nes-proj/arch/cpu/cc26xx-cc13xx/clock.c

218 lines
6.7 KiB
C

/*
* Copyright (c) 2014, Texas Instruments Incorporated - http://www.ti.com/
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*---------------------------------------------------------------------------*/
/**
* \addtogroup cc26xx-clocks
* @{
*
* \defgroup cc26xx-software-clock Software Clock
*
* Implementation of the clock module for the CC26xx and CC13xx.
*
* The software clock uses the facilities provided by the AON RTC driver
* @{
*
* \file
* Software clock implementation for the TI CC13xx/CC26xx
*/
/*---------------------------------------------------------------------------*/
#include "contiki.h"
#include "ti-lib.h"
/*---------------------------------------------------------------------------*/
static volatile uint64_t count;
/*---------------------------------------------------------------------------*/
static void
power_domain_on(void)
{
ti_lib_prcm_power_domain_on(PRCM_DOMAIN_PERIPH);
while(ti_lib_prcm_power_domain_status(PRCM_DOMAIN_PERIPH) !=
PRCM_DOMAIN_POWER_ON);
}
/*---------------------------------------------------------------------------*/
void
clock_init(void)
{
count = 0;
/*
* Here, we configure GPT0 Timer A, which we subsequently use in
* clock_delay_usec
*
* We need to access registers, so firstly power up the PD and then enable
* the clock to GPT0.
*/
if(ti_lib_prcm_power_domain_status(PRCM_DOMAIN_PERIPH) !=
PRCM_DOMAIN_POWER_ON) {
power_domain_on();
}
ti_lib_prcm_peripheral_run_enable(PRCM_PERIPH_TIMER0);
ti_lib_prcm_load_set();
while(!ti_lib_prcm_load_get());
/* Disable both GPT0 timers */
HWREG(GPT0_BASE + GPT_O_CTL) &= ~(GPT_CTL_TAEN | GPT_CTL_TBEN);
/*
* We assume that the clock is running at 48MHz, we use GPT0 Timer A,
* one-shot, countdown, prescaled by 48 gives us 1 tick per usec
*/
ti_lib_timer_configure(GPT0_BASE,
TIMER_CFG_SPLIT_PAIR | TIMER_CFG_B_ONE_SHOT);
/* Global config: split pair (2 x 16-bit wide) */
HWREG(GPT0_BASE + GPT_O_CFG) = TIMER_CFG_SPLIT_PAIR >> 24;
/*
* Pre-scale value 47 pre-scales by 48
*
* ToDo: The theoretical value here should be 47 (to provide x48 prescale)
* However, 49 seems to give results much closer to the desired delay
*/
ti_lib_timer_prescale_set(GPT0_BASE, TIMER_B, 49);
/* GPT0 / Timer B: One shot, PWM interrupt enable */
HWREG(GPT0_BASE + GPT_O_TBMR) =
((TIMER_CFG_B_ONE_SHOT >> 8) & 0xFF) | GPT_TBMR_TBPWMIE;
/* enable sync with radio timer */
HWREGBITW(AON_RTC_BASE + AON_RTC_O_CTL, AON_RTC_CTL_RTC_UPD_EN_BITN) = 1;
}
/*---------------------------------------------------------------------------*/
static void
update_clock_variable(void)
{
uint32_t aon_rtc_secs_now;
uint32_t aon_rtc_secs_now2;
uint16_t aon_rtc_ticks_now;
do {
aon_rtc_secs_now = HWREG(AON_RTC_BASE + AON_RTC_O_SEC);
aon_rtc_ticks_now = HWREG(AON_RTC_BASE + AON_RTC_O_SUBSEC) >> 16;
aon_rtc_secs_now2 = HWREG(AON_RTC_BASE + AON_RTC_O_SEC);
} while(aon_rtc_secs_now != aon_rtc_secs_now2);
/* Convert AON RTC ticks to clock tick counter */
count = (aon_rtc_secs_now * CLOCK_SECOND) + (aon_rtc_ticks_now >> 9);
}
/*---------------------------------------------------------------------------*/
clock_time_t
clock_time(void)
{
update_clock_variable();
return (clock_time_t)(count & 0xFFFFFFFF);
}
/*---------------------------------------------------------------------------*/
void
clock_update(void)
{
update_clock_variable();
if(etimer_pending()) {
etimer_request_poll();
}
}
/*---------------------------------------------------------------------------*/
unsigned long
clock_seconds(void)
{
bool interrupts_disabled;
uint32_t secs_now;
interrupts_disabled = ti_lib_int_master_disable();
secs_now = ti_lib_aon_rtc_sec_get();
/* Re-enable interrupts */
if(!interrupts_disabled) {
ti_lib_int_master_enable();
}
return (unsigned long)secs_now;
}
/*---------------------------------------------------------------------------*/
void
clock_wait(clock_time_t i)
{
clock_time_t start;
start = clock_time();
while(clock_time() - start < (clock_time_t)i);
}
/*---------------------------------------------------------------------------*/
void
clock_delay_usec(uint16_t len)
{
uint32_t clock_status;
if(ti_lib_prcm_power_domain_status(PRCM_DOMAIN_PERIPH) !=
PRCM_DOMAIN_POWER_ON) {
power_domain_on();
}
clock_status = HWREG(PRCM_BASE + PRCM_O_GPTCLKGR) & PRCM_GPIOCLKGR_CLK_EN;
ti_lib_prcm_peripheral_run_enable(PRCM_PERIPH_TIMER0);
ti_lib_prcm_load_set();
while(!ti_lib_prcm_load_get());
ti_lib_timer_load_set(GPT0_BASE, TIMER_B, len);
ti_lib_timer_enable(GPT0_BASE, TIMER_B);
/*
* Wait for TBEN to clear. CC26xxware does not provide us with a convenient
* function, hence the direct register access here
*/
while(HWREG(GPT0_BASE + GPT_O_CTL) & GPT_CTL_TBEN);
if(clock_status == 0) {
ti_lib_prcm_peripheral_run_disable(PRCM_PERIPH_TIMER0);
ti_lib_prcm_load_set();
while(!ti_lib_prcm_load_get());
}
}
/*---------------------------------------------------------------------------*/
/**
* \brief Obsolete delay function but we implement it here since some code
* still uses it
*/
void
clock_delay(unsigned int i)
{
clock_delay_usec(i);
}
/*---------------------------------------------------------------------------*/
/**
* @}
* @}
*/