[deliverable/linux.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;
	u32 phybase;
	u32 physize;
	void __iomem *virtbase;
	int irq;
#ifdef CONFIG_PM
	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 = dev_get_drvdata(&pdev->dev);

	if (rtap) {
		rtc_device_unregister(rtap->rtc);
		clk_unprepare(rtap->clk);
		clk_put(rtap->clk);
		platform_set_drvdata(pdev, NULL);
	}

	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);
	if (!res)
		return -ENOENT;

	rtap->phybase = res->start;
	rtap->physize = resource_size(res);

	if (devm_request_mem_region(&pdev->dev, rtap->phybase, rtap->physize,
				    "rtc-coh901331") == NULL)
		return -EBUSY;

	rtap->virtbase = devm_ioremap(&pdev->dev, rtap->phybase, rtap->physize);
	if (!rtap->virtbase)
		return -ENOMEM;

	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 = 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");
		goto out_no_clk_prepenable;
	}
	clk_disable(rtap->clk);

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

	return 0;

 out_no_rtc:
	platform_set_drvdata(pdev, NULL);
	clk_unprepare(rtap->clk);
 out_no_clk_prepenable:
	clk_put(rtap->clk);
	return ret;
}

#ifdef CONFIG_PM
static int coh901331_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct coh901331_port *rtap = dev_get_drvdata(&pdev->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(&pdev->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 platform_device *pdev)
{
	struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);

	clk_prepare(rtap->clk);
	if (device_may_wakeup(&pdev->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;
}
#else
#define coh901331_suspend NULL
#define coh901331_resume NULL
#endif

static void coh901331_shutdown(struct platform_device *pdev)
{
	struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);

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

static struct platform_driver coh901331_driver = {
	.driver = {
		.name = "rtc-coh901331",
		.owner = THIS_MODULE,
	},
	.remove = __exit_p(coh901331_remove),
	.suspend = coh901331_suspend,
	.resume = coh901331_resume,
	.shutdown = coh901331_shutdown,
};

static int __init coh901331_init(void)
{
	return platform_driver_probe(&coh901331_driver, coh901331_probe);
}

static void __exit coh901331_exit(void)
{
	platform_driver_unregister(&coh901331_driver);
}

module_init(coh901331_init);
module_exit(coh901331_exit);

