blob: c41edabf0b2cd60708c2679d003f29ac45a8b40e [file] [log] [blame]
/*
* drivers/rtc/rtc-tps6586x.c
*
* RTC driver for TI TPS6586x
*
* Copyright (c) 2010, NVIDIA Corporation.
*
* 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.
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mfd/tps6586x.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#define RTC_CTRL 0xc0
#define POR_RESET_N BIT(7)
#define OSC_SRC_SEL BIT(6)
#define RTC_ENABLE BIT(5) /* enables alarm */
#define RTC_BUF_ENABLE BIT(4) /* 32 KHz buffer enable */
#define PRE_BYPASS BIT(3) /* 0=1KHz or 1=32KHz updates */
#define CL_SEL_MASK (BIT(2)|BIT(1))
#define CL_SEL_POS 1
#define RTC_ALARM1_HI 0xc1
#define RTC_COUNT4 0xc6
#define RTC_COUNT4_DUMMYREAD 0xc5 /* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */
#define ALM1_VALID_RANGE_IN_SEC 0x3FFF /*only 14-bits width in second*/
struct tps6586x_rtc {
unsigned long epoch_start;
int irq;
struct rtc_device *rtc;
bool irq_en;
};
static inline struct device *to_tps6586x_dev(struct device *dev)
{
return dev->parent;
}
static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
struct device *tps_dev = to_tps6586x_dev(dev);
unsigned long long ticks = 0;
unsigned long seconds;
u8 buff[6];
int err;
int i;
err = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff);
if (err < 0) {
dev_err(dev, "failed to read counter\n");
return err;
}
for (i = 1; i < sizeof(buff); i++) {
ticks <<= 8;
ticks |= buff[i];
}
seconds = ticks >> 10;
seconds += rtc->epoch_start;
rtc_time_to_tm(seconds, tm);
return rtc_valid_tm(tm);
}
static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
struct device *tps_dev = to_tps6586x_dev(dev);
unsigned long long ticks;
unsigned long seconds;
u8 buff[5];
int err;
rtc_tm_to_time(tm, &seconds);
if (WARN_ON(seconds < rtc->epoch_start)) {
dev_err(dev, "requested time unsupported\n");
return -EINVAL;
}
seconds -= rtc->epoch_start;
ticks = (unsigned long long)seconds << 10;
buff[0] = (ticks >> 32) & 0xff;
buff[1] = (ticks >> 24) & 0xff;
buff[2] = (ticks >> 16) & 0xff;
buff[3] = (ticks >> 8) & 0xff;
buff[4] = ticks & 0xff;
err = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
if (err < 0) {
dev_err(dev, "failed to clear RTC_ENABLE\n");
return err;
}
err = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff);
if (err < 0) {
dev_err(dev, "failed to program new time\n");
return err;
}
err = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
if (err < 0) {
dev_err(dev, "failed to set RTC_ENABLE\n");
return err;
}
return 0;
}
static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
struct device *tps_dev = to_tps6586x_dev(dev);
unsigned long seconds;
unsigned long ticks;
unsigned long rtc_current_time;
unsigned long long rticks = 0;
u8 buff[3];
u8 rbuff[6];
int err;
int i;
if (rtc->irq == -1)
return -EIO;
rtc_tm_to_time(&alrm->time, &seconds);
if (WARN_ON(alrm->enabled && (seconds < rtc->epoch_start))) {
dev_err(dev, "can't set alarm to requested time\n");
return -EINVAL;
}
if (alrm->enabled && !rtc->irq_en) {
enable_irq(rtc->irq);
rtc->irq_en = true;
} else if (!alrm->enabled && rtc->irq_en) {
disable_irq(rtc->irq);
rtc->irq_en = false;
}
seconds -= rtc->epoch_start;
err = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(rbuff), rbuff);
if (err < 0) {
dev_err(dev, "failed to read counter\n");
return err;
}
for (i = 1; i < sizeof(rbuff); i++) {
rticks <<= 8;
rticks |= rbuff[i];
}
rtc_current_time = rticks >> 10;
if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC)
seconds = rtc_current_time - 1;
ticks = (unsigned long long)seconds << 10;
buff[0] = (ticks >> 16) & 0xff;
buff[1] = (ticks >> 8) & 0xff;
buff[2] = ticks & 0xff;
err = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
if (err)
dev_err(tps_dev, "unable to program alarm\n");
return err;
}
static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
struct device *tps_dev = to_tps6586x_dev(dev);
unsigned long ticks;
unsigned long seconds;
