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nrf52_clockconfig: support HFCLK via XTAL and LFCLK

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This commit is contained in:
Matias N 2020-08-30 16:11:03 -03:00 committed by Mateusz Szafoni
parent ab37b14972
commit 3176f2c3f0
2 changed files with 77 additions and 1 deletions
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38
arch/arm/src/nrf52/Kconfig
View File

@ -246,6 +246,44 @@ config NRF52_COMP
endmenu # NRF52 Peripheral Selection
menu "Clock Configuration"
config NRF52_HFCLK_XTAL
bool "Enable HFCLK from external crystal"
default n
---help---
If the board includes an external high-frequency crystal, enable this
option to supply the HFCLK. If this option is disabled, the internal
oscillator will be used.
Note that the RADIO peripheral requires the HFCLK to be used.
config NRF52_USE_LFCLK
bool "Enable LFCLK"
default n
---help---
Enable low-frequency clock.
if NRF52_USE_LFCLK
choice
prompt "LFCLK source"
default NRF52_LFCLK_XTAL
config NRF52_LFCLK_XTAL
bool "External 32.768Khz crystal"
config NRF52_LFCLK_RC
bool "Internal RC oscillator"
config NRF52_LFCLK_SYNTH
bool "Synthesized from HFCLK"
endchoice
endif # NRF52_USE_LFCLK
endmenu # Clock Configuration
config NRF52_FLASH_PREFETCH
bool "Enable FLASH Pre-fetch"
default y

40
arch/arm/src/nrf52/nrf52_clockconfig.c
View File

@ -49,6 +49,7 @@
#include "arm_internal.h"
#include "nrf52_clockconfig.h"
#include "hardware/nrf52_clock.h"
/****************************************************************************
* Public Functions
@ -65,6 +66,43 @@
*
****************************************************************************/
void nrf52_clockconfig()
void nrf52_clockconfig(void)
{
#ifdef CONFIG_NRF52_HFCLK_XTAL
/* Initilize HFCLK crystal oscillator */
putreg32(0x0, NRF52_CLOCK_EVENTS_HFCLKSTARTED);
putreg32(0x1, NRF52_CLOCK_TASKS_HFCLKSTART);
while (!getreg32(NRF52_CLOCK_EVENTS_HFCLKSTARTED))
{
/* wait for external oscillator to start */
}
#endif
#ifdef CONFIG_NRF52_USE_LFCLK
/* Initialize LFCLK */
#if defined(CONFIG_NRF52_LFCLK_XTAL)
putreg32(CLOCK_LFCLKSRC_SRC_XTAL, NRF52_CLOCK_LFCLKSRC);
#elif defined(CONFIG_NRF52_LFCLK_SYNTH)
putreg32(CLOCK_LFCLKSRC_SRC_SYNTH, NRF52_CLOCK_LFCLKSRC);
#else
putreg32(CLOCK_LFCLKSRC_SRC_RC, NRF52_CLOCK_LFCLKSRC);
#endif
/* Trigger LFCLK start */
putreg32(0x0, NRF52_CLOCK_EVENTS_LFCLKSTARTED);
putreg32(0x1, NRF52_CLOCK_TASKS_LFCLKSTART);
while (!getreg32(NRF52_CLOCK_EVENTS_LFCLKSTARTED))
{
/* Wait for LFCLK to be running */
}
#if defined(CONFIG_NRF52_LFCLK_RC)
/* TODO: calibrate LFCLK RC oscillator */
#endif
#endif
}