[net-next-2.6.git] / drivers / rtc / rtc-ds1742.c

/*
 * An rtc driver for the Dallas DS1742
 *
 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk>
 *  - nvram size determined from resource
 *  - this ds1742 driver now supports ds1743.
 */

#include <linux/bcd.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/io.h>

#define DRV_VERSION "0.4"

#define RTC_SIZE		8

#define RTC_CONTROL		0
#define RTC_CENTURY		0
#define RTC_SECONDS		1
#define RTC_MINUTES		2
#define RTC_HOURS		3
#define RTC_DAY			4
#define RTC_DATE		5
#define RTC_MONTH		6
#define RTC_YEAR		7

#define RTC_CENTURY_MASK	0x3f
#define RTC_SECONDS_MASK	0x7f
#define RTC_DAY_MASK		0x07

/* Bits in the Control/Century register */
#define RTC_WRITE		0x80
#define RTC_READ		0x40

/* Bits in the Seconds register */
#define RTC_STOP		0x80

/* Bits in the Day register */
#define RTC_BATT_FLAG		0x80

struct rtc_plat_data {
	struct rtc_device *rtc;
	void __iomem *ioaddr_nvram;
	void __iomem *ioaddr_rtc;
	size_t size_nvram;
	size_t size;
	unsigned long last_jiffies;
	struct bin_attribute nvram_attr;
};

static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr_rtc;
	u8 century;

	century = bin2bcd((tm->tm_year + 1900) / 100);

	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);

	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);

	/* RTC_CENTURY and RTC_CONTROL share same register */
	writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	return 0;
}

static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr_rtc;
	unsigned int year, month, day, hour, minute, second, week;
	unsigned int century;

	/* give enough time to update RTC in case of continuous read */
	if (pdata->last_jiffies == jiffies)
		msleep(1);
	pdata->last_jiffies = jiffies;
	writeb(RTC_READ, ioaddr + RTC_CONTROL);
	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	minute = readb(ioaddr + RTC_MINUTES);
	hour = readb(ioaddr + RTC_HOURS);
	day = readb(ioaddr + RTC_DATE);
	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	month = readb(ioaddr + RTC_MONTH);
	year = readb(ioaddr + RTC_YEAR);
	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	writeb(0, ioaddr + RTC_CONTROL);
	tm->tm_sec = bcd2bin(second);
	tm->tm_min = bcd2bin(minute);
	tm->tm_hour = bcd2bin(hour);
	tm->tm_mday = bcd2bin(day);
	tm->tm_wday = bcd2bin(week);
	tm->tm_mon = bcd2bin(month) - 1;
	/* year is 1900 + tm->tm_year */
	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;

	if (rtc_valid_tm(tm) < 0) {
		dev_err(dev, "retrieved date/time is not valid.\n");
		rtc_time_to_tm(0, tm);
	}
	return 0;
}

static const struct rtc_class_ops ds1742_rtc_ops = {
	.read_time	= ds1742_rtc_read_time,
	.set_time	= ds1742_rtc_set_time,
};

static ssize_t ds1742_nvram_read(struct kobject *kobj,
				 struct bin_attribute *bin_attr,
				 char *buf, loff_t pos, size_t size)
{
	struct platform_device *pdev =
		to_platform_device(container_of(kobj, struct device, kobj));
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr_nvram;
	ssize_t count;

	for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
		*buf++ = readb(ioaddr + pos++);
	return count;
}

static ssize_t ds1742_nvram_write(struct kobject *kobj,
				  struct bin_attribute *bin_attr,
				  char *buf, loff_t pos, size_t size)
{
	struct platform_device *pdev =
		to_platform_device(container_of(kobj, struct device, kobj));
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr_nvram;
	ssize_t count;

	for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
		writeb(*buf++, ioaddr + pos++);
	return count;
}

static int __devinit ds1742_rtc_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;
	struct resource *res;
	unsigned int cen, sec;
	struct rtc_plat_data *pdata;
	void __iomem *ioaddr;
	int ret = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;
	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;
	pdata->size = res->end - res->start + 1;
	if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
		pdev->name))
		return -EBUSY;
	ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
	if (!ioaddr)
		return -ENOMEM;

	pdata->ioaddr_nvram = ioaddr;
	pdata->size_nvram = pdata->size - RTC_SIZE;
	pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;

	pdata->nvram_attr.attr.name = "nvram";
	pdata->nvram_attr.attr.mode = S_IRUGO | S_IWUSR;
	pdata->nvram_attr.read = ds1742_nvram_read;
	pdata->nvram_attr.write = ds1742_nvram_write;
	pdata->nvram_attr.size = pdata->size_nvram;

