[deliverable/linux.git] / drivers / rtc / rtc-r9701.c

/*
 * Driver for Epson RTC-9701JE
 *
 * Copyright (C) 2008 Magnus Damm
 *
 * Based on rtc-max6902.c
 *
 * Copyright (C) 2006 8D Technologies inc.
 * Copyright (C) 2004 Compulab 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/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/bitops.h>

#define RSECCNT	0x00	/* Second Counter */
#define RMINCNT	0x01	/* Minute Counter */
#define RHRCNT	0x02	/* Hour Counter */
#define RWKCNT	0x03	/* Week Counter */
#define RDAYCNT	0x04	/* Day Counter */
#define RMONCNT	0x05	/* Month Counter */
#define RYRCNT	0x06	/* Year Counter */
#define R100CNT	0x07	/* Y100 Counter */
#define RMINAR	0x08	/* Minute Alarm */
#define RHRAR	0x09	/* Hour Alarm */
#define RWKAR	0x0a	/* Week/Day Alarm */
#define RTIMCNT	0x0c	/* Interval Timer */
#define REXT	0x0d	/* Extension Register */
#define RFLAG	0x0e	/* RTC Flag Register */
#define RCR	0x0f	/* RTC Control Register */

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

	buf[0] = address & 0x7f;
	buf[1] = data;

	return spi_write(spi, buf, ARRAY_SIZE(buf));
}

static int read_regs(struct device *dev, unsigned char *regs, int no_regs)
{
	struct spi_device *spi = to_spi_device(dev);
	u8 txbuf[1], rxbuf[1];
	int k, ret;

	ret = 0;

	for (k = 0; ret == 0 && k < no_regs; k++) {
		txbuf[0] = 0x80 | regs[k];
		ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
		regs[k] = rxbuf[0];
	}

	return ret;
}

static int r9701_get_datetime(struct device *dev, struct rtc_time *dt)
{
	int ret;
	unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT,
				RDAYCNT, RMONCNT, RYRCNT };

	ret = read_regs(dev, buf, ARRAY_SIZE(buf));
	if (ret)
		return ret;

	memset(dt, 0, sizeof(*dt));

	dt->tm_sec = BCD2BIN(buf[0]); /* RSECCNT */
	dt->tm_min = BCD2BIN(buf[1]); /* RMINCNT */
	dt->tm_hour = BCD2BIN(buf[2]); /* RHRCNT */

	dt->tm_mday = BCD2BIN(buf[3]); /* RDAYCNT */
	dt->tm_mon = BCD2BIN(buf[4]) - 1; /* RMONCNT */
	dt->tm_year = BCD2BIN(buf[5]) + 100; /* RYRCNT */

	/* the rtc device may contain illegal values on power up
	 * according to the data sheet. make sure they are valid.
	 */

	return rtc_valid_tm(dt);
}

static int r9701_set_datetime(struct device *dev, struct rtc_time *dt)
{
	int ret, year;

	year = dt->tm_year + 1900;
	if (year >= 2100 || year < 2000)
		return -EINVAL;

	ret = write_reg(dev, RHRCNT, BIN2BCD(dt->tm_hour));
	ret = ret ? ret : write_reg(dev, RMINCNT, BIN2BCD(dt->tm_min));
	ret = ret ? ret : write_reg(dev, RSECCNT, BIN2BCD(dt->tm_sec));
	ret = ret ? ret : write_reg(dev, RDAYCNT, BIN2BCD(dt->tm_mday));
	ret = ret ? ret : write_reg(dev, RMONCNT, BIN2BCD(dt->tm_mon + 1));
	ret = ret ? ret : write_reg(dev, RYRCNT, BIN2BCD(dt->tm_year - 100));
	ret = ret ? ret : write_reg(dev, RWKCNT, 1 << dt->tm_wday);

	return ret;
}

static const struct rtc_class_ops r9701_rtc_ops = {
	.read_time	= r9701_get_datetime,
	.set_time	= r9701_set_datetime,
};

static int __devinit r9701_probe(struct spi_device *spi)
{
	struct rtc_device *rtc;
	unsigned char tmp;
	int res;

