[linux-2.6-block.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/of.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/sysfs.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);

	ret = kstrtoul(r->name, 16, &reg);
	if (ret)
		return ret;

	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);

	ret = kstrtoul(r->name, 16, &reg);
	if (ret)
		return ret;

	ret = kstrtoul(buffer, 10, &val);
	if (ret)
		return ret;

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

	pdata = devm_kzalloc(&spi->dev, 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");
		ret = -ENODEV;
		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 = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name,
			&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++) {
		sysfs_attr_init(&pdata->regs[i].attr.attr);
		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:
	spi->dev.platform_data = NULL;
	return ret;
}

static int pcf2123_remove(struct spi_device *spi)
{
	struct pcf2123_plat_data *pdata = dev_get_platdata(&spi->dev);
	int i;

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

	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id pcf2123_dt_ids[] = {
	{ .compatible = "nxp,rtc-pcf2123", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, pcf2123_dt_ids);
#endif

static struct spi_driver pcf2123_driver = {
	.driver	= {
			.name	= "rtc-pcf2123",
			.owner	= THIS_MODULE,
			.of_match_table = of_match_ptr(pcf2123_dt_ids),
	},
	.probe	= pcf2123_probe,
	.remove	= pcf2123_remove,
};

module_spi_driver(pcf2123_driver);

MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
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[] = {
369015fb SK	21	* ...
	22	* {
	23	* .modalias = "rtc-pcf2123",
	24	* .chip_select = 1,
	25	* .controller_data = (void *)AT91_PIN_PA10,
7f3923a1 CV	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>
3fc70077	41	#include <linux/of.h>
7f3923a1	42	#include <linux/string.h>
5a0e3ad6	43	#include <linux/slab.h>
7f3923a1 CV	44	#include <linux/rtc.h>
7f3923a1 CV	45	#include <linux/spi/spi.h>
2113852b	46	#include <linux/module.h>
5ed12f12	47	#include <linux/sysfs.h>
7f3923a1	48
f3d2570a	49	#define DRV_VERSION "0.6"
7f3923a1 CV	50
	51	#define PCF2123_REG_CTRL1 (0x00) /* Control Register 1 */
	52	#define PCF2123_REG_CTRL2 (0x01) /* Control Register 2 */
	53	#define PCF2123_REG_SC (0x02) /* datetime */
	54	#define PCF2123_REG_MN (0x03)
	55	#define PCF2123_REG_HR (0x04)
	56	#define PCF2123_REG_DM (0x05)
	57	#define PCF2123_REG_DW (0x06)
	58	#define PCF2123_REG_MO (0x07)
	59	#define PCF2123_REG_YR (0x08)
	60
	61	#define PCF2123_SUBADDR (1 << 4)
	62	#define PCF2123_WRITE ((0 << 7) \| PCF2123_SUBADDR)
	63	#define PCF2123_READ ((1 << 7) \| PCF2123_SUBADDR)
	64
	65	static struct spi_driver pcf2123_driver;
	66
	67	struct pcf2123_sysfs_reg {
f3d2570a	68	struct device_attribute attr;
7f3923a1 CV	69	char name[2];
	70	};
	71
	72	struct pcf2123_plat_data {
	73	struct rtc_device *rtc;
	74	struct pcf2123_sysfs_reg regs[16];
	75	};
	76
	77	/*
	78	* Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
	79	* is released properly after an SPI write. This function should be
	80	* called after EVERY read/write call over SPI.
	81	*/
	82	static inline void pcf2123_delay_trec(void)
	83	{
	84	ndelay(30);
	85	}
	86
	87	static ssize_t pcf2123_show(struct device dev, struct device_attribute attr,
	88	char *buffer)
	89	{
	90	struct spi_device *spi = to_spi_device(dev);
f3d2570a	91	struct pcf2123_sysfs_reg *r;
7f3923a1	92	u8 txbuf[1], rxbuf[1];
f3d2570a	93	unsigned long reg;
7f3923a1 CV	94	int ret;
7f3923a1 CV	95
f3d2570a CV	96	r = container_of(attr, struct pcf2123_sysfs_reg, attr);
f3d2570a CV	97
4c5591c1 JH	98	ret = kstrtoul(r->name, 16, &reg);
	99	if (ret)
	100	return ret;
f3d2570a CV	101
f3d2570a CV	102	txbuf[0] = PCF2123_READ \| reg;
7f3923a1 CV	103	ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
7f3923a1 CV	104	if (ret < 0)
f3d2570a	105	return -EIO;
7f3923a1	106	pcf2123_delay_trec();
f3d2570a	107	return sprintf(buffer, "0x%x\n", rxbuf[0]);
7f3923a1 CV	108	}
	109
	110	static ssize_t pcf2123_store(struct device dev, struct device_attribute attr,
	111	const char *buffer, size_t count) {
	112	struct spi_device *spi = to_spi_device(dev);
f3d2570a	113	struct pcf2123_sysfs_reg *r;
7f3923a1	114	u8 txbuf[2];
f3d2570a CV	115	unsigned long reg;
	116	unsigned long val;
	117
7f3923a1 CV	118	int ret;
7f3923a1 CV	119
f3d2570a CV	120	r = container_of(attr, struct pcf2123_sysfs_reg, attr);
f3d2570a CV	121
4c5591c1 JH	122	ret = kstrtoul(r->name, 16, &reg);
	123	if (ret)
	124	return ret;
	125
	126	ret = kstrtoul(buffer, 10, &val);
	127	if (ret)
	128	return ret;
f3d2570a CV	129
	130	txbuf[0] = PCF2123_WRITE \| reg;
	131	txbuf[1] = val;
7f3923a1 CV	132	ret = spi_write(spi, txbuf, sizeof(txbuf));
	133	if (ret < 0)
	134	return -EIO;
	135	pcf2123_delay_trec();
	136	return count;
	137	}
	138
	139	static int pcf2123_rtc_read_time(struct device dev, struct rtc_time tm)
	140	{
	141	struct spi_device *spi = to_spi_device(dev);
	142	u8 txbuf[1], rxbuf[7];
	143	int ret;
	144
	145	txbuf[0] = PCF2123_READ \| PCF2123_REG_SC;
	146	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
	147	rxbuf, sizeof(rxbuf));
	148	if (ret < 0)
	149	return ret;
	150	pcf2123_delay_trec();
	151
	152	tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
	153	tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
	154	tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
	155	tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
	156	tm->tm_wday = rxbuf[4] & 0x07;
	157	tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
	158	tm->tm_year = bcd2bin(rxbuf[6]);
	159	if (tm->tm_year < 70)
	160	tm->tm_year += 100; /* assume we are in 1970...2069 */
	161
	162	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	163	"mday=%d, mon=%d, year=%d, wday=%d\n",
	164	__func__,
	165	tm->tm_sec, tm->tm_min, tm->tm_hour,
	166	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	167
	168	/* the clock can give out invalid datetime, but we cannot return
	169	* -EINVAL otherwise hwclock will refuse to set the time on bootup.
	170	*/
	171	if (rtc_valid_tm(tm) < 0)
	172	dev_err(dev, "retrieved date/time is not valid.\n");
	173
	174	return 0;
	175	}
	176
	177	static int pcf2123_rtc_set_time(struct device dev, struct rtc_time tm)
	178	{
	179	struct spi_device *spi = to_spi_device(dev);
	180	u8 txbuf[8];
	181	int ret;
	182
	183	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	184	"mday=%d, mon=%d, year=%d, wday=%d\n",
	185	__func__,
	186	tm->tm_sec, tm->tm_min, tm->tm_hour,
	187	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	188
	189	/* Stop the counter first */
	190	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
	191	txbuf[1] = 0x20;
	192	ret = spi_write(spi, txbuf, 2);
	193	if (ret < 0)
	194	return ret;
	195	pcf2123_delay_trec();
196
197	/* Set the new time */
