[mirror_ubuntu-eoan-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>
#include <linux/io.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)

struct m48t86_rtc_info {
	void __iomem *index_reg;
	void __iomem *data_reg;
	struct rtc_device *rtc;
	struct m48t86_ops *ops;
};

static unsigned char m48t86_readb(struct device *dev, unsigned long addr)
{
	struct m48t86_rtc_info *info = dev_get_drvdata(dev);
	unsigned char value;

	if (info->ops) {
		value = info->ops->readbyte(addr);
	} else {
		writeb(addr, info->index_reg);
		value = readb(info->data_reg);
	}
	return value;
}

static void m48t86_writeb(struct device *dev,
			  unsigned char value, unsigned long addr)
{
	struct m48t86_rtc_info *info = dev_get_drvdata(dev);

	if (info->ops) {
		info->ops->writebyte(value, addr);
	} else {
		writeb(addr, info->index_reg);
		writeb(value, info->data_reg);
	}
}

static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char reg;

	reg = m48t86_readb(dev, M48T86_B);

	if (reg & M48T86_B_DM) {
		/* data (binary) mode */
		tm->tm_sec	= m48t86_readb(dev, M48T86_SEC);
		tm->tm_min	= m48t86_readb(dev, M48T86_MIN);
		tm->tm_hour	= m48t86_readb(dev, M48T86_HOUR) & 0x3f;
		tm->tm_mday	= m48t86_readb(dev, M48T86_DOM);
		/* tm_mon is 0-11 */
		tm->tm_mon	= m48t86_readb(dev, M48T86_MONTH) - 1;
		tm->tm_year	= m48t86_readb(dev, M48T86_YEAR) + 100;
		tm->tm_wday	= m48t86_readb(dev, M48T86_DOW);
	} else {
		/* bcd mode */
		tm->tm_sec	= bcd2bin(m48t86_readb(dev, M48T86_SEC));
		tm->tm_min	= bcd2bin(m48t86_readb(dev, M48T86_MIN));
		tm->tm_hour	= bcd2bin(m48t86_readb(dev, M48T86_HOUR) &
					  0x3f);
		tm->tm_mday	= bcd2bin(m48t86_readb(dev, M48T86_DOM));
		/* tm_mon is 0-11 */
		tm->tm_mon	= bcd2bin(m48t86_readb(dev, M48T86_MONTH)) - 1;
		tm->tm_year	= bcd2bin(m48t86_readb(dev, M48T86_YEAR)) + 100;
		tm->tm_wday	= bcd2bin(m48t86_readb(dev, M48T86_DOW));
	}

	/* correct the hour if the clock is in 12h mode */
	if (!(reg & M48T86_B_H24))
		if (m48t86_readb(dev, 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;

	reg = m48t86_readb(dev, M48T86_B);

	/* update flag and 24h mode */
	reg |= M48T86_B_SET | M48T86_B_H24;
	m48t86_writeb(dev, reg, M48T86_B);

	if (reg & M48T86_B_DM) {
		/* data (binary) mode */
		m48t86_writeb(dev, tm->tm_sec, M48T86_SEC);
		m48t86_writeb(dev, tm->tm_min, M48T86_MIN);
		m48t86_writeb(dev, tm->tm_hour, M48T86_HOUR);
		m48t86_writeb(dev, tm->tm_mday, M48T86_DOM);
		m48t86_writeb(dev, tm->tm_mon + 1, M48T86_MONTH);
		m48t86_writeb(dev, tm->tm_year % 100, M48T86_YEAR);
		m48t86_writeb(dev, tm->tm_wday, M48T86_DOW);
	} else {
		/* bcd mode */
		m48t86_writeb(dev, bin2bcd(tm->tm_sec), M48T86_SEC);
		m48t86_writeb(dev, bin2bcd(tm->tm_min), M48T86_MIN);
		m48t86_writeb(dev, bin2bcd(tm->tm_hour), M48T86_HOUR);
		m48t86_writeb(dev, bin2bcd(tm->tm_mday), M48T86_DOM);
		m48t86_writeb(dev, bin2bcd(tm->tm_mon + 1), M48T86_MONTH);
		m48t86_writeb(dev, bin2bcd(tm->tm_year % 100), M48T86_YEAR);
		m48t86_writeb(dev, bin2bcd(tm->tm_wday), M48T86_DOW);
	}

