/*
* rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver
*
* RTC driver for TI TPS80031/TPS80032 Fully Integrated
* Power Management with Power Path and Battery Charger
*
* Copyright (c) 2012, NVIDIA Corporation.
*
* 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 version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
* whether express or implied; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307, USA
*/
#include <linux/bcd.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mfd/tps80031.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#define ENABLE_ALARM_INT 0x08
#define ALARM_INT_STATUS 0x40
/**
* Setting bit to 1 in STOP_RTC will run the RTC and
* setting this bit to 0 will freeze RTC.
*/
#define STOP_RTC 0x1
/* Power on reset Values of RTC registers */
#define TPS80031_RTC_POR_YEAR 0
#define TPS80031_RTC_POR_MONTH 1
#define TPS80031_RTC_POR_DAY 1
/* Numbers of registers for time and alarms */
#define TPS80031_RTC_TIME_NUM_REGS 7
#define TPS80031_RTC_ALARM_NUM_REGS 6
/**
* PMU RTC have only 2 nibbles to store year information, so using an
* offset of 100 to set the base year as 2000 for our driver.
*/
#define RTC_YEAR_OFFSET 100
struct tps80031_rtc {
struct rtc_device *rtc;
int irq;
};
static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
u8 buff[TPS80031_RTC_TIME_NUM_REGS];
int ret;
ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff);
if (ret < 0) {
dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret);
return ret;
}
tm->tm_sec = bcd2bin(buff[0]);
tm->tm_min = bcd2bin(buff[1]);
tm->tm_hour = bcd2bin(buff[2]);
tm->tm_mday = bcd2bin(buff[3]);
tm->tm_mon = bcd2bin(buff[4]) - 1;
tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
tm->tm_wday = bcd2bin(buff[6]);
return 0;
}
static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
u8 buff[7];
int ret;
buff[0] = bin2bcd(tm->tm_sec);
buff[1] = bin2bcd(tm->tm_min);
buff[2] = bin2bcd(tm->tm_hour);
buff[3] = bin2bcd(tm->tm_mday);
buff[4] = bin2bcd(tm->tm_mon + 1);
buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET);
buff[6] = bin2bcd(tm->tm_wday);
/* Stop RTC while updating the RTC time registers */
ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_RTC_CTRL_REG, STOP_RTC);
if (ret < 0) {
dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret);
return ret;
}
ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_SECONDS_REG,
TPS80031_RTC_TIME_NUM_REGS, buff);
if (ret < 0) {
dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret);
return ret;
}
ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_RTC_CTRL_REG, STOP_RTC);
if (ret < 0)
dev_err(dev->parent, "Start RTC failed, err = %d\n", ret);
return ret;
}
static int tps80031_rtc_alarm_irq_enable(struct device *dev,
unsigned int enable)
{
int ret;
if (enable)
ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
else
ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
if (ret < 0) {
dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret);
return ret;
}
return 0;
}
static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
u8 buff[TPS80031_RTC_ALARM_NUM_REGS];
int ret;
buff[0] = bin2bcd(alrm->time.tm_sec);
buff[1] = bin2bcd(alrm->time.tm_min);
buff[2] = bin2bcd(alrm->time.tm_hour);
buff[3] = bin2bcd(alrm->time.tm_mday);
buff[4] = bin2bcd(alrm->time.tm_mon + 1);
buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET);
ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_ALARM_SECONDS_REG,
TPS80031_RTC_ALARM_NUM_REGS, buff);
if (ret < 0) {
dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret);
return ret;
}
return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled);
}
static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
u8 buff[6];
int ret;
ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_ALARM_SECONDS_REG,
TPS80031_RTC_ALARM_NUM_REGS, buff);
if (ret < 0) {
dev_err(dev->parent,
"reading RTC_ALARM failed, err = %d\n", ret);
return ret;
}
alrm->time.tm_sec = bcd2bin(buff[0]);
alrm->time.tm_min = bcd2bin(buff[1]);
alrm->time.tm_hour = bcd2bin(buff[2]);
alrm->time.tm_mday = bcd2bin(buff[3]);
alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
return 0;
}
static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc)
{
int ret;
u8 buf;
/**
* As per datasheet, A dummy read of this RTC_STATUS_REG register
* is necessary before each I2C read in order to update the status
* register value.
*/
ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_RTC_STATUS_REG, &buf);
if (ret < 0) {
dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret);
return ret;
}
/* clear Alarm status bits.*/
ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS);
if (ret < 0) {
dev_err(dev, "clear Alarm INT failed, err = %d\n", ret);
return ret;
}
return 0;
}
static irqreturn_t tps80031_rtc_irq(int irq, void *data)
{
struct device *dev = data;
struct tps80031_rtc *rtc = dev_get_drvdata(dev);
int ret;
ret = clear_alarm_int_status(dev, rtc);
if (ret < 0)
return ret;
rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static const struct rtc_class_ops tps80031_rtc_ops = {
.read_time = tps80031_rtc_read_time,
.set_time = tps80031_rtc_set_time,
.set_alarm = tps80031_rtc_set_alarm,
.read_alarm = tps80031_rtc_read_alarm,
.alarm_irq_enable = tps80031_rtc_alarm_irq_enable,
};
static int tps80031_rtc_probe(struct platform_device *pdev)
{
struct tps80031_rtc *rtc;
struct rtc_time tm;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->irq = platform_get_irq(pdev, 0);
platform_set_drvdata(pdev, rtc);
/* Start RTC */
ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1,
TPS80031_RTC_CTRL_REG, STOP_RTC);
if (ret < 0) {
dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret);
return ret;
}
/* If RTC have POR values, set time 01:01:2000 */
tps80031_rtc_read_time(&pdev->dev, &tm);
if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) &&
(tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) &&
(tm.tm_mday == TPS80031_RTC_POR_DAY)) {
tm.tm_year = 2000;
tm.tm_mday = 1;
tm.tm_mon = 1;
ret = tps80031_rtc_set_time(&pdev->dev, &tm);
if (ret < 0) {
dev_err(&pdev->dev,
"RTC set time failed, err = %d\n", ret);
return ret;
}
}
/* Clear alarm intretupt status if it is there */
ret = clear_alarm_int_status(&pdev->dev, rtc);
if (ret < 0) {
dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret);
return ret;
}
rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&tps80031_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc)) {
ret = PTR_ERR(rtc->rtc);
dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret);
return ret;
}
ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
tps80031_rtc_irq,
IRQF_ONESHOT,
dev_name(&pdev->dev), rtc);
if (ret < 0) {
dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
rtc->irq, ret);
return ret;
}
device_set_wakeup_capable(&pdev->dev, 1);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int tps80031_rtc_suspend(struct device *dev)
{
struct tps80031_rtc *rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(rtc->irq);
return 0;
}
static int tps80031_rtc_resume(struct device *dev)
{
struct tps80031_rtc *rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
disable_irq_wake(rtc->irq);
return 0;
};
#endif
static SIMPLE_DEV_PM_OPS(tps80031_pm_ops, tps80031_rtc_suspend,
tps80031_rtc_resume);
static struct platform_driver tps80031_rtc_driver = {
.driver = {
.name = "tps80031-rtc",
.pm = &tps80031_pm_ops,
},
.probe = tps80031_rtc_probe,
};
module_platform_driver(tps80031_rtc_driver);
MODULE_ALIAS("platform:tps80031-rtc");
MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");
