MIPI DSI 接口的 LCD

[English]

  1. 创建 DSI 总线,并对 D-PHY 进行初始化设置。

    esp_lcd_dsi_bus_handle_t mipi_dsi_bus = NULL;
    esp_lcd_dsi_bus_config_t bus_config = {
        .bus_id = 0, // 从 0 开始编号,指定要使用的 DSI 主机
        .num_data_lanes = 2, // 要使用的数据通道数,不能超过芯片支持的数量
        .phy_clk_src = MIPI_DSI_PHY_CLK_SRC_DEFAULT, // DPHY 的时钟源
        .lane_bit_rate_mbps = EXAMPLE_MIPI_DSI_LANE_BITRATE_MBPS, // 数据通道的比特率 (Mbps)
    };
    ESP_ERROR_CHECK(esp_lcd_new_dsi_bus(&bus_config, &mipi_dsi_bus));
    
  2. 从 DSI 总线派生 DBI 接口。DBI 接口主要用作 esp_lcd 组件中的控制 IO 层。使用该接口可读写 LCD 设备内部的配置寄存器。在此步骤中,需要提供以下信息:

    esp_lcd_panel_io_handle_t mipi_dbi_io = NULL;
    esp_lcd_dbi_io_config_t dbi_config = {
        .virtual_channel = 0,
        .lcd_cmd_bits = 8,   // 依据 LCD 规格书说明来设置
        .lcd_param_bits = 8, // 依据 LCD 规格书说明来设置
    };
    ESP_ERROR_CHECK(esp_lcd_new_panel_io_dbi(mipi_dsi_bus, &dbi_config, &mipi_dbi_io));
    
  3. 安装 LCD 控制器驱动程序。LCD 控制器驱动程序负责向 LCD 控制器芯片发送命令和参数。在此步骤中,需要指定上一步骤中分配到的 MIPI DBI IO 设备句柄以及一些面板特定配置:

    • esp_lcd_panel_dev_config_t::bits_per_pixel 设置每个像素的位宽。LCD 驱动程序使用此值计算要发送到 LCD 控制器芯片的字节数。

    • esp_lcd_panel_dev_config_t::reset_gpio_num 设置复位管脚的 GPIO 编号。如果 LCD 控制器芯片没有硬件复位管脚,则将此设置为 -1

    • esp_lcd_panel_dev_config_t::rgb_ele_order 设置像素数据的 RGB 元素顺序,可以是 RGBBGR

    esp_lcd_panel_handle_t ili9881c_ctrl_panel = NULL;
    esp_lcd_panel_dev_config_t lcd_dev_config = {
        .bits_per_pixel = 24, // MIPI LCD 上通常每像素使用 24 位(即 RGB888)
        .rgb_ele_order = LCD_RGB_ELEMENT_ORDER_RGB,
        .reset_gpio_num = EXAMPLE_PIN_NUM_LCD_RST,
    };
    ESP_ERROR_CHECK(esp_lcd_new_panel_ili9881c(mipi_dbi_io, &lcd_dev_config, &ili9881c_ctrl_panel));
    
  4. 使用上一步骤中返回的 LCD 控制面板,在基本初始化完成后可以重置 LCD 设备。之后,可以打开显示器。

    ESP_ERROR_CHECK(esp_lcd_panel_reset(ili9881c_ctrl_panel));
    ESP_ERROR_CHECK(esp_lcd_panel_init(ili9881c_ctrl_panel));
    ESP_ERROR_CHECK(esp_lcd_panel_disp_on_off(ili9881c_ctrl_panel, true));
    
  5. 此时仍然无法使用控制面板向 MIPI LCD 发送像素数据,因为 MIPI LCD 具有高分辨率,而 LCD 控制器中没有 GRAM。因此需要维护 LCD 帧 buffer,并通过 MIPI DSI DPI 接口将其刷新到 LCD 屏幕上。分配 DPI 数据面板需要许多基本参数,例如 DPI 时钟频率、像素格式、视频时序等。

    esp_lcd_panel_handle_t mipi_dpi_panel = NULL;
    esp_lcd_dpi_panel_config_t dpi_config = {
        .virtual_channel = 0,
        .dpi_clk_src = MIPI_DSI_DPI_CLK_SRC_DEFAULT,
        .dpi_clock_freq_mhz = 1 * 1000,
        .pixel_format = LCD_COLOR_PIXEL_FORMAT_RGB888,
        .video_timing = {
            .h_size = EXAMPLE_MIPI_DSI_LCD_H_RES,
            .v_size = EXAMPLE_MIPI_DSI_LCD_V_RES,
            .hsync_back_porch = EXAMPLE_MIPI_DSI_LCD_HBP,
            .hsync_pulse_width = EXAMPLE_MIPI_DSI_LCD_HSYNC,
            .hsync_front_porch = EXAMPLE_MIPI_DSI_LCD_HFP,
            .vsync_back_porch = EXAMPLE_MIPI_DSI_LCD_VBP,
            .vsync_pulse_width = EXAMPLE_MIPI_DSI_LCD_VSYNC,
            .vsync_front_porch = EXAMPLE_MIPI_DSI_LCD_VFP,
        },
        .flags.use_dma2d = true,
    };
    ESP_ERROR_CHECK(esp_lcd_new_panel_dpi(mipi_dsi_bus, &dpi_config, &mipi_dpi_panel));
    ESP_ERROR_CHECK(esp_lcd_panel_init(mipi_dpi_panel));
    

