[linux.git] / drivers / rtc / rtc-ab3100.c

/*
 * Copyright (C) 2007-2009 ST-Ericsson AB
 * License terms: GNU General Public License (GPL) version 2
 * RTC clock driver for the AB3100 Analog Baseband Chip
 * Author: Linus Walleij <[email protected]>
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/mfd/abx500.h>

/* Clock rate in Hz */
#define AB3100_RTC_CLOCK_RATE	32768

/*
 * The AB3100 RTC registers. These are the same for
 * AB3000 and AB3100.
 * Control register:
 * Bit 0: RTC Monitor cleared=0, active=1, if you set it
 *        to 1 it remains active until RTC power is lost.
 * Bit 1: 32 kHz Oscillator, 0 = on, 1 = bypass
 * Bit 2: Alarm on, 0 = off, 1 = on
 * Bit 3: 32 kHz buffer disabling, 0 = enabled, 1 = disabled
 */
#define AB3100_RTC		0x53
/* default setting, buffer disabled, alarm on */
#define RTC_SETTING		0x30
/* Alarm when AL0-AL3 == TI0-TI3  */
#define AB3100_AL0		0x56
#define AB3100_AL1		0x57
#define AB3100_AL2		0x58
#define AB3100_AL3		0x59
/* This 48-bit register that counts up at 32768 Hz */
#define AB3100_TI0		0x5a
#define AB3100_TI1		0x5b
#define AB3100_TI2		0x5c
#define AB3100_TI3		0x5d
#define AB3100_TI4		0x5e
#define AB3100_TI5		0x5f

/*
 * RTC clock functions and device struct declaration
 */
static int ab3100_rtc_set_mmss(struct device *dev, unsigned long secs)
{
	u8 regs[] = {AB3100_TI0, AB3100_TI1, AB3100_TI2,
		     AB3100_TI3, AB3100_TI4, AB3100_TI5};
	unsigned char buf[6];
	u64 fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
	int err = 0;
	int i;

	buf[0] = (fat_time) & 0xFF;
	buf[1] = (fat_time >> 8) & 0xFF;
	buf[2] = (fat_time >> 16) & 0xFF;
	buf[3] = (fat_time >> 24) & 0xFF;
	buf[4] = (fat_time >> 32) & 0xFF;
	buf[5] = (fat_time >> 40) & 0xFF;

	for (i = 0; i < 6; i++) {
		err = abx500_set_register_interruptible(dev, 0,
							regs[i], buf[i]);
		if (err)
			return err;
	}

	/* Set the flag to mark that the clock is now set */
	return abx500_mask_and_set_register_interruptible(dev, 0,
							  AB3100_RTC,
							  0x01, 0x01);

}

static int ab3100_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned long time;
	u8 rtcval;
	int err;

	err = abx500_get_register_interruptible(dev, 0,
						AB3100_RTC, &rtcval);
	if (err)
		return err;

	if (!(rtcval & 0x01)) {
		dev_info(dev, "clock not set (lost power)");
		return -EINVAL;
	} else {
		u64 fat_time;
		u8 buf[6];

		/* Read out time registers */
		err = abx500_get_register_page_interruptible(dev, 0,
							     AB3100_TI0,
							     buf, 6);
		if (err != 0)
			return err;

		fat_time = ((u64) buf[5] << 40) | ((u64) buf[4] << 32) |
			((u64) buf[3] << 24) | ((u64) buf[2] << 16) |
			((u64) buf[1] << 8) | (u64) buf[0];
		time = (unsigned long) (fat_time /
					(u64) (AB3100_RTC_CLOCK_RATE * 2));
	}

	rtc_time_to_tm(time, tm);

	return rtc_valid_tm(tm);
}

static int ab3100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	unsigned long time;
	u64 fat_time;
	u8 buf[6];
	u8 rtcval;
	int err;

