[deliverable/linux.git] / drivers / rtc / rtc-pcf2123.c

/*
 * An SPI driver for the Philips PCF2123 RTC
 * Copyright 2009 Cyber Switching, Inc.
 *
 * Author: Chris Verges <chrisv@cyberswitching.com>
 * Maintainers: http://www.cyberswitching.com
 *
 * based on the RS5C348 driver in this same directory.
 *
 * Thanks to Christian Pellegrin <chripell@fsfe.org> for
 * the sysfs contributions to this driver.
 *
 * 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.
 *
 * Please note that the CS is active high, so platform data
 * should look something like:
 *
 * static struct spi_board_info ek_spi_devices[] = {
 * 	...
 * 	{
 * 		.modalias		= "rtc-pcf2123",
 * 		.chip_select		= 1,
 * 		.controller_data	= (void *)AT91_PIN_PA10,
 *		.max_speed_hz		= 1000 * 1000,
 *		.mode			= SPI_CS_HIGH,
 *		.bus_num		= 0,
 *	},
 *	...
 *};
 *
 */

#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/spi/spi.h>
#include <linux/module.h>

#define DRV_VERSION "0.6"

#define PCF2123_REG_CTRL1	(0x00)	/* Control Register 1 */
#define PCF2123_REG_CTRL2	(0x01)	/* Control Register 2 */
#define PCF2123_REG_SC		(0x02)	/* datetime */
#define PCF2123_REG_MN		(0x03)
#define PCF2123_REG_HR		(0x04)
#define PCF2123_REG_DM		(0x05)
#define PCF2123_REG_DW		(0x06)
#define PCF2123_REG_MO		(0x07)
#define PCF2123_REG_YR		(0x08)

#define PCF2123_SUBADDR		(1 << 4)
#define PCF2123_WRITE		((0 << 7) | PCF2123_SUBADDR)
#define PCF2123_READ		((1 << 7) | PCF2123_SUBADDR)

static struct spi_driver pcf2123_driver;

struct pcf2123_sysfs_reg {
	struct device_attribute attr;
	char name[2];
};

struct pcf2123_plat_data {
	struct rtc_device *rtc;
	struct pcf2123_sysfs_reg regs[16];
};

/*
 * Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
 * is released properly after an SPI write.  This function should be
 * called after EVERY read/write call over SPI.
 */
static inline void pcf2123_delay_trec(void)
{
	ndelay(30);
}

static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,
			    char *buffer)
{
	struct spi_device *spi = to_spi_device(dev);
	struct pcf2123_sysfs_reg *r;
	u8 txbuf[1], rxbuf[1];
	unsigned long reg;
	int ret;

	r = container_of(attr, struct pcf2123_sysfs_reg, attr);

	if (strict_strtoul(r->name, 16, &reg))
		return -EINVAL;

	txbuf[0] = PCF2123_READ | reg;
	ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
	if (ret < 0)
		return -EIO;
	pcf2123_delay_trec();
	return sprintf(buffer, "0x%x\n", rxbuf[0]);
}

static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
			     const char *buffer, size_t count) {
	struct spi_device *spi = to_spi_device(dev);
	struct pcf2123_sysfs_reg *r;
	u8 txbuf[2];
	unsigned long reg;
	unsigned long val;

	int ret;

	r = container_of(attr, struct pcf2123_sysfs_reg, attr);

	if (strict_strtoul(r->name, 16, &reg)
		|| strict_strtoul(buffer, 10, &val))
		return -EINVAL;

	txbuf[0] = PCF2123_WRITE | reg;
	txbuf[1] = val;
	ret = spi_write(spi, txbuf, sizeof(txbuf));
	if (ret < 0)
		return -EIO;
	pcf2123_delay_trec();
	return count;
}

static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct spi_device *spi = to_spi_device(dev);
	u8 txbuf[1], rxbuf[7];
	int ret;

	txbuf[0] = PCF2123_READ | PCF2123_REG_SC;
	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
			rxbuf, sizeof(rxbuf));
	if (ret < 0)
		return ret;
	pcf2123_delay_trec();

	tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
	tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
	tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
	tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
	tm->tm_wday = rxbuf[4] & 0x07;
	tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(rxbuf[6]);
	if (tm->tm_year < 70)
		tm->tm_year += 100;	/* assume we are in 1970...2069 */

