[linux.git] / drivers / rtc / rtc-rs5c348.c

/*
 * A SPI driver for the Ricoh RS5C348 RTC
 *
 * Copyright (C) 2006 Atsushi Nemoto <[email protected]>
 *
 * 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.
 *
 * The board specific init code should provide characteristics of this
 * device:
 *     Mode 1 (High-Active, Shift-Then-Sample), High Avtive CS
 */

#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/workqueue.h>
#include <linux/spi/spi.h>
#include <linux/module.h>

#define DRV_VERSION "0.2"

#define RS5C348_REG_SECS	0
#define RS5C348_REG_MINS	1
#define RS5C348_REG_HOURS	2
#define RS5C348_REG_WDAY	3
#define RS5C348_REG_DAY	4
#define RS5C348_REG_MONTH	5
#define RS5C348_REG_YEAR	6
#define RS5C348_REG_CTL1	14
#define RS5C348_REG_CTL2	15

#define RS5C348_SECS_MASK	0x7f
#define RS5C348_MINS_MASK	0x7f
#define RS5C348_HOURS_MASK	0x3f
#define RS5C348_WDAY_MASK	0x03
#define RS5C348_DAY_MASK	0x3f
#define RS5C348_MONTH_MASK	0x1f

#define RS5C348_BIT_PM	0x20	/* REG_HOURS */
#define RS5C348_BIT_Y2K	0x80	/* REG_MONTH */
#define RS5C348_BIT_24H	0x20	/* REG_CTL1 */
#define RS5C348_BIT_XSTP	0x10	/* REG_CTL2 */
#define RS5C348_BIT_VDET	0x40	/* REG_CTL2 */

#define RS5C348_CMD_W(addr)	(((addr) << 4) | 0x08)	/* single write */
#define RS5C348_CMD_R(addr)	(((addr) << 4) | 0x0c)	/* single read */
#define RS5C348_CMD_MW(addr)	(((addr) << 4) | 0x00)	/* burst write */
#define RS5C348_CMD_MR(addr)	(((addr) << 4) | 0x04)	/* burst read */

struct rs5c348_plat_data {
	struct rtc_device *rtc;
	int rtc_24h;
};

static int
rs5c348_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct spi_device *spi = to_spi_device(dev);
	struct rs5c348_plat_data *pdata = spi->dev.platform_data;
	u8 txbuf[5+7], *txp;
	int ret;

	/* Transfer 5 bytes before writing SEC.  This gives 31us for carry. */
	txp = txbuf;
	txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	txbuf[1] = 0;	/* dummy */
	txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	txbuf[3] = 0;	/* dummy */
	txbuf[4] = RS5C348_CMD_MW(RS5C348_REG_SECS); /* cmd, sec, ... */
	txp = &txbuf[5];
	txp[RS5C348_REG_SECS] = bin2bcd(tm->tm_sec);
	txp[RS5C348_REG_MINS] = bin2bcd(tm->tm_min);
	if (pdata->rtc_24h) {
		txp[RS5C348_REG_HOURS] = bin2bcd(tm->tm_hour);
	} else {
		/* hour 0 is AM12, noon is PM12 */
		txp[RS5C348_REG_HOURS] = bin2bcd((tm->tm_hour + 11) % 12 + 1) |
			(tm->tm_hour >= 12 ? RS5C348_BIT_PM : 0);
	}
	txp[RS5C348_REG_WDAY] = bin2bcd(tm->tm_wday);
	txp[RS5C348_REG_DAY] = bin2bcd(tm->tm_mday);
	txp[RS5C348_REG_MONTH] = bin2bcd(tm->tm_mon + 1) |
		(tm->tm_year >= 100 ? RS5C348_BIT_Y2K : 0);
	txp[RS5C348_REG_YEAR] = bin2bcd(tm->tm_year % 100);
	/* write in one transfer to avoid data inconsistency */
	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), NULL, 0);
	udelay(62);	/* Tcsr 62us */
	return ret;
}

static int
rs5c348_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct spi_device *spi = to_spi_device(dev);
	struct rs5c348_plat_data *pdata = spi->dev.platform_data;
	u8 txbuf[5], rxbuf[7];
	int ret;

