[linux-2.6-block.git] / drivers / rtc / rtc-m48t86.c

/*
 * ST M48T86 / Dallas DS12887 RTC driver
 * Copyright (c) 2006 Tower Technologies
 *
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 *
 * 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.
 *
 * This drivers only supports the clock running in BCD and 24H mode.
 * If it will be ever adapted to binary and 12H mode, care must be taken
 * to not introduce bugs.
 */

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/m48t86.h>
#include <linux/bcd.h>

#define M48T86_REG_SEC		0x00
#define M48T86_REG_SECALRM	0x01
#define M48T86_REG_MIN		0x02
#define M48T86_REG_MINALRM	0x03
#define M48T86_REG_HOUR		0x04
#define M48T86_REG_HOURALRM	0x05
#define M48T86_REG_DOW		0x06 /* 1 = sunday */
#define M48T86_REG_DOM		0x07
#define M48T86_REG_MONTH	0x08 /* 1 - 12 */
#define M48T86_REG_YEAR		0x09 /* 0 - 99 */
#define M48T86_REG_A		0x0A
#define M48T86_REG_B		0x0B
#define M48T86_REG_C		0x0C
#define M48T86_REG_D		0x0D

#define M48T86_REG_B_H24	(1 << 1)
#define M48T86_REG_B_DM		(1 << 2)
#define M48T86_REG_B_SET	(1 << 7)
#define M48T86_REG_D_VRT	(1 << 7)

static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char reg;
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);

	reg = ops->readbyte(M48T86_REG_B);

	if (reg & M48T86_REG_B_DM) {
		/* data (binary) mode */
		tm->tm_sec	= ops->readbyte(M48T86_REG_SEC);
		tm->tm_min	= ops->readbyte(M48T86_REG_MIN);
		tm->tm_hour	= ops->readbyte(M48T86_REG_HOUR) & 0x3F;
		tm->tm_mday	= ops->readbyte(M48T86_REG_DOM);
		/* tm_mon is 0-11 */
		tm->tm_mon	= ops->readbyte(M48T86_REG_MONTH) - 1;
		tm->tm_year	= ops->readbyte(M48T86_REG_YEAR) + 100;
		tm->tm_wday	= ops->readbyte(M48T86_REG_DOW);
	} else {
		/* bcd mode */
		tm->tm_sec	= bcd2bin(ops->readbyte(M48T86_REG_SEC));
		tm->tm_min	= bcd2bin(ops->readbyte(M48T86_REG_MIN));
		tm->tm_hour	= bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F);
		tm->tm_mday	= bcd2bin(ops->readbyte(M48T86_REG_DOM));
		/* tm_mon is 0-11 */
		tm->tm_mon	= bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1;
		tm->tm_year	= bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100;
		tm->tm_wday	= bcd2bin(ops->readbyte(M48T86_REG_DOW));
	}

	/* correct the hour if the clock is in 12h mode */
	if (!(reg & M48T86_REG_B_H24))
		if (ops->readbyte(M48T86_REG_HOUR) & 0x80)
			tm->tm_hour += 12;

	return rtc_valid_tm(tm);
}

static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char reg;
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);

	reg = ops->readbyte(M48T86_REG_B);

	/* update flag and 24h mode */
	reg |= M48T86_REG_B_SET | M48T86_REG_B_H24;
	ops->writebyte(reg, M48T86_REG_B);

	if (reg & M48T86_REG_B_DM) {
		/* data (binary) mode */
		ops->writebyte(tm->tm_sec, M48T86_REG_SEC);
		ops->writebyte(tm->tm_min, M48T86_REG_MIN);
		ops->writebyte(tm->tm_hour, M48T86_REG_HOUR);
		ops->writebyte(tm->tm_mday, M48T86_REG_DOM);
		ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH);
		ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR);
		ops->writebyte(tm->tm_wday, M48T86_REG_DOW);
	} else {
		/* bcd mode */
		ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC);
		ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN);
		ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR);
		ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM);
		ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH);
		ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR);
		ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW);
	}

	/* update ended */
	reg &= ~M48T86_REG_B_SET;
	ops->writebyte(reg, M48T86_REG_B);

	return 0;
}

static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq)
{
	unsigned char reg;
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);

	reg = ops->readbyte(M48T86_REG_B);

	seq_printf(seq, "mode\t\t: %s\n",
		 (reg & M48T86_REG_B_DM) ? "binary" : "bcd");

	reg = ops->readbyte(M48T86_REG_D);

	seq_printf(seq, "battery\t\t: %s\n",
		 (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");

	return 0;
}

static const struct rtc_class_ops m48t86_rtc_ops = {
	.read_time	= m48t86_rtc_read_time,
	.set_time	= m48t86_rtc_set_time,
	.proc		= m48t86_rtc_proc,
};

static int m48t86_rtc_probe(struct platform_device *dev)
{
	unsigned char reg;
	struct m48t86_ops *ops = dev_get_platdata(&dev->dev);
	struct rtc_device *rtc;

	rtc = devm_rtc_device_register(&dev->dev, "m48t86",
				&m48t86_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	platform_set_drvdata(dev, rtc);

