Display Interface

Detailed Description

Interface for LCD panel displays.

Summary

The display interface provides standard display functionality:

• Signal timing configuration for LCD panels with RGB interface.
• Dot clock source selection (internal or external) and frequency divider.
• Blending of multiple graphics layers on the background screen.
• Color correction (brightness/configuration/gamma correction).
• Interrupts and callback function.

Data Structures
struct	display_timing_t
struct	display_color_t
struct	display_coordinate_t
struct	display_brightness_t
struct	display_contrast_t
struct	display_correction_t
struct	gamma_correction_t
struct	display_gamma_correction_t
struct	display_clut_t
struct	display_colorkeying_cfg_t
struct	display_colorkeying_layer_t
struct	display_input_cfg_t
struct	display_output_cfg_t
struct	display_layer_t
struct	display_callback_args_t
struct	display_cfg_t
struct	display_runtime_cfg_t
struct	display_clut_cfg_t
struct	display_status_t
struct	display_api_t
struct	display_instance_t

Typedefs
typedef void	display_ctrl_t

Enumerations
enum	display_frame_layer_t
enum	display_state_t
enum	display_event_t
enum	display_in_format_t
enum	display_out_format_t
enum	display_endian_t
enum	display_color_order_t
enum	display_signal_polarity_t
enum	display_sync_edge_t
enum	display_fade_control_t
enum	display_fade_status_t
enum	display_color_keying_t
enum	display_data_swap_t

---

Data Structure Documentation

display_timing_t

struct display_timing_t

Display signal timing setting

Data Fields
uint16_t	total_cyc	Total cycles in one line or total lines in one frame.
uint16_t	display_cyc	Active video cycles or lines.
uint16_t	back_porch	Back porch cycles or lines.
uint16_t	sync_width	Sync signal asserting width.
display_signal_polarity_t	sync_polarity	Sync signal polarity.

display_color_t

struct display_color_t

RGB Color setting

display_coordinate_t

struct display_coordinate_t

Contrast (gain) correction setting

Data Fields
int16_t	x	Coordinate X, this allows to set signed value.
int16_t	y	Coordinate Y, this allows to set signed value.

display_brightness_t

struct display_brightness_t

Brightness (DC) correction setting

Data Fields
bool	enable	Brightness Correction On/Off.
uint16_t	r	Brightness (DC) adjustment for R channel.
uint16_t	g	Brightness (DC) adjustment for G channel.
uint16_t	b	Brightness (DC) adjustment for B channel.

display_contrast_t

struct display_contrast_t

Contrast (gain) correction setting

Data Fields
bool	enable	Contrast Correction On/Off.
uint8_t	r	Contrast (gain) adjustment for R channel.
uint8_t	g	Contrast (gain) adjustment for G channel.
uint8_t	b	Contrast (gain) adjustment for B channel.

display_correction_t

struct display_correction_t

Color correction setting

Data Fields
display_brightness_t	brightness	Brightness.
display_contrast_t	contrast	Contrast.

gamma_correction_t

struct gamma_correction_t

Gamma correction setting for each color

Data Fields
bool	enable	Gamma Correction On/Off.
uint16_t *	gain	Gain adjustment.
uint16_t *	threshold	Start threshold.

display_gamma_correction_t

struct display_gamma_correction_t

Gamma correction setting

Data Fields
gamma_correction_t	r	Gamma correction for R channel.
gamma_correction_t	g	Gamma correction for G channel.
gamma_correction_t	b	Gamma correction for B channel.

display_clut_t

struct display_clut_t

CLUT setting

Data Fields
uint32_t	color_num	The number of colors in CLUT.
const uint32_t *	p_clut	Address of the area storing the CLUT data (in ARGB8888 format)

display_colorkeying_cfg_t

struct display_colorkeying_cfg_t

Color Keying setting

Data Fields
display_color_t	src_color	Source color.
display_color_t	dst_color	Destination color.
display_color_keying_t	enable_ckey	Select enable or disable.

display_colorkeying_layer_t

struct display_colorkeying_layer_t

Color Keying layer setting

display_input_cfg_t

struct display_input_cfg_t

Graphics plane input configuration structure

Data Fields
uint32_t *	p_base	Base address to the frame buffer.
uint16_t	hsize	Horizontal pixel size in a line.
uint16_t	vsize	Vertical pixel size in a frame.
uint32_t	hstride	Memory stride (bytes) in a line.
display_in_format_t	format	Input format setting.
bool	line_descending_enable	Line descending enable.
bool	lines_repeat_enable	Line repeat enable.
uint16_t	lines_repeat_times	Expected number of line repeating.