	/* Transfer 5 byte befores reading SEC.  This gives 31us for carry. */
	txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	txbuf[1] = 0;	/* dummy */
	txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	txbuf[3] = 0;	/* dummy */
	txbuf[4] = RS5C348_CMD_MR(RS5C348_REG_SECS); /* cmd, sec, ... */

	/* read in one transfer to avoid data inconsistency */
	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
				  rxbuf, sizeof(rxbuf));
	udelay(62);	/* Tcsr 62us */
	if (ret < 0)
		return ret;

	tm->tm_sec = bcd2bin(rxbuf[RS5C348_REG_SECS] & RS5C348_SECS_MASK);
	tm->tm_min = bcd2bin(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
	tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
	if (!pdata->rtc_24h) {
		if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM) {
			tm->tm_hour -= 20;
			tm->tm_hour %= 12;
			tm->tm_hour += 12;
		} else
			tm->tm_hour %= 12;
	}
	tm->tm_wday = bcd2bin(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
	tm->tm_mday = bcd2bin(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);
	tm->tm_mon =
		bcd2bin(rxbuf[RS5C348_REG_MONTH] & RS5C348_MONTH_MASK) - 1;
	/* year is 1900 + tm->tm_year */
	tm->tm_year = bcd2bin(rxbuf[RS5C348_REG_YEAR]) +
		((rxbuf[RS5C348_REG_MONTH] & RS5C348_BIT_Y2K) ? 100 : 0);

	if (rtc_valid_tm(tm) < 0) {
		dev_err(&spi->dev, "retrieved date/time is not valid.\n");
		rtc_time_to_tm(0, tm);
	}

	return 0;
}

static const struct rtc_class_ops rs5c348_rtc_ops = {
	.read_time	= rs5c348_rtc_read_time,
	.set_time	= rs5c348_rtc_set_time,
};

static struct spi_driver rs5c348_driver;

static int rs5c348_probe(struct spi_device *spi)
{
	int ret;
	struct rtc_device *rtc;
	struct rs5c348_plat_data *pdata;

	pdata = devm_kzalloc(&spi->dev, sizeof(struct rs5c348_plat_data),
				GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;
	spi->dev.platform_data = pdata;

	/* Check D7 of SECOND register */
	ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_SECS));
	if (ret < 0 || (ret & 0x80)) {
		dev_err(&spi->dev, "not found.\n");
		goto kfree_exit;
	}

	dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
	dev_info(&spi->dev, "spiclk %u KHz.\n",
		 (spi->max_speed_hz + 500) / 1000);

	/* turn RTC on if it was not on */
	ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
	if (ret < 0)
		goto kfree_exit;
	if (ret & (RS5C348_BIT_XSTP | RS5C348_BIT_VDET)) {
		u8 buf[2];
		struct rtc_time tm;
		if (ret & RS5C348_BIT_VDET)
			dev_warn(&spi->dev, "voltage-low detected.\n");
		if (ret & RS5C348_BIT_XSTP)
			dev_warn(&spi->dev, "oscillator-stop detected.\n");
		rtc_time_to_tm(0, &tm);	/* 1970/1/1 */
		ret = rs5c348_rtc_set_time(&spi->dev, &tm);
		if (ret < 0)
			goto kfree_exit;
		buf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
		buf[1] = 0;
		ret = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0);
		if (ret < 0)
			goto kfree_exit;
	}

	ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL1));
	if (ret < 0)
		goto kfree_exit;
	if (ret & RS5C348_BIT_24H)
		pdata->rtc_24h = 1;

	rtc = devm_rtc_device_register(&spi->dev, rs5c348_driver.driver.name,
				  &rs5c348_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc)) {
		ret = PTR_ERR(rtc);
		goto kfree_exit;
	}

	pdata->rtc = rtc;

	return 0;
 kfree_exit:
	return ret;
}

static int rs5c348_remove(struct spi_device *spi)
{
	return 0;
}

static struct spi_driver rs5c348_driver = {
	.driver = {
		.name	= "rtc-rs5c348",
		.owner	= THIS_MODULE,
	},
	.probe	= rs5c348_probe,
	.remove	= rs5c348_remove,
};

module_spi_driver(rs5c348_driver);

