[net-next-2.6.git] / drivers / rtc / rtc-ds3234.c

/* rtc-ds3234.c
 *
 * Driver for Dallas Semiconductor (DS3234) SPI RTC with Integrated Crystal
 * and SRAM.
 *
 * Copyright (C) 2008 MIMOMax Wireless Ltd.
 *
 * 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.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/bcd.h>

#define DS3234_REG_SECONDS	0x00
#define DS3234_REG_MINUTES	0x01
#define DS3234_REG_HOURS	0x02
#define DS3234_REG_DAY		0x03
#define DS3234_REG_DATE		0x04
#define DS3234_REG_MONTH	0x05
#define DS3234_REG_YEAR		0x06
#define DS3234_REG_CENTURY	(1 << 7) /* Bit 7 of the Month register */

#define DS3234_REG_CONTROL	0x0E
#define DS3234_REG_CONT_STAT	0x0F

static int ds3234_set_reg(struct device *dev, unsigned char address,
				unsigned char data)
{
	struct spi_device *spi = to_spi_device(dev);
	unsigned char buf[2];

	/* MSB must be '1' to indicate write */
	buf[0] = address | 0x80;
	buf[1] = data;

	return spi_write_then_read(spi, buf, 2, NULL, 0);
}

static int ds3234_get_reg(struct device *dev, unsigned char address,
				unsigned char *data)
{
	struct spi_device *spi = to_spi_device(dev);

	*data = address & 0x7f;

	return spi_write_then_read(spi, data, 1, data, 1);
}

static int ds3234_read_time(struct device *dev, struct rtc_time *dt)
{
	int err;
	unsigned char buf[8];
	struct spi_device *spi = to_spi_device(dev);

	buf[0] = 0x00; /* Start address */

	err = spi_write_then_read(spi, buf, 1, buf, 8);
	if (err != 0)
		return err;

	/* Seconds, Minutes, Hours, Day, Date, Month, Year */
	dt->tm_sec	= bcd2bin(buf[0]);
	dt->tm_min	= bcd2bin(buf[1]);
	dt->tm_hour	= bcd2bin(buf[2] & 0x3f);
	dt->tm_wday	= bcd2bin(buf[3]) - 1; /* 0 = Sun */
	dt->tm_mday	= bcd2bin(buf[4]);
	dt->tm_mon	= bcd2bin(buf[5] & 0x1f) - 1; /* 0 = Jan */
	dt->tm_year 	= bcd2bin(buf[6] & 0xff) + 100; /* Assume 20YY */

	return rtc_valid_tm(dt);
}

static int ds3234_set_time(struct device *dev, struct rtc_time *dt)
{
	ds3234_set_reg(dev, DS3234_REG_SECONDS, bin2bcd(dt->tm_sec));
	ds3234_set_reg(dev, DS3234_REG_MINUTES, bin2bcd(dt->tm_min));
	ds3234_set_reg(dev, DS3234_REG_HOURS, bin2bcd(dt->tm_hour) & 0x3f);

	/* 0 = Sun */
	ds3234_set_reg(dev, DS3234_REG_DAY, bin2bcd(dt->tm_wday + 1));
	ds3234_set_reg(dev, DS3234_REG_DATE, bin2bcd(dt->tm_mday));

	/* 0 = Jan */
	ds3234_set_reg(dev, DS3234_REG_MONTH, bin2bcd(dt->tm_mon + 1));

	/* Assume 20YY although we just want to make sure not to go negative. */
	if (dt->tm_year > 100)
		dt->tm_year -= 100;

	ds3234_set_reg(dev, DS3234_REG_YEAR, bin2bcd(dt->tm_year));

	return 0;
}

static const struct rtc_class_ops ds3234_rtc_ops = {
	.read_time	= ds3234_read_time,
	.set_time	= ds3234_set_time,
};

static int __devinit ds3234_probe(struct spi_device *spi)
{
	struct rtc_device *rtc;
	unsigned char tmp;
	int res;

	spi->mode = SPI_MODE_3;
	spi->bits_per_word = 8;
	spi_setup(spi);

	res = ds3234_get_reg(&spi->dev, DS3234_REG_SECONDS, &tmp);
	if (res != 0)
		return res;

	/* Control settings
	 *
	 * CONTROL_REG
	 * BIT 7	6	5	4	3	2	1	0
	 *     EOSC	BBSQW	CONV	RS2	RS1	INTCN	A2IE	A1IE
	 *
	 *     0	0	0	1	1	1	0	0
	 *
	 * CONTROL_STAT_REG
	 * BIT 7	6	5	4	3	2	1	0
	 *     OSF	BB32kHz	CRATE1	CRATE0	EN32kHz	BSY	A2F	A1F
	 *
	 *     1	0	0	0	1	0	0	0
	 */
	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
	ds3234_set_reg(&spi->dev, DS3234_REG_CONTROL, tmp & 0x1c);