display_output_cfg_t

struct display_output_cfg_t

Display output configuration structure

Data Fields
display_timing_t	htiming	Horizontal display cycle setting.
display_timing_t	vtiming	Vertical display cycle setting.
display_out_format_t	format	Output format setting.
display_endian_t	endian	Bit order of output data.
display_color_order_t	color_order	Color order in pixel.
display_signal_polarity_t	data_enable_polarity	Data Enable signal polarity.
display_sync_edge_t	sync_edge	Signal sync edge selection.
display_color_t	bg_color	Background color.
display_brightness_t	brightness	Brightness setting.
display_contrast_t	contrast	Contrast setting.
display_gamma_correction_t *	p_gamma_correction	Pointer to gamma correction setting.
bool	dithering_on	Dithering on/off.

display_layer_t

struct display_layer_t

Graphics layer blend setup parameter structure

Data Fields
display_coordinate_t	coordinate	Blending location (starting point of image)
display_color_t	bg_color	Color outside region.
display_fade_control_t	fade_control	Layer fade-in/out control on/off.
uint8_t	fade_speed	Layer fade-in/out frame rate.

display_callback_args_t

struct display_callback_args_t

Display callback parameter definition

Data Fields
display_event_t	event	Event code.
void const *	p_context	Context provided to user during callback.

display_cfg_t

struct display_cfg_t

Display main configuration structure

Data Fields
display_input_cfg_t	input [2]
	Graphics input frame setting. More...
display_output_cfg_t	output
	Graphics output frame setting.
display_layer_t	layer [2]
	Graphics layer blend setting.
uint8_t	line_detect_ipl
	Line detect interrupt priority.
uint8_t	underflow_1_ipl
	Underflow 1 interrupt priority.
uint8_t	underflow_2_ipl
	Underflow 2 interrupt priority.
IRQn_Type	line_detect_irq
	Line detect interrupt vector.
IRQn_Type	underflow_1_irq
	Underflow 1 interrupt vector.
IRQn_Type	underflow_2_irq
	Underflow 2 interrupt vector.
void(*	p_callback )(display_callback_args_t *p_args)
	Pointer to callback function. More...
void const *	p_context
	User defined context passed into callback function.
void const *	p_extend
	Display hardware dependent configuration. More...

Field Documentation

input

display_input_cfg_t display_cfg_t::input[2]

Graphics input frame setting.

Generic configuration for display devices

p_callback

void(* display_cfg_t::p_callback) (display_callback_args_t *p_args)

Pointer to callback function.

Configuration for display event processing

p_extend

void const* display_cfg_t::p_extend

Display hardware dependent configuration.

Pointer to display peripheral specific configuration

display_runtime_cfg_t

struct display_runtime_cfg_t

Display main configuration structure

Data Fields
display_input_cfg_t	input	Graphics input frame setting. Generic configuration for display devices
display_layer_t	layer	Graphics layer alpha blending setting.

display_clut_cfg_t

struct display_clut_cfg_t

Display CLUT configuration structure

Data Fields
uint32_t *	p_base	Pointer to CLUT source data.
uint16_t	start	Beginning of CLUT entry to be updated.
uint16_t	size	Size of CLUT entry to be updated.

display_status_t

struct display_status_t

Display Status

Data Fields
display_state_t	state	Status of display module.
display_fade_status_t	fade_status[DISPLAY_FRAME_LAYER_2+1]	Status of fade-in/fade-out status.

display_api_t

struct display_api_t

Shared Interface definition for display peripheral

Data Fields
fsp_err_t(*	open )(display_ctrl_t *const p_ctrl, display_cfg_t const *const p_cfg)
fsp_err_t(*	close )(display_ctrl_t *const p_ctrl)
fsp_err_t(*	start )(display_ctrl_t *const p_ctrl)
fsp_err_t(*	stop )(display_ctrl_t *const p_ctrl)
fsp_err_t(*	layerChange )(display_ctrl_t const *const p_ctrl, display_runtime_cfg_t const *const p_cfg, display_frame_layer_t frame)
fsp_err_t(*	bufferChange )(display_ctrl_t const *const p_ctrl, uint8_t *const framebuffer, display_frame_layer_t frame)
fsp_err_t(*	correction )(display_ctrl_t const *const p_ctrl, display_correction_t const *const p_param)
fsp_err_t(*	clut )(display_ctrl_t const *const p_ctrl, display_clut_cfg_t const *const p_clut_cfg, display_frame_layer_t layer)
fsp_err_t(*	clutEdit )(display_ctrl_t const *const p_ctrl, display_frame_layer_t layer, uint8_t index, uint32_t color)
fsp_err_t(*	colorKeySet )(display_ctrl_t const *const p_ctrl, display_colorkeying_layer_t key_cfg, display_frame_layer_t layer)
fsp_err_t(*	statusGet )(display_ctrl_t const *const p_ctrl, display_status_t *const p_status)

