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Commit 796b7abb authored by Søren Andersen's avatar Søren Andersen Committed by Linus Torvalds
Browse files

rtc: add pcf85063 support 



Add support for the pcf85063 rtc chip.

[akpm@linux-foundation.org: fix comment typo, tweak conding style]
Signed-off-by: default avatarSoeren Andersen <san@rosetechnology.dk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent db04d628

Documentation/devicetree/bindings/i2c/trivial-devices.txt

+1 −0
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ nuvoton,npct501 i2c trusted platform module (TPM) 
nxp,pca9556		Octal SMBus and I2C registered interface

nxp,pca9557		8-bit I2C-bus and SMBus I/O port with reset

nxp,pcf8563		Real-time clock/calendar

nxp,pcf85063		Tiny Real-Time Clock

ovti,ov5642		OV5642: Color CMOS QSXGA (5-megapixel) Image Sensor with OmniBSI and Embedded TrueFocus

pericom,pt7c4338	Real-time Clock Module

plx,pex8648		48-Lane, 12-Port PCI Express Gen 2 (5.0 GT/s) Switch

drivers/rtc/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -373,6 +373,14 @@ config RTC_DRV_PCF8563 
	  This driver can also be built as a module. If so, the module

	  will be called rtc-pcf8563.



config RTC_DRV_PCF85063

	tristate "nxp PCF85063"

	help

	  If you say yes here you get support for the PCF85063 RTC chip



	  This driver can also be built as a module. If so, the module

	  will be called rtc-pcf85063.



config RTC_DRV_PCF8583

	tristate "Philips PCF8583"

	help

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -97,6 +97,7 @@ obj-$(CONFIG_RTC_DRV_PCAP) += rtc-pcap.o 
obj-$(CONFIG_RTC_DRV_PCF2127)	+= rtc-pcf2127.o

obj-$(CONFIG_RTC_DRV_PCF8523)	+= rtc-pcf8523.o

obj-$(CONFIG_RTC_DRV_PCF8563)	+= rtc-pcf8563.o

obj-$(CONFIG_RTC_DRV_PCF85063)	+= rtc-pcf85063.o

obj-$(CONFIG_RTC_DRV_PCF8583)	+= rtc-pcf8583.o

obj-$(CONFIG_RTC_DRV_PCF2123)	+= rtc-pcf2123.o

obj-$(CONFIG_RTC_DRV_PCF50633)	+= rtc-pcf50633.o

drivers/rtc/rtc-pcf85063.c

0 → 100644
+204 −0
Original line number Diff line number Diff line 
/*

 * An I2C driver for the PCF85063 RTC

 * Copyright 2014 Rose Technology

 *

 * Author: Søren Andersen <san@rosetechnology.dk>

 * Maintainers: http://www.nslu2-linux.org/

 *

 * based on the other drivers in this same directory.

 *

 * 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/module.h>



#define DRV_VERSION "0.0.1"



#define PCF85063_REG_CTRL1		0x00 /* status */

#define PCF85063_REG_CTRL2		0x01



#define PCF85063_REG_SC			0x04 /* datetime */

#define PCF85063_REG_MN			0x05

#define PCF85063_REG_HR			0x06

#define PCF85063_REG_DM			0x07

#define PCF85063_REG_DW			0x08

#define PCF85063_REG_MO			0x09

#define PCF85063_REG_YR			0x0A



#define PCF85063_MO_C			0x80 /* century */



static struct i2c_driver pcf85063_driver;



struct pcf85063 {

	struct rtc_device *rtc;

	int c_polarity;	/* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */

	int voltage_low; /* indicates if a low_voltage was detected */

};



/*

 * In the routines that deal directly with the pcf85063 hardware, we use

 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.

