[mirror_ubuntu-artful-kernel.git] / drivers / rtc / rtc-ds1216.c

/*
 * Dallas DS1216 RTC driver
 *
 * Copyright (c) 2007 Thomas Bogendoerfer
 *
 */

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/bcd.h>
#include <linux/slab.h>

#define DRV_VERSION "0.2"

struct ds1216_regs {
	u8 tsec;
	u8 sec;
	u8 min;
	u8 hour;
	u8 wday;
	u8 mday;
	u8 month;
	u8 year;
};

#define DS1216_HOUR_1224	(1 << 7)
#define DS1216_HOUR_AMPM	(1 << 5)

struct ds1216_priv {
	struct rtc_device *rtc;
	void __iomem *ioaddr;
	size_t size;
	unsigned long baseaddr;
};

static const u8 magic[] = {
	0xc5, 0x3a, 0xa3, 0x5c, 0xc5, 0x3a, 0xa3, 0x5c
};

/*
 * Read the 64 bit we'd like to have - It a series
 * of 64 bits showing up in the LSB of the base register.
 *
 */
static void ds1216_read(u8 __iomem *ioaddr, u8 *buf)
{
	unsigned char c;
	int i, j;

	for (i = 0; i < 8; i++) {
		c = 0;
		for (j = 0; j < 8; j++)
			c |= (readb(ioaddr) & 0x1) << j;
		buf[i] = c;
	}
}

static void ds1216_write(u8 __iomem *ioaddr, const u8 *buf)
{
	unsigned char c;
	int i, j;

	for (i = 0; i < 8; i++) {
		c = buf[i];
		for (j = 0; j < 8; j++) {
			writeb(c, ioaddr);
			c = c >> 1;
		}
	}
}

static void ds1216_switch_ds_to_clock(u8 __iomem *ioaddr)
{
	/* Reset magic pointer */
	readb(ioaddr);
	/* Write 64 bit magic to DS1216 */
	ds1216_write(ioaddr, magic);
}

static int ds1216_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct ds1216_priv *priv = platform_get_drvdata(pdev);
	struct ds1216_regs regs;

	ds1216_switch_ds_to_clock(priv->ioaddr);
	ds1216_read(priv->ioaddr, (u8 *)&regs);

	tm->tm_sec = bcd2bin(regs.sec);
	tm->tm_min = bcd2bin(regs.min);
	if (regs.hour & DS1216_HOUR_1224) {
		/* AM/PM mode */
		tm->tm_hour = bcd2bin(regs.hour & 0x1f);
		if (regs.hour & DS1216_HOUR_AMPM)
			tm->tm_hour += 12;
	} else
		tm->tm_hour = bcd2bin(regs.hour & 0x3f);
	tm->tm_wday = (regs.wday & 7) - 1;
	tm->tm_mday = bcd2bin(regs.mday & 0x3f);
	tm->tm_mon = bcd2bin(regs.month & 0x1f);
	tm->tm_year = bcd2bin(regs.year);
	if (tm->tm_year < 70)
		tm->tm_year += 100;

	return rtc_valid_tm(tm);
}

static int ds1216_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct ds1216_priv *priv = platform_get_drvdata(pdev);
	struct ds1216_regs regs;

	ds1216_switch_ds_to_clock(priv->ioaddr);
	ds1216_read(priv->ioaddr, (u8 *)&regs);

	regs.tsec = 0; /* clear 0.1 and 0.01 seconds */
	regs.sec = bin2bcd(tm->tm_sec);
	regs.min = bin2bcd(tm->tm_min);
	regs.hour &= DS1216_HOUR_1224;
	if (regs.hour && tm->tm_hour > 12) {
		regs.hour |= DS1216_HOUR_AMPM;
		tm->tm_hour -= 12;
	}
	regs.hour |= bin2bcd(tm->tm_hour);
	regs.wday &= ~7;
	regs.wday |= tm->tm_wday;
	regs.mday = bin2bcd(tm->tm_mday);
	regs.month = bin2bcd(tm->tm_mon);
	regs.year = bin2bcd(tm->tm_year % 100);

	ds1216_switch_ds_to_clock(priv->ioaddr);
	ds1216_write(priv->ioaddr, (u8 *)&regs);
	return 0;
}

static const struct rtc_class_ops ds1216_rtc_ops = {
	.read_time	= ds1216_rtc_read_time,
	.set_time	= ds1216_rtc_set_time,
};

static int __init ds1216_rtc_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct ds1216_priv *priv;
	int ret = 0;
	u8 dummy[8];

