[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_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);
	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 = 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" },
	{},
};

static struct platform_driver coh901331_driver = {
	.driver = {
		.name = "rtc-coh901331",
		.owner = THIS_MODULE,
		.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;
	46	u32 phybase;
	47	u32 physize;
	48	void __iomem *virtbase;
	49	int irq;
62068e2c	50	#ifdef CONFIG_PM_SLEEP
aa958f57 LW	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	{
3a02893f	155	struct coh901331_port *rtap = platform_get_drvdata(pdev);
aa958f57	156
7fcbf5fd	157	if (rtap)
8384dfeb	158	clk_unprepare(rtap->clk);
aa958f57 LW	159
	160	return 0;
	161	}
	162
	163
	164	static int __init coh901331_probe(struct platform_device *pdev)
	165	{
	166	int ret;
	167	struct coh901331_port *rtap;
	168	struct resource *res;
	169
36ac1d24 LW	170	rtap = devm_kzalloc(&pdev->dev,
36ac1d24 LW	171	sizeof(struct coh901331_port), GFP_KERNEL);
aa958f57 LW	172	if (!rtap)
	173	return -ENOMEM;
	174
	175	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
36ac1d24 LW	176	if (!res)
	177	return -ENOENT;
	178
aa958f57 LW	179	rtap->phybase = res->start;
	180	rtap->physize = resource_size(res);
	181
36ac1d24 LW	182	if (devm_request_mem_region(&pdev->dev, rtap->phybase, rtap->physize,
	183	"rtc-coh901331") == NULL)
	184	return -EBUSY;
aa958f57	185
36ac1d24 LW	186	rtap->virtbase = devm_ioremap(&pdev->dev, rtap->phybase, rtap->physize);
	187	if (!rtap->virtbase)
	188	return -ENOMEM;
aa958f57 LW	189
aa958f57 LW	190	rtap->irq = platform_get_irq(pdev, 0);
36ac1d24 LW	191	if (devm_request_irq(&pdev->dev, rtap->irq, coh901331_interrupt, 0,
	192	"RTC COH 901 331 Alarm", rtap))
	193	return -EIO;
aa958f57	194
3b759d7f	195	rtap->clk = devm_clk_get(&pdev->dev, NULL);
aa958f57 LW	196	if (IS_ERR(rtap->clk)) {
	197	ret = PTR_ERR(rtap->clk);
	198	dev_err(&pdev->dev, "could not get clock\n");
36ac1d24	199	return ret;
aa958f57 LW	200	}
	201
	202	/* We enable/disable the clock only to assure it works */
8384dfeb	203	ret = clk_prepare_enable(rtap->clk);
aa958f57 LW	204	if (ret) {
aa958f57 LW	205	dev_err(&pdev->dev, "could not enable clock\n");
3b759d7f	206	return ret;
aa958f57 LW	207	}
	208	clk_disable(rtap->clk);
	209
9cf3b5fa	210	platform_set_drvdata(pdev, rtap);
94b60dba JH	211	rtap->rtc = devm_rtc_device_register(&pdev->dev, "coh901331",
94b60dba JH	212	&coh901331_ops, THIS_MODULE);
aa958f57 LW	213	if (IS_ERR(rtap->rtc)) {
	214	ret = PTR_ERR(rtap->rtc);
	215	goto out_no_rtc;
	216	}
	217
aa958f57 LW	218	return 0;
	219
	220	out_no_rtc:
8384dfeb	221	clk_unprepare(rtap->clk);
aa958f57 LW	222	return ret;
	223	}
	224
62068e2c JH	225	#ifdef CONFIG_PM_SLEEP
62068e2c JH	226	static int coh901331_suspend(struct device *dev)
aa958f57	227	{
62068e2c	228	struct coh901331_port *rtap = dev_get_drvdata(dev);
aa958f57 LW	229
	230	/*
	231	* If this RTC alarm will be used for waking the system up,
	232	* don't disable it of course. Else we just disable the alarm
	233	* and await suspension.
	234	*/
62068e2c	235	if (device_may_wakeup(dev)) {
aa958f57 LW	236	enable_irq_wake(rtap->irq);
	237	} else {
	238	clk_enable(rtap->clk);
	239	rtap->irqmaskstore = readl(rtap->virtbase + COH901331_IRQ_MASK);
	240	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
	241	clk_disable(rtap->clk);
	242	}
8384dfeb	243	clk_unprepare(rtap->clk);
aa958f57 LW	244	return 0;
	245	}
	246
62068e2c	247	static int coh901331_resume(struct device *dev)
aa958f57	248	{
62068e2c	249	struct coh901331_port *rtap = dev_get_drvdata(dev);
aa958f57	250
8384dfeb	251	clk_prepare(rtap->clk);
62068e2c	252	if (device_may_wakeup(dev)) {
aa958f57	253	disable_irq_wake(rtap->irq);
5a98c04d	254	} else {
aa958f57 LW	255	clk_enable(rtap->clk);
	256	writel(rtap->irqmaskstore, rtap->virtbase + COH901331_IRQ_MASK);
	257	clk_disable(rtap->clk);
5a98c04d	258	}
aa958f57 LW	259	return 0;
aa958f57 LW	260	}
aa958f57 LW	261	#endif
aa958f57 LW	262
62068e2c JH	263	static SIMPLE_DEV_PM_OPS(coh901331_pm_ops, coh901331_suspend, coh901331_resume);
62068e2c JH	264
aa958f57 LW	265	static void coh901331_shutdown(struct platform_device *pdev)
aa958f57 LW	266	{
3a02893f	267	struct coh901331_port *rtap = platform_get_drvdata(pdev);
aa958f57 LW	268
	269	clk_enable(rtap->clk);
	270	writel(0, rtap->virtbase + COH901331_IRQ_MASK);
828296de	271	clk_disable_unprepare(rtap->clk);
aa958f57 LW	272	}
aa958f57 LW	273
a16b6c63 LW	274	static const struct of_device_id coh901331_dt_match[] = {
	275	{ .compatible = "stericsson,coh901331" },
	276	{},
	277	};
	278
aa958f57 LW	279	static struct platform_driver coh901331_driver = {
	280	.driver = {
	281	.name = "rtc-coh901331",
	282	.owner = THIS_MODULE,
62068e2c	283	.pm = &coh901331_pm_ops,
a16b6c63	284	.of_match_table = coh901331_dt_match,
aa958f57 LW	285	},
aa958f57 LW	286	.remove = __exit_p(coh901331_remove),
aa958f57 LW	287	.shutdown = coh901331_shutdown,
	288	};
	289
4fdf7a9f	290	module_platform_driver_probe(coh901331_driver, coh901331_probe);
aa958f57 LW	291
	292	MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
	293	MODULE_DESCRIPTION("ST-Ericsson AB COH 901 331 RTC Driver");
	294	MODULE_LICENSE("GPL");