	/* read battery status */
	reg = ops->readbyte(M48T86_REG_D);
	dev_info(&dev->dev, "battery %s\n",
		(reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");

	return 0;
}

static struct platform_driver m48t86_rtc_platform_driver = {
	.driver		= {
		.name	= "rtc-m48t86",
	},
	.probe		= m48t86_rtc_probe,
};

module_platform_driver(m48t86_rtc_platform_driver);

MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("M48T86 RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rtc-m48t86");
Commit	Line	Data
1d98af87 AZ	1	/*
	2	* ST M48T86 / Dallas DS12887 RTC driver
	3	* Copyright (c) 2006 Tower Technologies
	4	*
	5	* Author: Alessandro Zummo <a.zummo@towertech.it>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* This drivers only supports the clock running in BCD and 24H mode.
	12	* If it will be ever adapted to binary and 12H mode, care must be taken
	13	* to not introduce bugs.
	14	*/
	15
	16	#include <linux/module.h>
	17	#include <linux/rtc.h>
	18	#include <linux/platform_device.h>
	19	#include <linux/m48t86.h>
	20	#include <linux/bcd.h>
	21
	22	#define M48T86_REG_SEC 0x00
	23	#define M48T86_REG_SECALRM 0x01
	24	#define M48T86_REG_MIN 0x02
	25	#define M48T86_REG_MINALRM 0x03
f90a6506	26	#define M48T86_REG_HOUR 0x04
1d98af87 AZ	27	#define M48T86_REG_HOURALRM 0x05
	28	#define M48T86_REG_DOW 0x06 /* 1 = sunday */
	29	#define M48T86_REG_DOM 0x07
	30	#define M48T86_REG_MONTH 0x08 /* 1 - 12 */
	31	#define M48T86_REG_YEAR 0x09 /* 0 - 99 */
	32	#define M48T86_REG_A 0x0A
	33	#define M48T86_REG_B 0x0B
	34	#define M48T86_REG_C 0x0C
	35	#define M48T86_REG_D 0x0D
	36
	37	#define M48T86_REG_B_H24 (1 << 1)
	38	#define M48T86_REG_B_DM (1 << 2)
	39	#define M48T86_REG_B_SET (1 << 7)
	40	#define M48T86_REG_D_VRT (1 << 7)
	41
1d98af87 AZ	42	static int m48t86_rtc_read_time(struct device dev, struct rtc_time tm)
	43	{
	44	unsigned char reg;
	45	struct platform_device *pdev = to_platform_device(dev);
b5f0902d	46	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
1d98af87	47
2d7b20c1	48	reg = ops->readbyte(M48T86_REG_B);
1d98af87 AZ	49
	50	if (reg & M48T86_REG_B_DM) {
	51	/* data (binary) mode */
2d7b20c1 AM	52	tm->tm_sec = ops->readbyte(M48T86_REG_SEC);
	53	tm->tm_min = ops->readbyte(M48T86_REG_MIN);
	54	tm->tm_hour = ops->readbyte(M48T86_REG_HOUR) & 0x3F;
	55	tm->tm_mday = ops->readbyte(M48T86_REG_DOM);
1d98af87	56	/* tm_mon is 0-11 */
2d7b20c1 AM	57	tm->tm_mon = ops->readbyte(M48T86_REG_MONTH) - 1;
	58	tm->tm_year = ops->readbyte(M48T86_REG_YEAR) + 100;
	59	tm->tm_wday = ops->readbyte(M48T86_REG_DOW);
1d98af87 AZ	60	} else {
1d98af87 AZ	61	/* bcd mode */
fe20ba70 AB	62	tm->tm_sec = bcd2bin(ops->readbyte(M48T86_REG_SEC));
	63	tm->tm_min = bcd2bin(ops->readbyte(M48T86_REG_MIN));
	64	tm->tm_hour = bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F);
	65	tm->tm_mday = bcd2bin(ops->readbyte(M48T86_REG_DOM));
1d98af87	66	/* tm_mon is 0-11 */
fe20ba70 AB	67	tm->tm_mon = bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1;
	68	tm->tm_year = bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100;
	69	tm->tm_wday = bcd2bin(ops->readbyte(M48T86_REG_DOW));
1d98af87 AZ	70	}
	71
	72	/* correct the hour if the clock is in 12h mode */
	73	if (!(reg & M48T86_REG_B_H24))
2d7b20c1	74	if (ops->readbyte(M48T86_REG_HOUR) & 0x80)
1d98af87 AZ	75	tm->tm_hour += 12;
1d98af87 AZ	76
52142ed4	77	return rtc_valid_tm(tm);
1d98af87 AZ	78	}
	79
	80	static int m48t86_rtc_set_time(struct device dev, struct rtc_time tm)
