mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 01:51:53 +00:00
364 lines
9.2 KiB
C
364 lines
9.2 KiB
C
|
/*
|
||
|
* Copyright (C) ST-Ericsson SA 2010
|
||
|
*
|
||
|
* License terms: GNU General Public License (GPL) version 2
|
||
|
* Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
|
||
|
*
|
||
|
* RTC clock driver for the RTC part of the AB8500 Power management chip.
|
||
|
* Based on RTC clock driver for the AB3100 Analog Baseband Chip by
|
||
|
* Linus Walleij <linus.walleij@stericsson.com>
|
||
|
*/
|
||
|
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/kernel.h>
|
||
|
#include <linux/init.h>
|
||
|
#include <linux/platform_device.h>
|
||
|
#include <linux/rtc.h>
|
||
|
#include <linux/mfd/ab8500.h>
|
||
|
#include <linux/delay.h>
|
||
|
|
||
|
#define AB8500_RTC_SOFF_STAT_REG 0x0F00
|
||
|
#define AB8500_RTC_CC_CONF_REG 0x0F01
|
||
|
#define AB8500_RTC_READ_REQ_REG 0x0F02
|
||
|
#define AB8500_RTC_WATCH_TSECMID_REG 0x0F03
|
||
|
#define AB8500_RTC_WATCH_TSECHI_REG 0x0F04
|
||
|
#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x0F05
|
||
|
#define AB8500_RTC_WATCH_TMIN_MID_REG 0x0F06
|
||
|
#define AB8500_RTC_WATCH_TMIN_HI_REG 0x0F07
|
||
|
#define AB8500_RTC_ALRM_MIN_LOW_REG 0x0F08
|
||
|
#define AB8500_RTC_ALRM_MIN_MID_REG 0x0F09
|
||
|
#define AB8500_RTC_ALRM_MIN_HI_REG 0x0F0A
|
||
|
#define AB8500_RTC_STAT_REG 0x0F0B
|
||
|
#define AB8500_RTC_BKUP_CHG_REG 0x0F0C
|
||
|
#define AB8500_RTC_FORCE_BKUP_REG 0x0F0D
|
||
|
#define AB8500_RTC_CALIB_REG 0x0F0E
|
||
|
#define AB8500_RTC_SWITCH_STAT_REG 0x0F0F
|
||
|
#define AB8500_REV_REG 0x1080
|
||
|
|
||
|
/* RtcReadRequest bits */
|
||
|
#define RTC_READ_REQUEST 0x01
|
||
|
#define RTC_WRITE_REQUEST 0x02
|
||
|
|
||
|
/* RtcCtrl bits */
|
||
|
#define RTC_ALARM_ENA 0x04
|
||
|
#define RTC_STATUS_DATA 0x01
|
||
|
|
||
|
#define COUNTS_PER_SEC (0xF000 / 60)
|
||
|
#define AB8500_RTC_EPOCH 2000
|
||
|
|
||
|
static const unsigned long ab8500_rtc_time_regs[] = {
|
||
|
AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
|
||
|
AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
|
||
|
AB8500_RTC_WATCH_TSECMID_REG
|
||
|
};
|
||
|
|
||
|
static const unsigned long ab8500_rtc_alarm_regs[] = {
|
||
|
AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
|
||
|
AB8500_RTC_ALRM_MIN_LOW_REG
|
||
|
};
|
||
|
|
||
|
/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
|
||
|
static unsigned long get_elapsed_seconds(int year)
|
||
|
{
|
||
|
unsigned long secs;
|
||
|
struct rtc_time tm = {
|
||
|
.tm_year = year - 1900,
|
||
|
.tm_mday = 1,
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* This function calculates secs from 1970 and not from
|
||
|
* 1900, even if we supply the offset from year 1900.
