[mirror_ubuntu-jammy-kernel.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/platform_data/rtc-m48t86.h>
#include <linux/bcd.h>

#define M48T86_SEC		0x00
#define M48T86_SECALRM		0x01
#define M48T86_MIN		0x02
#define M48T86_MINALRM		0x03
#define M48T86_HOUR		0x04
#define M48T86_HOURALRM		0x05
#define M48T86_DOW		0x06 /* 1 = sunday */
#define M48T86_DOM		0x07
#define M48T86_MONTH		0x08 /* 1 - 12 */
#define M48T86_YEAR		0x09 /* 0 - 99 */
#define M48T86_A		0x0a
#define M48T86_B		0x0b
#define M48T86_B_SET		BIT(7)
#define M48T86_B_DM		BIT(2)
#define M48T86_B_H24		BIT(1)
#define M48T86_C		0x0c
#define M48T86_D		0x0d
#define M48T86_D_VRT		BIT(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_B);

	if (reg & M48T86_B_DM) {
		/* data (binary) mode */
		tm->tm_sec	= ops->readbyte(M48T86_SEC);
		tm->tm_min	= ops->readbyte(M48T86_MIN);
		tm->tm_hour	= ops->readbyte(M48T86_HOUR) & 0x3f;
		tm->tm_mday	= ops->readbyte(M48T86_DOM);
		/* tm_mon is 0-11 */
		tm->tm_mon	= ops->readbyte(M48T86_MONTH) - 1;
		tm->tm_year	= ops->readbyte(M48T86_YEAR) + 100;
		tm->tm_wday	= ops->readbyte(M48T86_DOW);
	} else {
		/* bcd mode */
		tm->tm_sec	= bcd2bin(ops->readbyte(M48T86_SEC));
		tm->tm_min	= bcd2bin(ops->readbyte(M48T86_MIN));
		tm->tm_hour	= bcd2bin(ops->readbyte(M48T86_HOUR) & 0x3f);
		tm->tm_mday	= bcd2bin(ops->readbyte(M48T86_DOM));
		/* tm_mon is 0-11 */
		tm->tm_mon	= bcd2bin(ops->readbyte(M48T86_MONTH)) - 1;
		tm->tm_year	= bcd2bin(ops->readbyte(M48T86_YEAR)) + 100;
		tm->tm_wday	= bcd2bin(ops->readbyte(M48T86_DOW));
	}

	/* correct the hour if the clock is in 12h mode */
	if (!(reg & M48T86_B_H24))
		if (ops->readbyte(M48T86_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_B);

	/* update flag and 24h mode */
	reg |= M48T86_B_SET | M48T86_B_H24;
	ops->writebyte(reg, M48T86_B);

	if (reg & M48T86_B_DM) {
		/* data (binary) mode */
		ops->writebyte(tm->tm_sec, M48T86_SEC);
		ops->writebyte(tm->tm_min, M48T86_MIN);
		ops->writebyte(tm->tm_hour, M48T86_HOUR);
		ops->writebyte(tm->tm_mday, M48T86_DOM);
		ops->writebyte(tm->tm_mon + 1, M48T86_MONTH);
		ops->writebyte(tm->tm_year % 100, M48T86_YEAR);
		ops->writebyte(tm->tm_wday, M48T86_DOW);
	} else {
		/* bcd mode */
		ops->writebyte(bin2bcd(tm->tm_sec), M48T86_SEC);
		ops->writebyte(bin2bcd(tm->tm_min), M48T86_MIN);
		ops->writebyte(bin2bcd(tm->tm_hour), M48T86_HOUR);
		ops->writebyte(bin2bcd(tm->tm_mday), M48T86_DOM);
		ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_MONTH);
		ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_YEAR);
		ops->writebyte(bin2bcd(tm->tm_wday), M48T86_DOW);
	}

