/**
* @file
*
* @ingroup arm_beagle
*
* @brief RTC driver for AM335x SoC.
*
*/
/*
* Copyright (c) 2015 Ragunath <ragunath3252@gmail.com>.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#include <bspopts.h>
#if IS_AM335X
#include <rtems.h>
#include <bsp.h>
#include <time.h>
#include <libchip/rtc.h>
#include <libcpu/omap3.h>
#define setbit(a,x) (a | (1<<x))
#define bcd(a) ((a & 0x0f)+ (((a & 0xf0) >> 4 )*10))
#define dec(a) (((a / 10) << 4) | (a % 10))
#define WRITE_WAIT_MAX_COUNT 10000
size_t RTC_Count = 1;
static void rtc_write_enable(void);
static void rtc_write_disable(void);
static int rtc_write_wait(void);
static void rtc_clk_init(void);
void rtc_init(int minor);
void print_time(void);
int am335x_rtc_gettime(int minor,rtems_time_of_day *t);
int am335x_rtc_settime(int minor, const rtems_time_of_day *t);
void am335x_rtc_debug(void);
/*
* probe for a rtc. we always claim to have one.
*/
static bool am335x_rtc_probe (int minor)
{
return true;
}
/*
* Write key values to kick0 and kick1 registers to enable write access
*/
static void rtc_write_enable(void)
{
mmio_write(AM335X_RTC_BASE+AM335X_RTC_KICK0,AM335X_RTC_KICK0_KEY);
mmio_write(AM335X_RTC_BASE+AM335X_RTC_KICK1,AM335X_RTC_KICK1_KEY);
}
/*
* Write random (0x11111111) value to kick0 and kick1 registers to disable write access
*/
static void rtc_write_disable(void)
{
/* Write some random value other than key to disable*/
mmio_write(AM335X_RTC_BASE+AM335X_RTC_KICK0,0x11111111);
mmio_write(AM335X_RTC_BASE+AM335X_RTC_KICK1,0x11111111);
}
/*
* Wait till busy bit is reset
*/
static int rtc_write_wait(void)
{
int i = WRITE_WAIT_MAX_COUNT;
while((mmio_read(AM335X_RTC_BASE+AM335X_RTC_STATUS_REG) & 0x1) && (i--));
if(i == 0)
return RTEMS_RESOURCE_IN_USE;
else
return RTEMS_SUCCESSFUL;
}
/*
* Initialize RTC clock
*/
static void rtc_clk_init(void)
{
uint32_t a = 0x0;
a = setbit(a,1);
/* IDLEST = 0x0 & MODULEMODE = 0x1*/
mmio_write(CM_RTC_BASE+CM_RTC_RTC_CLKCTRL,a);
a = 0x0;
/*32K rtc clock active*/
a = setbit(a,9);
a = setbit(a,8);
mmio_write(CM_RTC_BASE+CM_RTC_CLKSTCTRL,a);
}
void rtc_init(int minor)
{
uint32_t a = 0x0;
rtc_clk_init();
/*
* Steps to enable RTC
* 1. Enable the module clock domains (rtc_clk_init).
* 2. Enable the RTC module using CTRL_REG.RTC_disable. (Default enabled. Nothing done)
* 3. Enable the 32K clock from PER PLL, if using the internal RTC oscillator.
* 4. Write to the kick registers (KICK0R, KICK1R) in the RTC.
* 5. Configure the timer in RTCSS for desired application (set time and date, alarm wakeup, and so on).
* 6. Start the RTC (in CTRL_REG.STOP_RTC).