MODULE_AUTHOR("Atsushi Nemoto <[email protected]>");
MODULE_DESCRIPTION("Ricoh RS5C348 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
MODULE_ALIAS("spi:rtc-rs5c348");
Commit	Line	Data
e0ac4761 AN	1	/*
	2	* A SPI driver for the Ricoh RS5C348 RTC
	3	*
	4	* Copyright (C) 2006 Atsushi Nemoto <[email protected]>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* The board specific init code should provide characteristics of this
	11	* device:
	12	* Mode 1 (High-Active, Shift-Then-Sample), High Avtive CS
	13	*/
	14
	15	#include <linux/bcd.h>
	16	#include <linux/delay.h>
	17	#include <linux/device.h>
	18	#include <linux/errno.h>
	19	#include <linux/init.h>
	20	#include <linux/kernel.h>
	21	#include <linux/string.h>
5a0e3ad6	22	#include <linux/slab.h>
e0ac4761 AN	23	#include <linux/rtc.h>
	24	#include <linux/workqueue.h>
	25	#include <linux/spi/spi.h>
2113852b	26	#include <linux/module.h>
e0ac4761	27
13c73f04	28	#define DRV_VERSION "0.2"
e0ac4761 AN	29
	30	#define RS5C348_REG_SECS 0
	31	#define RS5C348_REG_MINS 1
	32	#define RS5C348_REG_HOURS 2
	33	#define RS5C348_REG_WDAY 3
	34	#define RS5C348_REG_DAY 4
	35	#define RS5C348_REG_MONTH 5
	36	#define RS5C348_REG_YEAR 6
	37	#define RS5C348_REG_CTL1 14
	38	#define RS5C348_REG_CTL2 15
	39
	40	#define RS5C348_SECS_MASK 0x7f
	41	#define RS5C348_MINS_MASK 0x7f
	42	#define RS5C348_HOURS_MASK 0x3f
	43	#define RS5C348_WDAY_MASK 0x03
	44	#define RS5C348_DAY_MASK 0x3f
	45	#define RS5C348_MONTH_MASK 0x1f
	46
	47	#define RS5C348_BIT_PM 0x20 /* REG_HOURS */
	48	#define RS5C348_BIT_Y2K 0x80 /* REG_MONTH */
	49	#define RS5C348_BIT_24H 0x20 /* REG_CTL1 */
	50	#define RS5C348_BIT_XSTP 0x10 /* REG_CTL2 */
	51	#define RS5C348_BIT_VDET 0x40 /* REG_CTL2 */
	52
	53	#define RS5C348_CMD_W(addr) (((addr) << 4) \| 0x08) /* single write */
	54	#define RS5C348_CMD_R(addr) (((addr) << 4) \| 0x0c) /* single read */
	55	#define RS5C348_CMD_MW(addr) (((addr) << 4) \| 0x00) /* burst write */
	56	#define RS5C348_CMD_MR(addr) (((addr) << 4) \| 0x04) /* burst read */
	57
	58	struct rs5c348_plat_data {
	59	struct rtc_device *rtc;
	60	int rtc_24h;
	61	};
	62
	63	static int
	64	rs5c348_rtc_set_time(struct device dev, struct rtc_time tm)
	65	{
	66	struct spi_device *spi = to_spi_device(dev);
	67	struct rs5c348_plat_data *pdata = spi->dev.platform_data;
	68	u8 txbuf[5+7], *txp;
	69	int ret;
	70
	71	/* Transfer 5 bytes before writing SEC. This gives 31us for carry. */
	72	txp = txbuf;
	73	txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	74	txbuf[1] = 0; /* dummy */
	75	txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	76	txbuf[3] = 0; /* dummy */
	77	txbuf[4] = RS5C348_CMD_MW(RS5C348_REG_SECS); /* cmd, sec, ... */
	78	txp = &txbuf[5];
fe20ba70 AB	79	txp[RS5C348_REG_SECS] = bin2bcd(tm->tm_sec);
fe20ba70 AB	80	txp[RS5C348_REG_MINS] = bin2bcd(tm->tm_min);