 */

static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)

{

	struct pcf85063 *pcf85063 = i2c_get_clientdata(client);

	unsigned char buf[13] = { PCF85063_REG_CTRL1 };

	struct i2c_msg msgs[] = {

		{/* setup read ptr */

			.addr = client->addr,

			.len = 1,

			.buf = buf

		},

		{/* read status + date */

			.addr = client->addr,

			.flags = I2C_M_RD,

			.len = 13,

			.buf = buf

		},

	};



	/* read registers */

	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {

		dev_err(&client->dev, "%s: read error\n", __func__);

		return -EIO;

	}



	tm->tm_sec = bcd2bin(buf[PCF85063_REG_SC] & 0x7F);

	tm->tm_min = bcd2bin(buf[PCF85063_REG_MN] & 0x7F);

	tm->tm_hour = bcd2bin(buf[PCF85063_REG_HR] & 0x3F); /* rtc hr 0-23 */

	tm->tm_mday = bcd2bin(buf[PCF85063_REG_DM] & 0x3F);

	tm->tm_wday = buf[PCF85063_REG_DW] & 0x07;

	tm->tm_mon = bcd2bin(buf[PCF85063_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */

	tm->tm_year = bcd2bin(buf[PCF85063_REG_YR]);

	if (tm->tm_year < 70)

		tm->tm_year += 100;	/* assume we are in 1970...2069 */

	/* detect the polarity heuristically. see note above. */

	pcf85063->c_polarity = (buf[PCF85063_REG_MO] & PCF85063_MO_C) ?

		(tm->tm_year >= 100) : (tm->tm_year < 100);



	/* 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(&client->dev, "retrieved date/time is not valid.\n");



	return 0;

}



static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)

{

	int i = 0, err = 0;

	unsigned char buf[11];



	/* Control & status */

	buf[PCF85063_REG_CTRL1] = 0;

	buf[PCF85063_REG_CTRL2] = 5;



	/* hours, minutes and seconds */

	buf[PCF85063_REG_SC] = bin2bcd(tm->tm_sec) & 0x7F;



	buf[PCF85063_REG_MN] = bin2bcd(tm->tm_min);

	buf[PCF85063_REG_HR] = bin2bcd(tm->tm_hour);



	/* Day of month, 1 - 31 */

	buf[PCF85063_REG_DM] = bin2bcd(tm->tm_mday);



	/* Day, 0 - 6 */

	buf[PCF85063_REG_DW] = tm->tm_wday & 0x07;



	/* month, 1 - 12 */

	buf[PCF85063_REG_MO] = bin2bcd(tm->tm_mon + 1);



	/* year and century */

	buf[PCF85063_REG_YR] = bin2bcd(tm->tm_year % 100);



	/* write register's data */

	for (i = 0; i < sizeof(buf); i++) {

		unsigned char data[2] = { i, buf[i] };



		err = i2c_master_send(client, data, sizeof(data));

		if (err != sizeof(data)) {

			dev_err(&client->dev, "%s: err=%d addr=%02x, data=%02x\n",

					__func__, err, data[0], data[1]);

			return -EIO;

		}

	}



	return 0;

}



static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	return pcf85063_get_datetime(to_i2c_client(dev), tm);

}



static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)

{

	return pcf85063_set_datetime(to_i2c_client(dev), tm);

}



static const struct rtc_class_ops pcf85063_rtc_ops = {

	.read_time	= pcf85063_rtc_read_time,

	.set_time	= pcf85063_rtc_set_time

};



static int pcf85063_probe(struct i2c_client *client,

				const struct i2c_device_id *id)

{

	struct pcf85063 *pcf85063;



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



	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))

		return -ENODEV;



	pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),

				GFP_KERNEL);

	if (!pcf85063)

		return -ENOMEM;



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



	i2c_set_clientdata(client, pcf85063);



	pcf85063->rtc = devm_rtc_device_register(&client->dev,

				pcf85063_driver.driver.name,

				&pcf85063_rtc_ops, THIS_MODULE);



	return PTR_ERR_OR_ZERO(pcf85063->rtc);

}



static const struct i2c_device_id pcf85063_id[] = {

	{ "pcf85063", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, pcf85063_id);



#ifdef CONFIG_OF

static const struct of_device_id pcf85063_of_match[] = {

	{ .compatible = "nxp,pcf85063" },

	{}

};

MODULE_DEVICE_TABLE(of, pcf85063_of_match);

#endif



static struct i2c_driver pcf85063_driver = {

	.driver		= {

		.name	= "rtc-pcf85063",

		.owner	= THIS_MODULE,

		.of_match_table = of_match_ptr(pcf85063_of_match),

	},

	.probe		= pcf85063_probe,

	.id_table	= pcf85063_id,

};



module_i2c_driver(pcf85063_driver);



MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");

MODULE_DESCRIPTION("PCF85063 RTC driver");

MODULE_LICENSE("GPL");

MODULE_VERSION(DRV_VERSION);