	/* Figure out if alarm is enabled or not */
	err = abx500_get_register_interruptible(dev, 0,
						AB3100_RTC, &rtcval);
	if (err)
		return err;
	if (rtcval & 0x04)
		alarm->enabled = 1;
	else
		alarm->enabled = 0;
	/* No idea how this could be represented */
	alarm->pending = 0;
	/* Read out alarm registers, only 4 bytes */
	err = abx500_get_register_page_interruptible(dev, 0,
						     AB3100_AL0, buf, 4);
	if (err)
		return err;
	fat_time = ((u64) buf[3] << 40) | ((u64) buf[2] << 32) |
		((u64) buf[1] << 24) | ((u64) buf[0] << 16);
	time = (unsigned long) (fat_time / (u64) (AB3100_RTC_CLOCK_RATE * 2));

	rtc_time_to_tm(time, &alarm->time);

	return rtc_valid_tm(&alarm->time);
}

static int ab3100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	u8 regs[] = {AB3100_AL0, AB3100_AL1, AB3100_AL2, AB3100_AL3};
	unsigned char buf[4];
	unsigned long secs;
	u64 fat_time;
	int err;
	int i;

	rtc_tm_to_time(&alarm->time, &secs);
	fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
	buf[0] = (fat_time >> 16) & 0xFF;
	buf[1] = (fat_time >> 24) & 0xFF;
	buf[2] = (fat_time >> 32) & 0xFF;
	buf[3] = (fat_time >> 40) & 0xFF;

	/* Set the alarm */
	for (i = 0; i < 4; i++) {
		err = abx500_set_register_interruptible(dev, 0,
							regs[i], buf[i]);
		if (err)
			return err;
	}
	/* Then enable the alarm */
	return abx500_mask_and_set_register_interruptible(dev, 0,
							  AB3100_RTC, (1 << 2),
							  alarm->enabled << 2);
}

static int ab3100_rtc_irq_enable(struct device *dev, unsigned int enabled)
{
	/*
	 * It's not possible to enable/disable the alarm IRQ for this RTC.
	 * It does not actually trigger any IRQ: instead its only function is
	 * to power up the system, if it wasn't on. This will manifest as
	 * a "power up cause" in the AB3100 power driver (battery charging etc)
	 * and need to be handled there instead.
	 */
	if (enabled)
		return abx500_mask_and_set_register_interruptible(dev, 0,
						    AB3100_RTC, (1 << 2),
						    1 << 2);
	else
		return abx500_mask_and_set_register_interruptible(dev, 0,
						    AB3100_RTC, (1 << 2),
						    0);
}

static const struct rtc_class_ops ab3100_rtc_ops = {
	.read_time	= ab3100_rtc_read_time,
	.set_mmss	= ab3100_rtc_set_mmss,
	.read_alarm	= ab3100_rtc_read_alarm,
	.set_alarm	= ab3100_rtc_set_alarm,
	.alarm_irq_enable = ab3100_rtc_irq_enable,
};

static int __init ab3100_rtc_probe(struct platform_device *pdev)
{
	int err;
	u8 regval;
	struct rtc_device *rtc;

	/* The first RTC register needs special treatment */
	err = abx500_get_register_interruptible(&pdev->dev, 0,
						AB3100_RTC, &regval);
	if (err) {
		dev_err(&pdev->dev, "unable to read RTC register\n");
		return -ENODEV;
	}

	if ((regval & 0xFE) != RTC_SETTING) {
		dev_warn(&pdev->dev, "not default value in RTC reg 0x%x\n",
			 regval);
	}

	if ((regval & 1) == 0) {
		/*
		 * Set bit to detect power loss.
		 * This bit remains until RTC power is lost.
		 */
		regval = 1 | RTC_SETTING;
		err = abx500_set_register_interruptible(&pdev->dev, 0,
							AB3100_RTC, regval);
		/* Ignore any error on this write */
	}

	rtc = rtc_device_register("ab3100-rtc", &pdev->dev, &ab3100_rtc_ops,
				  THIS_MODULE);
	if (IS_ERR(rtc)) {
		err = PTR_ERR(rtc);
		return err;
	}
	platform_set_drvdata(pdev, rtc);

	return 0;
}

static int __exit ab3100_rtc_remove(struct platform_device *pdev)
{
	struct rtc_device *rtc = platform_get_drvdata(pdev);