	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
			"mday=%d, mon=%d, year=%d, wday=%d\n",
			__func__,
			tm->tm_sec, tm->tm_min, tm->tm_hour,
			tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	/* the clock can give out invalid datetime, but we cannot return
	 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
	 */
	if (rtc_valid_tm(tm) < 0)
		dev_err(dev, "retrieved date/time is not valid.\n");

	return 0;
}

static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct spi_device *spi = to_spi_device(dev);
	u8 txbuf[8];
	int ret;

	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
			"mday=%d, mon=%d, year=%d, wday=%d\n",
			__func__,
			tm->tm_sec, tm->tm_min, tm->tm_hour,
			tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	/* Stop the counter first */
	txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
	txbuf[1] = 0x20;
	ret = spi_write(spi, txbuf, 2);
	if (ret < 0)
		return ret;
	pcf2123_delay_trec();

	/* Set the new time */
	txbuf[0] = PCF2123_WRITE | PCF2123_REG_SC;
	txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
	txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
	txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
	txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
	txbuf[5] = tm->tm_wday & 0x07;
	txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
	txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);

	ret = spi_write(spi, txbuf, sizeof(txbuf));
	if (ret < 0)
		return ret;
	pcf2123_delay_trec();

	/* Start the counter */
	txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
	txbuf[1] = 0x00;
	ret = spi_write(spi, txbuf, 2);
	if (ret < 0)
		return ret;
	pcf2123_delay_trec();

	return 0;
}

static const struct rtc_class_ops pcf2123_rtc_ops = {
	.read_time	= pcf2123_rtc_read_time,
	.set_time	= pcf2123_rtc_set_time,
};

static int __devinit pcf2123_probe(struct spi_device *spi)
{
	struct rtc_device *rtc;
	struct pcf2123_plat_data *pdata;
	u8 txbuf[2], rxbuf[2];
	int ret, i;

	pdata = kzalloc(sizeof(struct pcf2123_plat_data), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;
	spi->dev.platform_data = pdata;

	/* Send a software reset command */
	txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
	txbuf[1] = 0x58;
	dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
			txbuf[0], txbuf[1]);
	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
	if (ret < 0)
		goto kfree_exit;
	pcf2123_delay_trec();

	/* Stop the counter */
	txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
	txbuf[1] = 0x20;
	dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
			txbuf[0], txbuf[1]);
	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
	if (ret < 0)
		goto kfree_exit;
	pcf2123_delay_trec();

	/* See if the counter was actually stopped */
	txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1;
	dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
			txbuf[0]);
	ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
					rxbuf, 2 * sizeof(u8));
	dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
			rxbuf[0], rxbuf[1]);
	if (ret < 0)
		goto kfree_exit;
	pcf2123_delay_trec();

	if (!(rxbuf[0] & 0x20)) {
		dev_err(&spi->dev, "chip 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);

	/* Start the counter */
	txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
	txbuf[1] = 0x00;
	ret = spi_write(spi, txbuf, sizeof(txbuf));
	if (ret < 0)
		goto kfree_exit;
	pcf2123_delay_trec();

	/* Finalize the initialization */
	rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,
			&pcf2123_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc)) {
		dev_err(&spi->dev, "failed to register.\n");
		ret = PTR_ERR(rtc);
		goto kfree_exit;
	}

	pdata->rtc = rtc;

	for (i = 0; i < 16; i++) {
		sprintf(pdata->regs[i].name, "%1x", i);
		pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
		pdata->regs[i].attr.attr.name = pdata->regs[i].name;
		pdata->regs[i].attr.show = pcf2123_show;
		pdata->regs[i].attr.store = pcf2123_store;
		ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
		if (ret) {
			dev_err(&spi->dev, "Unable to create sysfs %s\n",
				pdata->regs[i].name);
			goto sysfs_exit;
		}
	}

	return 0;

sysfs_exit:
	for (i--; i >= 0; i--)
		device_remove_file(&spi->dev, &pdata->regs[i].attr);

kfree_exit:
	kfree(pdata);
	spi->dev.platform_data = NULL;
	return ret;
}

static int __devexit pcf2123_remove(struct spi_device *spi)
{
	struct pcf2123_plat_data *pdata = spi->dev.platform_data;
	int i;

	if (pdata) {
		struct rtc_device *rtc = pdata->rtc;

		if (rtc)
			rtc_device_unregister(rtc);
		for (i = 0; i < 16; i++)
			if (pdata->regs[i].name[0])
				device_remove_file(&spi->dev,
						   &pdata->regs[i].attr);
		kfree(pdata);
	}

	return 0;
}

static struct spi_driver pcf2123_driver = {
	.driver	= {
			.name	= "rtc-pcf2123",
			.owner	= THIS_MODULE,
	},
	.probe	= pcf2123_probe,
	.remove	= __devexit_p(pcf2123_remove),
};

static int __init pcf2123_init(void)
{
	return spi_register_driver(&pcf2123_driver);
}

static void __exit pcf2123_exit(void)
{
	spi_unregister_driver(&pcf2123_driver);
}

MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_init(pcf2123_init);
module_exit(pcf2123_exit);
Commit	Line	Data
7f3923a1 CV	1	/*
	2	* An SPI driver for the Philips PCF2123 RTC
	3	* Copyright 2009 Cyber Switching, Inc.
	4	*
	5	* Author: Chris Verges <chrisv@cyberswitching.com>
	6	* Maintainers: http://www.cyberswitching.com
	7	*
	8	* based on the RS5C348 driver in this same directory.
	9	*
	10	* Thanks to Christian Pellegrin <chripell@fsfe.org> for
	11	* the sysfs contributions to this driver.
	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License version 2 as
	15	* published by the Free Software Foundation.
	16	*
	17	* Please note that the CS is active high, so platform data
	18	* should look something like:
	19	*
	20	* static struct spi_board_info ek_spi_devices[] = {
	21	* ...
	22	* {
	23	* .modalias = "rtc-pcf2123",
	24	* .chip_select = 1,
	25	* .controller_data = (void *)AT91_PIN_PA10,
	26	* .max_speed_hz = 1000 * 1000,
	27	* .mode = SPI_CS_HIGH,
	28	* .bus_num = 0,
	29	* },
	30	* ...
	31	*};
	32	*
	33	*/
	34
	35	#include <linux/bcd.h>
	36	#include <linux/delay.h>
	37	#include <linux/device.h>
	38	#include <linux/errno.h>
	39	#include <linux/init.h>
	40	#include <linux/kernel.h>
	41	#include <linux/string.h>
5a0e3ad6	42	#include <linux/slab.h>
7f3923a1 CV	43	#include <linux/rtc.h>
7f3923a1 CV	44	#include <linux/spi/spi.h>
2113852b	45	#include <linux/module.h>
7f3923a1	46
f3d2570a	47	#define DRV_VERSION "0.6"
7f3923a1 CV	48
	49	#define PCF2123_REG_CTRL1 (0x00) /* Control Register 1 */
	50	#define PCF2123_REG_CTRL2 (0x01) /* Control Register 2 */
	51	#define PCF2123_REG_SC (0x02) /* datetime */
	52	#define PCF2123_REG_MN (0x03)
	53	#define PCF2123_REG_HR (0x04)
	54	#define PCF2123_REG_DM (0x05)
	55	#define PCF2123_REG_DW (0x06)
	56	#define PCF2123_REG_MO (0x07)
	57	#define PCF2123_REG_YR (0x08)
	58
	59	#define PCF2123_SUBADDR (1 << 4)
	60	#define PCF2123_WRITE ((0 << 7) \| PCF2123_SUBADDR)
	61	#define PCF2123_READ ((1 << 7) \| PCF2123_SUBADDR)
	62
	63	static struct spi_driver pcf2123_driver;
	64
	65	struct pcf2123_sysfs_reg {
f3d2570a	66	struct device_attribute attr;
7f3923a1 CV	67	char name[2];
	68	};
	69
	70	struct pcf2123_plat_data {
	71	struct rtc_device *rtc;
	72	struct pcf2123_sysfs_reg regs[16];
	73	};
	74
	75	/*
	76	* Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
	77	* is released properly after an SPI write. This function should be
	78	* called after EVERY read/write call over SPI.
	79	*/
	80	static inline void pcf2123_delay_trec(void)
	81	{
	82	ndelay(30);
	83	}
	84
	85	static ssize_t pcf2123_show(struct device dev, struct device_attribute attr,
	86	char *buffer)
	87	{
	88	struct spi_device *spi = to_spi_device(dev);
f3d2570a	89	struct pcf2123_sysfs_reg *r;
7f3923a1	90	u8 txbuf[1], rxbuf[1];
f3d2570a	91	unsigned long reg;
7f3923a1 CV	92	int ret;
7f3923a1 CV	93
f3d2570a CV	94	r = container_of(attr, struct pcf2123_sysfs_reg, attr);
	95
	96	if (strict_strtoul(r->name, 16, &reg))
	97	return -EINVAL;
	98
	99	txbuf[0] = PCF2123_READ \| reg;
7f3923a1 CV	100	ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
7f3923a1 CV	101	if (ret < 0)
f3d2570a	102	return -EIO;
7f3923a1	103	pcf2123_delay_trec();
f3d2570a	104	return sprintf(buffer, "0x%x\n", rxbuf[0]);
7f3923a1 CV	105	}
	106
	107	static ssize_t pcf2123_store(struct device dev, struct device_attribute attr,
	108	const char *buffer, size_t count) {
	109	struct spi_device *spi = to_spi_device(dev);
f3d2570a	110	struct pcf2123_sysfs_reg *r;
7f3923a1	111	u8 txbuf[2];
f3d2570a CV	112	unsigned long reg;
	113	unsigned long val;
	114
7f3923a1 CV	115	int ret;
7f3923a1 CV	116
f3d2570a CV	117	r = container_of(attr, struct pcf2123_sysfs_reg, attr);
	118