	/* update ended */
	reg &= ~M48T86_B_SET;
	m48t86_writeb(dev, reg, M48T86_B);

	return 0;
}

static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq)
{
	unsigned char reg;

	reg = m48t86_readb(dev, M48T86_B);

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

	reg = m48t86_readb(dev, 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 *pdev)
{
	struct m48t86_rtc_info *info;
	unsigned char reg;

	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	info->ops = dev_get_platdata(&pdev->dev);
	if (!info->ops) {
		struct resource *res;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		if (!res)
			return -ENODEV;
		info->index_reg = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(info->index_reg))
			return PTR_ERR(info->index_reg);

		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
		if (!res)
			return -ENODEV;
		info->data_reg = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(info->data_reg))
			return PTR_ERR(info->data_reg);
	}

	dev_set_drvdata(&pdev->dev, info);

	info->rtc = devm_rtc_device_register(&pdev->dev, "m48t86",
					     &m48t86_rtc_ops, THIS_MODULE);
	if (IS_ERR(info->rtc))
		return PTR_ERR(info->rtc);

	/* read battery status */
	reg = m48t86_readb(&pdev->dev, M48T86_D);
	dev_info(&pdev->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	20	#include <linux/bcd.h>
8057c86d	21	#include <linux/io.h>
1d98af87	22
68b54f47 HS	23	#define M48T86_SEC 0x00
	24	#define M48T86_SECALRM 0x01
	25	#define M48T86_MIN 0x02
	26	#define M48T86_MINALRM 0x03
	27	#define M48T86_HOUR 0x04
	28	#define M48T86_HOURALRM 0x05
	29	#define M48T86_DOW 0x06 /* 1 = sunday */
	30	#define M48T86_DOM 0x07
	31	#define M48T86_MONTH 0x08 /* 1 - 12 */
	32	#define M48T86_YEAR 0x09 /* 0 - 99 */
	33	#define M48T86_A 0x0a
	34	#define M48T86_B 0x0b
	35	#define M48T86_B_SET BIT(7)
	36	#define M48T86_B_DM BIT(2)
	37	#define M48T86_B_H24 BIT(1)
	38	#define M48T86_C 0x0c
	39	#define M48T86_D 0x0d
	40	#define M48T86_D_VRT BIT(7)
1d98af87	41
8057c86d HS	42	struct m48t86_rtc_info {
	43	void __iomem *index_reg;
	44	void __iomem *data_reg;
	45	struct rtc_device *rtc;
	46	struct m48t86_ops *ops;
	47	};
	48
	49	static unsigned char m48t86_readb(struct device *dev, unsigned long addr)
	50	{
	51	struct m48t86_rtc_info *info = dev_get_drvdata(dev);
	52	unsigned char value;
	53
	54	if (info->ops) {
	55	value = info->ops->readbyte(addr);
	56	} else {
	57	writeb(addr, info->index_reg);
	58	value = readb(info->data_reg);
	59	}
	60	return value;
	61	}
	62
	63	static void m48t86_writeb(struct device *dev,
	64	unsigned char value, unsigned long addr)
	65	{
	66	struct m48t86_rtc_info *info = dev_get_drvdata(dev);
	67
	68	if (info->ops) {
	69	info->ops->writebyte(value, addr);
	70	} else {
	71	writeb(addr, info->index_reg);
	72	writeb(value, info->data_reg);
	73	}
	74	}
	75
1d98af87 AZ	76	static int m48t86_rtc_read_time(struct device dev, struct rtc_time tm)
	77	{
	78	unsigned char reg;
1d98af87	79
8057c86d	80	reg = m48t86_readb(dev, M48T86_B);
1d98af87	81
68b54f47	82	if (reg & M48T86_B_DM) {
1d98af87	83	/* data (binary) mode */
8057c86d HS	84	tm->tm_sec = m48t86_readb(dev, M48T86_SEC);
	85	tm->tm_min = m48t86_readb(dev, M48T86_MIN);
	86	tm->tm_hour = m48t86_readb(dev, M48T86_HOUR) & 0x3f;
	87	tm->tm_mday = m48t86_readb(dev, M48T86_DOM);
1d98af87	88	/* tm_mon is 0-11 */
8057c86d HS	89	tm->tm_mon = m48t86_readb(dev, M48T86_MONTH) - 1;
	90	tm->tm_year = m48t86_readb(dev, M48T86_YEAR) + 100;
	91	tm->tm_wday = m48t86_readb(dev, M48T86_DOW);
1d98af87 AZ	92	} else {
1d98af87 AZ	93	/* bcd mode */
8057c86d HS	94	tm->tm_sec = bcd2bin(m48t86_readb(dev, M48T86_SEC));
	95	tm->tm_min = bcd2bin(m48t86_readb(dev, M48T86_MIN));
	96	tm->tm_hour = bcd2bin(m48t86_readb(dev, M48T86_HOUR) &
	97	0x3f);
	98	tm->tm_mday = bcd2bin(m48t86_readb(dev, M48T86_DOM));
1d98af87	99	/* tm_mon is 0-11 */
8057c86d HS	100	tm->tm_mon = bcd2bin(m48t86_readb(dev, M48T86_MONTH)) - 1;
	101	tm->tm_year = bcd2bin(m48t86_readb(dev, M48T86_YEAR)) + 100;
	102	tm->tm_wday = bcd2bin(m48t86_readb(dev, M48T86_DOW));
1d98af87 AZ	103	}
	104
	105	/* correct the hour if the clock is in 12h mode */
68b54f47	106	if (!(reg & M48T86_B_H24))
8057c86d	107	if (m48t86_readb(dev, M48T86_HOUR) & 0x80)
1d98af87 AZ	108	tm->tm_hour += 12;
1d98af87 AZ	109
52142ed4	110	return rtc_valid_tm(tm);
1d98af87 AZ	111	}
	112
	113	static int m48t86_rtc_set_time(struct device dev, struct rtc_time tm)
	114	{
	115	unsigned char reg;
1d98af87	116
8057c86d	117	reg = m48t86_readb(dev, M48T86_B);
1d98af87 AZ	118
1d98af87 AZ	119	/* update flag and 24h mode */
68b54f47	120	reg \|= M48T86_B_SET \| M48T86_B_H24;
8057c86d	121	m48t86_writeb(dev, reg, M48T86_B);
1d98af87	122
68b54f47	123	if (reg & M48T86_B_DM) {
1d98af87	124	/* data (binary) mode */
8057c86d HS	125	m48t86_writeb(dev, tm->tm_sec, M48T86_SEC);
	126	m48t86_writeb(dev, tm->tm_min, M48T86_MIN);
	127	m48t86_writeb(dev, tm->tm_hour, M48T86_HOUR);
	128	m48t86_writeb(dev, tm->tm_mday, M48T86_DOM);
	129	m48t86_writeb(dev, tm->tm_mon + 1, M48T86_MONTH);
	130	m48t86_writeb(dev, tm->tm_year % 100, M48T86_YEAR);
	131	m48t86_writeb(dev, tm->tm_wday, M48T86_DOW);
1d98af87 AZ	132	} else {
1d98af87 AZ	133	/* bcd mode */
8057c86d HS	134	m48t86_writeb(dev, bin2bcd(tm->tm_sec), M48T86_SEC);
	135	m48t86_writeb(dev, bin2bcd(tm->tm_min), M48T86_MIN);
	136	m48t86_writeb(dev, bin2bcd(tm->tm_hour), M48T86_HOUR);
	137	m48t86_writeb(dev, bin2bcd(tm->tm_mday), M48T86_DOM);
	138	m48t86_writeb(dev, bin2bcd(tm->tm_mon + 1), M48T86_MONTH);
	139	m48t86_writeb(dev, bin2bcd(tm->tm_year % 100), M48T86_YEAR);
	140	m48t86_writeb(dev, bin2bcd(tm->tm_wday), M48T86_DOW);
1d98af87 AZ	141	}
	142
	143	/* update ended */
68b54f47	144	reg &= ~M48T86_B_SET;
8057c86d	145	m48t86_writeb(dev, reg, M48T86_B);
1d98af87 AZ	146
	147	return 0;
	148	}
	149
	150	static int m48t86_rtc_proc(struct device dev, struct seq_file seq)
	151	{
	152	unsigned char reg;
1d98af87	153
8057c86d	154	reg = m48t86_readb(dev, M48T86_B);
1d98af87	155
1d98af87	156	seq_printf(seq, "mode\t\t: %s\n",
68b54f47	157	(reg & M48T86_B_DM) ? "binary" : "bcd");
1d98af87	158
8057c86d	159	reg = m48t86_readb(dev, M48T86_D);
1d98af87 AZ	160
1d98af87 AZ	161	seq_printf(seq, "battery\t\t: %s\n",
68b54f47	162	(reg & M48T86_D_VRT) ? "ok" : "exhausted");
1d98af87 AZ	163
	164	return 0;
	165	}
	166
ff8371ac	167	static const struct rtc_class_ops m48t86_rtc_ops = {
1d98af87 AZ	168	.read_time = m48t86_rtc_read_time,
	169	.set_time = m48t86_rtc_set_time,
	170	.proc = m48t86_rtc_proc,
	171	};
	172
8057c86d	173	static int m48t86_rtc_probe(struct platform_device *pdev)
1d98af87	174	{
8057c86d	175	struct m48t86_rtc_info *info;
1d98af87	176	unsigned char reg;
d5b6bb0a	177
8057c86d HS	178	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	179	if (!info)
	180	return -ENOMEM;
	181
	182	info->ops = dev_get_platdata(&pdev->dev);
	183	if (!info->ops) {
	184	struct resource *res;
	185
	186	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	187	if (!res)
	188	return -ENODEV;
	189	info->index_reg = devm_ioremap_resource(&pdev->dev, res);
	190	if (IS_ERR(info->index_reg))
	191	return PTR_ERR(info->index_reg);
	192
	193	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	194	if (!res)
	195	return -ENODEV;
	196	info->data_reg = devm_ioremap_resource(&pdev->dev, res);
	197	if (IS_ERR(info->data_reg))
	198	return PTR_ERR(info->data_reg);
	199	}
1d98af87	200
8057c86d	201	dev_set_drvdata(&pdev->dev, info);
1d98af87	202
8057c86d HS	203	info->rtc = devm_rtc_device_register(&pdev->dev, "m48t86",
	204	&m48t86_rtc_ops, THIS_MODULE);
	205	if (IS_ERR(info->rtc))
	206	return PTR_ERR(info->rtc);
1d98af87 AZ	207
1d98af87 AZ	208	/* read battery status */
8057c86d HS	209	reg = m48t86_readb(&pdev->dev, M48T86_D);
8057c86d HS	210	dev_info(&pdev->dev, "battery %s\n",
68b54f47	211	(reg & M48T86_D_VRT) ? "ok" : "exhausted");
1d98af87 AZ	212
	213	return 0;
	214	}
	215
1d98af87 AZ	216	static struct platform_driver m48t86_rtc_platform_driver = {
	217	.driver = {
	218	.name = "rtc-m48t86",
1d98af87 AZ	219	},
1d98af87 AZ	220	.probe = m48t86_rtc_probe,
1d98af87 AZ	221	};
1d98af87 AZ	222
0c4eae66	223	module_platform_driver(m48t86_rtc_platform_driver);
1d98af87 AZ	224
	225	MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
	226	MODULE_DESCRIPTION("M48T86 RTC driver");
	227	MODULE_LICENSE("GPL");
ad28a07b	228	MODULE_ALIAS("platform:rtc-m48t86");