Overview

The MCUXpresso SDK provides a driver for the camera function using Flexible I/O.

FlexIO Camera driver includes functional APIs and eDMA transactional APIs. Functional APIs target low level APIs. Users can use functional APIs for FlexIO Camera initialization/configuration/operation purpose. Using the functional API requires knowledge of the FlexIO Camera peripheral and how to organize functional APIs to meet the requirements of the application. All functional API use the FLEXIO_CAMERA_Type * as the first parameter. FlexIO Camera functional operation groups provide the functional APIs set.

eDMA transactional APIs target high-level APIs. Users can use the transactional API to enable the peripheral quickly and can also use in the application if the code size and performance of transactional APIs satisfy requirements. If the code size and performance are critical requirements, see the transactional API implementation and write custom code. All transactional APIs use the flexio_camera_edma_handle_t as the second parameter. Users need to initialize the handle by calling the FLEXIO_CAMERA_TransferCreateHandleEDMA() API.

eDMA transactional APIs support asynchronous receive. This means that the functions FLEXIO_CAMERA_TransferReceiveEDMA() set up an interrupt for data receive. When the receive is complete, the upper layer is notified through a callback function with the status kStatus_FLEXIO_CAMERA_RxIdle.

Typical use case

FlexIO Camera Receive using eDMA method

volatile uint32_t isEDMAGetOnePictureFinish = false;
edma_handle_t g_edmaHandle;
flexio_camera_edma_handle_t g_cameraEdmaHandle;
edma_config_t edmaConfig;
FLEXIO_CAMERA_Type g_FlexioCameraDevice = {.flexioBase = FLEXIO0,
                                       .datPinStartIdx = 24U, /* fxio_pin 24 -31 are used. */
                                       .pclkPinIdx = 1U,      /* fxio_pin 1 is used as pclk pin. */
                                       .hrefPinIdx = 18U,     /* flexio_pin 18 is used as href pin. */
                                       .shifterStartIdx = 0U, /* Shifter 0 = 7 are used. */
                                       .shifterCount = 8U,
                                       .timerIdx = 0U};
flexio_camera_config_t cameraConfig;
/* Configure DMAMUX */
DMAMUX_Init(DMAMUX0);
/* Configure DMA */
EDMA_GetDefaultConfig(&edmaConfig);
EDMA_Init(DMA0, &edmaConfig);
DMAMUX_SetSource(DMAMUX0, DMA_CHN_FLEXIO_TO_FRAMEBUFF, (g_FlexioCameraDevice.shifterStartIdx + 1U));
DMAMUX_EnableChannel(DMAMUX0, DMA_CHN_FLEXIO_TO_FRAMEBUFF);
EDMA_CreateHandle(&g_edmaHandle, DMA0, DMA_CHN_FLEXIO_TO_FRAMEBUFF);
FLEXIO_CAMERA_GetDefaultConfig(&cameraConfig);
FLEXIO_CAMERA_Init(&g_FlexioCameraDevice, &cameraConfig);
/* Clear all the flag. */
FLEXIO_CAMERA_ClearStatusFlags(&g_FlexioCameraDevice,
                               kFLEXIO_CAMERA_RxDataRegFullFlag | kFLEXIO_CAMERA_RxErrorFlag);
FLEXIO_ClearTimerStatusFlags(FLEXIO0, 0xFF);
FLEXIO_CAMERA_TransferCreateHandleEDMA(&g_FlexioCameraDevice, &g_cameraEdmaHandle, FLEXIO_CAMERA_UserCallback, NULL,
                               &g_edmaHandle);
cameraTransfer.dataAddress = (uint32_t)u16CameraFrameBuffer;
cameraTransfer.dataNum = sizeof(u16CameraFrameBuffer);
FLEXIO_CAMERA_TransferReceiveEDMA(&g_FlexioCameraDevice, &g_cameraEdmaHandle, &cameraTransfer);
while (!(isEDMAGetOnePictureFinish))
{
    ;
}
/* A callback function is also needed */
void FLEXIO_CAMERA_UserCallback(FLEXIO_CAMERA_Type *base,
                            flexio_camera_edma_handle_t *handle,
                            status_t status,
                            void *userData)
{
    userData = userData;
    /* eDMA Transfer finished */
    if (kStatus_FLEXIO_CAMERA_RxIdle == status)
    {
        isEDMAGetOnePictureFinish = true;
    }
}

Data Structures
struct	FLEXIO_CAMERA_Type
	Define structure of configuring the FlexIO Camera device. More...

struct	flexio_camera_config_t
	Define FlexIO Camera user configuration structure. More...

struct	flexio_camera_transfer_t
	Define FlexIO Camera transfer structure. More...