|
||
|
*/
|
||
|
rtc_tm_to_time(&tm, &secs);
|
||
|
return secs;
|
||
|
}
|
||
|
|
||
|
static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
||
|
{
|
||
|
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
|
||
|
unsigned long timeout = jiffies + HZ;
|
||
|
int retval, i;
|
||
|
unsigned long mins, secs;
|
||
|
unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
|
||
|
|
||
|
/* Request a data read */
|
||
|
retval = ab8500_write(ab8500, AB8500_RTC_READ_REQ_REG,
|
||
|
RTC_READ_REQUEST);
|
||
|
if (retval < 0)
|
||
|
return retval;
|
||
|
|
||
|
/* Early AB8500 chips will not clear the rtc read request bit */
|
||
|
if (ab8500->revision == 0) {
|
||
|
msleep(1);
|
||
|
} else {
|
||
|
/* Wait for some cycles after enabling the rtc read in ab8500 */
|
||
|
while (time_before(jiffies, timeout)) {
|
||
|
retval = ab8500_read(ab8500, AB8500_RTC_READ_REQ_REG);
|
||
|
if (retval < 0)
|
||
|
return retval;
|
||
|
|
||
|
if (!(retval & RTC_READ_REQUEST))
|
||
|
break;
|
||
|
|
||
|
msleep(1);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Read the Watchtime registers */
|
||
|
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
|
||
|
retval = ab8500_read(ab8500, ab8500_rtc_time_regs[i]);
|
||
|
if (retval < 0)
|
||
|
return retval;
|
||
|
buf[i] = retval;
|
||
|
}
|
||
|
|
||
|
mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
|
||
|
|
||
|
secs = (buf[3] << 8) | buf[4];
|
||
|
secs = secs / COUNTS_PER_SEC;
|
||
|
secs = secs + (mins * 60);
|
||
|
|
||
|
/* Add back the initially subtracted number of seconds */
|
||
|
secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
|
||
|
|
||
|
rtc_time_to_tm(secs, tm);
|
||
|
return rtc_valid_tm(tm);
|
||
|
}
|
||
|
|
||
|
static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
||
|
{
|
||
|
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
|
||
|
int retval, i;
|
||
|
unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
|
||
|
unsigned long no_secs, no_mins, secs = 0;
|
||
|
|
||
|
if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
|
||
|
dev_dbg(dev, "year should be equal to or greater than %d\n",
|
||
|
AB8500_RTC_EPOCH);
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
/* Get the number of seconds since 1970 */
|
||
|
rtc_tm_to_time(tm, &secs);
|
||
|
|
||
|
/*
|
||
|
* Convert it to the number of seconds since 01-01-2000 00:00:00, since
|
||
|
* we only have a small counter in the RTC.
|
||
|
*/
|
||
|
secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
|
||
|
|
||
|
no_mins = secs / 60;
|
||
|
|
||
|
no_secs = secs % 60;
|
||
|
/* Make the seconds count as per the RTC resolution */
|
||
|
no_secs = no_secs * COUNTS_PER_SEC;
|
||
|
|
||
|
buf[4] = no_secs & 0xFF;
|
||
|
buf[3] = (no_secs >> 8) & 0xFF;
|
||
|
|
||
|
buf[2] = no_mins & 0xFF;
|
||
|
buf[1] = (no_mins >> 8) & 0xFF;
|
||
|
buf[0] = (no_mins >> 16) & 0xFF;
|
||
|
|
||
|
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
|
||
|
retval = ab8500_write(ab8500, ab8500_rtc_time_regs[i], buf[i]);
|
||
|
if (retval < 0)
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
/* Request a data write */
|
||
|
return ab8500_write(ab8500, AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
|
||
|
}
|
||
|
|
||
|
static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
|
||
|
{
|
||
|
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
|
||
|
int retval, i;
|
||
|
int rtc_ctrl;
|
||
|
unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
|
||
|
unsigned long secs, mins;
|
||
|
|
||
|
/* Check if the alarm is enabled or not */
|
||
|
rtc_ctrl = ab8500_read(ab8500, AB8500_RTC_STAT_REG);
|
||
|
if (rtc_ctrl < 0)
|
||
|
return rtc_ctrl;
|
||
|
|
||
|
if (rtc_ctrl & RTC_ALARM_ENA)
|
||
|
alarm->enabled = 1;
|
||
|
else
|
||
|
alarm->enabled = 0;
|
||
|
|
||
|
alarm->pending = 0;
|
||
|
|
||
|
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
|
||
|
retval = ab8500_read(ab8500, ab8500_rtc_alarm_regs[i]);
|
||
|
if (retval < 0)
|
||
|
return retval;
|
||
|
buf[i] = retval;
|
||
|
}
|
||
|
|
||
|
mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
|
||
|
secs = mins * 60;
|
||
|
|
||
|
/* Add back the initially subtracted number of seconds */
|
||
|
secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
|
||
|
|
||
|
rtc_time_to_tm(secs, &alarm->time);
|
||
|
|
||
|
return rtc_valid_tm(&alarm->time);
|
||
|
}
|
||
|
|
||
|
static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
|
||
|
{
|
||
|
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
|
||
|
|
||
|
return ab8500_set_bits(ab8500, AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
|
||
|
enabled ? RTC_ALARM_ENA : 0);
|
||
|
}
|
||
|
|
||
|
static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
|
||
|
{
|
||
|
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
|
||
|
int retval, i;
|
||
|
unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
|
||
|
unsigned long mins, secs = 0;
|
||
|
|
||
|
if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
|
||
|
dev_dbg(dev, "year should be equal to or greater than %d\n",
|
||
|
AB8500_RTC_EPOCH);
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
/* Get the number of seconds since 1970 */
|
||
|
rtc_tm_to_time(&alarm->time, &secs);
|
||
|
|
||
|
/*
|
||
|
* Convert it to the number of seconds since 01-01-2000 00:00:00, since
|
||
|
* we only have a small counter in the RTC.
