/*
* Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/io.h>
#include <linux/rtc.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#define RTC_INPUT_CLK_32768HZ (0x00 << 5)
#define RTC_INPUT_CLK_32000HZ (0x01 << 5)
#define RTC_INPUT_CLK_38400HZ (0x02 << 5)
#define RTC_SW_BIT (1 << 0)
#define RTC_ALM_BIT (1 << 2)
#define RTC_1HZ_BIT (1 << 4)
#define RTC_2HZ_BIT (1 << 7)
#define RTC_SAM0_BIT (1 << 8)
#define RTC_SAM1_BIT (1 << 9)
#define RTC_SAM2_BIT (1 << 10)
#define RTC_SAM3_BIT (1 << 11)
#define RTC_SAM4_BIT (1 << 12)
#define RTC_SAM5_BIT (1 << 13)
#define RTC_SAM6_BIT (1 << 14)
#define RTC_SAM7_BIT (1 << 15)
#define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
#define RTC_ENABLE_BIT (1 << 7)
#define MAX_PIE_NUM 9
#define MAX_PIE_FREQ 512
static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = {
{ 2, RTC_2HZ_BIT },
{ 4, RTC_SAM0_BIT },
{ 8, RTC_SAM1_BIT },
{ 16, RTC_SAM2_BIT },
{ 32, RTC_SAM3_BIT },
{ 64, RTC_SAM4_BIT },
{ 128, RTC_SAM5_BIT },
{ 256, RTC_SAM6_BIT },
{ MAX_PIE_FREQ, RTC_SAM7_BIT },
};
#define MXC_RTC_TIME 0
#define MXC_RTC_ALARM 1
#define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
#define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
#define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
#define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
#define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
#define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
#define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
#define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
#define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
#define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
#define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
#define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
#define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
enum imx_rtc_type {
IMX1_RTC,
IMX21_RTC,
};
struct rtc_plat_data {
struct rtc_device *rtc;
void __iomem *ioaddr;
int irq;
struct clk *clk;
struct rtc_time g_rtc_alarm;
enum imx_rtc_type devtype;
};
static const struct platform_device_id imx_rtc_devtype[] = {
{
.name = "imx1-rtc",
.driver_data = IMX1_RTC,
}, {
.name = "imx21-rtc",
.driver_data = IMX21_RTC,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(platform, imx_rtc_devtype);
static inline int is_imx1_rtc(struct rtc_plat_data *data)
{
return data->devtype == IMX1_RTC;
}
/*
* This function is used to obtain the RTC time or the alarm value in
* second.
*/
static time64_t get_alarm_or_time(struct device *dev, int time_alarm)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
switch (time_alarm) {
case MXC_RTC_TIME:
day = readw(ioaddr + RTC_DAYR);
hr_min = readw(ioaddr + RTC_HOURMIN);
sec = readw(ioaddr + RTC_SECOND);
break;
case MXC_RTC_ALARM:
day = readw(ioaddr + RTC_DAYALARM);
hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
sec = readw(ioaddr + RTC_ALRM_SEC);
break;
}
hr = hr_min >> 8;
min = hr_min & 0xff;
return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec;
}
/*
* This function sets the RTC alarm value or the time value.
*/
static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time)
{
u32 tod, day, hr, min, sec, temp;
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
day = div_s64_rem(time, 86400, &tod);
/* time is within a day now */
hr = tod / 3600;
tod -= hr * 3600;
/* time is within an hour now */
min = tod / 60;
sec = tod - min * 60;
temp = (hr << 8) + min;
switch (time_alarm) {
case MXC_RTC_TIME:
writew(day, ioaddr + RTC_DAYR);
writew(sec, ioaddr + RTC_SECOND);
writew(temp, ioaddr + RTC_HOURMIN);
break;
case MXC_RTC_ALARM:
writew(day, ioaddr + RTC_DAYALARM);
writew(sec, ioaddr + RTC_ALRM_SEC);
writew(temp, ioaddr + RTC_ALRM_HM);
break;
}
}
/*
* This function updates the RTC alarm registers and then clears all the
* interrupt status bits.
*/
static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
{
time64_t time;
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
time = rtc_tm_to_time64(alrm);
/* clear all the interrupt status bits */
writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
set_alarm_or_time(dev, MXC_RTC_ALARM, time);
}
static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
unsigned int enabled)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
u32 reg;
spin_lock_irq(&pdata->rtc->irq_lock);
reg = readw(ioaddr + RTC_RTCIENR);
if (enabled)
reg |= bit;
else
reg &= ~bit;
writew(reg, ioaddr + RTC_RTCIENR);
spin_unlock_irq(&pdata->rtc->irq_lock);
}
/* This function is the RTC interrupt service routine. */
static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
{
struct platform_device *pdev = dev_id;
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
unsigned long flags;
u32 status;
u32 events = 0;
spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
/* clear interrupt sources */
writew(status, ioaddr + RTC_RTCISR);
/* update irq data & counter */
if (status & RTC_ALM_BIT) {
events |= (RTC_AF | RTC_IRQF);
/* RTC alarm should be one-shot */
mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0);
}
if (status & RTC_1HZ_BIT)
events |= (RTC_UF | RTC_IRQF);
if (status & PIT_ALL_ON)
events |= (RTC_PF | RTC_IRQF);
rtc_update_irq(pdata->rtc, 1, events);
spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
return IRQ_HANDLED;
}
/*
* Clear all interrupts and release the IRQ
*/
static void mxc_rtc_release(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
spin_lock_irq(&pdata->rtc->irq_lock);
/* Disable all rtc interrupts */
writew(0, ioaddr + RTC_RTCIENR);
/* Clear all interrupt status */
writew(0xffffffff, ioaddr + RTC_RTCISR);
spin_unlock_irq(&pdata->rtc->irq_lock);
}
static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
return 0;
}
/*
* This function reads the current RTC time into tm in Gregorian date.
