dt_match,
aa958f57 LW	273	},
aa958f57 LW	274	.remove = __exit_p(coh901331_remove),
aa958f57 LW	275	.shutdown = coh901331_shutdown,
	276	};
	277
4fdf7a9f	278	module_platform_driver_probe(coh901331_driver, coh901331_probe);
aa958f57 LW	279
	280	MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
	281	MODULE_DESCRIPTION("ST-Ericsson AB COH 901 331 RTC Driver");
	282	MODULE_LICENSE("GPL");