drivers/rtc/rtc-pcf2127.c - kernel/msm-4.9 - Gitiles

 /*
  * An I2C driver for the NXP PCF2127 RTC
  * Copyright 2013 Til-Technologies
  *
  * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
  *
  * based on the other drivers in this same directory.
  *
  * http://www.nxp.com/documents/data_sheet/PCF2127AT.pdf
  *
  * 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.
  */

 #include <linux/i2c.h>
 #include <linux/bcd.h>
 #include <linux/rtc.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/of.h>

 #define DRV_VERSION "0.0.1"

 #define PCF2127_REG_CTRL1       (0x00)  /* Control Register 1 */
 #define PCF2127_REG_CTRL2       (0x01)  /* Control Register 2 */
 #define PCF2127_REG_CTRL3       (0x02)  /* Control Register 3 */
 #define PCF2127_REG_SC          (0x03)  /* datetime */
 #define PCF2127_REG_MN          (0x04)
 #define PCF2127_REG_HR          (0x05)
 #define PCF2127_REG_DM          (0x06)
 #define PCF2127_REG_DW          (0x07)
 #define PCF2127_REG_MO          (0x08)
 #define PCF2127_REG_YR          (0x09)

 #define PCF2127_OSF             BIT(7)  /* Oscillator Fail flag */

 static struct i2c_driver pcf2127_driver;

 struct pcf2127 {
 	struct rtc_device *rtc;
 	int voltage_low; /* indicates if a low_voltage was detected */
 	int oscillator_failed; /* OSF was detected and date is unreliable */
 };

 /*
  * In the routines that deal directly with the pcf2127 hardware, we use
  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
  */
 static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
 	unsigned char buf[10] = { PCF2127_REG_CTRL1 };

 	/* read registers */
 	if (i2c_master_send(client, buf, 1) != 1 ||
 		i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
 		dev_err(&client->dev, "%s: read error\n", __func__);
 		return -EIO;
 	}

 	if (buf[PCF2127_REG_CTRL3] & 0x04) {
 		pcf2127->voltage_low = 1;
 		dev_info(&client->dev,
 			"low voltage detected, check/replace RTC battery.\n");
 	}

 	if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
 		/*
 		 * no need clear the flag here,
 		 * it will be cleared once the new date is saved
 		 */
 		pcf2127->oscillator_failed = 1;
 		dev_warn(&client->dev,
 			 "oscillator stop detected, date/time is not reliable\n");
 		return -EINVAL;
 	}

 	dev_dbg(&client->dev,
 		"%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
 		"sec=%02x, min=%02x, hr=%02x, "
 		"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
 		__func__,
 		buf[0], buf[1], buf[2],
 		buf[3], buf[4], buf[5],
 		buf[6], buf[7], buf[8], buf[9]);


 	tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
 	tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
 	tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
 	tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
 	tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
 	tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
 	tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
 	if (tm->tm_year < 70)
 		tm->tm_year += 100;	/* assume we are in 1970...2069 */

 	dev_dbg(&client->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);

 	return rtc_valid_tm(tm);
 }

 static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
 	unsigned char buf[8];
 	int i = 0, err;

 	dev_dbg(&client->dev, "%s: 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);

 	/* start register address */
 	buf[i++] = PCF2127_REG_SC;

 	/* hours, minutes and seconds */
 	buf[i++] = bin2bcd(tm->tm_sec);	/* this will also clear OSF flag */
 	buf[i++] = bin2bcd(tm->tm_min);
 	buf[i++] = bin2bcd(tm->tm_hour);
 	buf[i++] = bin2bcd(tm->tm_mday);
 	buf[i++] = tm->tm_wday & 0x07;

 	/* month, 1 - 12 */
 	buf[i++] = bin2bcd(tm->tm_mon + 1);

 	/* year */
 	buf[i++] = bin2bcd(tm->tm_year % 100);

 	/* write register's data */
 	err = i2c_master_send(client, buf, i);
 	if (err != i) {
 		dev_err(&client->dev,
 			"%s: err=%d", __func__, err);
 		return -EIO;
 	}

