owner-nrf52sdk/std/camera/target/xclk.c

#include <stdio.h>
#include <string.h>
#include "nrf_drv_pwm.h"
#include "app_util_platform.h"
#include "app_timer.h"
#include "nrf_drv_clock.h"
#include "app_error.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "xclk.h"
#include "nrf_camera.h"

static nrf_drv_pwm_t pwm_instance = NRF_DRV_PWM_INSTANCE(0);

static void xclk_init(camera_config_t* config)
{
	nrfx_pwm_config_t const pwm_cfg = {
		.output_pins = {
			config->pin_xclk | NRF_DRV_PWM_PIN_INVERTED,				//将pwm0的通道0映射到引脚17
			NRF_DRV_PWM_PIN_NOT_USED,
			NRF_DRV_PWM_PIN_NOT_USED,					
			NRF_DRV_PWM_PIN_NOT_USED,														//其他通道不使用
		},
		.irq_priority = APP_IRQ_PRIORITY_LOWEST,							//设置优先级
		.base_clock = NRF_PWM_CLK_16MHz,											//设置时钟频率1M
		.count_mode = NRF_PWM_MODE_UP,												//设置向上计数模式
		.top_value = 16,																			//设置top值
		.load_mode = NRF_PWM_LOAD_COMMON,											//设置装载模式common
		.step_mode = NRF_PWM_STEP_AUTO												//序列周期自动推进
	};

	return nrfx_pwm_init(&pwm_instance, &pwm_cfg, pwm_handler);
}

/**
 * 开启pwm函数
 */
static void xclk_play(void)
{	
	static nrf_pwm_values_common_t seq0_values = 8;
	//设置pwm播放设置
	nrf_pwm_sequence_t const seq0 = {
		.values.p_individual = &seq0_values,			//指向pwm占空比序列
		.length = NRF_PWM_VALUES_LENGTH(seq0_values),	//计算pwm包含周期数200
		.repeats = 0,									//序列中周期重复数为0
		.end_delay = 0									//序列后不插入延时
	};
	//自动触发pwm重新播放
	(void)nrfx_pwm_simple_playback(&pwm_instance,&seq0,1,NRFX_PWM_FLAG_LOOP);
}

static void xclk_stop(void)
{
	nrfx_pwm_stop(&pwm_instance, true);
}

static void xclk_uninit(void)
{
	nrfx_pwm_uninit(&pwm_instance);
}

ret_code_t xclk_timer_conf(camera_config_t* config)
{
	ret_code_t err = xclk_init(&timer_conf);
	if (err != NRF_SUCCESS) {
			NRF_LOG_INFO("xclk pwm failed for rc=%x", err);
	}
	return err;
}

ret_code_t camera_enable_out_clock(camera_config_t* config)
{
    xclk_play();
    return ESP_OK;
}

void camera_disable_out_clock()
{
	xclk_stop();
}