	119	if (strict_strtoul(r->name, 16, &reg)
	120	\|\| strict_strtoul(buffer, 10, &val))
	121	return -EINVAL;
	122
	123	txbuf[0] = PCF2123_WRITE \| reg;
	124	txbuf[1] = val;
7f3923a1 CV	125	ret = spi_write(spi, txbuf, sizeof(txbuf));
	126	if (ret < 0)
	127	return -EIO;
	128	pcf2123_delay_trec();
	129	return count;
	130	}
	131
	132	static int pcf2123_rtc_read_time(struct device dev, struct rtc_time tm)
	133	{
	134	struct spi_device *spi = to_spi_device(dev);
	135	u8 txbuf[1], rxbuf[7];
	136	int ret;
	137
	138	txbuf[0] = PCF2123_READ \| PCF2123_REG_SC;
	139	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
	140	rxbuf, sizeof(rxbuf));
	141	if (ret < 0)
	142	return ret;
	143	pcf2123_delay_trec();
	144
	145	tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
	146	tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
	147	tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
	148	tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
	149	tm->tm_wday = rxbuf[4] & 0x07;
	150	tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
	151	tm->tm_year = bcd2bin(rxbuf[6]);
	152	if (tm->tm_year < 70)
	153	tm->tm_year += 100; /* assume we are in 1970...2069 */
	154
	155	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	156	"mday=%d, mon=%d, year=%d, wday=%d\n",
	157	__func__,
	158	tm->tm_sec, tm->tm_min, tm->tm_hour,
	159	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	160
	161	/* the clock can give out invalid datetime, but we cannot return
	162	* -EINVAL otherwise hwclock will refuse to set the time on bootup.
	163	*/
	164	if (rtc_valid_tm(tm) < 0)
	165	dev_err(dev, "retrieved date/time is not valid.\n");
	166
	167	return 0;
	168	}
	169
	170	static int pcf2123_rtc_set_time(struct device dev, struct rtc_time tm)
	171	{
	172	struct spi_device *spi = to_spi_device(dev);
	173	u8 txbuf[8];
	174	int ret;
	175
	176	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	177	"mday=%d, mon=%d, year=%d, wday=%d\n",
	178	__func__,
	179	tm->tm_sec, tm->tm_min, tm->tm_hour,
	180	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	181
	182	/* Stop the counter first */
	183	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
	184	txbuf[1] = 0x20;
	185	ret = spi_write(spi, txbuf, 2);
	186	if (ret < 0)
	187	return ret;
	188	pcf2123_delay_trec();
189
190	/* Set the new time */
191	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_SC;
192	txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
193	txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
194	txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
195	txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
196	txbuf[5] = tm->tm_wday & 0x07;
197	txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
198	txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
199
200	ret = spi_write(spi, txbuf, sizeof(txbuf));
201	if (ret < 0)
202	return ret;
203	pcf2123_delay_trec();
204
205	/* Start the counter */
206	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
207	txbuf[1] = 0x00;
208	ret = spi_write(spi, txbuf, 2);
209	if (ret < 0)
210	return ret;
211	pcf2123_delay_trec();
212
213	return 0;
214	}
215
216	static const struct rtc_class_ops pcf2123_rtc_ops = {
217	.read_time = pcf2123_rtc_read_time,
218	.set_time = pcf2123_rtc_set_time,
219	};
220
221	static int __devinit pcf2123_probe(struct spi_device *spi)
222	{
223	struct rtc_device *rtc;
224	struct pcf2123_plat_data *pdata;
225	u8 txbuf[2], rxbuf[2];
226	int ret, i;
227
228	pdata = kzalloc(sizeof(struct pcf2123_plat_data), GFP_KERNEL);
229	if (!pdata)
230	return -ENOMEM;
231	spi->dev.platform_data = pdata;
232
233	/* Send a software reset command */
234	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
235	txbuf[1] = 0x58;
