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Commit b4506261 authored by Laxman Dewangan's avatar Laxman Dewangan Committed by Linus Torvalds
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drivers/rtc/rtc-as3722: add RTC driver 



The ams AS3722 is a compact system PMU suitable for mobile phones, tablets
etc.

Add a driver to support accessing the RTC found on the ams AS3722 PMIC
using RTC framework.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: default avatarFlorian Lobmaier <florian.lobmaier@ams.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5bccae6e

drivers/rtc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -153,6 +153,16 @@ config RTC_DRV_88PM80X 
	  This driver can also be built as a module. If so, the module

	  will be called rtc-88pm80x.



config RTC_DRV_AS3722

	tristate "ams AS3722 RTC driver"

	depends on MFD_AS3722

	help

	  If you say yes here you get support for the RTC of ams AS3722 PMIC

	  chips.



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

	  will be called rtc-as3722.



config RTC_DRV_DS1307

	tristate "Dallas/Maxim DS1307/37/38/39/40, ST M41T00, EPSON RX-8025"

	help

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ obj-$(CONFIG_RTC_DRV_88PM860X) += rtc-88pm860x.o 
obj-$(CONFIG_RTC_DRV_88PM80X)	+= rtc-88pm80x.o

obj-$(CONFIG_RTC_DRV_AB3100)	+= rtc-ab3100.o

obj-$(CONFIG_RTC_DRV_AB8500)	+= rtc-ab8500.o

obj-$(CONFIG_RTC_DRV_AS3722)	+= rtc-as3722.o

obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o

obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o

obj-$(CONFIG_RTC_DRV_AT91SAM9)	+= rtc-at91sam9.o

drivers/rtc/rtc-as3722.c

0 → 100644
+275 −0
Original line number Diff line number Diff line 
/*

 * rtc-as3722.c - Real Time Clock driver for ams AS3722 PMICs

 *

 * Copyright (C) 2013 ams AG

 * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.

 *

 * Author: Florian Lobmaier <florian.lobmaier@ams.com>

 * Author: Laxman Dewangan <ldewangan@nvidia.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/bcd.h>

#include <linux/completion.h>

#include <linux/delay.h>

#include <linux/interrupt.h>

#include <linux/ioctl.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/mfd/as3722.h>

#include <linux/platform_device.h>

#include <linux/rtc.h>

#include <linux/time.h>



#define AS3722_RTC_START_YEAR	  2000

struct as3722_rtc {

	struct rtc_device	*rtc;

	struct device		*dev;

	struct as3722		*as3722;

	int			alarm_irq;

	bool			irq_enable;

};



static void as3722_time_to_reg(u8 *rbuff, struct rtc_time *tm)

{

	rbuff[0] = bin2bcd(tm->tm_sec);

	rbuff[1] = bin2bcd(tm->tm_min);

	rbuff[2] = bin2bcd(tm->tm_hour);

	rbuff[3] = bin2bcd(tm->tm_mday);

	rbuff[4] = bin2bcd(tm->tm_mon);

	rbuff[5] = bin2bcd(tm->tm_year - (AS3722_RTC_START_YEAR - 1900));

}



static void as3722_reg_to_time(u8 *rbuff, struct rtc_time *tm)

{

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

	tm->tm_min = bcd2bin(rbuff[1] & 0x7F);

	tm->tm_hour = bcd2bin(rbuff[2] & 0x3F);

	tm->tm_mday = bcd2bin(rbuff[3] & 0x3F);

	tm->tm_mon = bcd2bin(rbuff[4] & 0x1F);

	tm->tm_year = (AS3722_RTC_START_YEAR - 1900) + bcd2bin(rbuff[5] & 0x7F);

	return;

}



static int as3722_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);

	struct as3722 *as3722 = as3722_rtc->as3722;

	u8 as_time_array[6];

	int ret;



	ret = as3722_block_read(as3722, AS3722_RTC_SECOND_REG,

			6, as_time_array);

	if (ret < 0) {

		dev_err(dev, "RTC_SECOND reg block read failed %d\n", ret);

		return ret;

	}

	as3722_reg_to_time(as_time_array, tm);

	return 0;

}



static int as3722_rtc_set_time(struct device *dev, struct rtc_time *tm)

{

	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);

	struct as3722 *as3722 = as3722_rtc->as3722;

	u8 as_time_array[6];

	int ret;



	if (tm->tm_year < (AS3722_RTC_START_YEAR - 1900))

		return -EINVAL;



	as3722_time_to_reg(as_time_array, tm);

	ret = as3722_block_write(as3722, AS3722_RTC_SECOND_REG, 6,

			as_time_array);

	if (ret < 0)

		dev_err(dev, "RTC_SECOND reg block write failed %d\n", ret);

	return ret;

}



static int as3722_rtc_alarm_irq_enable(struct device *dev,

		unsigned int enabled)

{

	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);



	if (enabled && !as3722_rtc->irq_enable) {

		enable_irq(as3722_rtc->alarm_irq);

		as3722_rtc->irq_enable = true;

	} else if (!enabled && as3722_rtc->irq_enable)  {

		disable_irq(as3722_rtc->alarm_irq);

		as3722_rtc->irq_enable = false;

	}

	return 0;