u8 buff[3];
int err;
err = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
if (err)
return err;
ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2];
seconds = ticks >> 10;
seconds += rtc->epoch_start;
rtc_time_to_tm(seconds, &alrm->time);
return 0;
}
static int tps6586x_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
struct device *tps_dev = to_tps6586x_dev(dev);
u8 buff;
int err;
if (rtc->irq == -1)
return -EIO;
err = tps6586x_read(tps_dev, RTC_CTRL, &buff);
if (err < 0) {
dev_err(dev, "failed to read RTC_CTRL\n");
return err;
}
if ((enabled && (buff & RTC_ENABLE)) ||
(!enabled && !(buff & RTC_ENABLE)))
return 0;
if (enabled) {
err = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
if (err < 0) {
dev_err(dev, "failed to set RTC_ENABLE\n");
return err;
}
if (!rtc->irq_en) {
enable_irq(rtc->irq);
rtc->irq_en = true;
}
} else {
err = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
if (err < 0) {
dev_err(dev, "failed to clear RTC_ENABLE\n");
return err;
}
if (rtc->irq_en) {
disable_irq(rtc->irq);
rtc->irq_en = false;
}
}
return 0;
}
static const struct rtc_class_ops tps6586x_rtc_ops = {
.read_time = tps6586x_rtc_read_time,
.set_time = tps6586x_rtc_set_time,
.set_alarm = tps6586x_rtc_set_alarm,
.read_alarm = tps6586x_rtc_read_alarm,
.alarm_irq_enable = tps6586x_rtc_alarm_irq_enable,
};
static irqreturn_t tps6586x_rtc_irq(int irq, void *data)
{
struct device *dev = data;
struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static int __devinit tps6586x_rtc_probe(struct platform_device *pdev)
{
struct tps6586x_rtc_platform_data *pdata = pdev->dev.platform_data;
struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
struct tps6586x_rtc *rtc;
int err;
struct tps6586x_epoch_start *epoch;
if (!pdata) {
dev_err(&pdev->dev, "no platform_data specified\n");
return -EINVAL;
}
rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->irq = -1;
if (pdata->irq < 0)
dev_warn(&pdev->dev, "no IRQ specified, wakeup is disabled\n");
epoch = &pdata->start;
rtc->epoch_start = mktime(epoch->year, epoch->month, epoch->day,
epoch->hour, epoch->min, epoch->sec);
dev_set_drvdata(&pdev->dev, rtc);
device_init_wakeup(&pdev->dev, 1);
rtc->rtc = rtc_device_register("tps6586x-rtc", &pdev->dev,
&tps6586x_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc)) {
err = PTR_ERR(rtc->rtc);
goto fail;
}
/* 1 kHz tick mode, enable tick counting */
err = tps6586x_update(tps_dev, RTC_CTRL,
RTC_ENABLE | OSC_SRC_SEL | ((pdata->cl_sel << CL_SEL_POS) &
CL_SEL_MASK),
RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
if (err < 0) {
dev_err(&pdev->dev, "unable to start counter\n");
goto fail;
}
if (pdata && (pdata->irq >= 0)) {
rtc->irq = pdata->irq;
err = request_threaded_irq(pdata->irq, NULL, tps6586x_rtc_irq,
IRQF_ONESHOT, "tps6586x-rtc",
&pdev->dev);
if (err) {
dev_warn(&pdev->dev, "unable to request IRQ(%d)\n", rtc->irq);
rtc->irq = -1;
} else {
enable_irq_wake(rtc->irq);
disable_irq(rtc->irq);
}
}
return 0;
fail:
if (!IS_ERR_OR_NULL(rtc->rtc))
rtc_device_unregister(rtc->rtc);
device_init_wakeup(&pdev->dev, 0);
kfree(rtc);
return err;
}
static int __devexit tps6586x_rtc_remove(struct platform_device *pdev)
{
struct tps6586x_rtc *rtc = dev_get_drvdata(&pdev->dev);
if (rtc->irq != -1)
free_irq(rtc->irq, rtc);
rtc_device_unregister(rtc->rtc);
kfree(rtc);
return 0;
}
static struct platform_driver tps6586x_rtc_driver = {
.driver = {
.name = "tps6586x-rtc",
.owner = THIS_MODULE,
},
.probe = tps6586x_rtc_probe,
.remove = __devexit_p(tps6586x_rtc_remove),
};
static int __init tps6586x_rtc_init(void)
{
return platform_driver_register(&tps6586x_rtc_driver);
}
module_init(tps6586x_rtc_init);
static void __exit tps6586x_rtc_exit(void)
{
platform_driver_unregister(&tps6586x_rtc_driver);
}
module_exit(tps6586x_rtc_exit);
MODULE_DESCRIPTION("TI TPS6586x RTC driver");
MODULE_AUTHOR("NVIDIA Corporation");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rtc-tps6586x");