drivers/rtc/rtc-ds3234.c - kernel/msm-4.9 - Gitiles

 /* drivers/rtc/rtc-ds3234.c
  *
  * Driver for Dallas Semiconductor (DS3234) SPI RTC with Integrated Crystal
  * and SRAM.
  *
  * Copyright (C) 2008 MIMOMax Wireless 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.
  *
  * Changelog:
  *
  * 07-May-2008: Dennis Aberilla <denzzzhome@yahoo.com>
  *		- Created based on the max6902 code. Only implements the
  *		  date/time keeping functions; no SRAM yet.
  */

 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/rtc.h>
 #include <linux/spi/spi.h>
 #include <linux/bcd.h>

 #define DS3234_REG_SECONDS	0x00
 #define DS3234_REG_MINUTES	0x01
 #define DS3234_REG_HOURS	0x02
 #define DS3234_REG_DAY		0x03
 #define DS3234_REG_DATE		0x04
 #define DS3234_REG_MONTH	0x05
 #define DS3234_REG_YEAR		0x06
 #define DS3234_REG_CENTURY	(1 << 7) /* Bit 7 of the Month register */

 #define DS3234_REG_CONTROL	0x0E
 #define DS3234_REG_CONT_STAT	0x0F

 #undef DS3234_DEBUG

 struct ds3234 {
 	struct rtc_device *rtc;
 	u8 buf[8]; /* Burst read: addr + 7 regs */
 	u8 tx_buf[2];
 	u8 rx_buf[2];
 };

 static void ds3234_set_reg(struct device *dev, unsigned char address,
 				unsigned char data)
 {
 	struct spi_device *spi = to_spi_device(dev);
 	unsigned char buf[2];

 	/* MSB must be '1' to indicate write */
 	buf[0] = address | 0x80;
 	buf[1] = data;

 	spi_write(spi, buf, 2);
 }

 static int ds3234_get_reg(struct device *dev, unsigned char address,
 				unsigned char *data)
 {
 	struct spi_device *spi = to_spi_device(dev);
 	struct ds3234 *chip = dev_get_drvdata(dev);
 	struct spi_message message;
 	struct spi_transfer xfer;
 	int status;

 	if (!data)
 		return -EINVAL;

 	/* Build our spi message */
 	spi_message_init(&message);
 	memset(&xfer, 0, sizeof(xfer));

 	/* Address + dummy tx byte */
 	xfer.len = 2;
 	xfer.tx_buf = chip->tx_buf;
 	xfer.rx_buf = chip->rx_buf;

 	chip->tx_buf[0] = address;
 	chip->tx_buf[1] = 0xff;

 	spi_message_add_tail(&xfer, &message);

 	/* do the i/o */
 	status = spi_sync(spi, &message);
 	if (status == 0)
 		status = message.status;
 	else
 		return status;

 	*data = chip->rx_buf[1];

 	return status;
 }

 static int ds3234_get_datetime(struct device *dev, struct rtc_time *dt)
 {
 	struct spi_device *spi = to_spi_device(dev);
 	struct ds3234 *chip = dev_get_drvdata(dev);
 	struct spi_message message;
 	struct spi_transfer xfer;
 	int status;

 	/* build the message */
 	spi_message_init(&message);
 	memset(&xfer, 0, sizeof(xfer));
 	xfer.len = 1 + 7;	/* Addr + 7 registers */
 	xfer.tx_buf = chip->buf;
 	xfer.rx_buf = chip->buf;
 	chip->buf[0] = 0x00;	/* Start address */
 	spi_message_add_tail(&xfer, &message);

 	/* do the i/o */
 	status = spi_sync(spi, &message);
 	if (status == 0)
 		status = message.status;
 	else
 		return status;

 	/* Seconds, Minutes, Hours, Day, Date, Month, Year */
 	dt->tm_sec	= bcd2bin(chip->buf[1]);
 	dt->tm_min	= bcd2bin(chip->buf[2]);
 	dt->tm_hour	= bcd2bin(chip->buf[3] & 0x3f);
 	dt->tm_wday	= bcd2bin(chip->buf[4]) - 1; /* 0 = Sun */
 	dt->tm_mday	= bcd2bin(chip->buf[5]);
 	dt->tm_mon	= bcd2bin(chip->buf[6] & 0x1f) - 1; /* 0 = Jan */
 	dt->tm_year 	= bcd2bin(chip->buf[7] & 0xff) + 100; /* Assume 20YY */