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;
	priv = kzalloc(sizeof *priv, GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	platform_set_drvdata(pdev, priv);

	priv->size = resource_size(res);
	if (!request_mem_region(res->start, priv->size, pdev->name)) {
		ret = -EBUSY;
		goto out;
	}
	priv->baseaddr = res->start;
	priv->ioaddr = ioremap(priv->baseaddr, priv->size);
	if (!priv->ioaddr) {
		ret = -ENOMEM;
		goto out;
	}
	priv->rtc = rtc_device_register("ds1216", &pdev->dev,
				  &ds1216_rtc_ops, THIS_MODULE);
	if (IS_ERR(priv->rtc)) {
		ret = PTR_ERR(priv->rtc);
		goto out;
	}

	/* dummy read to get clock into a known state */
	ds1216_read(priv->ioaddr, dummy);
	return 0;

out:
	if (priv->ioaddr)
		iounmap(priv->ioaddr);
	if (priv->baseaddr)
		release_mem_region(priv->baseaddr, priv->size);
	kfree(priv);
	return ret;
}

static int __exit ds1216_rtc_remove(struct platform_device *pdev)
{
	struct ds1216_priv *priv = platform_get_drvdata(pdev);

	rtc_device_unregister(priv->rtc);
	iounmap(priv->ioaddr);
	release_mem_region(priv->baseaddr, priv->size);
	kfree(priv);
	return 0;
}

static struct platform_driver ds1216_rtc_platform_driver = {
	.driver		= {
		.name	= "rtc-ds1216",
		.owner	= THIS_MODULE,
	},
	.remove		= __exit_p(ds1216_rtc_remove),
};

static int __init ds1216_rtc_init(void)
{
	return platform_driver_probe(&ds1216_rtc_platform_driver, ds1216_rtc_probe);
}

static void __exit ds1216_rtc_exit(void)
{
	platform_driver_unregister(&ds1216_rtc_platform_driver);
}

MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
MODULE_DESCRIPTION("DS1216 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:rtc-ds1216");

