[mirror_ubuntu-zesty-kernel.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/rtc.h>
#include <linux/spi/spi.h>

#define DRV_VERSION "0.5"

#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; /* must be first */
	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 = (struct pcf2123_sysfs_reg *) attr;
	u8 txbuf[1], rxbuf[1];
	int ret;

	txbuf[0] = PCF2123_READ | simple_strtoul(r->name, NULL, 16);
	ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
	if (ret < 0)
		return sprintf(buffer, "error: %d", ret);
	pcf2123_delay_trec();
	return sprintf(buffer, "0x%x", 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 = (struct pcf2123_sysfs_reg *) attr;
	u8 txbuf[2];
	int ret;

	txbuf[0] = PCF2123_WRITE | simple_strtoul(r->name, NULL, 16);
	txbuf[1] = simple_strtoul(buffer, NULL, 0);
	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)
		return ret;
	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)
		return ret;
	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);
			pdata->regs[i].name[0] = '\0';
		}
	}

	return 0;
kfree_exit:
	kfree(pdata);
	spi->dev.platform_data = NULL;
	return ret;
}

static int 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",
			.bus	= &spi_bus_type,
			.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>
	42	#include <linux/rtc.h>
	43	#include <linux/spi/spi.h>
	44
	45	#define DRV_VERSION "0.5"
	46
	47	#define PCF2123_REG_CTRL1 (0x00) /* Control Register 1 */
	48	#define PCF2123_REG_CTRL2 (0x01) /* Control Register 2 */
	49	#define PCF2123_REG_SC (0x02) /* datetime */
	50	#define PCF2123_REG_MN (0x03)
	51	#define PCF2123_REG_HR (0x04)
	52	#define PCF2123_REG_DM (0x05)
	53	#define PCF2123_REG_DW (0x06)
	54	#define PCF2123_REG_MO (0x07)
	55	#define PCF2123_REG_YR (0x08)
	56
	57	#define PCF2123_SUBADDR (1 << 4)
	58	#define PCF2123_WRITE ((0 << 7) \| PCF2123_SUBADDR)
	59	#define PCF2123_READ ((1 << 7) \| PCF2123_SUBADDR)
	60
	61	static struct spi_driver pcf2123_driver;
	62
	63	struct pcf2123_sysfs_reg {
	64	struct device_attribute attr; /* must be first */
65	char name[2];
66	};
67
68	struct pcf2123_plat_data {
69	struct rtc_device *rtc;
70	struct pcf2123_sysfs_reg regs[16];
71	};
72
73	/*
74	* Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
75	* is released properly after an SPI write. This function should be
76	* called after EVERY read/write call over SPI.
77	*/
78	static inline void pcf2123_delay_trec(void)
79	{
80	ndelay(30);
81	}
82
83	static ssize_t pcf2123_show(struct device dev, struct device_attribute attr,
84	char *buffer)
85	{
86	struct spi_device *spi = to_spi_device(dev);
87	struct pcf2123_sysfs_reg r = (struct pcf2123_sysfs_reg ) attr;
88	u8 txbuf[1], rxbuf[1];
89	int ret;
90
91	txbuf[0] = PCF2123_READ \| simple_strtoul(r->name, NULL, 16);
92	ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
93	if (ret < 0)
94	return sprintf(buffer, "error: %d", ret);
95	pcf2123_delay_trec();
96	return sprintf(buffer, "0x%x", rxbuf[0]);
97	}
98
99	static ssize_t pcf2123_store(struct device dev, struct device_attribute attr,
100	const char *buffer, size_t count) {
101	struct spi_device *spi = to_spi_device(dev);
102	struct pcf2123_sysfs_reg r = (struct pcf2123_sysfs_reg ) attr;
103	u8 txbuf[2];
104	int ret;
105
106	txbuf[0] = PCF2123_WRITE \| simple_strtoul(r->name, NULL, 16);
107	txbuf[1] = simple_strtoul(buffer, NULL, 0);
108	ret = spi_write(spi, txbuf, sizeof(txbuf));
109	if (ret < 0)
110	return -EIO;
111	pcf2123_delay_trec();
112	return count;
113	}
114
115	static int pcf2123_rtc_read_time(struct device dev, struct rtc_time tm)
116	{
117	struct spi_device *spi = to_spi_device(dev);
118	u8 txbuf[1], rxbuf[7];
119	int ret;
120
121	txbuf[0] = PCF2123_READ \| PCF2123_REG_SC;
122	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
123	rxbuf, sizeof(rxbuf));
124	if (ret < 0)
125	return ret;
126	pcf2123_delay_trec();
127
128	tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
129	tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
130	tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
131	tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
132	tm->tm_wday = rxbuf[4] & 0x07;
133	tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
134	tm->tm_year = bcd2bin(rxbuf[6]);
135	if (tm->tm_year < 70)
136	tm->tm_year += 100; /* assume we are in 1970...2069 */
137
138	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
139	"mday=%d, mon=%d, year=%d, wday=%d\n",
140	__func__,
141	tm->tm_sec, tm->tm_min, tm->tm_hour,
142	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
143
144	/* the clock can give out invalid datetime, but we cannot return
145	* -EINVAL otherwise hwclock will refuse to set the time on bootup.
146	*/
147	if (rtc_valid_tm(tm) < 0)
148	dev_err(dev, "retrieved date/time is not valid.\n");
149
150	return 0;
151	}
152
153	static int pcf2123_rtc_set_time(struct device dev, struct rtc_time tm)
154	{
155	struct spi_device *spi = to_spi_device(dev);
156	u8 txbuf[8];
157	int ret;
158
159	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
160	"mday=%d, mon=%d, year=%d, wday=%d\n",
161	__func__,
162	tm->tm_sec, tm->tm_min, tm->tm_hour,