 #ifdef DS3234_DEBUG
 	dev_dbg(dev, "\n%s : Read RTC values\n", __func__);
 	dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
 	dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
 	dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
 	dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
 	dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
 	dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
 	dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
 #endif

 	return 0;
 }

 static int ds3234_set_datetime(struct device *dev, struct rtc_time *dt)
 {
 #ifdef DS3234_DEBUG
 	dev_dbg(dev, "\n%s : Setting RTC values\n", __func__);
 	dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
 	dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
 	dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
 	dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
 	dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
 	dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
 	dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
 #endif

 	ds3234_set_reg(dev, DS3234_REG_SECONDS, bin2bcd(dt->tm_sec));
 	ds3234_set_reg(dev, DS3234_REG_MINUTES, bin2bcd(dt->tm_min));
 	ds3234_set_reg(dev, DS3234_REG_HOURS, bin2bcd(dt->tm_hour) & 0x3f);

 	/* 0 = Sun */
 	ds3234_set_reg(dev, DS3234_REG_DAY, bin2bcd(dt->tm_wday + 1));
 	ds3234_set_reg(dev, DS3234_REG_DATE, bin2bcd(dt->tm_mday));

 	/* 0 = Jan */
 	ds3234_set_reg(dev, DS3234_REG_MONTH, bin2bcd(dt->tm_mon + 1));

 	/* Assume 20YY although we just want to make sure not to go negative. */
 	if (dt->tm_year > 100)
 		dt->tm_year -= 100;

 	ds3234_set_reg(dev, DS3234_REG_YEAR, bin2bcd(dt->tm_year));

 	return 0;
 }

 static int ds3234_read_time(struct device *dev, struct rtc_time *tm)
 {
 	return ds3234_get_datetime(dev, tm);
 }

 static int ds3234_set_time(struct device *dev, struct rtc_time *tm)
 {
 	return ds3234_set_datetime(dev, tm);
 }

 static const struct rtc_class_ops ds3234_rtc_ops = {
 	.read_time	= ds3234_read_time,
 	.set_time	= ds3234_set_time,
 };

 static int ds3234_probe(struct spi_device *spi)
 {
 	struct rtc_device *rtc;
 	unsigned char tmp;
 	struct ds3234 *chip;
 	int res;

 	rtc = rtc_device_register("ds3234",
 				&spi->dev, &ds3234_rtc_ops, THIS_MODULE);
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);

 	spi->mode = SPI_MODE_3;
 	spi->bits_per_word = 8;
 	spi_setup(spi);

 	chip = kzalloc(sizeof(struct ds3234), GFP_KERNEL);
 	if (!chip) {
 		rtc_device_unregister(rtc);
 		return -ENOMEM;
 	}
 	chip->rtc = rtc;
 	dev_set_drvdata(&spi->dev, chip);

 	res = ds3234_get_reg(&spi->dev, DS3234_REG_SECONDS, &tmp);
 	if (res) {
 		rtc_device_unregister(rtc);
 		return res;
 	}

 	/* Control settings
 	 *
 	 * CONTROL_REG
 	 * BIT 7	6	5	4	3	2	1	0
 	 *     EOSC	BBSQW	CONV	RS2	RS1	INTCN	A2IE	A1IE
 	 *
 	 *     0	0	0	1	1	1	0	0
 	 *
 	 * CONTROL_STAT_REG
 	 * BIT 7	6	5	4	3	2	1	0
 	 *     OSF	BB32kHz	CRATE1	CRATE0	EN32kHz	BSY	A2F	A1F
 	 *
 	 *     1	0	0	0	1	0	0	0
 	 */
 	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
 	ds3234_set_reg(&spi->dev, DS3234_REG_CONTROL, tmp & 0x1c);

 	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
 	ds3234_set_reg(&spi->dev, DS3234_REG_CONT_STAT, tmp & 0x88);

 	/* Print our settings */
 	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
 	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);

 	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
 	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);

 	return 0;
 }

 static int __exit ds3234_remove(struct spi_device *spi)
 {
 	struct ds3234 *chip = platform_get_drvdata(spi);
 	struct rtc_device *rtc = chip->rtc;

 	if (rtc)
 		rtc_device_unregister(rtc);

 	kfree(chip);

 	return 0;
 }

 static struct spi_driver ds3234_driver = {
 	.driver = {
 		.name	 = "ds3234",
 		.bus	= &spi_bus_type,
 		.owner	= THIS_MODULE,
 	},
 	.probe	 = ds3234_probe,
 	.remove = __devexit_p(ds3234_remove),
 };

 static __init int ds3234_init(void)
 {
 	printk(KERN_INFO "DS3234 SPI RTC Driver\n");
 	return spi_register_driver(&ds3234_driver);
 }
 module_init(ds3234_init);

 static __exit void ds3234_exit(void)
 {
 	spi_unregister_driver(&ds3234_driver);
 }
 module_exit(ds3234_exit);