|
||
|
*/
|
||
|
secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
|
||
|
|
||
|
mins = secs / 60;
|
||
|
|
||
|
buf[2] = mins & 0xFF;
|
||
|
buf[1] = (mins >> 8) & 0xFF;
|
||
|
buf[0] = (mins >> 16) & 0xFF;
|
||
|
|
||
|
/* Set the alarm time */
|
||
|
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
|
||
|
retval = ab8500_write(ab8500, ab8500_rtc_alarm_regs[i], buf[i]);
|
||
|
if (retval < 0)
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
return ab8500_rtc_irq_enable(dev, alarm->enabled);
|
||
|
}
|
||
|
|
||
|
static irqreturn_t rtc_alarm_handler(int irq, void *data)
|
||
|
{
|
||
|
struct rtc_device *rtc = data;
|
||
|
unsigned long events = RTC_IRQF | RTC_AF;
|
||
|
|
||
|
dev_dbg(&rtc->dev, "%s\n", __func__);
|
||
|
rtc_update_irq(rtc, 1, events);
|
||
|
|
||
|
return IRQ_HANDLED;
|
||
|
}
|
||
|
|
||
|
static const struct rtc_class_ops ab8500_rtc_ops = {
|
||
|
.read_time = ab8500_rtc_read_time,
|
||
|
.set_time = ab8500_rtc_set_time,
|
||
|
.read_alarm = ab8500_rtc_read_alarm,
|
||
|
.set_alarm = ab8500_rtc_set_alarm,
|
||
|
.alarm_irq_enable = ab8500_rtc_irq_enable,
|
||
|
};
|
||
|
|
||
|
static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
|
||
|
{
|
||
|
struct ab8500 *ab8500 = dev_get_drvdata(pdev->dev.parent);
|
||
|
int err;
|
||
|
struct rtc_device *rtc;
|
||
|
int rtc_ctrl;
|
||
|
int irq;
|
||
|
|
||
|
irq = platform_get_irq_byname(pdev, "ALARM");
|
||
|
if (irq < 0)
|
||
|
return irq;
|
||
|
|
||
|
/* For RTC supply test */
|
||
|
err = ab8500_set_bits(ab8500, AB8500_RTC_STAT_REG, RTC_STATUS_DATA,
|
||
|
RTC_STATUS_DATA);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
/* Wait for reset by the PorRtc */
|
||
|
msleep(1);
|
||
|
|
||
|
rtc_ctrl = ab8500_read(ab8500, AB8500_RTC_STAT_REG);
|
||
|
if (rtc_ctrl < 0)
|
||
|
return rtc_ctrl;
|
||
|
|
||
|
/* Check if the RTC Supply fails */
|
||
|
if (!(rtc_ctrl & RTC_STATUS_DATA)) {
|
||
|
dev_err(&pdev->dev, "RTC supply failure\n");
|
||
|
return -ENODEV;
|
||
|
}
|
||
|
|
||
|
rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
|
||
|
THIS_MODULE);
|
||
|
if (IS_ERR(rtc)) {
|
||
|
dev_err(&pdev->dev, "Registration failed\n");
|
||
|
err = PTR_ERR(rtc);
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
err = request_threaded_irq(irq, NULL, rtc_alarm_handler, 0,
|
||
|
"ab8500-rtc", rtc);
|
||
|
if (err < 0) {
|
||
|
rtc_device_unregister(rtc);
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
platform_set_drvdata(pdev, rtc);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int __devexit ab8500_rtc_remove(struct platform_device *pdev)
|
||
|
{
|
||
|
struct rtc_device *rtc = platform_get_drvdata(pdev);
|
||
|
int irq = platform_get_irq_byname(pdev, "ALARM");
|
||
|
|
||
|
free_irq(irq, rtc);
|
||
|
rtc_device_unregister(rtc);
|
||
|
platform_set_drvdata(pdev, NULL);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static struct platform_driver ab8500_rtc_driver = {
|
||
|
.driver = {
|
||
|
.name = "ab8500-rtc",
|
||
|
.owner = THIS_MODULE,
|
||
|
},
|
||
|
.probe = ab8500_rtc_probe,
|
||
|
.remove = __devexit_p(ab8500_rtc_remove),
|
||
|
};
|
||
|
|
||
|
static int __init ab8500_rtc_init(void)
|
||
|
{
|
||
|
return platform_driver_register(&ab8500_rtc_driver);
|
||
|
}
|
||
|
|
||
|
static void __exit ab8500_rtc_exit(void)
|
||
|
{
|
||
|
platform_driver_unregister(&ab8500_rtc_driver);
|
||
|
}
|
||
|
|
||
|
module_init(ab8500_rtc_init);
|
||
|
module_exit(ab8500_rtc_exit);
|
||
|
MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
|
||
|
MODULE_DESCRIPTION("AB8500 RTC Driver");
|
||
|
MODULE_LICENSE("GPL v2");
|