module_init(ds1216_rtc_init);
module_exit(ds1216_rtc_exit);
Commit	Line	Data
537739de TB	1	/*
	2	* Dallas DS1216 RTC driver
	3	*
	4	* Copyright (c) 2007 Thomas Bogendoerfer
	5	*
	6	*/
	7
	8	#include <linux/module.h>
	9	#include <linux/rtc.h>
	10	#include <linux/platform_device.h>
	11	#include <linux/bcd.h>
5a0e3ad6	12	#include <linux/slab.h>
537739de	13
97a1f953	14	#define DRV_VERSION "0.2"
537739de TB	15
	16	struct ds1216_regs {
	17	u8 tsec;
	18	u8 sec;
	19	u8 min;
	20	u8 hour;
	21	u8 wday;
	22	u8 mday;
	23	u8 month;
	24	u8 year;
	25	};
	26
	27	#define DS1216_HOUR_1224 (1 << 7)
	28	#define DS1216_HOUR_AMPM (1 << 5)
	29
	30	struct ds1216_priv {
	31	struct rtc_device *rtc;
	32	void __iomem *ioaddr;
	33	size_t size;
	34	unsigned long baseaddr;
	35	};
	36
	37	static const u8 magic[] = {
	38	0xc5, 0x3a, 0xa3, 0x5c, 0xc5, 0x3a, 0xa3, 0x5c
	39	};
	40
	41	/*
	42	* Read the 64 bit we'd like to have - It a series
	43	* of 64 bits showing up in the LSB of the base register.
	44	*
	45	*/
	46	static void ds1216_read(u8 __iomem ioaddr, u8 buf)
	47	{
	48	unsigned char c;
	49	int i, j;
	50
	51	for (i = 0; i < 8; i++) {
	52	c = 0;
	53	for (j = 0; j < 8; j++)
	54	c \|= (readb(ioaddr) & 0x1) << j;
	55	buf[i] = c;
	56	}
	57	}
	58
	59	static void ds1216_write(u8 __iomem ioaddr, const u8 buf)
	60	{
	61	unsigned char c;
	62	int i, j;
	63
	64	for (i = 0; i < 8; i++) {
	65	c = buf[i];
	66	for (j = 0; j < 8; j++) {
	67	writeb(c, ioaddr);
	68	c = c >> 1;
	69	}
	70	}
	71	}
	72
	73	static void ds1216_switch_ds_to_clock(u8 __iomem *ioaddr)
	74	{
	75	/* Reset magic pointer */
	76	readb(ioaddr);
	77	/* Write 64 bit magic to DS1216 */
	78	ds1216_write(ioaddr, magic);
79	}
80
81	static int ds1216_rtc_read_time(struct device dev, struct rtc_time tm)
82	{
83	struct platform_device *pdev = to_platform_device(dev);
84	struct ds1216_priv *priv = platform_get_drvdata(pdev);
85	struct ds1216_regs regs;
86
87	ds1216_switch_ds_to_clock(priv->ioaddr);
88	ds1216_read(priv->ioaddr, (u8 *)&regs);
89
fe20ba70 AB	90	tm->tm_sec = bcd2bin(regs.sec);
fe20ba70 AB	91	tm->tm_min = bcd2bin(regs.min);
537739de TB	92	if (regs.hour & DS1216_HOUR_1224) {
537739de TB	93	/* AM/PM mode */
fe20ba70	94	tm->tm_hour = bcd2bin(regs.hour & 0x1f);
537739de TB	95	if (regs.hour & DS1216_HOUR_AMPM)
	96	tm->tm_hour += 12;
	97	} else
fe20ba70	98	tm->tm_hour = bcd2bin(regs.hour & 0x3f);
537739de	99	tm->tm_wday = (regs.wday & 7) - 1;
fe20ba70 AB	100	tm->tm_mday = bcd2bin(regs.mday & 0x3f);
	101	tm->tm_mon = bcd2bin(regs.month & 0x1f);
	102	tm->tm_year = bcd2bin(regs.year);
537739de TB	103	if (tm->tm_year < 70)
537739de TB	104	tm->tm_year += 100;
97a1f953 AZ	105
97a1f953 AZ	106	return rtc_valid_tm(tm);
537739de TB	107	}
	108
	109	static int ds1216_rtc_set_time(struct device dev, struct rtc_time tm)
	110	{
	111	struct platform_device *pdev = to_platform_device(dev);
	112	struct ds1216_priv *priv = platform_get_drvdata(pdev);
	113	struct ds1216_regs regs;
	114
	115	ds1216_switch_ds_to_clock(priv->ioaddr);
	116	ds1216_read(priv->ioaddr, (u8 *)&regs);
	117
	118	regs.tsec = 0; /* clear 0.1 and 0.01 seconds */
fe20ba70 AB	119	regs.sec = bin2bcd(tm->tm_sec);
fe20ba70 AB	120	regs.min = bin2bcd(tm->tm_min);