 MODULE_DESCRIPTION("DS3234 SPI RTC driver");
 MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
 MODULE_LICENSE("GPL");
	/* drivers/rtc/rtc-ds3234.c
	*
	* Driver for Dallas Semiconductor (DS3234) SPI RTC with Integrated Crystal
	* and SRAM.
	*
	* Copyright (C) 2008 MIMOMax Wireless 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.
	*
	* Changelog:
	*
	* 07-May-2008: Dennis Aberilla <denzzzhome@yahoo.com>
	* - Created based on the max6902 code. Only implements the
	* date/time keeping functions; no SRAM yet.
	*/

	#include <linux/device.h>
	#include <linux/platform_device.h>
	#include <linux/rtc.h>
	#include <linux/spi/spi.h>
	#include <linux/bcd.h>

	#define DS3234_REG_SECONDS 0x00
	#define DS3234_REG_MINUTES 0x01
	#define DS3234_REG_HOURS 0x02
	#define DS3234_REG_DAY 0x03
	#define DS3234_REG_DATE 0x04
	#define DS3234_REG_MONTH 0x05
	#define DS3234_REG_YEAR 0x06
	#define DS3234_REG_CENTURY (1 << 7) /* Bit 7 of the Month register */

	#define DS3234_REG_CONTROL 0x0E
	#define DS3234_REG_CONT_STAT 0x0F

	#undef DS3234_DEBUG

	struct ds3234 {
	struct rtc_device *rtc;
	u8 buf[8]; /* Burst read: addr + 7 regs */
	u8 tx_buf[2];
	u8 rx_buf[2];
	};

	static void ds3234_set_reg(struct device *dev, unsigned char address,
	unsigned char data)
	{
	struct spi_device *spi = to_spi_device(dev);
	unsigned char buf[2];

	/* MSB must be '1' to indicate write */
	buf[0] = address \| 0x80;
	buf[1] = data;

	spi_write(spi, buf, 2);
	}

	static int ds3234_get_reg(struct device *dev, unsigned char address,
	unsigned char *data)
	{
	struct spi_device *spi = to_spi_device(dev);
	struct ds3234 *chip = dev_get_drvdata(dev);
	struct spi_message message;
	struct spi_transfer xfer;
	int status;

	if (!data)
	return -EINVAL;

	/* Build our spi message */
	spi_message_init(&message);
	memset(&xfer, 0, sizeof(xfer));

	/* Address + dummy tx byte */
	xfer.len = 2;
	xfer.tx_buf = chip->tx_buf;
	xfer.rx_buf = chip->rx_buf;

	chip->tx_buf[0] = address;
	chip->tx_buf[1] = 0xff;

	spi_message_add_tail(&xfer, &message);

	/* do the i/o */
	status = spi_sync(spi, &message);
	if (status == 0)
	status = message.status;
	else
	return status;

	*data = chip->rx_buf[1];

	return status;
	}

	static int ds3234_get_datetime(struct device dev, struct rtc_time dt)
	{
	struct spi_device *spi = to_spi_device(dev);
	struct ds3234 *chip = dev_get_drvdata(dev);
	struct spi_message message;
	struct spi_transfer xfer;
	int status;

	/* build the message */
	spi_message_init(&message);
	memset(&xfer, 0, sizeof(xfer));
	xfer.len = 1 + 7; /* Addr + 7 registers */
	xfer.tx_buf = chip->buf;
	xfer.rx_buf = chip->buf;
	chip->buf[0] = 0x00; /* Start address */
	spi_message_add_tail(&xfer, &message);

	/* do the i/o */
	status = spi_sync(spi, &message);
	if (status == 0)
	status = message.status;
	else
	return status;

	/* Seconds, Minutes, Hours, Day, Date, Month, Year */
	dt->tm_sec = bcd2bin(chip->buf[1]);
	dt->tm_min = bcd2bin(chip->buf[2]);
	dt->tm_hour = bcd2bin(chip->buf[3] & 0x3f);
	dt->tm_wday = bcd2bin(chip->buf[4]) - 1; /* 0 = Sun */
	dt->tm_mday = bcd2bin(chip->buf[5]);
	dt->tm_mon = bcd2bin(chip->buf[6] & 0x1f) - 1; /* 0 = Jan */
	dt->tm_year = bcd2bin(chip->buf[7] & 0xff) + 100; /* Assume 20YY */

