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drivers/rtc/rtc-as3722: add RTC driver
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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.

[[email protected]: coding-style fixes]
Signed-off-by: Laxman Dewangan <[email protected]>
Signed-off-by: Florian Lobmaier <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Linus Walleij <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@ldewangan @torvalds
ldewangan authored and torvalds committed Nov 13, 2013
1 parent 5bccae6 commit b450626
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10 changes: 10 additions & 0 deletions drivers/rtc/Kconfig
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Expand Up @@ -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
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1 change: 1 addition & 0 deletions drivers/rtc/Makefile
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Expand Up @@ -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
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275 changes: 275 additions & 0 deletions drivers/rtc/rtc-as3722.c
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@@ -0,0 +1,275 @@
/*
* 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 <[email protected]>
* Author: Laxman Dewangan <[email protected]>
*
* 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 <[email protected]>");
MODULE_AUTHOR("Laxman Dewangan <[email protected]>");
MODULE_LICENSE("GPL");

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