 	/* clear OSF flag in client data */
 	pcf2127->oscillator_failed = 0;

 	return 0;
 }

 #ifdef CONFIG_RTC_INTF_DEV
 static int pcf2127_rtc_ioctl(struct device *dev,
 				unsigned int cmd, unsigned long arg)
 {
 	struct pcf2127 *pcf2127 = i2c_get_clientdata(to_i2c_client(dev));

 	switch (cmd) {
 	case RTC_VL_READ:
 		if (pcf2127->voltage_low)
 			dev_info(dev, "low voltage detected, check/replace battery\n");
 		if (pcf2127->oscillator_failed)
 			dev_info(dev, "oscillator stop detected, date/time is not reliable\n");

 		if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
 					sizeof(int)))
 			return -EFAULT;
 		return 0;
 	default:
 		return -ENOIOCTLCMD;
 	}
 }
 #else
 #define pcf2127_rtc_ioctl NULL
 #endif

 static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	return pcf2127_get_datetime(to_i2c_client(dev), tm);
 }

 static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	return pcf2127_set_datetime(to_i2c_client(dev), tm);
 }

 static const struct rtc_class_ops pcf2127_rtc_ops = {
 	.ioctl		= pcf2127_rtc_ioctl,
 	.read_time	= pcf2127_rtc_read_time,
 	.set_time	= pcf2127_rtc_set_time,
 };

 static int pcf2127_probe(struct i2c_client *client,
 				const struct i2c_device_id *id)
 {
 	struct pcf2127 *pcf2127;

 	dev_dbg(&client->dev, "%s\n", __func__);

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -ENODEV;

 	pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
 				GFP_KERNEL);
 	if (!pcf2127)
 		return -ENOMEM;

 	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");

 	i2c_set_clientdata(client, pcf2127);

 	pcf2127->rtc = devm_rtc_device_register(&client->dev,
 				pcf2127_driver.driver.name,
 				&pcf2127_rtc_ops, THIS_MODULE);

 	return PTR_ERR_OR_ZERO(pcf2127->rtc);
 }

 static const struct i2c_device_id pcf2127_id[] = {
 	{ "pcf2127", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, pcf2127_id);

 #ifdef CONFIG_OF
 static const struct of_device_id pcf2127_of_match[] = {
 	{ .compatible = "nxp,pcf2127" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, pcf2127_of_match);
 #endif

 static struct i2c_driver pcf2127_driver = {
 	.driver		= {
 		.name	= "rtc-pcf2127",
 		.of_match_table = of_match_ptr(pcf2127_of_match),
 	},
 	.probe		= pcf2127_probe,
 	.id_table	= pcf2127_id,
 };

 module_i2c_driver(pcf2127_driver);

 MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
 MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
	/*
	* An I2C driver for the NXP PCF2127 RTC
	* Copyright 2013 Til-Technologies
	*
	* Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
	*
	* based on the other drivers in this same directory.
	*
	* http://www.nxp.com/documents/data_sheet/PCF2127AT.pdf
	*
	* 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.
	*/

	#include <linux/i2c.h>
	#include <linux/bcd.h>
	#include <linux/rtc.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/of.h>

	#define DRV_VERSION "0.0.1"

	#define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */
	#define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */
	#define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */
	#define PCF2127_REG_SC (0x03) /* datetime */
	#define PCF2127_REG_MN (0x04)
	#define PCF2127_REG_HR (0x05)
	#define PCF2127_REG_DM (0x06)
	#define PCF2127_REG_DW (0x07)
	#define PCF2127_REG_MO (0x08)
	#define PCF2127_REG_YR (0x09)

	#define PCF2127_OSF BIT(7) /* Oscillator Fail flag */

	static struct i2c_driver pcf2127_driver;

	struct pcf2127 {
	struct rtc_device *rtc;
	int voltage_low; /* indicates if a low_voltage was detected */
	int oscillator_failed; /* OSF was detected and date is unreliable */
	};

	/*
	* In the routines that deal directly with the pcf2127 hardware, we use
	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	*/
	static int pcf2127_get_datetime(struct i2c_client client, struct rtc_time tm)
	{
	struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
	unsigned char buf[10] = { PCF2127_REG_CTRL1 };