API 参考

Header File

  • components/esp_lcd/dsi/include/esp_lcd_mipi_dsi.h

  • This header file can be included with:

    #include "esp_lcd_mipi_dsi.h"
    
  • This header file is a part of the API provided by the esp_lcd component. To declare that your component depends on esp_lcd, add the following to your CMakeLists.txt:

    REQUIRES esp_lcd
    

    or

    PRIV_REQUIRES esp_lcd
    

Functions

esp_err_t esp_lcd_new_dsi_bus(const esp_lcd_dsi_bus_config_t *bus_config, esp_lcd_dsi_bus_handle_t *ret_bus)

Create MIPI DSI bus handle.

参数
  • bus_config -- [in] Bus configuration

  • ret_bus -- [out] Returned bus handle

返回

  • ESP_OK: Create MIPI DSI bus successfully

  • ESP_ERR_INVALID_ARG: Create MIPI DSI bus failed because of invalid argument

  • ESP_ERR_NO_MEM: Create MIPI DSI bus failed because of out of memory

  • ESP_ERR_NOT_FOUND: Create MIPI DSI bus failed because no more free DSI hardware instance

  • ESP_FAIL: Create MIPI DSI bus failed because of other error

esp_err_t esp_lcd_del_dsi_bus(esp_lcd_dsi_bus_handle_t bus)

Destroy MIPI DSI bus handle.

参数

bus -- [in] MIPI DSI bus handle, returned from esp_lcd_new_dsi_bus

返回

  • ESP_OK: Destroy MIPI DSI bus successfully

  • ESP_ERR_INVALID_ARG: Destroy MIPI DSI bus failed because of invalid argument

  • ESP_FAIL: Destroy MIPI DSI bus failed because of other error

esp_err_t esp_lcd_new_panel_io_dbi(esp_lcd_dsi_bus_handle_t bus, const esp_lcd_dbi_io_config_t *io_config, esp_lcd_panel_io_handle_t *ret_io)

Create LCD panel IO, for MIPI DSI DBI interface.

备注

Although we call it "DBI", internally the driver is using a co-called "generic" interface for transmitting/receiving LCD commands and parameters.

参数
  • bus -- [in] MIPI DSI bus handle, returned from esp_lcd_new_dsi_bus

  • io_config -- [in] IO configuration

  • ret_io -- [out] Returned panel IO handle

返回

  • ESP_OK: Create MIPI DSI command IO successfully

  • ESP_ERR_INVALID_ARG: Create MIPI DSI command IO failed because of invalid argument

  • ESP_ERR_NO_MEM: Create MIPI DSI command IO failed because of out of memory

  • ESP_FAIL: Create MIPI DSI command IO failed because of other error

esp_err_t esp_lcd_new_panel_dpi(esp_lcd_dsi_bus_handle_t bus, const esp_lcd_dpi_panel_config_t *panel_config, esp_lcd_panel_handle_t *ret_panel)

Create LCD panel for MIPI DSI DPI interface.

参数
  • bus -- [in] MIPI DSI bus handle, returned from esp_lcd_new_dsi_bus

  • panel_config -- [in] DSI data panel configuration

  • ret_panel -- [out] Returned LCD panel handle

返回

  • ESP_OK: Create MIPI DSI data panel successfully

  • ESP_ERR_INVALID_ARG: Create MIPI DSI data panel failed because of invalid argument

  • ESP_ERR_NO_MEM: Create MIPI DSI data panel failed because of out of memory

  • ESP_ERR_NOT_SUPPORTED: Create MIPI DSI data panel failed because of unsupported feature

  • ESP_FAIL: Create MIPI DSI data panel failed because of other error

esp_err_t esp_lcd_dpi_panel_get_frame_buffer(esp_lcd_panel_handle_t dpi_panel, uint32_t fb_num, void **fb0, ...)

Get the address of the frame buffer(s) that allocated by the driver.

参数
  • dpi_panel -- [in] MIPI DPI panel handle, returned from esp_lcd_new_panel_dpi()

  • fb_num -- [in] Number of frame buffer(s) to get. This value must be the same as the number of the followed parameters.