	/* update ended */
	reg &= ~M48T86_B_SET;
	ops->writebyte(reg, M48T86_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_B);

	seq_printf(seq, "mode\t\t: %s\n",
		   (reg & M48T86_B_DM) ? "binary" : "bcd");

	reg = ops->readbyte(M48T86_D);

	seq_printf(seq, "battery\t\t: %s\n",
		   (reg & M48T86_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_D);
	dev_info(&dev->dev, "battery %s\n",
		 (reg & M48T86_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>
803bb301	19	#include <linux/platform_data/rtc-m48t86.h>
1d98af87 AZ	20	#include <linux/bcd.h>
1d98af87 AZ	21
68b54f47 HS	22	#define M48T86_SEC 0x00
	23	#define M48T86_SECALRM 0x01
	24	#define M48T86_MIN 0x02
	25	#define M48T86_MINALRM 0x03
	26	#define M48T86_HOUR 0x04
	27	#define M48T86_HOURALRM 0x05
	28	#define M48T86_DOW 0x06 /* 1 = sunday */
	29	#define M48T86_DOM 0x07
	30	#define M48T86_MONTH 0x08 /* 1 - 12 */
	31	#define M48T86_YEAR 0x09 /* 0 - 99 */
	32	#define M48T86_A 0x0a
	33	#define M48T86_B 0x0b
	34	#define M48T86_B_SET BIT(7)
	35	#define M48T86_B_DM BIT(2)
	36	#define M48T86_B_H24 BIT(1)
	37	#define M48T86_C 0x0c
	38	#define M48T86_D 0x0d
	39	#define M48T86_D_VRT BIT(7)
1d98af87	40
1d98af87 AZ	41	static int m48t86_rtc_read_time(struct device dev, struct rtc_time tm)
	42	{
	43	unsigned char reg;
	44	struct platform_device *pdev = to_platform_device(dev);
b5f0902d	45	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
1d98af87	46
68b54f47	47	reg = ops->readbyte(M48T86_B);
1d98af87	48
68b54f47	49	if (reg & M48T86_B_DM) {
1d98af87	50	/* data (binary) mode */
68b54f47 HS	51	tm->tm_sec = ops->readbyte(M48T86_SEC);
	52	tm->tm_min = ops->readbyte(M48T86_MIN);
	53	tm->tm_hour = ops->readbyte(M48T86_HOUR) & 0x3f;
	54	tm->tm_mday = ops->readbyte(M48T86_DOM);
1d98af87	55	/* tm_mon is 0-11 */
68b54f47 HS	56	tm->tm_mon = ops->readbyte(M48T86_MONTH) - 1;
	57	tm->tm_year = ops->readbyte(M48T86_YEAR) + 100;
	58	tm->tm_wday = ops->readbyte(M48T86_DOW);
1d98af87 AZ	59	} else {
1d98af87 AZ	60	/* bcd mode */
68b54f47 HS	61	tm->tm_sec = bcd2bin(ops->readbyte(M48T86_SEC));
	62	tm->tm_min = bcd2bin(ops->readbyte(M48T86_MIN));
	63	tm->tm_hour = bcd2bin(ops->readbyte(M48T86_HOUR) & 0x3f);
	64	tm->tm_mday = bcd2bin(ops->readbyte(M48T86_DOM));
1d98af87	65	/* tm_mon is 0-11 */
68b54f47 HS	66	tm->tm_mon = bcd2bin(ops->readbyte(M48T86_MONTH)) - 1;
	67	tm->tm_year = bcd2bin(ops->readbyte(M48T86_YEAR)) + 100;
	68	tm->tm_wday = bcd2bin(ops->readbyte(M48T86_DOW));
1d98af87 AZ	69	}
	70
	71	/* correct the hour if the clock is in 12h mode */
68b54f47 HS	72	if (!(reg & M48T86_B_H24))
68b54f47 HS	73	if (ops->readbyte(M48T86_HOUR) & 0x80)
1d98af87 AZ	74	tm->tm_hour += 12;
1d98af87 AZ	75
52142ed4	76	return rtc_valid_tm(tm);
1d98af87 AZ	77	}
	78
	79	static int m48t86_rtc_set_time(struct device dev, struct rtc_time tm)
	80	{
	81	unsigned char reg;
	82	struct platform_device *pdev = to_platform_device(dev);
b5f0902d	83	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
1d98af87	84
68b54f47	85	reg = ops->readbyte(M48T86_B);
1d98af87 AZ	86
1d98af87 AZ	87	/* update flag and 24h mode */
68b54f47 HS	88	reg \|= M48T86_B_SET \| M48T86_B_H24;