	#ifdef DS3234_DEBUG
	dev_dbg(dev, "\n%s : Read RTC values\n", __func__);
	dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
	dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
	dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
	dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
	dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
	dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
	dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
	#endif

	return 0;
	}

	static int ds3234_set_datetime(struct device dev, struct rtc_time dt)
	{
	#ifdef DS3234_DEBUG
	dev_dbg(dev, "\n%s : Setting RTC values\n", __func__);
	dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
	dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
	dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
	dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
	dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
	dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
	dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
	#endif

	ds3234_set_reg(dev, DS3234_REG_SECONDS, bin2bcd(dt->tm_sec));
	ds3234_set_reg(dev, DS3234_REG_MINUTES, bin2bcd(dt->tm_min));
	ds3234_set_reg(dev, DS3234_REG_HOURS, bin2bcd(dt->tm_hour) & 0x3f);

	/* 0 = Sun */
	ds3234_set_reg(dev, DS3234_REG_DAY, bin2bcd(dt->tm_wday + 1));
	ds3234_set_reg(dev, DS3234_REG_DATE, bin2bcd(dt->tm_mday));

	/* 0 = Jan */
	ds3234_set_reg(dev, DS3234_REG_MONTH, bin2bcd(dt->tm_mon + 1));

	/* Assume 20YY although we just want to make sure not to go negative. */
	if (dt->tm_year > 100)
	dt->tm_year -= 100;

	ds3234_set_reg(dev, DS3234_REG_YEAR, bin2bcd(dt->tm_year));

	return 0;
	}

	static int ds3234_read_time(struct device dev, struct rtc_time tm)
	{
	return ds3234_get_datetime(dev, tm);
	}

	static int ds3234_set_time(struct device dev, struct rtc_time tm)
	{
	return ds3234_set_datetime(dev, tm);
	}

	static const struct rtc_class_ops ds3234_rtc_ops = {
	.read_time = ds3234_read_time,
	.set_time = ds3234_set_time,
	};

	static int ds3234_probe(struct spi_device *spi)
	{
	struct rtc_device *rtc;
	unsigned char tmp;
	struct ds3234 *chip;
	int res;

	rtc = rtc_device_register("ds3234",
	&spi->dev, &ds3234_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc))
	return PTR_ERR(rtc);

	spi->mode = SPI_MODE_3;
	spi->bits_per_word = 8;
	spi_setup(spi);

	chip = kzalloc(sizeof(struct ds3234), GFP_KERNEL);
	if (!chip) {
	rtc_device_unregister(rtc);
	return -ENOMEM;
	}
	chip->rtc = rtc;
	dev_set_drvdata(&spi->dev, chip);

	res = ds3234_get_reg(&spi->dev, DS3234_REG_SECONDS, &tmp);
	if (res) {
	rtc_device_unregister(rtc);
	return res;
	}

	/* Control settings
	*
	* CONTROL_REG
	* BIT 7 6 5 4 3 2 1 0
	* EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE
	*
	* 0 0 0 1 1 1 0 0
	*
	* CONTROL_STAT_REG
	* BIT 7 6 5 4 3 2 1 0
	* OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F
	*
	* 1 0 0 0 1 0 0 0
	*/
	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
	ds3234_set_reg(&spi->dev, DS3234_REG_CONTROL, tmp & 0x1c);

	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
	ds3234_set_reg(&spi->dev, DS3234_REG_CONT_STAT, tmp & 0x88);

	/* Print our settings */
	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);

	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);

	return 0;
	}

	static int __exit ds3234_remove(struct spi_device *spi)
	{
	struct ds3234 *chip = platform_get_drvdata(spi);
	struct rtc_device *rtc = chip->rtc;

	if (rtc)
	rtc_device_unregister(rtc);

	kfree(chip);

	return 0;
	}

	static struct spi_driver ds3234_driver = {
	.driver = {
	.name = "ds3234",
	.bus = &spi_bus_type,
	.owner = THIS_MODULE,
	},
	.probe = ds3234_probe,
	.remove = __devexit_p(ds3234_remove),
	};

	static __init int ds3234_init(void)
	{
	printk(KERN_INFO "DS3234 SPI RTC Driver\n");
	return spi_register_driver(&ds3234_driver);
	}
	module_init(ds3234_init);

	static __exit void ds3234_exit(void)
	{
	spi_unregister_driver(&ds3234_driver);
	}
	module_exit(ds3234_exit);

	MODULE_DESCRIPTION("DS3234 SPI RTC driver");
	MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
	MODULE_LICENSE("GPL");