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;
	46	u32 phybase;
	47	u32 physize;
	48	void __iomem *virtbase;
	49	int irq;
	50	#ifdef CONFIG_PM
	51	u32 irqmaskstore;
	52	#endif
	53	};
	54
	55	static irqreturn_t coh901331_interrupt(int irq, void *data)
	56	{
	57	struct coh901331_port *rtap = data;
	58
	59	clk_enable(rtap->clk);
	60	/* Ack IRQ */
	61	writel(1, rtap->virtbase + COH901331_IRQ_EVENT);
378ce74b LW	62	/*
	63	* Disable the interrupt. This is necessary because
	64	* the RTC lives on a lower-clocked line and will
	65	* not release the IRQ line until after a few (slower)
	66	* clock cycles. The interrupt will be re-enabled when
	67	* a new alarm is set anyway.
	68	*/
	69	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
aa958f57	70	clk_disable(rtap->clk);
378ce74b	71
aa958f57 LW	72	/* Set alarm flag */
	73	rtc_update_irq(rtap->rtc, 1, RTC_AF);
	74
	75	return IRQ_HANDLED;
	76	}
	77
	78	static int coh901331_read_time(struct device dev, struct rtc_time tm)
	79	{
	80	struct coh901331_port *rtap = dev_get_drvdata(dev);
	81
	82	clk_enable(rtap->clk);
	83	/* Check if the time is valid */
	84	if (readl(rtap->virtbase + COH901331_VALID)) {
	85	rtc_time_to_tm(readl(rtap->virtbase + COH901331_CUR_TIME), tm);
	86	clk_disable(rtap->clk);
	87	return rtc_valid_tm(tm);
	88	}
	89	clk_disable(rtap->clk);
	90	return -EINVAL;
	91	}
	92
	93	static int coh901331_set_mmss(struct device *dev, unsigned long secs)
	94	{
	95	struct coh901331_port *rtap = dev_get_drvdata(dev);
	96
	97	clk_enable(rtap->clk);
	98	writel(secs, rtap->virtbase + COH901331_SET_TIME);
	99	clk_disable(rtap->clk);
	100
	101	return 0;
	102	}
	103
	104	static int coh901331_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	105	{
	106	struct coh901331_port *rtap = dev_get_drvdata(dev);
	107
	108	clk_enable(rtap->clk);
	109	rtc_time_to_tm(readl(rtap->virtbase + COH901331_ALARM), &alarm->time);
	110	alarm->pending = readl(rtap->virtbase + COH901331_IRQ_EVENT) & 1U;
	111	alarm->enabled = readl(rtap->virtbase + COH901331_IRQ_MASK) & 1U;
	112	clk_disable(rtap->clk);
	113
	114	return 0;
	115	}
	116
	117	static int coh901331_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	118	{
	119	struct coh901331_port *rtap = dev_get_drvdata(dev);
	120	unsigned long time;
	121
	122	rtc_tm_to_time(&alarm->time, &time);
	123	clk_enable(rtap->clk);
	124	writel(time, rtap->virtbase + COH901331_ALARM);
	125	writel(alarm->enabled, rtap->virtbase + COH901331_IRQ_MASK);
	126	clk_disable(rtap->clk);
	127
	128	return 0;
	129	}
	130
	131	static int coh901331_alarm_irq_enable(struct device *dev, unsigned int enabled)
	132	{
	133	struct coh901331_port *rtap = dev_get_drvdata(dev);
	134
	135	clk_enable(rtap->clk);
136	if (enabled)
137	writel(1, rtap->virtbase + COH901331_IRQ_MASK);
138	else
139	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
140	clk_disable(rtap->clk);
378ce74b LW	141
378ce74b LW	142	return 0;
aa958f57 LW	143	}
	144
	145	static struct rtc_class_ops coh901331_ops = {
	146	.read_time = coh901331_read_time,
	147	.set_mmss = coh901331_set_mmss,
	148	.read_alarm = coh901331_read_alarm,
	149	.set_alarm = coh901331_set_alarm,
	150	.alarm_irq_enable = coh901331_alarm_irq_enable,
	151	};
	152
	153	static int __exit coh901331_remove(struct platform_device *pdev)
	154	{
	155	struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
	156
	157	if (rtap) {
aa958f57	158	rtc_device_unregister(rtap->rtc);
8384dfeb	159	clk_unprepare(rtap->clk);
aa958f57	160	clk_put(rtap->clk);
aa958f57	161	platform_set_drvdata(pdev, NULL);
aa958f57 LW	162	}
	163
	164	return 0;
	165	}
	166
	167
	168	static int __init coh901331_probe(struct platform_device *pdev)
	169	{
	170	int ret;
	171	struct coh901331_port *rtap;
	172	struct resource *res;
	173
36ac1d24 LW	174	rtap = devm_kzalloc(&pdev->dev,
36ac1d24 LW	175	sizeof(struct coh901331_port), GFP_KERNEL);
aa958f57 LW	176	if (!rtap)
	177	return -ENOMEM;
	178
	179	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
36ac1d24 LW	180	if (!res)
	181	return -ENOENT;