68b54f47 HS	89	ops->writebyte(reg, M48T86_B);
1d98af87	90
68b54f47	91	if (reg & M48T86_B_DM) {
1d98af87	92	/* data (binary) mode */
68b54f47 HS	93	ops->writebyte(tm->tm_sec, M48T86_SEC);
	94	ops->writebyte(tm->tm_min, M48T86_MIN);
	95	ops->writebyte(tm->tm_hour, M48T86_HOUR);
	96	ops->writebyte(tm->tm_mday, M48T86_DOM);
	97	ops->writebyte(tm->tm_mon + 1, M48T86_MONTH);
	98	ops->writebyte(tm->tm_year % 100, M48T86_YEAR);
	99	ops->writebyte(tm->tm_wday, M48T86_DOW);
1d98af87 AZ	100	} else {
1d98af87 AZ	101	/* bcd mode */
68b54f47 HS	102	ops->writebyte(bin2bcd(tm->tm_sec), M48T86_SEC);
	103	ops->writebyte(bin2bcd(tm->tm_min), M48T86_MIN);
	104	ops->writebyte(bin2bcd(tm->tm_hour), M48T86_HOUR);
	105	ops->writebyte(bin2bcd(tm->tm_mday), M48T86_DOM);
	106	ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_MONTH);
	107	ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_YEAR);
	108	ops->writebyte(bin2bcd(tm->tm_wday), M48T86_DOW);
1d98af87 AZ	109	}
	110
	111	/* update ended */
68b54f47 HS	112	reg &= ~M48T86_B_SET;
68b54f47 HS	113	ops->writebyte(reg, M48T86_B);
1d98af87 AZ	114
	115	return 0;
	116	}
	117
	118	static int m48t86_rtc_proc(struct device dev, struct seq_file seq)
	119	{
	120	unsigned char reg;
	121	struct platform_device *pdev = to_platform_device(dev);
b5f0902d	122	struct m48t86_ops *ops = dev_get_platdata(&pdev->dev);
1d98af87	123
68b54f47	124	reg = ops->readbyte(M48T86_B);
1d98af87	125
1d98af87	126	seq_printf(seq, "mode\t\t: %s\n",
68b54f47	127	(reg & M48T86_B_DM) ? "binary" : "bcd");
1d98af87	128
68b54f47	129	reg = ops->readbyte(M48T86_D);
1d98af87 AZ	130
1d98af87 AZ	131	seq_printf(seq, "battery\t\t: %s\n",
68b54f47	132	(reg & M48T86_D_VRT) ? "ok" : "exhausted");
1d98af87 AZ	133
	134	return 0;
	135	}
	136
ff8371ac	137	static const struct rtc_class_ops m48t86_rtc_ops = {
1d98af87 AZ	138	.read_time = m48t86_rtc_read_time,
	139	.set_time = m48t86_rtc_set_time,
	140	.proc = m48t86_rtc_proc,
	141	};
	142
5a167f45	143	static int m48t86_rtc_probe(struct platform_device *dev)
1d98af87 AZ	144	{
1d98af87 AZ	145	unsigned char reg;
b5f0902d	146	struct m48t86_ops *ops = dev_get_platdata(&dev->dev);
d5b6bb0a JH	147	struct rtc_device *rtc;
	148
	149	rtc = devm_rtc_device_register(&dev->dev, "m48t86",
68b54f47	150	&m48t86_rtc_ops, THIS_MODULE);
1d98af87	151
d1d65b77	152	if (IS_ERR(rtc))
1d98af87	153	return PTR_ERR(rtc);
1d98af87 AZ	154
	155	platform_set_drvdata(dev, rtc);
	156
	157	/* read battery status */
68b54f47	158	reg = ops->readbyte(M48T86_D);
1d98af87	159	dev_info(&dev->dev, "battery %s\n",
68b54f47	160	(reg & M48T86_D_VRT) ? "ok" : "exhausted");
1d98af87 AZ	161
	162	return 0;
	163	}
	164
1d98af87 AZ	165	static struct platform_driver m48t86_rtc_platform_driver = {
	166	.driver = {
	167	.name = "rtc-m48t86",
1d98af87 AZ	168	},
1d98af87 AZ	169	.probe = m48t86_rtc_probe,
1d98af87 AZ	170	};
1d98af87 AZ	171
0c4eae66	172	module_platform_driver(m48t86_rtc_platform_driver);
1d98af87 AZ	173
	174	MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
	175	MODULE_DESCRIPTION("M48T86 RTC driver");
	176	MODULE_LICENSE("GPL");
ad28a07b	177	MODULE_ALIAS("platform:rtc-m48t86");