	rtc_device_unregister(rtc);
	platform_set_drvdata(pdev, NULL);
	return 0;
}

static struct platform_driver ab3100_rtc_driver = {
	.driver = {
		.name = "ab3100-rtc",
		.owner = THIS_MODULE,
	},
	.remove	 = __exit_p(ab3100_rtc_remove),
};

static int __init ab3100_rtc_init(void)
{
	return platform_driver_probe(&ab3100_rtc_driver,
				     ab3100_rtc_probe);
}

static void __exit ab3100_rtc_exit(void)
{
	platform_driver_unregister(&ab3100_rtc_driver);
}

module_init(ab3100_rtc_init);
module_exit(ab3100_rtc_exit);

MODULE_AUTHOR("Linus Walleij <[email protected]>");
MODULE_DESCRIPTION("AB3100 RTC Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
bd207cfb LW	1	/*
	2	* Copyright (C) 2007-2009 ST-Ericsson AB
	3	* License terms: GNU General Public License (GPL) version 2
	4	* RTC clock driver for the AB3100 Analog Baseband Chip
	5	* Author: Linus Walleij <[email protected]>
	6	*/
	7	#include <linux/module.h>
	8	#include <linux/kernel.h>
	9	#include <linux/init.h>
	10	#include <linux/platform_device.h>
	11	#include <linux/rtc.h>
812f9e9d	12	#include <linux/mfd/abx500.h>
bd207cfb LW	13
	14	/* Clock rate in Hz */
	15	#define AB3100_RTC_CLOCK_RATE 32768
	16
	17	/*
	18	* The AB3100 RTC registers. These are the same for
	19	* AB3000 and AB3100.
	20	* Control register:
	21	* Bit 0: RTC Monitor cleared=0, active=1, if you set it
	22	* to 1 it remains active until RTC power is lost.
	23	* Bit 1: 32 kHz Oscillator, 0 = on, 1 = bypass
	24	* Bit 2: Alarm on, 0 = off, 1 = on
	25	* Bit 3: 32 kHz buffer disabling, 0 = enabled, 1 = disabled
	26	*/
	27	#define AB3100_RTC 0x53
	28	/* default setting, buffer disabled, alarm on */
	29	#define RTC_SETTING 0x30
	30	/* Alarm when AL0-AL3 == TI0-TI3 */
	31	#define AB3100_AL0 0x56
	32	#define AB3100_AL1 0x57
	33	#define AB3100_AL2 0x58
	34	#define AB3100_AL3 0x59
	35	/* This 48-bit register that counts up at 32768 Hz */
	36	#define AB3100_TI0 0x5a
	37	#define AB3100_TI1 0x5b
	38	#define AB3100_TI2 0x5c
	39	#define AB3100_TI3 0x5d
	40	#define AB3100_TI4 0x5e
	41	#define AB3100_TI5 0x5f
	42
	43	/*
	44	* RTC clock functions and device struct declaration
	45	*/
	46	static int ab3100_rtc_set_mmss(struct device *dev, unsigned long secs)
	47	{
bd207cfb LW	48	u8 regs[] = {AB3100_TI0, AB3100_TI1, AB3100_TI2,
	49	AB3100_TI3, AB3100_TI4, AB3100_TI5};
	50	unsigned char buf[6];
	51	u64 fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
	52	int err = 0;
	53	int i;
	54
	55	buf[0] = (fat_time) & 0xFF;
	56	buf[1] = (fat_time >> 8) & 0xFF;
	57	buf[2] = (fat_time >> 16) & 0xFF;
	58	buf[3] = (fat_time >> 24) & 0xFF;
	59	buf[4] = (fat_time >> 32) & 0xFF;
	60	buf[5] = (fat_time >> 40) & 0xFF;
	61
	62	for (i = 0; i < 6; i++) {
fa661258	63	err = abx500_set_register_interruptible(dev, 0,
bd207cfb LW	64	regs[i], buf[i]);
	65	if (err)
	66	return err;
	67	}
	68
	69	/* Set the flag to mark that the clock is now set */
fa661258	70	return abx500_mask_and_set_register_interruptible(dev, 0,
bd207cfb	71	AB3100_RTC,
fa661258	72	0x01, 0x01);