Field Documentation

open

fsp_err_t(* display_api_t::open) (display_ctrl_t *const p_ctrl, display_cfg_t const *const p_cfg)

Open display device.

Parameters

[in,out]	p_ctrl	Pointer to display interface control block. Must be declared by user. Value set here.
[in]	p_cfg	Pointer to display configuration structure. All elements of this structure must be set by user.

close

fsp_err_t(* display_api_t::close) (display_ctrl_t *const p_ctrl)

Close display device.

Parameters

[in]

p_ctrl

Pointer to display interface control block.

start

fsp_err_t(* display_api_t::start) (display_ctrl_t *const p_ctrl)

Display start.

Parameters

[in]

p_ctrl

Pointer to display interface control block.

stop

fsp_err_t(* display_api_t::stop) (display_ctrl_t *const p_ctrl)

Display stop.

Parameters

[in]

p_ctrl

Pointer to display interface control block.

layerChange

fsp_err_t(* display_api_t::layerChange) (display_ctrl_t const *const p_ctrl, display_runtime_cfg_t const *const p_cfg, display_frame_layer_t frame)

Change layer parameters at runtime.

Parameters

[in]	p_ctrl	Pointer to display interface control block.
[in]	p_cfg	Pointer to run-time layer configuration structure.
[in]	frame	Number of graphic frames.

bufferChange

fsp_err_t(* display_api_t::bufferChange) (display_ctrl_t const *const p_ctrl, uint8_t *const framebuffer, display_frame_layer_t frame)

Change layer framebuffer pointer.

Parameters

[in]	p_ctrl	Pointer to display interface control block.
[in]	framebuffer	Pointer to desired framebuffer.
[in]	frame	Number of graphic frames.

correction

fsp_err_t(* display_api_t::correction) (display_ctrl_t const *const p_ctrl, display_correction_t const *const p_param)

Color correction.

Parameters

[in]	p_ctrl	Pointer to display interface control block.
[in]	param	Pointer to color correction configuration structure.

clut

fsp_err_t(* display_api_t::clut) (display_ctrl_t const *const p_ctrl, display_clut_cfg_t const *const p_clut_cfg, display_frame_layer_t layer)

Set CLUT for display device.

Parameters

[in]	p_ctrl	Pointer to display interface control block.
[in]	p_clut_cfg	Pointer to CLUT configuration structure.
[in]	layer	Layer number corresponding to the CLUT.

clutEdit

fsp_err_t(* display_api_t::clutEdit) (display_ctrl_t const *const p_ctrl, display_frame_layer_t layer, uint8_t index, uint32_t color)

Set CLUT element for display device.

Parameters

[in]	p_ctrl	Pointer to display interface control block.
[in]	layer	Layer number corresponding to the CLUT.
[in]	index	CLUT element index.
[in]	color	Desired CLUT index color.

colorKeySet

fsp_err_t(* display_api_t::colorKeySet) (display_ctrl_t const *const p_ctrl, display_colorkeying_layer_t key_cfg, display_frame_layer_t layer)

Configure color keying.

Parameters

[in]	p_ctrl	Pointer to display interface control block.
[in]	key_cfg	Pointer to color keying configuration.
[in]	layer	Layer to apply color keying.

statusGet

fsp_err_t(* display_api_t::statusGet) (display_ctrl_t const *const p_ctrl, display_status_t *const p_status)

Get status for display device.

Parameters

[in]	p_ctrl	Pointer to display interface control block.
[in]	status	Pointer to display interface status structure.

display_instance_t

struct display_instance_t

This structure encompasses everything that is needed to use an instance of this interface.

Data Fields
display_ctrl_t *	p_ctrl	Pointer to the control structure for this instance.
display_cfg_t const *	p_cfg	Pointer to the configuration structure for this instance.
display_api_t const *	p_api	Pointer to the API structure for this instance.