198	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_SC;
199	txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
200	txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
201	txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
202	txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
203	txbuf[5] = tm->tm_wday & 0x07;
204	txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
205	txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
206
207	ret = spi_write(spi, txbuf, sizeof(txbuf));
208	if (ret < 0)
209	return ret;
210	pcf2123_delay_trec();
211
212	/* Start the counter */
213	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
214	txbuf[1] = 0x00;
215	ret = spi_write(spi, txbuf, 2);
216	if (ret < 0)
217	return ret;
218	pcf2123_delay_trec();
219
220	return 0;
221	}
222
223	static const struct rtc_class_ops pcf2123_rtc_ops = {
224	.read_time = pcf2123_rtc_read_time,
225	.set_time = pcf2123_rtc_set_time,
226	};
227
5a167f45	228	static int pcf2123_probe(struct spi_device *spi)
7f3923a1 CV	229	{
	230	struct rtc_device *rtc;
	231	struct pcf2123_plat_data *pdata;
	232	u8 txbuf[2], rxbuf[2];
	233	int ret, i;
	234
dd48ccc4 JH	235	pdata = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_plat_data),
dd48ccc4 JH	236	GFP_KERNEL);
7f3923a1 CV	237	if (!pdata)
	238	return -ENOMEM;
	239	spi->dev.platform_data = pdata;
	240
	241	/* Send a software reset command */
	242	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
	243	txbuf[1] = 0x58;
	244	dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
	245	txbuf[0], txbuf[1]);
	246	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
	247	if (ret < 0)
f3d2570a	248	goto kfree_exit;
7f3923a1 CV	249	pcf2123_delay_trec();
	250
	251	/* Stop the counter */
	252	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
	253	txbuf[1] = 0x20;
	254	dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
	255	txbuf[0], txbuf[1]);
	256	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
	257	if (ret < 0)
f3d2570a	258	goto kfree_exit;
7f3923a1 CV	259	pcf2123_delay_trec();
	260
	261	/* See if the counter was actually stopped */
	262	txbuf[0] = PCF2123_READ \| PCF2123_REG_CTRL1;
	263	dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
	264	txbuf[0]);
	265	ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
	266	rxbuf, 2 * sizeof(u8));
	267	dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
	268	rxbuf[0], rxbuf[1]);
	269	if (ret < 0)
	270	goto kfree_exit;
	271	pcf2123_delay_trec();
	272
	273	if (!(rxbuf[0] & 0x20)) {
	274	dev_err(&spi->dev, "chip not found\n");
35623715	275	ret = -ENODEV;
7f3923a1 CV	276	goto kfree_exit;
	277	}
	278
	279	dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
	280	dev_info(&spi->dev, "spiclk %u KHz.\n",
	281	(spi->max_speed_hz + 500) / 1000);
	282
	283	/* Start the counter */
	284	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
	285	txbuf[1] = 0x00;
	286	ret = spi_write(spi, txbuf, sizeof(txbuf));
	287	if (ret < 0)
	288	goto kfree_exit;
	289	pcf2123_delay_trec();
	290
	291	/* Finalize the initialization */
dd48ccc4	292	rtc = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name,
7f3923a1 CV	293	&pcf2123_rtc_ops, THIS_MODULE);
	294
	295	if (IS_ERR(rtc)) {
	296	dev_err(&spi->dev, "failed to register.\n");
	297	ret = PTR_ERR(rtc);
	298	goto kfree_exit;
	299	}
	300
	301	pdata->rtc = rtc;
	302
	303	for (i = 0; i < 16; i++) {
5ed12f12	304	sysfs_attr_init(&pdata->regs[i].attr.attr);
7f3923a1 CV	305	sprintf(pdata->regs[i].name, "%1x", i);
	306	pdata->regs[i].attr.attr.mode = S_IRUGO \| S_IWUSR;
	307	pdata->regs[i].attr.attr.name = pdata->regs[i].name;
	308	pdata->regs[i].attr.show = pcf2123_show;
	309	pdata->regs[i].attr.store = pcf2123_store;
	310	ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
	311	if (ret) {
	312	dev_err(&spi->dev, "Unable to create sysfs %s\n",
	313	pdata->regs[i].name);
f3d2570a	314	goto sysfs_exit;
7f3923a1 CV	315	}
	316	}
	317
	318	return 0;
f3d2570a CV	319
	320	sysfs_exit:
	321	for (i--; i >= 0; i--)
	322	device_remove_file(&spi->dev, &pdata->regs[i].attr);
	323
7f3923a1	324	kfree_exit:
7f3923a1 CV	325	spi->dev.platform_data = NULL;
	326	return ret;
	327	}
	328
5a167f45	329	static int pcf2123_remove(struct spi_device *spi)
7f3923a1	330	{
ffc75bb8	331	struct pcf2123_plat_data *pdata = dev_get_platdata(&spi->dev);
7f3923a1 CV	332	int i;
	333
	334	if (pdata) {
7f3923a1 CV	335	for (i = 0; i < 16; i++)
	336	if (pdata->regs[i].name[0])
	337	device_remove_file(&spi->dev,
	338	&pdata->regs[i].attr);
7f3923a1 CV	339	}
	340
	341	return 0;
	342	}
	343
3fc70077 JC	344	#ifdef CONFIG_OF
	345	static const struct of_device_id pcf2123_dt_ids[] = {
	346	{ .compatible = "nxp,rtc-pcf2123", },
	347	{ /* sentinel */ }
	348	};
	349	MODULE_DEVICE_TABLE(of, pcf2123_dt_ids);
	350	#endif
	351
7f3923a1 CV	352	static struct spi_driver pcf2123_driver = {
	353	.driver = {
	354	.name = "rtc-pcf2123",
7f3923a1	355	.owner = THIS_MODULE,
3fc70077	356	.of_match_table = of_match_ptr(pcf2123_dt_ids),
7f3923a1 CV	357	},
7f3923a1 CV	358	.probe = pcf2123_probe,
5a167f45	359	.remove = pcf2123_remove,
7f3923a1 CV	360	};
7f3923a1 CV	361
109e9418	362	module_spi_driver(pcf2123_driver);
7f3923a1 CV	363
	364	MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
	365	MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
	366	MODULE_LICENSE("GPL");
	367	MODULE_VERSION(DRV_VERSION);