*/
rtc_write_enable();
a = setbit(a,0);
mmio_write(AM335X_RTC_BASE+AM335X_RTC_SYSCONFIG,a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_OSC_CLOCK);
a = setbit(a,6);
mmio_write(AM335X_RTC_BASE+AM335X_RTC_OSC_CLOCK,a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_CTRL_REG);
a = setbit(a,0);
mmio_write(AM335X_RTC_BASE+AM335X_RTC_CTRL_REG,a);
rtc_write_disable();
}
int am335x_rtc_gettime(int minor,rtems_time_of_day *t)
{
uint32_t a = 0x0;
if(minor != 0)
return RTEMS_INVALID_NUMBER;
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_SECS);
t->second = bcd(a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_MINS);
t->minute = bcd(a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_HOURS);
t->hour = bcd(a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_DAYS);
t->day = bcd(a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_MONTHS);
t->month = bcd(a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_YEARS);
t->year = bcd(a)+2000;
t->ticks=0;
return RTEMS_SUCCESSFUL;
}
int am335x_rtc_settime(int minor,const rtems_time_of_day *t)
{
uint32_t a=0x0;
int rv;
if(minor != 0)
return RTEMS_INVALID_NUMBER;
rtc_write_enable();
/* Wait till the busy bit is reset to write again*/
a = t->second;
rv=rtc_write_wait();
if(rv != RTEMS_SUCCESSFUL)
return rv;
a = mmio_write(AM335X_RTC_BASE+AM335X_RTC_SECS,dec(a) & 0x7f);
a = t->minute;
rv=rtc_write_wait();
if(rv != RTEMS_SUCCESSFUL)
return rv;
a = mmio_write(AM335X_RTC_BASE+AM335X_RTC_MINS,dec(a) & 0x7f);
a = t->hour;
rv=rtc_write_wait();
if(rv != RTEMS_SUCCESSFUL)
return rv;
a = mmio_write(AM335X_RTC_BASE+AM335X_RTC_HOURS,dec(a) & 0x3f);
a = t->day;
rv=rtc_write_wait();
if(rv != RTEMS_SUCCESSFUL)
return rv;
a = mmio_write(AM335X_RTC_BASE+AM335X_RTC_DAYS,dec(a) & 0x3f);
a = t->month;
rv=rtc_write_wait();
if(rv != RTEMS_SUCCESSFUL)
return rv;
a = mmio_write(AM335X_RTC_BASE+AM335X_RTC_MONTHS,dec(a) & 0x1f);
a = t->year;
rv=rtc_write_wait();
if(rv != RTEMS_SUCCESSFUL)
return rv;
a = mmio_write(AM335X_RTC_BASE+AM335X_RTC_YEARS,(dec(a)%100) & 0xff);
rtc_write_disable();
return rv;
}
#if BBB_DEBUG
void print_time(void)
{
uint32_t a = 0x0;
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_SECS);
printk("\n\rSecs %x",a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_MINS);
printk("\n\rMins %x",a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_HOURS);
printk("\n\rHours %x",a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_DAYS);
printk("\n\rDays %x",a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_MONTHS);
printk("\n\r Months %x",a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_YEARS);
printk("\n\rYears %x",a);
a = mmio_read(AM335X_RTC_BASE+AM335X_RTC_WEEKS);
printk("\n\rWeeks %x",a);
}
void am335x_rtc_debug(void)
{
int i;
rtems_time_of_day t,r;
t.second = 1;
t.minute = 1;
t.hour = 1;
t.day = 7;
t.month = 3;
t. year = 2015;
am335x_rtc_settime(0,&t);
am335x_rtc_gettime(0,&r);
printk("Secs %x",r.second);
printk("Mins %x",r.minute);
printk("Hours %x",r.hour);
printk("Days %x",r.day);
printk("Months %x",r.month);
printk("Years %x",r.year);
}
#endif
/*
* driver function table.
*/
rtc_fns am335x_rtc_fns = {
rtc_init,
am335x_rtc_gettime,
am335x_rtc_settime
};
/*
* the following table configures the RTC drivers used in this BSP
*/
rtc_tbl RTC_Table[] = {
{
"/dev/rtc", /* sDeviceName */
RTC_CUSTOM, /* deviceType */
&am335x_rtc_fns, /* pDeviceFns */
am335x_rtc_probe, /* deviceProbe */
NULL, /* pDeviceParams */
0, /* ulCtrlPort1 */
0, /* ulDataPort */
NULL, /* getRegister */
NULL /* setRegister */
}
};
#endif