bd207cfb LW	73
	74	}
	75
	76	static int ab3100_rtc_read_time(struct device dev, struct rtc_time tm)
	77	{
bd207cfb LW	78	unsigned long time;
	79	u8 rtcval;
	80	int err;
	81
fa661258	82	err = abx500_get_register_interruptible(dev, 0,
bd207cfb LW	83	AB3100_RTC, &rtcval);
	84	if (err)
	85	return err;
	86
	87	if (!(rtcval & 0x01)) {
	88	dev_info(dev, "clock not set (lost power)");
	89	return -EINVAL;
	90	} else {
	91	u64 fat_time;
	92	u8 buf[6];
	93
	94	/* Read out time registers */
fa661258	95	err = abx500_get_register_page_interruptible(dev, 0,
bd207cfb LW	96	AB3100_TI0,
	97	buf, 6);
	98	if (err != 0)
	99	return err;
	100
	101	fat_time = ((u64) buf[5] << 40) \| ((u64) buf[4] << 32) \|
	102	((u64) buf[3] << 24) \| ((u64) buf[2] << 16) \|
	103	((u64) buf[1] << 8) \| (u64) buf[0];
	104	time = (unsigned long) (fat_time /
	105	(u64) (AB3100_RTC_CLOCK_RATE * 2));
	106	}
	107
	108	rtc_time_to_tm(time, tm);
	109
	110	return rtc_valid_tm(tm);
	111	}
	112
	113	static int ab3100_rtc_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	114	{
bd207cfb LW	115	unsigned long time;
	116	u64 fat_time;
	117	u8 buf[6];
	118	u8 rtcval;
	119	int err;
	120
	121	/* Figure out if alarm is enabled or not */
fa661258	122	err = abx500_get_register_interruptible(dev, 0,
bd207cfb LW	123	AB3100_RTC, &rtcval);
	124	if (err)
	125	return err;
	126	if (rtcval & 0x04)
	127	alarm->enabled = 1;
	128	else
	129	alarm->enabled = 0;
	130	/* No idea how this could be represented */
	131	alarm->pending = 0;
	132	/* Read out alarm registers, only 4 bytes */
fa661258	133	err = abx500_get_register_page_interruptible(dev, 0,
bd207cfb LW	134	AB3100_AL0, buf, 4);
	135	if (err)
	136	return err;
	137	fat_time = ((u64) buf[3] << 40) \| ((u64) buf[2] << 32) \|
	138	((u64) buf[1] << 24) \| ((u64) buf[0] << 16);
	139	time = (unsigned long) (fat_time / (u64) (AB3100_RTC_CLOCK_RATE * 2));
	140
	141	rtc_time_to_tm(time, &alarm->time);
	142
	143	return rtc_valid_tm(&alarm->time);
	144	}
	145
	146	static int ab3100_rtc_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	147	{
bd207cfb LW	148	u8 regs[] = {AB3100_AL0, AB3100_AL1, AB3100_AL2, AB3100_AL3};
	149	unsigned char buf[4];
	150	unsigned long secs;
	151	u64 fat_time;
	152	int err;
	153	int i;
	154
	155	rtc_tm_to_time(&alarm->time, &secs);
	156	fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
	157	buf[0] = (fat_time >> 16) & 0xFF;
	158	buf[1] = (fat_time >> 24) & 0xFF;
	159	buf[2] = (fat_time >> 32) & 0xFF;
	160	buf[3] = (fat_time >> 40) & 0xFF;
	161
	162	/* Set the alarm */
	163	for (i = 0; i < 4; i++) {
fa661258	164	err = abx500_set_register_interruptible(dev, 0,
bd207cfb LW	165	regs[i], buf[i]);
	166	if (err)
	167	return err;
	168	}
	169	/* Then enable the alarm */
fa661258 MW	170	return abx500_mask_and_set_register_interruptible(dev, 0,
fa661258 MW	171	AB3100_RTC, (1 << 2),
bd207cfb LW	172	alarm->enabled << 2);
	173	}
	174
	175	static int ab3100_rtc_irq_enable(struct device *dev, unsigned int enabled)
	176	{
bd207cfb LW	177	/*