}



static int as3722_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)

{

	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);

	struct as3722 *as3722 = as3722_rtc->as3722;

	u8 as_time_array[6];

	int ret;



	ret = as3722_block_read(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,

			as_time_array);

	if (ret < 0) {

		dev_err(dev, "RTC_ALARM_SECOND block read failed %d\n", ret);

		return ret;

	}



	as3722_reg_to_time(as_time_array, &alrm->time);

	return 0;

}



static int as3722_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)

{

	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);

	struct as3722 *as3722 = as3722_rtc->as3722;

	u8 as_time_array[6];

	int ret;



	if (alrm->time.tm_year < (AS3722_RTC_START_YEAR - 1900))

		return -EINVAL;



	ret = as3722_rtc_alarm_irq_enable(dev, 0);

	if (ret < 0) {

		dev_err(dev, "Disable RTC alarm failed\n");

		return ret;

	}



	as3722_time_to_reg(as_time_array, &alrm->time);

	ret = as3722_block_write(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,

			as_time_array);

	if (ret < 0) {

		dev_err(dev, "RTC_ALARM_SECOND block write failed %d\n", ret);

		return ret;

	}



	if (alrm->enabled)

		ret = as3722_rtc_alarm_irq_enable(dev, alrm->enabled);

	return ret;

}



static irqreturn_t as3722_alarm_irq(int irq, void *data)

{

	struct as3722_rtc *as3722_rtc = data;



	rtc_update_irq(as3722_rtc->rtc, 1, RTC_IRQF | RTC_AF);

	return IRQ_HANDLED;

}



static const struct rtc_class_ops as3722_rtc_ops = {

	.read_time = as3722_rtc_read_time,

	.set_time = as3722_rtc_set_time,

	.read_alarm = as3722_rtc_read_alarm,

	.set_alarm = as3722_rtc_set_alarm,

	.alarm_irq_enable = as3722_rtc_alarm_irq_enable,

};



static int as3722_rtc_probe(struct platform_device *pdev)

{

	struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);

	struct as3722_rtc *as3722_rtc;

	int ret;



	as3722_rtc = devm_kzalloc(&pdev->dev, sizeof(*as3722_rtc), GFP_KERNEL);

	if (!as3722_rtc)

		return -ENOMEM;



	as3722_rtc->as3722 = as3722;

	as3722_rtc->dev = &pdev->dev;

	platform_set_drvdata(pdev, as3722_rtc);



	/* Enable the RTC to make sure it is running. */

	ret = as3722_update_bits(as3722, AS3722_RTC_CONTROL_REG,

			AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN,

			AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN);

	if (ret < 0) {

		dev_err(&pdev->dev, "RTC_CONTROL reg write failed: %d\n", ret);

		return ret;

	}



	device_init_wakeup(&pdev->dev, 1);



	as3722_rtc->rtc = rtc_device_register("as3722", &pdev->dev,

				&as3722_rtc_ops, THIS_MODULE);

	if (IS_ERR(as3722_rtc->rtc)) {

		ret = PTR_ERR(as3722_rtc->rtc);

		dev_err(&pdev->dev, "RTC register failed: %d\n", ret);

		return ret;

	}



	as3722_rtc->alarm_irq = platform_get_irq(pdev, 0);

	dev_info(&pdev->dev, "RTC interrupt %d\n", as3722_rtc->alarm_irq);



	ret = request_threaded_irq(as3722_rtc->alarm_irq, NULL,

			as3722_alarm_irq, IRQF_ONESHOT | IRQF_EARLY_RESUME,

			"rtc-alarm", as3722_rtc);

	if (ret < 0) {

		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",

				as3722_rtc->alarm_irq, ret);

		goto scrub;

	}

	disable_irq(as3722_rtc->alarm_irq);

	return 0;

scrub:

	rtc_device_unregister(as3722_rtc->rtc);

	return ret;

}



static int as3722_rtc_remove(struct platform_device *pdev)

{

	struct as3722_rtc *as3722_rtc = platform_get_drvdata(pdev);



	free_irq(as3722_rtc->alarm_irq, as3722_rtc);

	rtc_device_unregister(as3722_rtc->rtc);

	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int as3722_rtc_suspend(struct device *dev)

{

	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);



	if (device_may_wakeup(dev))

		enable_irq_wake(as3722_rtc->alarm_irq);



	return 0;

}



static int as3722_rtc_resume(struct device *dev)

{

	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);



	if (device_may_wakeup(dev))

		disable_irq_wake(as3722_rtc->alarm_irq);

	return 0;

}

#endif



static const struct dev_pm_ops as3722_rtc_pm_ops = {

	SET_SYSTEM_SLEEP_PM_OPS(as3722_rtc_suspend, as3722_rtc_resume)

};



static struct platform_driver as3722_rtc_driver = {

	.probe = as3722_rtc_probe,

	.remove = as3722_rtc_remove,

	.driver = {

		.name = "as3722-rtc",

		.pm = &as3722_rtc_pm_ops,

	},

};

module_platform_driver(as3722_rtc_driver);



MODULE_DESCRIPTION("RTC driver for AS3722 PMICs");

MODULE_ALIAS("platform:as3722-rtc");

MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");

MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");

MODULE_LICENSE("GPL");