163	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
164
165	/* Stop the counter first */
166	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
167	txbuf[1] = 0x20;
168	ret = spi_write(spi, txbuf, 2);
169	if (ret < 0)
170	return ret;
171	pcf2123_delay_trec();
172
173	/* Set the new time */
174	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_SC;
175	txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
176	txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
177	txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
178	txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
179	txbuf[5] = tm->tm_wday & 0x07;
180	txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
181	txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
182
183	ret = spi_write(spi, txbuf, sizeof(txbuf));
184	if (ret < 0)
185	return ret;
186	pcf2123_delay_trec();
187
188	/* Start the counter */
189	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
190	txbuf[1] = 0x00;
191	ret = spi_write(spi, txbuf, 2);
192	if (ret < 0)
193	return ret;
194	pcf2123_delay_trec();
195
196	return 0;
197	}
198
199	static const struct rtc_class_ops pcf2123_rtc_ops = {
200	.read_time = pcf2123_rtc_read_time,
201	.set_time = pcf2123_rtc_set_time,
202	};
203
204	static int __devinit pcf2123_probe(struct spi_device *spi)
205	{
206	struct rtc_device *rtc;
207	struct pcf2123_plat_data *pdata;
208	u8 txbuf[2], rxbuf[2];
209	int ret, i;
210
211	pdata = kzalloc(sizeof(struct pcf2123_plat_data), GFP_KERNEL);
212	if (!pdata)
213	return -ENOMEM;
214	spi->dev.platform_data = pdata;
215
216	/* Send a software reset command */
217	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
218	txbuf[1] = 0x58;
219	dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
220	txbuf[0], txbuf[1]);
221	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
222	if (ret < 0)
223	return ret;
224	pcf2123_delay_trec();
225
226	/* Stop the counter */
227	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
228	txbuf[1] = 0x20;
229	dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
230	txbuf[0], txbuf[1]);
231	ret = spi_write(spi, txbuf, 2 * sizeof(u8));
232	if (ret < 0)
233	return ret;
234	pcf2123_delay_trec();
235
236	/* See if the counter was actually stopped */
237	txbuf[0] = PCF2123_READ \| PCF2123_REG_CTRL1;
238	dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n",
239	txbuf[0]);
240	ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8),
241	rxbuf, 2 * sizeof(u8));
242	dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n",
243	rxbuf[0], rxbuf[1]);
244	if (ret < 0)
245	goto kfree_exit;
246	pcf2123_delay_trec();
247
248	if (!(rxbuf[0] & 0x20)) {
249	dev_err(&spi->dev, "chip not found\n");
250	goto kfree_exit;
251	}
252
253	dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
254	dev_info(&spi->dev, "spiclk %u KHz.\n",
255	(spi->max_speed_hz + 500) / 1000);
256
257	/* Start the counter */
258	txbuf[0] = PCF2123_WRITE \| PCF2123_REG_CTRL1;
259	txbuf[1] = 0x00;
260	ret = spi_write(spi, txbuf, sizeof(txbuf));
261	if (ret < 0)
262	goto kfree_exit;
263	pcf2123_delay_trec();
264
265	/* Finalize the initialization */
266	rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,
267	&pcf2123_rtc_ops, THIS_MODULE);
268
269	if (IS_ERR(rtc)) {
270	dev_err(&spi->dev, "failed to register.\n");
271	ret = PTR_ERR(rtc);
272	goto kfree_exit;
273	}
274
275	pdata->rtc = rtc;
276
277	for (i = 0; i < 16; i++) {
278	sprintf(pdata->regs[i].name, "%1x", i);
279	pdata->regs[i].attr.attr.mode = S_IRUGO \| S_IWUSR;
280	pdata->regs[i].attr.attr.name = pdata->regs[i].name;
281	pdata->regs[i].attr.show = pcf2123_show;
282	pdata->regs[i].attr.store = pcf2123_store;
283	ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
284	if (ret) {
285	dev_err(&spi->dev, "Unable to create sysfs %s\n",
286	pdata->regs[i].name);
287	pdata->regs[i].name[0] = '\0';
288	}
289	}
290
291	return 0;
292	kfree_exit:
293	kfree(pdata);
294	spi->dev.platform_data = NULL;
295	return ret;
296	}
297
298	static int pcf2123_remove(struct spi_device *spi)
299	{
300	struct pcf2123_plat_data *pdata = spi->dev.platform_data;
301	int i;
302
303	if (pdata) {
304	struct rtc_device *rtc = pdata->rtc;
305
306	if (rtc)
307	rtc_device_unregister(rtc);
308	for (i = 0; i < 16; i++)
309	if (pdata->regs[i].name[0])
310	device_remove_file(&spi->dev,
311	&pdata->regs[i].attr);
312	kfree(pdata);
313	}
314
315	return 0;
316	}
317
318	static struct spi_driver pcf2123_driver = {
319	.driver = {
320	.name = "rtc-pcf2123",
321	.bus = &spi_bus_type,
322	.owner = THIS_MODULE,
323	},
324	.probe = pcf2123_probe,
325	.remove = __devexit_p(pcf2123_remove),
326	};
327
328	static int __init pcf2123_init(void)
329	{
330	return spi_register_driver(&pcf2123_driver);
331	}
332
333	static void __exit pcf2123_exit(void)
334	{
335	spi_unregister_driver(&pcf2123_driver);
336	}
337
338	MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
339	MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
340	MODULE_LICENSE("GPL");
341	MODULE_VERSION(DRV_VERSION);
342
343	module_init(pcf2123_init);
344	module_exit(pcf2123_exit);