  • fb0 -- [out] Address of the frame buffer 0 (first frame buffer)

  • ... -- [out] List of other frame buffers if any

返回

  • ESP_ERR_INVALID_ARG: Get frame buffer address failed because of invalid argument

  • ESP_OK: Get frame buffer address successfully

esp_err_t esp_lcd_dpi_panel_set_pattern(esp_lcd_panel_handle_t dpi_panel, mipi_dsi_pattern_type_t pattern)

Set pre-defined pattern to the screen for testing or debugging purpose.

参数
  • dpi_panel -- [in] MIPI DPI panel handle, returned from esp_lcd_new_panel_dpi()

  • pattern -- [in] Pattern type

返回

  • ESP_OK: Set pattern successfully

  • ESP_ERR_INVALID_ARG: Set pattern failed because of invalid argument

  • ESP_FAIL: Set pattern failed because of other error

esp_err_t esp_lcd_dpi_panel_register_event_callbacks(esp_lcd_panel_handle_t dpi_panel, const esp_lcd_dpi_panel_event_callbacks_t *cbs, void *user_ctx)

Register LCD DPI panel callbacks.

参数
  • dpi_panel -- [in] LCD DPI panel handle, which is returned from esp_lcd_new_panel_dpi()

  • cbs -- [in] structure with all LCD panel callbacks

  • user_ctx -- [in] User private data, passed directly to callback's user_ctx

返回

  • ESP_ERR_INVALID_ARG: Register callbacks failed because of invalid argument

  • ESP_OK: Register callbacks successfully

Structures

struct esp_lcd_dsi_bus_config_t

MIPI DSI bus configuration structure.

Public Members

int bus_id

Select which DSI controller, index from 0

uint8_t num_data_lanes

Number of data lanes, if set to 0, the driver will fallback to use maximum number of lanes

mipi_dsi_phy_clock_source_t phy_clk_src

MIPI DSI PHY clock source

uint32_t lane_bit_rate_mbps

Lane bit rate in Mbps

struct esp_lcd_dbi_io_config_t

Panel IO configuration structure, for MIPI DSI command interface.

Public Members

uint8_t virtual_channel

Virtual channel ID, index from 0

int lcd_cmd_bits

Bit-width of LCD command

int lcd_param_bits

Bit-width of LCD parameter

struct esp_lcd_dpi_panel_config_t

MIPI DSI DPI panel configuration structure.

Public Members

uint8_t virtual_channel

Virtual channel ID, index from 0

mipi_dsi_dpi_clock_source_t dpi_clk_src

MIPI DSI DPI clock source

uint32_t dpi_clock_freq_mhz

DPI clock frequency in MHz

lcd_color_rgb_pixel_format_t pixel_format

Pixel format that used by the MIPI LCD device

uint8_t num_fbs

Number of screen-sized frame buffers that allocated by the driver By default (set to either 0 or 1) only one frame buffer will be created

esp_lcd_video_timing_t video_timing

Video timing

struct esp_lcd_dpi_panel_config_t::extra_dpi_panel_flags flags

Extra configuration flags

struct extra_dpi_panel_flags

Extra configuration flags for MIPI DSI DPI panel.

Public Members

uint32_t use_dma2d

Use DMA2D to copy user buffer to the frame buffer when necessary

uint32_t disable_lp

Disable low-power for DPI

struct esp_lcd_dpi_panel_event_data_t

Type of LCD DPI panel event data.

struct esp_lcd_dpi_panel_event_callbacks_t

Type of LCD DPI panel callbacks.

Public Members

esp_lcd_dpi_panel_color_trans_done_cb_t on_color_trans_done

Invoked when user's color buffer copied to the internal frame buffer. This is an indicator that the draw buffer can be recycled safely. But doesn't mean the draw buffer finishes the refreshing to the screen.

esp_lcd_dpi_panel_refresh_done_cb_t on_refresh_done

Invoked when the internal frame buffer finishes refreshing to the screen

Type Definitions

typedef struct esp_lcd_dsi_bus_t *esp_lcd_dsi_bus_handle_t

Type of MIPI DSI bus handle

typedef bool (*esp_lcd_dpi_panel_general_cb_t)(esp_lcd_panel_handle_t panel, esp_lcd_dpi_panel_event_data_t *edata, void *user_ctx)

A general function callback prototype for DPI panel driver.

Param panel

[in] LCD panel handle, which is created by factory API like esp_lcd_new_panel_dpi()

Param edata

[in] DPI panel event data, fed by driver

Param user_ctx

[in] User data

Return

Whether a high priority task has been waken up by this function

typedef esp_lcd_dpi_panel_general_cb_t esp_lcd_dpi_panel_color_trans_done_cb_t

Declare the prototype of the function that will be invoked when driver finishes coping user's color buffer to frame buffer.

typedef esp_lcd_dpi_panel_general_cb_t esp_lcd_dpi_panel_refresh_done_cb_t

Declare the prototype of the function that will be invoked when driver finishes refreshing the frame buffer to the screen.


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