	/* turn RTC on if it was not on */
	ioaddr = pdata->ioaddr_rtc;
	sec = readb(ioaddr + RTC_SECONDS);
	if (sec & RTC_STOP) {
		sec &= RTC_SECONDS_MASK;
		cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
		writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
		writeb(sec, ioaddr + RTC_SECONDS);
		writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	}
	if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
		dev_warn(&pdev->dev, "voltage-low detected.\n");

	pdata->last_jiffies = jiffies;
	platform_set_drvdata(pdev, pdata);
	rtc = rtc_device_register(pdev->name, &pdev->dev,
				  &ds1742_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);
	pdata->rtc = rtc;

	ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
	if (ret) {
		dev_err(&pdev->dev, "creating nvram file in sysfs failed\n");
		rtc_device_unregister(rtc);
	}
	return ret;
}

static int __devexit ds1742_rtc_remove(struct platform_device *pdev)
{
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
	rtc_device_unregister(pdata->rtc);
	return 0;
}

static struct platform_driver ds1742_rtc_driver = {
	.probe		= ds1742_rtc_probe,
	.remove		= __devexit_p(ds1742_rtc_remove),
	.driver		= {
		.name	= "rtc-ds1742",
		.owner	= THIS_MODULE,
	},
};

static __init int ds1742_init(void)
{
	return platform_driver_register(&ds1742_rtc_driver);
}

static __exit void ds1742_exit(void)
{
	platform_driver_unregister(&ds1742_rtc_driver);
}

module_init(ds1742_init);
module_exit(ds1742_exit);

MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("platform:rtc-ds1742");
Commit	Line	Data
5ec3e4b7 AN	1	/*
	2	* An rtc driver for the Dallas DS1742
	3	*
	4	* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
f9231a0c TER	9	*
	10	* Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk>
	11	* - nvram size determined from resource
	12	* - this ds1742 driver now supports ds1743.
5ec3e4b7 AN	13	*/
	14
	15	#include <linux/bcd.h>
	16	#include <linux/init.h>
	17	#include <linux/kernel.h>
	18	#include <linux/delay.h>
	19	#include <linux/jiffies.h>
	20	#include <linux/rtc.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/io.h>
	23
ac18eb62	24	#define DRV_VERSION "0.4"
5ec3e4b7	25
f9231a0c	26	#define RTC_SIZE 8
5ec3e4b7	27
f9231a0c TER	28	#define RTC_CONTROL 0
	29	#define RTC_CENTURY 0
	30	#define RTC_SECONDS 1
	31	#define RTC_MINUTES 2
	32	#define RTC_HOURS 3
	33	#define RTC_DAY 4
	34	#define RTC_DATE 5
	35	#define RTC_MONTH 6
	36	#define RTC_YEAR 7
5ec3e4b7 AN	37
	38	#define RTC_CENTURY_MASK 0x3f
	39	#define RTC_SECONDS_MASK 0x7f
	40	#define RTC_DAY_MASK 0x07
	41
	42	/* Bits in the Control/Century register */
	43	#define RTC_WRITE 0x80
	44	#define RTC_READ 0x40
	45
	46	/* Bits in the Seconds register */
	47	#define RTC_STOP 0x80
	48
	49	/* Bits in the Day register */
	50	#define RTC_BATT_FLAG 0x80
	51
	52	struct rtc_plat_data {
	53	struct rtc_device *rtc;
f9231a0c TER	54	void __iomem *ioaddr_nvram;
	55	void __iomem *ioaddr_rtc;
	56	size_t size_nvram;
	57	size_t size;
5ec3e4b7	58	unsigned long last_jiffies;
3a729700	59	struct bin_attribute nvram_attr;
5ec3e4b7 AN	60	};
	61
	62	static int ds1742_rtc_set_time(struct device dev, struct rtc_time tm)
	63	{
	64	struct platform_device *pdev = to_platform_device(dev);
	65	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	66	void __iomem *ioaddr = pdata->ioaddr_rtc;
5ec3e4b7 AN	67	u8 century;
5ec3e4b7 AN	68
fe20ba70	69	century = bin2bcd((tm->tm_year + 1900) / 100);
5ec3e4b7 AN	70
	71	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
	72
fe20ba70 AB	73	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	74	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	75	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	76	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	77	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	78	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	79	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
5ec3e4b7 AN	80
	81	/* RTC_CENTURY and RTC_CONTROL share same register */
	82	writeb(RTC_WRITE \| (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
	83	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	84	return 0;
	85	}
	86
	87	static int ds1742_rtc_read_time(struct device dev, struct rtc_time tm)
	88	{
	89	struct platform_device *pdev = to_platform_device(dev);
	90	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	91	void __iomem *ioaddr = pdata->ioaddr_rtc;
5ec3e4b7 AN	92	unsigned int year, month, day, hour, minute, second, week;
	93	unsigned int century;
	94
	95	/* give enough time to update RTC in case of continuous read */
	96	if (pdata->last_jiffies == jiffies)
	97	msleep(1);
	98	pdata->last_jiffies = jiffies;
	99	writeb(RTC_READ, ioaddr + RTC_CONTROL);
	100	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	101	minute = readb(ioaddr + RTC_MINUTES);
	102	hour = readb(ioaddr + RTC_HOURS);
	103	day = readb(ioaddr + RTC_DATE);
	104	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	105	month = readb(ioaddr + RTC_MONTH);
	106	year = readb(ioaddr + RTC_YEAR);
	107	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	108	writeb(0, ioaddr + RTC_CONTROL);
fe20ba70 AB	109	tm->tm_sec = bcd2bin(second);
	110	tm->tm_min = bcd2bin(minute);
	111	tm->tm_hour = bcd2bin(hour);
	112	tm->tm_mday = bcd2bin(day);
	113	tm->tm_wday = bcd2bin(week);
	114	tm->tm_mon = bcd2bin(month) - 1;
5ec3e4b7	115	/* year is 1900 + tm->tm_year */
fe20ba70	116	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
5ec3e4b7 AN	117
	118	if (rtc_valid_tm(tm) < 0) {
	119	dev_err(dev, "retrieved date/time is not valid.\n");
	120	rtc_time_to_tm(0, tm);
	121	}
	122	return 0;
	123	}
	124
ff8371ac	125	static const struct rtc_class_ops ds1742_rtc_ops = {
5ec3e4b7 AN	126	.read_time = ds1742_rtc_read_time,
	127	.set_time = ds1742_rtc_set_time,
	128	};
	129
91a69029 ZR	130	static ssize_t ds1742_nvram_read(struct kobject *kobj,
	131	struct bin_attribute *bin_attr,
	132	char *buf, loff_t pos, size_t size)
