[deliverable/linux.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/gfp.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/module.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 file *filp, struct kobject *kobj,
				 struct bin_attribute *bin_attr,
				 char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct platform_device *pdev = to_platform_device(dev);
	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 file *filp, struct kobject *kobj,
				  struct bin_attribute *bin_attr,
				  char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct platform_device *pdev = to_platform_device(dev);
	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 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 = resource_size(res);
	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;

	sysfs_bin_attr_init(&pdata->nvram_attr);
	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 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		= ds1742_rtc_remove,
	.driver		= {
		.name	= "rtc-ds1742",
		.owner	= THIS_MODULE,
	},
};

module_platform_driver(ds1742_rtc_driver);

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>
5a0e3ad6	18	#include <linux/gfp.h>
5ec3e4b7 AN	19	#include <linux/delay.h>
	20	#include <linux/jiffies.h>
	21	#include <linux/rtc.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/io.h>
2113852b	24	#include <linux/module.h>
5ec3e4b7	25
ac18eb62	26	#define DRV_VERSION "0.4"
5ec3e4b7	27
f9231a0c	28	#define RTC_SIZE 8
5ec3e4b7	29
f9231a0c TER	30	#define RTC_CONTROL 0
	31	#define RTC_CENTURY 0
	32	#define RTC_SECONDS 1
	33	#define RTC_MINUTES 2
	34	#define RTC_HOURS 3
	35	#define RTC_DAY 4
	36	#define RTC_DATE 5
	37	#define RTC_MONTH 6
	38	#define RTC_YEAR 7
5ec3e4b7 AN	39
	40	#define RTC_CENTURY_MASK 0x3f
	41	#define RTC_SECONDS_MASK 0x7f
	42	#define RTC_DAY_MASK 0x07
	43
	44	/* Bits in the Control/Century register */
	45	#define RTC_WRITE 0x80
	46	#define RTC_READ 0x40
	47
	48	/* Bits in the Seconds register */
	49	#define RTC_STOP 0x80
	50
	51	/* Bits in the Day register */
	52	#define RTC_BATT_FLAG 0x80
	53
	54	struct rtc_plat_data {
	55	struct rtc_device *rtc;
f9231a0c TER	56	void __iomem *ioaddr_nvram;
	57	void __iomem *ioaddr_rtc;
	58	size_t size_nvram;
	59	size_t size;
5ec3e4b7	60	unsigned long last_jiffies;
3a729700	61	struct bin_attribute nvram_attr;
5ec3e4b7 AN	62	};
	63
	64	static int ds1742_rtc_set_time(struct device dev, struct rtc_time tm)
	65	{
	66	struct platform_device *pdev = to_platform_device(dev);
	67	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	68	void __iomem *ioaddr = pdata->ioaddr_rtc;
5ec3e4b7 AN	69	u8 century;
5ec3e4b7 AN	70
fe20ba70	71	century = bin2bcd((tm->tm_year + 1900) / 100);
5ec3e4b7 AN	72
	73	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
	74
fe20ba70 AB	75	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	76	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	77	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	78	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	79	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	80	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	81	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
5ec3e4b7 AN	82
	83	/* RTC_CENTURY and RTC_CONTROL share same register */
	84	writeb(RTC_WRITE \| (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
	85	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	86	return 0;
	87	}
	88
	89	static int ds1742_rtc_read_time(struct device dev, struct rtc_time tm)
	90	{
	91	struct platform_device *pdev = to_platform_device(dev);
	92	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	93	void __iomem *ioaddr = pdata->ioaddr_rtc;
5ec3e4b7 AN	94	unsigned int year, month, day, hour, minute, second, week;
	95	unsigned int century;
	96
	97	/* give enough time to update RTC in case of continuous read */
	98	if (pdata->last_jiffies == jiffies)
	99	msleep(1);
	100	pdata->last_jiffies = jiffies;
	101	writeb(RTC_READ, ioaddr + RTC_CONTROL);
	102	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	103	minute = readb(ioaddr + RTC_MINUTES);
	104	hour = readb(ioaddr + RTC_HOURS);
	105	day = readb(ioaddr + RTC_DATE);
	106	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	107	month = readb(ioaddr + RTC_MONTH);
	108	year = readb(ioaddr + RTC_YEAR);
	109	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	110	writeb(0, ioaddr + RTC_CONTROL);
fe20ba70 AB	111	tm->tm_sec = bcd2bin(second);
	112	tm->tm_min = bcd2bin(minute);
	113	tm->tm_hour = bcd2bin(hour);
	114	tm->tm_mday = bcd2bin(day);
	115	tm->tm_wday = bcd2bin(week);
	116	tm->tm_mon = bcd2bin(month) - 1;
5ec3e4b7	117	/* year is 1900 + tm->tm_year */
fe20ba70	118	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
5ec3e4b7 AN	119
	120	if (rtc_valid_tm(tm) < 0) {
	121	dev_err(dev, "retrieved date/time is not valid.\n");