	81	{
	82	unsigned char reg;
	83	struct platform_device *pdev = to_platform_device(dev);
b5f0902d	84	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
1d98af87	85
2d7b20c1	86	reg = ops->readbyte(M48T86_REG_B);
1d98af87 AZ	87
	88	/* update flag and 24h mode */
	89	reg \|= M48T86_REG_B_SET \| M48T86_REG_B_H24;
2d7b20c1	90	ops->writebyte(reg, M48T86_REG_B);
1d98af87 AZ	91
	92	if (reg & M48T86_REG_B_DM) {
	93	/* data (binary) mode */
2d7b20c1 AM	94	ops->writebyte(tm->tm_sec, M48T86_REG_SEC);
	95	ops->writebyte(tm->tm_min, M48T86_REG_MIN);
	96	ops->writebyte(tm->tm_hour, M48T86_REG_HOUR);
	97	ops->writebyte(tm->tm_mday, M48T86_REG_DOM);
	98	ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH);
	99	ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR);
	100	ops->writebyte(tm->tm_wday, M48T86_REG_DOW);
1d98af87 AZ	101	} else {
1d98af87 AZ	102	/* bcd mode */
fe20ba70 AB	103	ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC);
	104	ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN);
	105	ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR);
	106	ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM);
	107	ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH);
	108	ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR);
	109	ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW);
1d98af87 AZ	110	}
	111
	112	/* update ended */
	113	reg &= ~M48T86_REG_B_SET;
2d7b20c1	114	ops->writebyte(reg, M48T86_REG_B);
1d98af87 AZ	115
	116	return 0;
	117	}
	118
	119	static int m48t86_rtc_proc(struct device dev, struct seq_file seq)
	120	{
	121	unsigned char reg;
	122	struct platform_device *pdev = to_platform_device(dev);
b5f0902d	123	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
1d98af87	124
2d7b20c1	125	reg = ops->readbyte(M48T86_REG_B);
1d98af87	126
1d98af87 AZ	127	seq_printf(seq, "mode\t\t: %s\n",
	128	(reg & M48T86_REG_B_DM) ? "binary" : "bcd");
	129
2d7b20c1	130	reg = ops->readbyte(M48T86_REG_D);
1d98af87 AZ	131
	132	seq_printf(seq, "battery\t\t: %s\n",
	133	(reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
	134
	135	return 0;
	136	}
	137
ff8371ac	138	static const struct rtc_class_ops m48t86_rtc_ops = {
1d98af87 AZ	139	.read_time = m48t86_rtc_read_time,
	140	.set_time = m48t86_rtc_set_time,
	141	.proc = m48t86_rtc_proc,
	142	};
	143
5a167f45	144	static int m48t86_rtc_probe(struct platform_device *dev)
1d98af87 AZ	145	{
1d98af87 AZ	146	unsigned char reg;
b5f0902d	147	struct m48t86_ops *ops = dev_get_platdata(&dev->dev);
d5b6bb0a JH	148	struct rtc_device *rtc;
	149
	150	rtc = devm_rtc_device_register(&dev->dev, "m48t86",
	151	&m48t86_rtc_ops, THIS_MODULE);
1d98af87	152
d1d65b77	153	if (IS_ERR(rtc))
1d98af87	154	return PTR_ERR(rtc);
1d98af87 AZ	155
	156	platform_set_drvdata(dev, rtc);
	157
	158	/* read battery status */
2d7b20c1	159	reg = ops->readbyte(M48T86_REG_D);
1d98af87 AZ	160	dev_info(&dev->dev, "battery %s\n",
	161	(reg & M48T86_REG_D_VRT) ? "ok" : "exhausted");
	162
	163	return 0;
	164	}
	165
1d98af87 AZ	166	static struct platform_driver m48t86_rtc_platform_driver = {
	167	.driver = {
	168	.name = "rtc-m48t86",
1d98af87 AZ	169	},
1d98af87 AZ	170	.probe = m48t86_rtc_probe,
1d98af87 AZ	171	};
1d98af87 AZ	172
0c4eae66	173	module_platform_driver(m48t86_rtc_platform_driver);
1d98af87 AZ	174
	175	MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
	176	MODULE_DESCRIPTION("M48T86 RTC driver");
	177	MODULE_LICENSE("GPL");
ad28a07b	178	MODULE_ALIAS("platform:rtc-m48t86");