5ec3e4b7 AN	133	{
	134	struct platform_device *pdev =
	135	to_platform_device(container_of(kobj, struct device, kobj));
	136	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	137	void __iomem *ioaddr = pdata->ioaddr_nvram;
5ec3e4b7 AN	138	ssize_t count;
5ec3e4b7 AN	139
f9231a0c	140	for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
5ec3e4b7 AN	141	*buf++ = readb(ioaddr + pos++);
	142	return count;
	143	}
	144
91a69029 ZR	145	static ssize_t ds1742_nvram_write(struct kobject *kobj,
	146	struct bin_attribute *bin_attr,
	147	char *buf, loff_t pos, size_t size)
5ec3e4b7 AN	148	{
	149	struct platform_device *pdev =
	150	to_platform_device(container_of(kobj, struct device, kobj));
	151	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	152	void __iomem *ioaddr = pdata->ioaddr_nvram;
5ec3e4b7 AN	153	ssize_t count;
5ec3e4b7 AN	154
f9231a0c	155	for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
5ec3e4b7 AN	156	writeb(*buf++, ioaddr + pos++);
	157	return count;
	158	}
	159
c239122d	160	static int __devinit ds1742_rtc_probe(struct platform_device *pdev)
5ec3e4b7 AN	161	{
	162	struct rtc_device *rtc;
	163	struct resource *res;
	164	unsigned int cen, sec;
ac18eb62 AN	165	struct rtc_plat_data *pdata;
ac18eb62 AN	166	void __iomem *ioaddr;
5ec3e4b7 AN	167	int ret = 0;
	168
	169	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	170	if (!res)
	171	return -ENODEV;
ac18eb62	172	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
5ec3e4b7 AN	173	if (!pdata)
5ec3e4b7 AN	174	return -ENOMEM;
f9231a0c	175	pdata->size = res->end - res->start + 1;
ac18eb62 AN	176	if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
	177	pdev->name))
	178	return -EBUSY;
	179	ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
	180	if (!ioaddr)
	181	return -ENOMEM;
	182
f9231a0c TER	183	pdata->ioaddr_nvram = ioaddr;
	184	pdata->size_nvram = pdata->size - RTC_SIZE;
	185	pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
5ec3e4b7	186
3a729700 TER	187	pdata->nvram_attr.attr.name = "nvram";
	188	pdata->nvram_attr.attr.mode = S_IRUGO \| S_IWUSR;
	189	pdata->nvram_attr.read = ds1742_nvram_read;
	190	pdata->nvram_attr.write = ds1742_nvram_write;
	191	pdata->nvram_attr.size = pdata->size_nvram;
	192
5ec3e4b7	193	/* turn RTC on if it was not on */
f9231a0c	194	ioaddr = pdata->ioaddr_rtc;
5ec3e4b7 AN	195	sec = readb(ioaddr + RTC_SECONDS);
	196	if (sec & RTC_STOP) {
	197	sec &= RTC_SECONDS_MASK;
	198	cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	199	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
	200	writeb(sec, ioaddr + RTC_SECONDS);
	201	writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	202	}
391b1fe6	203	if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
5ec3e4b7 AN	204	dev_warn(&pdev->dev, "voltage-low detected.\n");
5ec3e4b7 AN	205
ac18eb62 AN	206	pdata->last_jiffies = jiffies;
ac18eb62 AN	207	platform_set_drvdata(pdev, pdata);
5ec3e4b7 AN	208	rtc = rtc_device_register(pdev->name, &pdev->dev,
5ec3e4b7 AN	209	&ds1742_rtc_ops, THIS_MODULE);
ac18eb62 AN	210	if (IS_ERR(rtc))
ac18eb62 AN	211	return PTR_ERR(rtc);
5ec3e4b7	212	pdata->rtc = rtc;
3a729700 TER	213
	214	ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
	215	if (ret) {
	216	dev_err(&pdev->dev, "creating nvram file in sysfs failed\n");
ac18eb62	217	rtc_device_unregister(rtc);
3a729700	218	}
5ec3e4b7 AN	219	return ret;
	220	}
	221
	222	static int __devexit ds1742_rtc_remove(struct platform_device *pdev)
	223	{
	224	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	225
3a729700	226	sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
5ec3e4b7	227	rtc_device_unregister(pdata->rtc);
5ec3e4b7 AN	228	return 0;
	229	}
	230
	231	static struct platform_driver ds1742_rtc_driver = {
	232	.probe = ds1742_rtc_probe,
	233	.remove = __devexit_p(ds1742_rtc_remove),
	234	.driver = {
a95e23a2	235	.name = "rtc-ds1742",
5ec3e4b7 AN	236	.owner = THIS_MODULE,
	237	},
	238	};
	239
	240	static __init int ds1742_init(void)
	241	{
	242	return platform_driver_register(&ds1742_rtc_driver);
	243	}
	244
	245	static __exit void ds1742_exit(void)
	246	{
ef154ec6	247	platform_driver_unregister(&ds1742_rtc_driver);
5ec3e4b7 AN	248	}
	249
	250	module_init(ds1742_init);
	251	module_exit(ds1742_exit);
	252
	253	MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
	254	MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
	255	MODULE_LICENSE("GPL");
	256	MODULE_VERSION(DRV_VERSION);
ad28a07b	257	MODULE_ALIAS("platform:rtc-ds1742");