ST7789 LCD Controller driver（ST7789液晶控制器驱动程序）
Overview（概览）
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The ST7789 is a single-chip controller/driver for 262K-color, graphic type TFT-LCD. It consists of 720 source line and 320 gate line driving circuits. This chip is capable of connecting directly to an external microprocessor, and accepts, 8-bits/9-bits/16-bits/18-bits parallel interface. Display data can be stored in the on-chip display data RAM of 240x320x18 bits. It can perform display data RAM read/write operation with no external operation clock to minimize power consumption. In addition, because of the integrated power supply circuit necessary to drive liquid crystal; it is possible to make a display system with the fewest components.
The ST7789 LCD controller driver is a platform-agnostic driver, based on the generic MIPI driver. It implements display initialization, supports display rotation and implements the display flush callback. The user needs to implement only two platform-specific functions to send a command or pixel data to the controller via SPI or parallel bus. Typically these are implemented by calling the appropriate SDK library functions on the given platform.
ST7789 是一款用于262K色彩图形型TFT-LCD的单芯片控制器/驱动器。它由720个源线和320个门线驱动电路组成。该芯片能够直接连接到外部微处理器，并接受8位/9位/16位/18位并行接口。显示数据可以存储在240x320x18位的芯片内显示数据RAM中。它可以在没有外部操作时钟的情况下执行显示数据RAM的读/写操作，以最小化功耗。此外，由于集成了驱动液晶所需的电源电路，可以使用最少的组件构建显示系统。
ST7789 LCD控制器 driver is a platform-agnostic driver, based on the generic MIPI driver 是一个平台无关的驱动器，基于通用的MIPI驱动器。它实现了显示初始化，支持显示旋转，并实现了显示刷新回调。用户只需要实现两个与平台相关的函数来通过SPI或并行总线向控制器发送命令或像素数据。通常情况下，这些函数通过在给定平台上调用相应的SDK库函数来实现。
Prerequisites（先决条件）
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There are no prerequisites.
没有先决条件。
Configuring the driver（配置驱动程序）
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Enable the ST7789 driver support in lv_conf.h, by cmake compiler define or by KConfig
#define LV_USE_ST7789 1
在lv_conf.h中启用ST7789驱动程序支持，可以通过CMake编译器定义或通过KConfig进行配置。
#define LV_USE_ST7789 1
Usage（用法）
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You need to implement two platform-dependent functions:
/* Send short command to the LCD. This function shall wait until the transaction finishes. */
int32_t my_lcd_send_cmd(lv_display_t *disp, const uint8_t *cmd, size_t cmd_size, const uint8_t *param, size_t param_size)
{
...
}
/* Send large array of pixel data to the LCD. If necessary, this function has to do the byte-swapping. This function can do the transfer in the background. */
int32_t my_lcd_send_color(lv_display_t *disp, const uint8_t *cmd, size_t cmd_size, uint8_t *param, size_t param_size)
{
...
}
To create an ST7789-based display use the function
/**
* Create an LCD display with ST7789 driver
* @param hor_res horizontal resolution
* @param ver_res vertical resolution
* @param flags default configuration settings (mirror, RGB ordering, etc.)
* @param send_cmd platform-dependent function to send a command to the LCD controller (usually uses polling transfer)
* @param send_color platform-dependent function to send pixel data to the LCD controller (usually uses DMA transfer: must implement a 'ready' callback)
* @return pointer to the created display
*/
lv_display_t * lv_st7789_create(uint32_t hor_res, uint32_t ver_res, lv_lcd_flag_t flags,
lv_st7789_send_cmd_cb_t send_cmd_cb, lv_st7789_send_color_cb_t send_color_cb);
For additional details and a working example see the generic MIPI driver documentation.
你需要实现两个平台相关的函数：
/* 向LCD发送短命令。此函数将等待事务完成。 */
int32_t my_lcd_send_cmd(lv_display_t *disp, const uint8_t *cmd, size_t cmd_size, const uint8_t *param, size_t param_size)
{
...
}
/* 向LCD发送大量像素数据。如果需要，此函数必须进行字节交换。此函数可以在后台进行传输。 */
int32_t my_lcd_send_color(lv_display_t *disp, const uint8_t *cmd, size_t cmd_size, uint8_t *param, size_t param_size)
{
...
}
要创建基于ST7789驱动的显示器，请使用以下函数
/**
* 使用ST7789驱动程序创建LCD显示器
* @param hor_res 水平分辨率
* @param ver_res 垂直分辨率
* @param flags 默认配置设置（镜像，RGB排序等）
* @param send_cmd 用于向LCD控制器发送命令的平台相关函数（通常使用轮询传输）
* @param send_color 用于向LCD控制器发送像素数据的平台相关函数（通常使用DMA传输：必须实现“ready”回调）
* @return 指向创建的显示器的指针
*/
lv_display_t * lv_st7789_create(uint32_t hor_res, uint32_t ver_res, lv_lcd_flag_t flags,
lv_st7789_send_cmd_cb_t send_cmd_cb, lv_st7789_send_color_cb_t send_color_cb);
有关更多详细信息和工作示例，请参阅 通用MIPI驱动文档。