	182
aa958f57 LW	183	rtap->phybase = res->start;
	184	rtap->physize = resource_size(res);
	185
36ac1d24 LW	186	if (devm_request_mem_region(&pdev->dev, rtap->phybase, rtap->physize,
	187	"rtc-coh901331") == NULL)
	188	return -EBUSY;
aa958f57	189
36ac1d24 LW	190	rtap->virtbase = devm_ioremap(&pdev->dev, rtap->phybase, rtap->physize);
	191	if (!rtap->virtbase)
	192	return -ENOMEM;
aa958f57 LW	193
aa958f57 LW	194	rtap->irq = platform_get_irq(pdev, 0);
36ac1d24 LW	195	if (devm_request_irq(&pdev->dev, rtap->irq, coh901331_interrupt, 0,
	196	"RTC COH 901 331 Alarm", rtap))
	197	return -EIO;
aa958f57 LW	198
	199	rtap->clk = clk_get(&pdev->dev, NULL);
	200	if (IS_ERR(rtap->clk)) {
	201	ret = PTR_ERR(rtap->clk);
	202	dev_err(&pdev->dev, "could not get clock\n");
36ac1d24	203	return ret;
aa958f57 LW	204	}
	205
	206	/* We enable/disable the clock only to assure it works */
8384dfeb	207	ret = clk_prepare_enable(rtap->clk);
aa958f57 LW	208	if (ret) {
aa958f57 LW	209	dev_err(&pdev->dev, "could not enable clock\n");
8384dfeb	210	goto out_no_clk_prepenable;
aa958f57 LW	211	}
	212	clk_disable(rtap->clk);
	213
9cf3b5fa	214	platform_set_drvdata(pdev, rtap);
aa958f57 LW	215	rtap->rtc = rtc_device_register("coh901331", &pdev->dev, &coh901331_ops,
	216	THIS_MODULE);
	217	if (IS_ERR(rtap->rtc)) {
	218	ret = PTR_ERR(rtap->rtc);
	219	goto out_no_rtc;
	220	}
	221
aa958f57 LW	222	return 0;
	223
	224	out_no_rtc:
9cf3b5fa	225	platform_set_drvdata(pdev, NULL);
8384dfeb LW	226	clk_unprepare(rtap->clk);
8384dfeb LW	227	out_no_clk_prepenable:
aa958f57	228	clk_put(rtap->clk);
aa958f57 LW	229	return ret;
	230	}
	231
	232	#ifdef CONFIG_PM
	233	static int coh901331_suspend(struct platform_device *pdev, pm_message_t state)
	234	{
	235	struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
	236
	237	/*
	238	* If this RTC alarm will be used for waking the system up,
	239	* don't disable it of course. Else we just disable the alarm
	240	* and await suspension.
	241	*/
	242	if (device_may_wakeup(&pdev->dev)) {
	243	enable_irq_wake(rtap->irq);
	244	} else {
	245	clk_enable(rtap->clk);
	246	rtap->irqmaskstore = readl(rtap->virtbase + COH901331_IRQ_MASK);
	247	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
	248	clk_disable(rtap->clk);
	249	}
8384dfeb	250	clk_unprepare(rtap->clk);
aa958f57 LW	251	return 0;
	252	}
	253
	254	static int coh901331_resume(struct platform_device *pdev)
	255	{
	256	struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
	257
8384dfeb	258	clk_prepare(rtap->clk);
5a98c04d	259	if (device_may_wakeup(&pdev->dev)) {
aa958f57	260	disable_irq_wake(rtap->irq);
5a98c04d	261	} else {
aa958f57 LW	262	clk_enable(rtap->clk);
	263	writel(rtap->irqmaskstore, rtap->virtbase + COH901331_IRQ_MASK);
	264	clk_disable(rtap->clk);
5a98c04d	265	}
aa958f57 LW	266	return 0;
	267	}
	268	#else
	269	#define coh901331_suspend NULL
	270	#define coh901331_resume NULL
	271	#endif
	272
	273	static void coh901331_shutdown(struct platform_device *pdev)
	274	{
	275	struct coh901331_port *rtap = dev_get_drvdata(&pdev->dev);
	276
	277	clk_enable(rtap->clk);
	278	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
	279	clk_disable(rtap->clk);
8384dfeb	280	clk_unprepare(rtap->clk);
aa958f57 LW	281	}
	282
	283	static struct platform_driver coh901331_driver = {
	284	.driver = {
	285	.name = "rtc-coh901331",
	286	.owner = THIS_MODULE,
	287	},
	288	.remove = __exit_p(coh901331_remove),
	289	.suspend = coh901331_suspend,
	290	.resume = coh901331_resume,
	291	.shutdown = coh901331_shutdown,
	292	};
	293
	294	static int __init coh901331_init(void)
	295	{
	296	return platform_driver_probe(&coh901331_driver, coh901331_probe);
	297	}
	298
	299	static void __exit coh901331_exit(void)
	300	{
	301	platform_driver_unregister(&coh901331_driver);
	302	}
	303
	304	module_init(coh901331_init);
	305	module_exit(coh901331_exit);
	306
	307	MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
	308	MODULE_DESCRIPTION("ST-Ericsson AB COH 901 331 RTC Driver");
	309	MODULE_LICENSE("GPL");