537739de TB	121	regs.hour &= DS1216_HOUR_1224;
	122	if (regs.hour && tm->tm_hour > 12) {
	123	regs.hour \|= DS1216_HOUR_AMPM;
	124	tm->tm_hour -= 12;
	125	}
fe20ba70	126	regs.hour \|= bin2bcd(tm->tm_hour);
537739de TB	127	regs.wday &= ~7;
537739de TB	128	regs.wday \|= tm->tm_wday;
fe20ba70 AB	129	regs.mday = bin2bcd(tm->tm_mday);
	130	regs.month = bin2bcd(tm->tm_mon);
	131	regs.year = bin2bcd(tm->tm_year % 100);
537739de TB	132
	133	ds1216_switch_ds_to_clock(priv->ioaddr);
	134	ds1216_write(priv->ioaddr, (u8 *)&regs);
	135	return 0;
	136	}
	137
	138	static const struct rtc_class_ops ds1216_rtc_ops = {
	139	.read_time = ds1216_rtc_read_time,
	140	.set_time = ds1216_rtc_set_time,
	141	};
	142
97a1f953	143	static int __init ds1216_rtc_probe(struct platform_device *pdev)
537739de	144	{
537739de TB	145	struct resource *res;
	146	struct ds1216_priv *priv;
	147	int ret = 0;
	148	u8 dummy[8];
	149
	150	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	151	if (!res)
	152	return -ENODEV;
	153	priv = kzalloc(sizeof *priv, GFP_KERNEL);
	154	if (!priv)
	155	return -ENOMEM;
97a1f953 AZ	156
	157	platform_set_drvdata(pdev, priv);
	158
	159	priv->size = resource_size(res);
537739de TB	160	if (!request_mem_region(res->start, priv->size, pdev->name)) {
	161	ret = -EBUSY;
	162	goto out;
	163	}
	164	priv->baseaddr = res->start;
	165	priv->ioaddr = ioremap(priv->baseaddr, priv->size);
	166	if (!priv->ioaddr) {
	167	ret = -ENOMEM;
	168	goto out;
	169	}
97a1f953	170	priv->rtc = rtc_device_register("ds1216", &pdev->dev,
537739de	171	&ds1216_rtc_ops, THIS_MODULE);
97a1f953 AZ	172	if (IS_ERR(priv->rtc)) {
97a1f953 AZ	173	ret = PTR_ERR(priv->rtc);
537739de TB	174	goto out;
537739de TB	175	}
537739de TB	176
	177	/* dummy read to get clock into a known state */
	178	ds1216_read(priv->ioaddr, dummy);
	179	return 0;
	180
	181	out:
537739de TB	182	if (priv->ioaddr)
	183	iounmap(priv->ioaddr);
	184	if (priv->baseaddr)
	185	release_mem_region(priv->baseaddr, priv->size);
	186	kfree(priv);
	187	return ret;
	188	}
	189
97a1f953	190	static int __exit ds1216_rtc_remove(struct platform_device *pdev)
537739de TB	191	{
	192	struct ds1216_priv *priv = platform_get_drvdata(pdev);
	193
	194	rtc_device_unregister(priv->rtc);
	195	iounmap(priv->ioaddr);
	196	release_mem_region(priv->baseaddr, priv->size);
	197	kfree(priv);
	198	return 0;
	199	}
	200
	201	static struct platform_driver ds1216_rtc_platform_driver = {
	202	.driver = {
	203	.name = "rtc-ds1216",
	204	.owner = THIS_MODULE,
	205	},
97a1f953	206	.remove = __exit_p(ds1216_rtc_remove),
537739de TB	207	};
	208
	209	static int __init ds1216_rtc_init(void)
	210	{
97a1f953	211	return platform_driver_probe(&ds1216_rtc_platform_driver, ds1216_rtc_probe);
537739de TB	212	}
	213
	214	static void __exit ds1216_rtc_exit(void)
	215	{
	216	platform_driver_unregister(&ds1216_rtc_platform_driver);
	217	}
	218
	219	MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
	220	MODULE_DESCRIPTION("DS1216 RTC driver");
	221	MODULE_LICENSE("GPL");
	222	MODULE_VERSION(DRV_VERSION);
ad28a07b	223	MODULE_ALIAS("platform:rtc-ds1216");
537739de TB	224
	225	module_init(ds1216_rtc_init);
	226	module_exit(ds1216_rtc_exit);