	/* read registers */
	if (i2c_master_send(client, buf, 1) != 1 \|\|
	i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
	dev_err(&client->dev, "%s: read error\n", __func__);
	return -EIO;
	}

	if (buf[PCF2127_REG_CTRL3] & 0x04) {
	pcf2127->voltage_low = 1;
	dev_info(&client->dev,
	"low voltage detected, check/replace RTC battery.\n");
	}

	if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
	/*
	* no need clear the flag here,
	* it will be cleared once the new date is saved
	*/
	pcf2127->oscillator_failed = 1;
	dev_warn(&client->dev,
	"oscillator stop detected, date/time is not reliable\n");
	return -EINVAL;
	}

	dev_dbg(&client->dev,
	"%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
	"sec=%02x, min=%02x, hr=%02x, "
	"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
	__func__,
	buf[0], buf[1], buf[2],
	buf[3], buf[4], buf[5],
	buf[6], buf[7], buf[8], buf[9]);


	tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
	tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
	tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
	tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
	if (tm->tm_year < 70)
	tm->tm_year += 100; /* assume we are in 1970...2069 */

	dev_dbg(&client->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);

	return rtc_valid_tm(tm);
	}

	static int pcf2127_set_datetime(struct i2c_client client, struct rtc_time tm)
	{
	struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
	unsigned char buf[8];
	int i = 0, err;

	dev_dbg(&client->dev, "%s: 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);

	/* start register address */
	buf[i++] = PCF2127_REG_SC;

	/* hours, minutes and seconds */
	buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
	buf[i++] = bin2bcd(tm->tm_min);
	buf[i++] = bin2bcd(tm->tm_hour);
	buf[i++] = bin2bcd(tm->tm_mday);
	buf[i++] = tm->tm_wday & 0x07;

	/* month, 1 - 12 */
	buf[i++] = bin2bcd(tm->tm_mon + 1);

	/* year */
	buf[i++] = bin2bcd(tm->tm_year % 100);

	/* write register's data */
	err = i2c_master_send(client, buf, i);
	if (err != i) {
	dev_err(&client->dev,
	"%s: err=%d", __func__, err);
	return -EIO;
	}

	/* clear OSF flag in client data */
	pcf2127->oscillator_failed = 0;

	return 0;
	}

	#ifdef CONFIG_RTC_INTF_DEV
	static int pcf2127_rtc_ioctl(struct device *dev,
	unsigned int cmd, unsigned long arg)
	{
	struct pcf2127 *pcf2127 = i2c_get_clientdata(to_i2c_client(dev));

	switch (cmd) {
	case RTC_VL_READ:
	if (pcf2127->voltage_low)
	dev_info(dev, "low voltage detected, check/replace battery\n");
	if (pcf2127->oscillator_failed)
	dev_info(dev, "oscillator stop detected, date/time is not reliable\n");

	if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
	sizeof(int)))
	return -EFAULT;
	return 0;
	default:
	return -ENOIOCTLCMD;
	}
	}
	#else
	#define pcf2127_rtc_ioctl NULL
	#endif

	static int pcf2127_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	return pcf2127_get_datetime(to_i2c_client(dev), tm);
	}

	static int pcf2127_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	return pcf2127_set_datetime(to_i2c_client(dev), tm);
	}

	static const struct rtc_class_ops pcf2127_rtc_ops = {
	.ioctl = pcf2127_rtc_ioctl,
	.read_time = pcf2127_rtc_read_time,
	.set_time = pcf2127_rtc_set_time,
	};

	static int pcf2127_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct pcf2127 *pcf2127;

	dev_dbg(&client->dev, "%s\n", __func__);

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	return -ENODEV;

	pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
	GFP_KERNEL);
	if (!pcf2127)
	return -ENOMEM;

	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");

	i2c_set_clientdata(client, pcf2127);

	pcf2127->rtc = devm_rtc_device_register(&client->dev,
	pcf2127_driver.driver.name,
	&pcf2127_rtc_ops, THIS_MODULE);

	return PTR_ERR_OR_ZERO(pcf2127->rtc);
	}

	static const struct i2c_device_id pcf2127_id[] = {
	{ "pcf2127", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, pcf2127_id);

	#ifdef CONFIG_OF
	static const struct of_device_id pcf2127_of_match[] = {
	{ .compatible = "nxp,pcf2127" },
	{}
	};
	MODULE_DEVICE_TABLE(of, pcf2127_of_match);
	#endif

	static struct i2c_driver pcf2127_driver = {
	.driver = {
	.name = "rtc-pcf2127",
	.of_match_table = of_match_ptr(pcf2127_of_match),
	},
	.probe = pcf2127_probe,
	.id_table = pcf2127_id,
	};

	module_i2c_driver(pcf2127_driver);

	MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
	MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
	MODULE_LICENSE("GPL");
	MODULE_VERSION(DRV_VERSION);