	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
	ds3234_set_reg(&spi->dev, DS3234_REG_CONT_STAT, tmp & 0x88);

	/* Print our settings */
	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);

	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);

	rtc = rtc_device_register("ds3234",
				&spi->dev, &ds3234_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	dev_set_drvdata(&spi->dev, rtc);

	return 0;
}

static int __devexit ds3234_remove(struct spi_device *spi)
{
	struct rtc_device *rtc = platform_get_drvdata(spi);

	rtc_device_unregister(rtc);
	return 0;
}

static struct spi_driver ds3234_driver = {
	.driver = {
		.name	 = "ds3234",
		.owner	= THIS_MODULE,
	},
	.probe	 = ds3234_probe,
	.remove = __devexit_p(ds3234_remove),
};

static __init int ds3234_init(void)
{
	return spi_register_driver(&ds3234_driver);
}
module_init(ds3234_init);

static __exit void ds3234_exit(void)
{
	spi_unregister_driver(&ds3234_driver);
}
module_exit(ds3234_exit);

MODULE_DESCRIPTION("DS3234 SPI RTC driver");
MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:ds3234");
Commit	Line	Data
f6009157	1	/* rtc-ds3234.c
2f9b75e0 DA	2	*
	3	* Driver for Dallas Semiconductor (DS3234) SPI RTC with Integrated Crystal
	4	* and SRAM.
	5	*
	6	* Copyright (C) 2008 MIMOMax Wireless Ltd.
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
2f9b75e0 DA	12	*/
2f9b75e0 DA	13
f6009157 AZ	14	#include <linux/init.h>
f6009157 AZ	15	#include <linux/module.h>
2f9b75e0 DA	16	#include <linux/device.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/rtc.h>
	19	#include <linux/spi/spi.h>
	20	#include <linux/bcd.h>
	21
	22	#define DS3234_REG_SECONDS 0x00
	23	#define DS3234_REG_MINUTES 0x01
	24	#define DS3234_REG_HOURS 0x02
	25	#define DS3234_REG_DAY 0x03
	26	#define DS3234_REG_DATE 0x04
	27	#define DS3234_REG_MONTH 0x05
	28	#define DS3234_REG_YEAR 0x06
	29	#define DS3234_REG_CENTURY (1 << 7) /* Bit 7 of the Month register */
	30
	31	#define DS3234_REG_CONTROL 0x0E
	32	#define DS3234_REG_CONT_STAT 0x0F
	33
f6009157	34	static int ds3234_set_reg(struct device *dev, unsigned char address,
2f9b75e0 DA	35	unsigned char data)
	36	{
	37	struct spi_device *spi = to_spi_device(dev);
	38	unsigned char buf[2];
	39
	40	/* MSB must be '1' to indicate write */
	41	buf[0] = address \| 0x80;
	42	buf[1] = data;
	43
f6009157	44	return spi_write_then_read(spi, buf, 2, NULL, 0);
2f9b75e0 DA	45	}
	46
	47	static int ds3234_get_reg(struct device *dev, unsigned char address,
	48	unsigned char *data)
	49	{
	50	struct spi_device *spi = to_spi_device(dev);
2f9b75e0	51
f6009157	52	*data = address & 0x7f;
2f9b75e0	53
f6009157	54	return spi_write_then_read(spi, data, 1, data, 1);
2f9b75e0 DA	55	}
2f9b75e0 DA	56
f6009157	57	static int ds3234_read_time(struct device dev, struct rtc_time dt)
2f9b75e0	58	{
f6009157 AZ	59	int err;
f6009157 AZ	60	unsigned char buf[8];
2f9b75e0	61	struct spi_device *spi = to_spi_device(dev);
2f9b75e0	62
f6009157	63	buf[0] = 0x00; /* Start address */
2f9b75e0	64
f6009157 AZ	65	err = spi_write_then_read(spi, buf, 1, buf, 8);
	66	if (err != 0)
	67	return err;
	68
	69	/* Seconds, Minutes, Hours, Day, Date, Month, Year */
	70	dt->tm_sec = bcd2bin(buf[0]);
	71	dt->tm_min = bcd2bin(buf[1]);
	72	dt->tm_hour = bcd2bin(buf[2] & 0x3f);
	73	dt->tm_wday = bcd2bin(buf[3]) - 1; /* 0 = Sun */
	74	dt->tm_mday = bcd2bin(buf[4]);
	75	dt->tm_mon = bcd2bin(buf[5] & 0x1f) - 1; /* 0 = Jan */
	76	dt->tm_year = bcd2bin(buf[6] & 0xff) + 100; /* Assume 20YY */