	122	rtc_time_to_tm(0, tm);
	123	}
	124	return 0;
	125	}
	126
ff8371ac	127	static const struct rtc_class_ops ds1742_rtc_ops = {
5ec3e4b7 AN	128	.read_time = ds1742_rtc_read_time,
	129	.set_time = ds1742_rtc_set_time,
	130	};
	131
2c3c8bea	132	static ssize_t ds1742_nvram_read(struct file filp, struct kobject kobj,
91a69029 ZR	133	struct bin_attribute *bin_attr,
91a69029 ZR	134	char *buf, loff_t pos, size_t size)
5ec3e4b7	135	{
50e49bee AN	136	struct device *dev = container_of(kobj, struct device, kobj);
50e49bee AN	137	struct platform_device *pdev = to_platform_device(dev);
5ec3e4b7	138	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	139	void __iomem *ioaddr = pdata->ioaddr_nvram;
5ec3e4b7 AN	140	ssize_t count;
5ec3e4b7 AN	141
f9231a0c	142	for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
5ec3e4b7 AN	143	*buf++ = readb(ioaddr + pos++);
	144	return count;
	145	}
	146
2c3c8bea	147	static ssize_t ds1742_nvram_write(struct file filp, struct kobject kobj,
91a69029 ZR	148	struct bin_attribute *bin_attr,
91a69029 ZR	149	char *buf, loff_t pos, size_t size)
5ec3e4b7	150	{
50e49bee AN	151	struct device *dev = container_of(kobj, struct device, kobj);
50e49bee AN	152	struct platform_device *pdev = to_platform_device(dev);
5ec3e4b7	153	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
f9231a0c	154	void __iomem *ioaddr = pdata->ioaddr_nvram;
5ec3e4b7 AN	155	ssize_t count;
5ec3e4b7 AN	156
f9231a0c	157	for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
5ec3e4b7 AN	158	writeb(*buf++, ioaddr + pos++);
	159	return count;
	160	}
	161
5a167f45	162	static int ds1742_rtc_probe(struct platform_device *pdev)
5ec3e4b7 AN	163	{
	164	struct rtc_device *rtc;
	165	struct resource *res;
	166	unsigned int cen, sec;
ac18eb62 AN	167	struct rtc_plat_data *pdata;
ac18eb62 AN	168	void __iomem *ioaddr;
5ec3e4b7 AN	169	int ret = 0;
	170
	171	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	172	if (!res)
	173	return -ENODEV;
ac18eb62	174	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
5ec3e4b7 AN	175	if (!pdata)
5ec3e4b7 AN	176	return -ENOMEM;
28f65c11	177	pdata->size = resource_size(res);
ac18eb62 AN	178	if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
	179	pdev->name))
	180	return -EBUSY;
	181	ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
	182	if (!ioaddr)
	183	return -ENOMEM;
	184
f9231a0c TER	185	pdata->ioaddr_nvram = ioaddr;
	186	pdata->size_nvram = pdata->size - RTC_SIZE;
	187	pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
5ec3e4b7	188
f937331b	189	sysfs_bin_attr_init(&pdata->nvram_attr);
3a729700 TER	190	pdata->nvram_attr.attr.name = "nvram";
	191	pdata->nvram_attr.attr.mode = S_IRUGO \| S_IWUSR;
	192	pdata->nvram_attr.read = ds1742_nvram_read;
	193	pdata->nvram_attr.write = ds1742_nvram_write;
	194	pdata->nvram_attr.size = pdata->size_nvram;
	195
5ec3e4b7	196	/* turn RTC on if it was not on */
f9231a0c	197	ioaddr = pdata->ioaddr_rtc;
5ec3e4b7 AN	198	sec = readb(ioaddr + RTC_SECONDS);
	199	if (sec & RTC_STOP) {
	200	sec &= RTC_SECONDS_MASK;
	201	cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	202	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
	203	writeb(sec, ioaddr + RTC_SECONDS);
	204	writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	205	}
391b1fe6	206	if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
5ec3e4b7 AN	207	dev_warn(&pdev->dev, "voltage-low detected.\n");
5ec3e4b7 AN	208
ac18eb62 AN	209	pdata->last_jiffies = jiffies;
ac18eb62 AN	210	platform_set_drvdata(pdev, pdata);
5ec3e4b7 AN	211	rtc = rtc_device_register(pdev->name, &pdev->dev,
5ec3e4b7 AN	212	&ds1742_rtc_ops, THIS_MODULE);
ac18eb62 AN	213	if (IS_ERR(rtc))
ac18eb62 AN	214	return PTR_ERR(rtc);
5ec3e4b7	215	pdata->rtc = rtc;
3a729700 TER	216
	217	ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
	218	if (ret) {
	219	dev_err(&pdev->dev, "creating nvram file in sysfs failed\n");
ac18eb62	220	rtc_device_unregister(rtc);
3a729700	221	}
5ec3e4b7 AN	222	return ret;
	223	}
	224
5a167f45	225	static int ds1742_rtc_remove(struct platform_device *pdev)
5ec3e4b7 AN	226	{
	227	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	228
3a729700	229	sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
5ec3e4b7	230	rtc_device_unregister(pdata->rtc);
5ec3e4b7 AN	231	return 0;
	232	}
	233
	234	static struct platform_driver ds1742_rtc_driver = {
	235	.probe = ds1742_rtc_probe,
5a167f45	236	.remove = ds1742_rtc_remove,
5ec3e4b7	237	.driver = {
a95e23a2	238	.name = "rtc-ds1742",
5ec3e4b7 AN	239	.owner = THIS_MODULE,
	240	},
	241	};
	242
0c4eae66	243	module_platform_driver(ds1742_rtc_driver);
5ec3e4b7 AN	244
	245	MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
	246	MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
	247	MODULE_LICENSE("GPL");
	248	MODULE_VERSION(DRV_VERSION);
ad28a07b	249	MODULE_ALIAS("platform:rtc-ds1742");