	rtc = rtc_device_register("r9701",
				&spi->dev, &r9701_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	dev_set_drvdata(&spi->dev, rtc);

	tmp = R100CNT;
	res = read_regs(&spi->dev, &tmp, 1);
	if (res || tmp != 0x20) {
		rtc_device_unregister(rtc);
		return res;
	}

	return 0;
}

static int __devexit r9701_remove(struct spi_device *spi)
{
	struct rtc_device *rtc = dev_get_drvdata(&spi->dev);

	rtc_device_unregister(rtc);
	return 0;
}

static struct spi_driver r9701_driver = {
	.driver = {
		.name	= "rtc-r9701",
		.owner	= THIS_MODULE,
	},
	.probe	= r9701_probe,
	.remove = __devexit_p(r9701_remove),
};

static __init int r9701_init(void)
{
	return spi_register_driver(&r9701_driver);
}
module_init(r9701_init);

static __exit void r9701_exit(void)
{
	spi_unregister_driver(&r9701_driver);
}
module_exit(r9701_exit);

MODULE_DESCRIPTION("r9701 spi RTC driver");
MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
MODULE_LICENSE("GPL");
Commit	Line	Data
75b61022	1	/*
2805b969 MD	2	* Driver for Epson RTC-9701JE
	3	*
	4	* Copyright (C) 2008 Magnus Damm
	5	*
75b61022	6	* Based on rtc-max6902.c
2805b969 MD	7	*
	8	* Copyright (C) 2006 8D Technologies inc.
	9	* Copyright (C) 2004 Compulab Ltd.
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
	15
	16	#include <linux/module.h>
	17	#include <linux/version.h>
	18	#include <linux/kernel.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/device.h>
	21	#include <linux/init.h>
	22	#include <linux/rtc.h>
	23	#include <linux/spi/spi.h>
	24	#include <linux/bcd.h>
	25	#include <linux/delay.h>
	26	#include <linux/bitops.h>
	27
	28	#define RSECCNT 0x00 /* Second Counter */
	29	#define RMINCNT 0x01 /* Minute Counter */
	30	#define RHRCNT 0x02 /* Hour Counter */
	31	#define RWKCNT 0x03 /* Week Counter */
	32	#define RDAYCNT 0x04 /* Day Counter */
	33	#define RMONCNT 0x05 /* Month Counter */
	34	#define RYRCNT 0x06 /* Year Counter */
	35	#define R100CNT 0x07 /* Y100 Counter */
	36	#define RMINAR 0x08 /* Minute Alarm */
	37	#define RHRAR 0x09 /* Hour Alarm */
	38	#define RWKAR 0x0a /* Week/Day Alarm */
	39	#define RTIMCNT 0x0c /* Interval Timer */
	40	#define REXT 0x0d /* Extension Register */
	41	#define RFLAG 0x0e /* RTC Flag Register */
	42	#define RCR 0x0f /* RTC Control Register */
	43
	44	static int write_reg(struct device *dev, int address, unsigned char data)
	45	{
	46	struct spi_device *spi = to_spi_device(dev);
	47	unsigned char buf[2];
	48
	49	buf[0] = address & 0x7f;
	50	buf[1] = data;
	51
	52	return spi_write(spi, buf, ARRAY_SIZE(buf));
	53	}
	54
	55	static int read_regs(struct device dev, unsigned char regs, int no_regs)
	56	{
	57	struct spi_device *spi = to_spi_device(dev);
	58	u8 txbuf[1], rxbuf[1];
	59	int k, ret;
	60
	61	ret = 0;
	62
	63	for (k = 0; ret == 0 && k < no_regs; k++) {
	64	txbuf[0] = 0x80 \| regs[k];
	65	ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
	66	regs[k] = rxbuf[0];
	67	}
	68
	69	return ret;
	70	}
71
72	static int r9701_get_datetime(struct device dev, struct rtc_time dt)
73	{
2805b969 MD	74	int ret;
	75	unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT,
	76	RDAYCNT, RMONCNT, RYRCNT };
	77
75b61022	78	ret = read_regs(dev, buf, ARRAY_SIZE(buf));
2805b969 MD	79	if (ret)
	80	return ret;
	81
	82	memset(dt, 0, sizeof(*dt));
	83
	84	dt->tm_sec = BCD2BIN(buf[0]); /* RSECCNT */
	85	dt->tm_min = BCD2BIN(buf[1]); /* RMINCNT */
	86	dt->tm_hour = BCD2BIN(buf[2]); /* RHRCNT */
	87
	88	dt->tm_mday = BCD2BIN(buf[3]); /* RDAYCNT */
	89	dt->tm_mon = BCD2BIN(buf[4]) - 1; /* RMONCNT */
	90	dt->tm_year = BCD2BIN(buf[5]) + 100; /* RYRCNT */
	91
	92	/* the rtc device may contain illegal values on power up
	93	* according to the data sheet. make sure they are valid.
	94	*/
	95
75b61022	96	return rtc_valid_tm(dt);
2805b969 MD	97	}
	98
	99	static int r9701_set_datetime(struct device dev, struct rtc_time dt)
	100	{
	101	int ret, year;
	102
	103	year = dt->tm_year + 1900;
	104	if (year >= 2100 \|\| year < 2000)
	105	return -EINVAL;
	106
	107	ret = write_reg(dev, RHRCNT, BIN2BCD(dt->tm_hour));
75b61022 MD	108	ret = ret ? ret : write_reg(dev, RMINCNT, BIN2BCD(dt->tm_min));
	109	ret = ret ? ret : write_reg(dev, RSECCNT, BIN2BCD(dt->tm_sec));
	110	ret = ret ? ret : write_reg(dev, RDAYCNT, BIN2BCD(dt->tm_mday));
	111	ret = ret ? ret : write_reg(dev, RMONCNT, BIN2BCD(dt->tm_mon + 1));
	112	ret = ret ? ret : write_reg(dev, RYRCNT, BIN2BCD(dt->tm_year - 100));
	113	ret = ret ? ret : write_reg(dev, RWKCNT, 1 << dt->tm_wday);
2805b969 MD	114
	115	return ret;
	116	}
	117
	118	static const struct rtc_class_ops r9701_rtc_ops = {
	119	.read_time = r9701_get_datetime,
	120	.set_time = r9701_set_datetime,
	121	};
	122
	123	static int __devinit r9701_probe(struct spi_device *spi)
	124	{
	125	struct rtc_device *rtc;
	126	unsigned char tmp;
	127	int res;
	128
	129	rtc = rtc_device_register("r9701",
	130	&spi->dev, &r9701_rtc_ops, THIS_MODULE);
	131	if (IS_ERR(rtc))
	132	return PTR_ERR(rtc);
	133
	134	dev_set_drvdata(&spi->dev, rtc);
	135
2805b969 MD	136	tmp = R100CNT;
	137	res = read_regs(&spi->dev, &tmp, 1);
	138	if (res \|\| tmp != 0x20) {
	139	rtc_device_unregister(rtc);
	140	return res;
	141	}
	142
	143	return 0;
	144	}
	145
	146	static int __devexit r9701_remove(struct spi_device *spi)
	147	{
	148	struct rtc_device *rtc = dev_get_drvdata(&spi->dev);
	149
	150	rtc_device_unregister(rtc);
	151	return 0;
	152	}
	153
	154	static struct spi_driver r9701_driver = {
	155	.driver = {
	156	.name = "rtc-r9701",
2805b969 MD	157	.owner = THIS_MODULE,
	158	},
	159	.probe = r9701_probe,
	160	.remove = __devexit_p(r9701_remove),
	161	};
	162
	163	static __init int r9701_init(void)
	164	{
	165	return spi_register_driver(&r9701_driver);
	166	}
	167	module_init(r9701_init);
	168
	169	static __exit void r9701_exit(void)
	170	{
	171	spi_unregister_driver(&r9701_driver);
	172	}
	173	module_exit(r9701_exit);
	174
	175	MODULE_DESCRIPTION("r9701 spi RTC driver");
	176	MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
	177	MODULE_LICENSE("GPL");