Typedef Documentation

display_ctrl_t

typedef void display_ctrl_t

Display control block. Allocate an instance specific control block to pass into the display API calls.Display control block

Enumeration Type Documentation

display_frame_layer_t

enum display_frame_layer_t

Display frame number

Enumerator
DISPLAY_FRAME_LAYER_1	Frame layer 1.
DISPLAY_FRAME_LAYER_2	Frame layer 2.

display_state_t

enum display_state_t

Display interface operation state

Enumerator
DISPLAY_STATE_CLOSED	Display closed.
DISPLAY_STATE_OPENED	Display opened.
DISPLAY_STATE_DISPLAYING	Displaying.

display_event_t

enum display_event_t

Display event codes

Enumerator
DISPLAY_EVENT_GR1_UNDERFLOW	Graphics frame1 underflow occurs.
DISPLAY_EVENT_GR2_UNDERFLOW	Graphics frame2 underflow occurs.
DISPLAY_EVENT_LINE_DETECTION	Designated line is processed.
DISPLAY_EVENT_FRAME_END	Frame end is processed.

display_in_format_t

enum display_in_format_t

Input format setting

Enumerator
DISPLAY_IN_FORMAT_32BITS_ARGB8888	ARGB8888, 32 bits.
DISPLAY_IN_FORMAT_32BITS_RGB888	RGB888, 32 bits.
DISPLAY_IN_FORMAT_16BITS_RGB565	RGB565, 16 bits.
DISPLAY_IN_FORMAT_16BITS_ARGB1555	ARGB1555, 16 bits.
DISPLAY_IN_FORMAT_16BITS_ARGB4444	ARGB4444, 16 bits.
DISPLAY_IN_FORMAT_CLUT8	CLUT8.
DISPLAY_IN_FORMAT_CLUT4	CLUT4.
DISPLAY_IN_FORMAT_CLUT1	CLUT1.

display_out_format_t

enum display_out_format_t

Output format setting

Enumerator
DISPLAY_OUT_FORMAT_24BITS_RGB888	RGB888, 24 bits.
DISPLAY_OUT_FORMAT_18BITS_RGB666	RGB666, 18 bits.
DISPLAY_OUT_FORMAT_16BITS_RGB565	RGB565, 16 bits.
DISPLAY_OUT_FORMAT_8BITS_SERIAL	SERIAL, 8 bits.

display_endian_t

enum display_endian_t

Data endian select

Enumerator
DISPLAY_ENDIAN_LITTLE	Little-endian.
DISPLAY_ENDIAN_BIG	Big-endian.

display_color_order_t

enum display_color_order_t

RGB color order select

Enumerator
DISPLAY_COLOR_ORDER_RGB	Color order RGB.
DISPLAY_COLOR_ORDER_BGR	Color order BGR.

display_signal_polarity_t

enum display_signal_polarity_t

Polarity of a signal select

Enumerator
DISPLAY_SIGNAL_POLARITY_LOACTIVE	Low active signal.
DISPLAY_SIGNAL_POLARITY_HIACTIVE	High active signal.

display_sync_edge_t

enum display_sync_edge_t

Signal synchronization edge select

Enumerator
DISPLAY_SIGNAL_SYNC_EDGE_RISING	Signal is synchronized to rising edge.
DISPLAY_SIGNAL_SYNC_EDGE_FALLING	Signal is synchronized to falling edge.

display_fade_control_t

enum display_fade_control_t

Fading control

Enumerator
DISPLAY_FADE_CONTROL_NONE	Applying no fading control.
DISPLAY_FADE_CONTROL_FADEIN	Applying fade-in control.
DISPLAY_FADE_CONTROL_FADEOUT	Applying fade-out control.

display_fade_status_t

enum display_fade_status_t

Fading status

Enumerator
DISPLAY_FADE_STATUS_NOT_UNDERWAY	Fade-in/fade-out is not in progress.
DISPLAY_FADE_STATUS_FADING_UNDERWAY	Fade-in or fade-out is in progress.
DISPLAY_FADE_STATUS_PENDING	Fade-in/fade-out is configured but not yet started.

display_color_keying_t

enum display_color_keying_t

Color Keying enable or disable

Enumerator
DISPLAY_COLOR_KEYING_DISABLE	Color keying disable.
DISPLAY_COLOR_KEYING_ENABLE	Color keying enable.

display_data_swap_t

enum display_data_swap_t

Data swap settings