e0ac4761	81	if (pdata->rtc_24h) {
fe20ba70	82	txp[RS5C348_REG_HOURS] = bin2bcd(tm->tm_hour);
e0ac4761 AN	83	} else {
e0ac4761 AN	84	/* hour 0 is AM12, noon is PM12 */
fe20ba70	85	txp[RS5C348_REG_HOURS] = bin2bcd((tm->tm_hour + 11) % 12 + 1) \|
e0ac4761 AN	86	(tm->tm_hour >= 12 ? RS5C348_BIT_PM : 0);
e0ac4761 AN	87	}
fe20ba70 AB	88	txp[RS5C348_REG_WDAY] = bin2bcd(tm->tm_wday);
	89	txp[RS5C348_REG_DAY] = bin2bcd(tm->tm_mday);
	90	txp[RS5C348_REG_MONTH] = bin2bcd(tm->tm_mon + 1) \|
e0ac4761	91	(tm->tm_year >= 100 ? RS5C348_BIT_Y2K : 0);
fe20ba70	92	txp[RS5C348_REG_YEAR] = bin2bcd(tm->tm_year % 100);
e0ac4761 AN	93	/* write in one transfer to avoid data inconsistency */
	94	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), NULL, 0);
	95	udelay(62); /* Tcsr 62us */
	96	return ret;
	97	}
	98
	99	static int
	100	rs5c348_rtc_read_time(struct device dev, struct rtc_time tm)
	101	{
	102	struct spi_device *spi = to_spi_device(dev);
	103	struct rs5c348_plat_data *pdata = spi->dev.platform_data;
	104	u8 txbuf[5], rxbuf[7];
	105	int ret;
	106
	107	/* Transfer 5 byte befores reading SEC. This gives 31us for carry. */
	108	txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	109	txbuf[1] = 0; /* dummy */
	110	txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
	111	txbuf[3] = 0; /* dummy */
	112	txbuf[4] = RS5C348_CMD_MR(RS5C348_REG_SECS); /* cmd, sec, ... */
	113
	114	/* read in one transfer to avoid data inconsistency */
	115	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
	116	rxbuf, sizeof(rxbuf));
	117	udelay(62); /* Tcsr 62us */
	118	if (ret < 0)
	119	return ret;
	120
fe20ba70 AB	121	tm->tm_sec = bcd2bin(rxbuf[RS5C348_REG_SECS] & RS5C348_SECS_MASK);
	122	tm->tm_min = bcd2bin(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
	123	tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
e0ac4761	124	if (!pdata->rtc_24h) {
7dbfb315 AN	125	if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM) {
	126	tm->tm_hour -= 20;
	127	tm->tm_hour %= 12;
e0ac4761	128	tm->tm_hour += 12;
7dbfb315 AN	129	} else
7dbfb315 AN	130	tm->tm_hour %= 12;
e0ac4761	131	}
fe20ba70 AB	132	tm->tm_wday = bcd2bin(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
fe20ba70 AB	133	tm->tm_mday = bcd2bin(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);
e0ac4761	134	tm->tm_mon =
fe20ba70	135	bcd2bin(rxbuf[RS5C348_REG_MONTH] & RS5C348_MONTH_MASK) - 1;
e0ac4761	136	/* year is 1900 + tm->tm_year */
fe20ba70	137	tm->tm_year = bcd2bin(rxbuf[RS5C348_REG_YEAR]) +
e0ac4761 AN	138	((rxbuf[RS5C348_REG_MONTH] & RS5C348_BIT_Y2K) ? 100 : 0);
	139
	140	if (rtc_valid_tm(tm) < 0) {
	141	dev_err(&spi->dev, "retrieved date/time is not valid.\n");
	142	rtc_time_to_tm(0, tm);
	143	}
	144
	145	return 0;
	146	}
	147
ff8371ac	148	static const struct rtc_class_ops rs5c348_rtc_ops = {
e0ac4761 AN	149	.read_time = rs5c348_rtc_read_time,
	150	.set_time = rs5c348_rtc_set_time,
	151	};
	152
	153	static struct spi_driver rs5c348_driver;
	154
5a167f45	155	static int rs5c348_probe(struct spi_device *spi)
e0ac4761 AN	156	{
	157	int ret;
	158	struct rtc_device *rtc;
	159	struct rs5c348_plat_data *pdata;
	160
8fb1ecb3 JH	161	pdata = devm_kzalloc(&spi->dev, sizeof(struct rs5c348_plat_data),
8fb1ecb3 JH	162	GFP_KERNEL);
e0ac4761 AN	163	if (!pdata)
	164	return -ENOMEM;
	165	spi->dev.platform_data = pdata;
	166
	167	/* Check D7 of SECOND register */
	168	ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_SECS));
	169	if (ret < 0 \|\| (ret & 0x80)) {
	170	dev_err(&spi->dev, "not found.\n");
	171	goto kfree_exit;
	172	}
	173
	174	dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
	175	dev_info(&spi->dev, "spiclk %u KHz.\n",
	176	(spi->max_speed_hz + 500) / 1000);
	177
	178	/* turn RTC on if it was not on */
	179	ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
	180	if (ret < 0)
	181	goto kfree_exit;
	182	if (ret & (RS5C348_BIT_XSTP \| RS5C348_BIT_VDET)) {
	183	u8 buf[2];
13c73f04	184	struct rtc_time tm;
e0ac4761 AN	185	if (ret & RS5C348_BIT_VDET)
e0ac4761 AN	186	dev_warn(&spi->dev, "voltage-low detected.\n");
13c73f04 AN	187	if (ret & RS5C348_BIT_XSTP)
	188	dev_warn(&spi->dev, "oscillator-stop detected.\n");
	189	rtc_time_to_tm(0, &tm); /* 1970/1/1 */
	190	ret = rs5c348_rtc_set_time(&spi->dev, &tm);
	191	if (ret < 0)
	192	goto kfree_exit;
e0ac4761 AN	193	buf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
	194	buf[1] = 0;
	195	ret = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0);
	196	if (ret < 0)
	197	goto kfree_exit;
	198	}
	199
	200	ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL1));
	201	if (ret < 0)
	202	goto kfree_exit;
	203	if (ret & RS5C348_BIT_24H)
	204	pdata->rtc_24h = 1;
	205
8fb1ecb3	206	rtc = devm_rtc_device_register(&spi->dev, rs5c348_driver.driver.name,
e0ac4761 AN	207	&rs5c348_rtc_ops, THIS_MODULE);
	208
	209	if (IS_ERR(rtc)) {
	210	ret = PTR_ERR(rtc);
	211	goto kfree_exit;
	212	}
	213
	214	pdata->rtc = rtc;
	215
	216	return 0;
	217	kfree_exit:
e0ac4761 AN	218	return ret;
	219	}
	220
5a167f45	221	static int rs5c348_remove(struct spi_device *spi)
e0ac4761	222	{
e0ac4761 AN	223	return 0;
	224	}
	225
	226	static struct spi_driver rs5c348_driver = {
	227	.driver = {
9f90a03a	228	.name = "rtc-rs5c348",
e0ac4761 AN	229	.owner = THIS_MODULE,
	230	},
	231	.probe = rs5c348_probe,
5a167f45	232	.remove = rs5c348_remove,
e0ac4761 AN	233	};
e0ac4761 AN	234
109e9418	235	module_spi_driver(rs5c348_driver);
e0ac4761 AN	236
	237	MODULE_AUTHOR("Atsushi Nemoto <[email protected]>");
	238	MODULE_DESCRIPTION("Ricoh RS5C348 RTC driver");
	239	MODULE_LICENSE("GPL");
	240	MODULE_VERSION(DRV_VERSION);
e0626e38	241	MODULE_ALIAS("spi:rtc-rs5c348");