	178	* It's not possible to enable/disable the alarm IRQ for this RTC.
	179	* It does not actually trigger any IRQ: instead its only function is
	180	* to power up the system, if it wasn't on. This will manifest as
	181	* a "power up cause" in the AB3100 power driver (battery charging etc)
	182	* and need to be handled there instead.
	183	*/
	184	if (enabled)
fa661258 MW	185	return abx500_mask_and_set_register_interruptible(dev, 0,
fa661258 MW	186	AB3100_RTC, (1 << 2),
bd207cfb LW	187	1 << 2);
bd207cfb LW	188	else
fa661258 MW	189	return abx500_mask_and_set_register_interruptible(dev, 0,
fa661258 MW	190	AB3100_RTC, (1 << 2),
bd207cfb LW	191	0);
	192	}
	193
	194	static const struct rtc_class_ops ab3100_rtc_ops = {
	195	.read_time = ab3100_rtc_read_time,
	196	.set_mmss = ab3100_rtc_set_mmss,
	197	.read_alarm = ab3100_rtc_read_alarm,
	198	.set_alarm = ab3100_rtc_set_alarm,
	199	.alarm_irq_enable = ab3100_rtc_irq_enable,
	200	};
	201
	202	static int __init ab3100_rtc_probe(struct platform_device *pdev)
	203	{
	204	int err;
	205	u8 regval;
	206	struct rtc_device *rtc;
bd207cfb LW	207
bd207cfb LW	208	/* The first RTC register needs special treatment */
fa661258	209	err = abx500_get_register_interruptible(&pdev->dev, 0,
bd207cfb LW	210	AB3100_RTC, &regval);
	211	if (err) {
	212	dev_err(&pdev->dev, "unable to read RTC register\n");
	213	return -ENODEV;
	214	}
	215
	216	if ((regval & 0xFE) != RTC_SETTING) {
	217	dev_warn(&pdev->dev, "not default value in RTC reg 0x%x\n",
	218	regval);
	219	}
	220
	221	if ((regval & 1) == 0) {
	222	/*
	223	* Set bit to detect power loss.
	224	* This bit remains until RTC power is lost.
	225	*/
	226	regval = 1 \| RTC_SETTING;
fa661258	227	err = abx500_set_register_interruptible(&pdev->dev, 0,
bd207cfb LW	228	AB3100_RTC, regval);
	229	/* Ignore any error on this write */
	230	}
	231
	232	rtc = rtc_device_register("ab3100-rtc", &pdev->dev, &ab3100_rtc_ops,
	233	THIS_MODULE);
	234	if (IS_ERR(rtc)) {
	235	err = PTR_ERR(rtc);
	236	return err;
	237	}
eba93fcc	238	platform_set_drvdata(pdev, rtc);
bd207cfb LW	239
	240	return 0;
	241	}
	242
	243	static int __exit ab3100_rtc_remove(struct platform_device *pdev)
	244	{
	245	struct rtc_device *rtc = platform_get_drvdata(pdev);
	246
	247	rtc_device_unregister(rtc);
eba93fcc	248	platform_set_drvdata(pdev, NULL);
bd207cfb LW	249	return 0;
	250	}
	251
	252	static struct platform_driver ab3100_rtc_driver = {
	253	.driver = {
	254	.name = "ab3100-rtc",
	255	.owner = THIS_MODULE,
	256	},
	257	.remove = __exit_p(ab3100_rtc_remove),
	258	};
	259
	260	static int __init ab3100_rtc_init(void)
	261	{
	262	return platform_driver_probe(&ab3100_rtc_driver,
	263	ab3100_rtc_probe);
	264	}
	265
	266	static void __exit ab3100_rtc_exit(void)
	267	{
	268	platform_driver_unregister(&ab3100_rtc_driver);
	269	}
	270
	271	module_init(ab3100_rtc_init);
	272	module_exit(ab3100_rtc_exit);
	273
	274	MODULE_AUTHOR("Linus Walleij <[email protected]>");
	275	MODULE_DESCRIPTION("AB3100 RTC Driver");
	276	MODULE_LICENSE("GPL");