Macros
#define	FLEXIO_CAMERA_PARALLEL_DATA_WIDTH (8U)
	Define the Camera CPI interface is constantly 8-bit width. More...

Enumerations
enum	{ kStatus_FLEXIO_CAMERA_RxBusy = MAKE_STATUS(kStatusGroup_FLEXIO_CAMERA, 0), kStatus_FLEXIO_CAMERA_RxIdle = MAKE_STATUS(kStatusGroup_FLEXIO_CAMERA, 1) }
	Error codes for the Camera driver. More...

enum	_flexio_camera_status_flags { kFLEXIO_CAMERA_RxDataRegFullFlag = 0x1U, kFLEXIO_CAMERA_RxErrorFlag = 0x2U }
	Define FlexIO Camera status mask. More...

Driver version
#define	FSL_FLEXIO_CAMERA_DRIVER_VERSION (MAKE_VERSION(2, 1, 3))
	FlexIO Camera driver version 2.1.3. More...

Initialization and configuration
void	FLEXIO_CAMERA_Init (FLEXIO_CAMERA_Type base, const flexio_camera_config_t config)
	Ungates the FlexIO clock, resets the FlexIO module, and configures the FlexIO Camera. More...

void	FLEXIO_CAMERA_Deinit (FLEXIO_CAMERA_Type *base)
	Resets the FLEXIO_CAMERA shifer and timer config. More...

void	FLEXIO_CAMERA_GetDefaultConfig (flexio_camera_config_t *config)
	Gets the default configuration to configure the FlexIO Camera. More...

static void	FLEXIO_CAMERA_Enable (FLEXIO_CAMERA_Type *base, bool enable)
	Enables/disables the FlexIO Camera module operation. More...

Status
uint32_t	FLEXIO_CAMERA_GetStatusFlags (FLEXIO_CAMERA_Type *base)
	Gets the FlexIO Camera status flags. More...

void	FLEXIO_CAMERA_ClearStatusFlags (FLEXIO_CAMERA_Type *base, uint32_t mask)
	Clears the receive buffer full flag manually. More...

Interrupts
void	FLEXIO_CAMERA_EnableInterrupt (FLEXIO_CAMERA_Type *base)
	Switches on the interrupt for receive buffer full event. More...

void	FLEXIO_CAMERA_DisableInterrupt (FLEXIO_CAMERA_Type *base)
	Switches off the interrupt for receive buffer full event. More...

DMA support
static void	FLEXIO_CAMERA_EnableRxDMA (FLEXIO_CAMERA_Type *base, bool enable)
	Enables/disables the FlexIO Camera receive DMA. More...

static uint32_t	FLEXIO_CAMERA_GetRxBufferAddress (FLEXIO_CAMERA_Type *base)
	Gets the data from the receive buffer. More...

Data Structure Documentation

struct FLEXIO_CAMERA_Type

Data Fields
FLEXIO_Type *	flexioBase
	FlexIO module base address. More...

uint32_t	datPinStartIdx
	First data pin (D0) index for flexio_camera. More...

uint32_t	pclkPinIdx
	Pixel clock pin (PCLK) index for flexio_camera. More...

uint32_t	hrefPinIdx
	Horizontal sync pin (HREF) index for flexio_camera. More...

uint32_t	shifterStartIdx
	First shifter index used for flexio_camera data FIFO. More...

uint32_t	shifterCount
	The count of shifters that are used as flexio_camera data FIFO. More...

uint32_t	timerIdx
	Timer index used for flexio_camera in FlexIO. More...

Field Documentation

FLEXIO_Type* FLEXIO_CAMERA_Type::flexioBase

uint32_t FLEXIO_CAMERA_Type::datPinStartIdx

Then the successive following FLEXIO_CAMERA_DATA_WIDTH-1 pins are used as D1-D7.

uint32_t FLEXIO_CAMERA_Type::pclkPinIdx

uint32_t FLEXIO_CAMERA_Type::hrefPinIdx

uint32_t FLEXIO_CAMERA_Type::shifterStartIdx

uint32_t FLEXIO_CAMERA_Type::shifterCount

uint32_t FLEXIO_CAMERA_Type::timerIdx

struct flexio_camera_config_t

Data Fields
bool	enablecamera
	Enable/disable FlexIO Camera TX & RX. More...

bool	enableInDoze
	Enable/disable FlexIO operation in doze mode.

bool	enableInDebug
	Enable/disable FlexIO operation in debug mode.

bool	enableFastAccess
	Enable/disable fast access to FlexIO registers, fast access requires the FlexIO clock to be at least twice the frequency of the bus clock. More...