	77
	78	return rtc_valid_tm(dt);
2f9b75e0 DA	79	}
2f9b75e0 DA	80
f6009157	81	static int ds3234_set_time(struct device dev, struct rtc_time dt)
2f9b75e0	82	{
2f9b75e0 DA	83	ds3234_set_reg(dev, DS3234_REG_SECONDS, bin2bcd(dt->tm_sec));
	84	ds3234_set_reg(dev, DS3234_REG_MINUTES, bin2bcd(dt->tm_min));
	85	ds3234_set_reg(dev, DS3234_REG_HOURS, bin2bcd(dt->tm_hour) & 0x3f);
	86
	87	/* 0 = Sun */
	88	ds3234_set_reg(dev, DS3234_REG_DAY, bin2bcd(dt->tm_wday + 1));
	89	ds3234_set_reg(dev, DS3234_REG_DATE, bin2bcd(dt->tm_mday));
	90
	91	/* 0 = Jan */
	92	ds3234_set_reg(dev, DS3234_REG_MONTH, bin2bcd(dt->tm_mon + 1));
	93
	94	/* Assume 20YY although we just want to make sure not to go negative. */
	95	if (dt->tm_year > 100)
	96	dt->tm_year -= 100;
	97
	98	ds3234_set_reg(dev, DS3234_REG_YEAR, bin2bcd(dt->tm_year));
	99
	100	return 0;
	101	}
	102
2f9b75e0 DA	103	static const struct rtc_class_ops ds3234_rtc_ops = {
	104	.read_time = ds3234_read_time,
	105	.set_time = ds3234_set_time,
	106	};
	107
bcc378e7	108	static int __devinit ds3234_probe(struct spi_device *spi)
2f9b75e0 DA	109	{
	110	struct rtc_device *rtc;
	111	unsigned char tmp;
2f9b75e0 DA	112	int res;
2f9b75e0 DA	113
2f9b75e0 DA	114	spi->mode = SPI_MODE_3;
	115	spi->bits_per_word = 8;
	116	spi_setup(spi);
	117
2f9b75e0	118	res = ds3234_get_reg(&spi->dev, DS3234_REG_SECONDS, &tmp);
f6009157	119	if (res != 0)
2f9b75e0	120	return res;
2f9b75e0 DA	121
	122	/* Control settings
	123	*
	124	* CONTROL_REG
	125	* BIT 7 6 5 4 3 2 1 0
	126	* EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE
	127	*
	128	* 0 0 0 1 1 1 0 0
	129	*
	130	* CONTROL_STAT_REG
	131	* BIT 7 6 5 4 3 2 1 0
	132	* OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F
	133	*
	134	* 1 0 0 0 1 0 0 0
	135	*/
	136	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
	137	ds3234_set_reg(&spi->dev, DS3234_REG_CONTROL, tmp & 0x1c);
	138
	139	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
	140	ds3234_set_reg(&spi->dev, DS3234_REG_CONT_STAT, tmp & 0x88);
	141
	142	/* Print our settings */
	143	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
	144	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
	145
	146	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
	147	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
	148
f6009157 AZ	149	rtc = rtc_device_register("ds3234",
	150	&spi->dev, &ds3234_rtc_ops, THIS_MODULE);
	151	if (IS_ERR(rtc))
	152	return PTR_ERR(rtc);
	153
	154	dev_set_drvdata(&spi->dev, rtc);
	155
2f9b75e0 DA	156	return 0;
	157	}
	158
bcc378e7	159	static int __devexit ds3234_remove(struct spi_device *spi)
2f9b75e0	160	{
f6009157	161	struct rtc_device *rtc = platform_get_drvdata(spi);
2f9b75e0	162
f6009157	163	rtc_device_unregister(rtc);
2f9b75e0 DA	164	return 0;
	165	}
	166
	167	static struct spi_driver ds3234_driver = {
	168	.driver = {
	169	.name = "ds3234",
2f9b75e0 DA	170	.owner = THIS_MODULE,
	171	},
	172	.probe = ds3234_probe,
	173	.remove = __devexit_p(ds3234_remove),
	174	};
	175
	176	static __init int ds3234_init(void)
	177	{
2f9b75e0 DA	178	return spi_register_driver(&ds3234_driver);
	179	}
	180	module_init(ds3234_init);
	181
	182	static __exit void ds3234_exit(void)
	183	{
	184	spi_unregister_driver(&ds3234_driver);
	185	}
	186	module_exit(ds3234_exit);
	187
	188	MODULE_DESCRIPTION("DS3234 SPI RTC driver");
	189	MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
	190	MODULE_LICENSE("GPL");
e0626e38	191	MODULE_ALIAS("spi:ds3234");