*/
static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
time64_t val;
/* Avoid roll-over from reading the different registers */
do {
val = get_alarm_or_time(dev, MXC_RTC_TIME);
} while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
rtc_time64_to_tm(val, tm);
return 0;
}
/*
* This function sets the internal RTC time based on tm in Gregorian date.
*/
static int mxc_rtc_set_mmss(struct device *dev, time64_t time)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
/*
* TTC_DAYR register is 9-bit in MX1 SoC, save time and day of year only
*/
if (is_imx1_rtc(pdata)) {
struct rtc_time tm;
rtc_time64_to_tm(time, &tm);
tm.tm_year = 70;
time = rtc_tm_to_time64(&tm);
}
/* Avoid roll-over from reading the different registers */
do {
set_alarm_or_time(dev, MXC_RTC_TIME, time);
} while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
return 0;
}
/*
* This function reads the current alarm value into the passed in 'alrm'
* argument. It updates the alrm's pending field value based on the whether
* an alarm interrupt occurs or not.
*/
static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
void __iomem *ioaddr = pdata->ioaddr;
rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
return 0;
}
/*
* This function sets the RTC alarm based on passed in alrm.
*/
static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct platform_device *pdev = to_platform_device(dev);
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
rtc_update_alarm(dev, &alrm->time);
memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
return 0;
}
/* RTC layer */
static struct rtc_class_ops mxc_rtc_ops = {
.release = mxc_rtc_release,
.read_time = mxc_rtc_read_time,
.set_mmss64 = mxc_rtc_set_mmss,
.read_alarm = mxc_rtc_read_alarm,
.set_alarm = mxc_rtc_set_alarm,
.alarm_irq_enable = mxc_rtc_alarm_irq_enable,
};
static int mxc_rtc_probe(struct platform_device *pdev)
{
struct resource *res;
struct rtc_device *rtc;
struct rtc_plat_data *pdata = NULL;
u32 reg;
unsigned long rate;
int ret;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
pdata->devtype = pdev->id_entry->driver_data;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(pdata->ioaddr))
return PTR_ERR(pdata->ioaddr);
pdata->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pdata->clk)) {
dev_err(&pdev->dev, "unable to get clock!\n");
return PTR_ERR(pdata->clk);
}
ret = clk_prepare_enable(pdata->clk);
if (ret)
return ret;
rate = clk_get_rate(pdata->clk);
if (rate == 32768)
reg = RTC_INPUT_CLK_32768HZ;
else if (rate == 32000)
reg = RTC_INPUT_CLK_32000HZ;
else if (rate == 38400)
reg = RTC_INPUT_CLK_38400HZ;
else {
dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
ret = -EINVAL;
goto exit_put_clk;
}
reg |= RTC_ENABLE_BIT;
writew(reg, (pdata->ioaddr + RTC_RTCCTL));
if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
dev_err(&pdev->dev, "hardware module can't be enabled!\n");
ret = -EIO;
goto exit_put_clk;
}
platform_set_drvdata(pdev, pdata);
/* Configure and enable the RTC */
pdata->irq = platform_get_irq(pdev, 0);
if (pdata->irq >= 0 &&
devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
IRQF_SHARED, pdev->name, pdev) < 0) {
dev_warn(&pdev->dev, "interrupt not available.\n");
pdata->irq = -1;
}
if (pdata->irq >= 0)
device_init_wakeup(&pdev->dev, 1);
rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &mxc_rtc_ops,
THIS_MODULE);
if (IS_ERR(rtc)) {
ret = PTR_ERR(rtc);
goto exit_put_clk;
}
pdata->rtc = rtc;
return 0;
exit_put_clk:
clk_disable_unprepare(pdata->clk);
return ret;
}
static int mxc_rtc_remove(struct platform_device *pdev)
{
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
clk_disable_unprepare(pdata->clk);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mxc_rtc_suspend(struct device *dev)
{
struct rtc_plat_data *pdata = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(pdata->irq);
return 0;
}
static int mxc_rtc_resume(struct device *dev)
{
struct rtc_plat_data *pdata = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
disable_irq_wake(pdata->irq);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(mxc_rtc_pm_ops, mxc_rtc_suspend, mxc_rtc_resume);
static struct platform_driver mxc_rtc_driver = {
.driver = {
.name = "mxc_rtc",
.pm = &mxc_rtc_pm_ops,
},
.id_table = imx_rtc_devtype,
.probe = mxc_rtc_probe,
.remove = mxc_rtc_remove,
};
module_platform_driver(mxc_rtc_driver)
MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
MODULE_DESCRIPTION("RTC driver for Freescale MXC");
MODULE_LICENSE("GPL");