236	dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
237	txbuf[0], txbuf[1]);
238	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
239	if (ret < 0)
f3d2570a	240	goto kfree_exit;
7f3923a1 CV	241	pcf2123_delay_trec();
	242
	243	/* Stop the counter */
	244	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
	245	txbuf[1] = 0x20;
	246	dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
	247	txbuf[0], txbuf[1]);
	248	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
	249	if (ret < 0)
f3d2570a	250	goto kfree_exit;
7f3923a1 CV	251	pcf2123_delay_trec();
	252
	253	/* See if the counter was actually stopped */
	254	txbuf[0] = PCF2123_READ \| PCF2123_REG_CTRL1;
	255	dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
	256	txbuf[0]);
	257	ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
	258	rxbuf, 2 * sizeof(u8));
	259	dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
	260	rxbuf[0], rxbuf[1]);
	261	if (ret < 0)
	262	goto kfree_exit;
	263	pcf2123_delay_trec();
	264
	265	if (!(rxbuf[0] & 0x20)) {
	266	dev_err(&spi->dev, "chip not found\n");
	267	goto kfree_exit;
	268	}
	269
	270	dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
	271	dev_info(&spi->dev, "spiclk %u KHz.\n",
	272	(spi->max_speed_hz + 500) / 1000);
	273
	274	/* Start the counter */
	275	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
	276	txbuf[1] = 0x00;
	277	ret = spi_write(spi, txbuf, sizeof(txbuf));
	278	if (ret < 0)
	279	goto kfree_exit;
	280	pcf2123_delay_trec();
	281
	282	/* Finalize the initialization */
	283	rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,
	284	&pcf2123_rtc_ops, THIS_MODULE);
	285
	286	if (IS_ERR(rtc)) {
	287	dev_err(&spi->dev, "failed to register.\n");
	288	ret = PTR_ERR(rtc);
	289	goto kfree_exit;
	290	}
	291
	292	pdata->rtc = rtc;
	293
	294	for (i = 0; i < 16; i++) {
	295	sprintf(pdata->regs[i].name, "%1x", i);
	296	pdata->regs[i].attr.attr.mode = S_IRUGO \| S_IWUSR;
	297	pdata->regs[i].attr.attr.name = pdata->regs[i].name;
	298	pdata->regs[i].attr.show = pcf2123_show;
	299	pdata->regs[i].attr.store = pcf2123_store;
	300	ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
	301	if (ret) {
	302	dev_err(&spi->dev, "Unable to create sysfs %s\n",
	303	pdata->regs[i].name);
f3d2570a	304	goto sysfs_exit;
7f3923a1 CV	305	}
	306	}
	307
	308	return 0;
f3d2570a CV	309
	310	sysfs_exit:
	311	for (i--; i >= 0; i--)
	312	device_remove_file(&spi->dev, &pdata->regs[i].attr);
	313
7f3923a1 CV	314	kfree_exit:
	315	kfree(pdata);
	316	spi->dev.platform_data = NULL;
	317	return ret;
	318	}
	319
b51e8293	320	static int __devexit pcf2123_remove(struct spi_device *spi)
7f3923a1 CV	321	{
	322	struct pcf2123_plat_data *pdata = spi->dev.platform_data;
	323	int i;
	324
	325	if (pdata) {
	326	struct rtc_device *rtc = pdata->rtc;
	327
	328	if (rtc)
	329	rtc_device_unregister(rtc);
	330	for (i = 0; i < 16; i++)
	331	if (pdata->regs[i].name[0])
	332	device_remove_file(&spi->dev,
	333	&pdata->regs[i].attr);
	334	kfree(pdata);
	335	}
	336
	337	return 0;
	338	}
	339
	340	static struct spi_driver pcf2123_driver = {
	341	.driver = {
	342	.name = "rtc-pcf2123",
7f3923a1 CV	343	.owner = THIS_MODULE,
	344	},
	345	.probe = pcf2123_probe,
	346	.remove = __devexit_p(pcf2123_remove),
	347	};
	348
	349	static int __init pcf2123_init(void)
	350	{
	351	return spi_register_driver(&pcf2123_driver);
	352	}
	353
	354	static void __exit pcf2123_exit(void)
	355	{
	356	spi_unregister_driver(&pcf2123_driver);
	357	}
	358
	359	MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
	360	MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
	361	MODULE_LICENSE("GPL");
	362	MODULE_VERSION(DRV_VERSION);
	363
	364	module_init(pcf2123_init);
	365	module_exit(pcf2123_exit);