clock.c File Reference

SAM L21 Clock Driver.

Copyright (c) 2014-2018 Microchip Technology Inc. and its subsidiaries.

#include <clock.h>
#include <conf_clocks.h>
#include <system.h>
#include "clock_config_check.h"

Data Structures
struct	_system_clock_dfll_config
	DFLL-specific data container. More...
struct	_system_clock_dpll_config
	DPLL-specific data container. More...
struct	_system_clock_module
	System clock module data container. More...
struct	_system_clock_xosc_config
	XOSC-specific data container. More...

Functions
static void	_system_clock_source_dfll_set_config_errata_9905 (void)
static void	_system_clock_source_osc16m_freq_sel (void)
	OSC16M frequency selection. Frequency selection can be done only when OSC16M is disabled,thus, OSCULP32K is temporarily used as a new clocksource for mainclock . More...
static void	_system_dfll_wait_for_sync (void)
	Wait for sync to the DFLL control registers. More...
static void	_system_osc32k_wait_for_sync (void)
	Wait for sync to the OSC32K control registers. More...
void	system_clock_init (void)
	Initialize clock system based on the configuration in conf_clocks.h. More...
void	system_clock_source_dfll_set_config (struct system_clock_source_dfll_config *const config)
	Configure the DFLL clock source. More...
enum status_code	system_clock_source_disable (const enum system_clock_source clock_source)
	Disables a clock source. More...
void	system_clock_source_dpll_set_config (struct system_clock_source_dpll_config *const config)
	Configure the DPLL clock source. More...
enum status_code	system_clock_source_enable (const enum system_clock_source clock_source)
	Enables a clock source. More...
uint32_t	system_clock_source_get_hz (const enum system_clock_source clock_source)
	Retrieve the frequency of a clock source. More...
bool	system_clock_source_is_ready (const enum system_clock_source clock_source)
	Checks if a clock source is ready. More...
void	system_clock_source_osc16m_set_config (struct system_clock_source_osc16m_config *const config)
	Configure the internal OSC16M oscillator clock source. More...
void	system_clock_source_osc32k_set_config (struct system_clock_source_osc32k_config *const config)
	Configure the internal OSC32K oscillator clock source. More...
void	system_clock_source_osculp32k_set_config (struct system_clock_source_osculp32k_config *const config)
	Configure the internal OSCULP32K oscillator clock source. More...
enum status_code	system_clock_source_write_calibration (const enum system_clock_source clock_source, const uint16_t calibration_value, const uint8_t freq_select)
	Writes the calibration values for a given oscillator clock source. More...
void	system_clock_source_xosc32k_set_config (struct system_clock_source_xosc32k_config *const config)
	Configure the XOSC32K external 32KHz oscillator clock source. More...
void	system_clock_source_xosc_set_config (struct system_clock_source_xosc_config *const config)
	Configure the external oscillator clock source. More...

Variables
static struct _system_clock_module	_system_clock_inst
	Internal module instance to cache configuration values. More...

static void _system_clock_source_dfll_set_config_errata_9905 ( void  )

inlinestatic

References _system_dfll_wait_for_sync(), _system_clock_dfll_config::control, _system_clock_module::dfll, _system_clock_dfll_config::mul, and _system_clock_dfll_config::val.

Referenced by system_clock_source_enable().

static void _system_clock_source_osc16m_freq_sel ( void  )

inlinestatic

OSC16M frequency selection. Frequency selection can be done only when OSC16M is disabled,thus, OSCULP32K is temporarily used as a new clocksource for mainclock .

References system_clock_source_osc16m_config::fsel, GCLK_GENERATOR_0, system_clock_source_osc16m_config::on_demand, system_clock_source_osc16m_config::run_in_standby, system_gclk_gen_config::source_clock, system_clock_source_disable(), system_clock_source_enable(), system_clock_source_is_ready(), SYSTEM_CLOCK_SOURCE_OSC16M, system_clock_source_osc16m_get_config_defaults(), system_clock_source_osc16m_set_config(), SYSTEM_CLOCK_SOURCE_ULP32K, system_gclk_gen_get_config_defaults(), and system_gclk_gen_set_config().

Referenced by system_clock_init().

static void _system_dfll_wait_for_sync ( void  )

inlinestatic

Wait for sync to the DFLL control registers.

Referenced by _system_clock_source_dfll_set_config_errata_9905(), and system_clock_source_get_hz().

static void _system_osc32k_wait_for_sync ( void  )

inlinestatic

Wait for sync to the OSC32K control registers.

Referenced by system_clock_source_write_calibration().

enum status_code system_clock_source_enable

(

const enum system_clock_source

clock_source

)

Enables a clock source.

Enables a clock source which has been previously configured.

Parameters

[in]

clock_source

Clock source to enable

Return values

STATUS_OK	Clock source was enabled successfully and is ready
STATUS_ERR_INVALID_ARG	The clock source is not available on this device

References _system_clock_source_dfll_set_config_errata_9905(), Assert, _system_clock_dfll_config::control, _system_clock_module::dfll, STATUS_ERR_INVALID_ARG, STATUS_OK, SYSTEM_CLOCK_SOURCE_DFLL, SYSTEM_CLOCK_SOURCE_DPLL, SYSTEM_CLOCK_SOURCE_OSC16M, SYSTEM_CLOCK_SOURCE_OSC32K, SYSTEM_CLOCK_SOURCE_ULP32K, SYSTEM_CLOCK_SOURCE_XOSC, and SYSTEM_CLOCK_SOURCE_XOSC32K.

Referenced by _system_clock_source_osc16m_freq_sel(), and system_clock_init().

enum status_code system_clock_source_write_calibration	(	const enum system_clock_source	clock_source,
		const uint16_t	calibration_value,
		const uint8_t	freq_select
	)

Writes the calibration values for a given oscillator clock source.

Writes an oscillator calibration value to the given oscillator control registers. The acceptable ranges are:

For OSC32K:

• 7 bits (max. value 128) For OSC16MHZ:
• 8 bits (max. value 255) For OSCULP:
• 5 bits (max. value 32)

Note

The frequency range parameter applies only when configuring the 8MHz oscillator and will be ignored for the other oscillators.

Parameters

[in]	clock_source	Clock source to calibrate
[in]	calibration_value	Calibration value to write
[in]	freq_range	Frequency range (8MHz oscillator only)

Return values

STATUS_OK	The calibration value was written successfully
STATUS_ERR_INVALID_ARG	The setting is not valid for selected clock source

References _system_osc32k_wait_for_sync(), Assert, STATUS_ERR_INVALID_ARG, STATUS_OK, SYSTEM_CLOCK_SOURCE_OSC16M, SYSTEM_CLOCK_SOURCE_OSC32K, and SYSTEM_CLOCK_SOURCE_ULP32K.

struct _system_clock_module _system_clock_inst

static

Initial value:

= {
        .dfll = {
            .control     = 0,
            .val     = 0,
            .mul     = 0,
        },
        .dpll = {
            .frequency   = 0,
        },
        .xosc = {
            .frequency   = 0,
        },
        .xosc32k = {
            .frequency   = 0,
        },
    }

Internal module instance to cache configuration values.