Field Documentation

bool flexio_camera_config_t::enablecamera

bool flexio_camera_config_t::enableFastAccess

struct flexio_camera_transfer_t

Data Fields
uint32_t	dataAddress
	Transfer buffer.

uint32_t	dataNum
	Transfer num.

Macro Definition Documentation

#define FSL_FLEXIO_CAMERA_DRIVER_VERSION (MAKE_VERSION(2, 1, 3))

#define FLEXIO_CAMERA_PARALLEL_DATA_WIDTH (8U)

Enumeration Type Documentation

anonymous enum

Enumerator
kStatus_FLEXIO_CAMERA_RxBusy	Receiver is busy.
kStatus_FLEXIO_CAMERA_RxIdle	Camera receiver is idle.

enum _flexio_camera_status_flags

Enumerator
kFLEXIO_CAMERA_RxDataRegFullFlag	Receive buffer full flag.
kFLEXIO_CAMERA_RxErrorFlag	Receive buffer error flag.

Function Documentation

void FLEXIO_CAMERA_Init	(	FLEXIO_CAMERA_Type *	base,
		const flexio_camera_config_t *	config
	)

Parameters

base	Pointer to FLEXIO_CAMERA_Type structure
config	Pointer to flexio_camera_config_t structure

void FLEXIO_CAMERA_Deinit ( FLEXIO_CAMERA_Type * base )

Note: After calling this API, call FLEXO_CAMERA_Init to use the FlexIO Camera module.

Parameters

base	Pointer to FLEXIO_CAMERA_Type structure

void FLEXIO_CAMERA_GetDefaultConfig ( flexio_camera_config_t * config )

The configuration can be used directly for calling the FLEXIO_CAMERA_Init(). Example:

flexio_camera_config_t config;

FLEXIO_CAMERA_GetDefaultConfig(&userConfig);

Parameters

config Pointer to the flexio_camera_config_t structure

static void FLEXIO_CAMERA_Enable	(	FLEXIO_CAMERA_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	Pointer to the FLEXIO_CAMERA_Type
enable	True to enable, false does not have any effect.

uint32_t FLEXIO_CAMERA_GetStatusFlags ( FLEXIO_CAMERA_Type * base )

Parameters

base	Pointer to FLEXIO_CAMERA_Type structure

Returns

FlexIO shifter status flags

FLEXIO_SHIFTSTAT_SSF_MASK
0

void FLEXIO_CAMERA_ClearStatusFlags	(	FLEXIO_CAMERA_Type *	base,
		uint32_t	mask
	)

Parameters

base	Pointer to the device.
mask	status flag The parameter can be any combination of the following values: kFLEXIO_CAMERA_RxDataRegFullFlag kFLEXIO_CAMERA_RxErrorFlag

void FLEXIO_CAMERA_EnableInterrupt ( FLEXIO_CAMERA_Type * base )

Parameters

base	Pointer to the device.

void FLEXIO_CAMERA_DisableInterrupt ( FLEXIO_CAMERA_Type * base )

Parameters

base	Pointer to the device.

static void FLEXIO_CAMERA_EnableRxDMA	(	FLEXIO_CAMERA_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	Pointer to FLEXIO_CAMERA_Type structure
enable	True to enable, false to disable.

The FlexIO Camera mode can't work without the DMA or eDMA support, Usually, it needs at least two DMA or eDMA channels, one for transferring data from Camera, such as 0V7670 to FlexIO buffer, another is for transferring data from FlexIO buffer to LCD.

static uint32_t FLEXIO_CAMERA_GetRxBufferAddress ( FLEXIO_CAMERA_Type * base )

inlinestatic

Parameters

base	Pointer to the device.

Returns: data Pointer to the buffer that keeps the data with count of base->shifterCount .

Overview

Typical use case

FlexIO Camera Receive using eDMA method

Data Structures

Macros

Enumerations

Driver version

Initialization and configuration

Status

Interrupts

DMA support

Data Structure Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation