/* * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Apache-2.0 */ #pragma once #include #include "esp_err.h" #include "esp_lcd_types.h" #include "soc/soc_caps.h" #include "hal/lcd_types.h" #ifdef __cplusplus extern "C" { #endif #if SOC_LCD_RGB_SUPPORTED /** * @brief LCD RGB timing structure * @verbatim * Total Width * <---------------------------------------------------> * HSYNC width HBP Active Width HFP * <---><--><--------------------------------------><---> * ____ ____|_______________________________________|____| * |___| | | | * | | | * __| | | | * /|\ /|\ | | | | * | VSYNC| | | | | * |Width\|/ |__ | | | * | /|\ | | | | * | VBP | | | | | * | \|/_____|_________|_______________________________________| | * | /|\ | | / / / / / / / / / / / / / / / / / / / | | * | | | |/ / / / / / / / / / / / / / / / / / / /| | * Total | | | |/ / / / / / / / / / / / / / / / / / / /| | * Height | | | |/ / / / / / / / / / / / / / / / / / / /| | * |Active| | |/ / / / / / / / / / / / / / / / / / / /| | * |Heigh | | |/ / / / / / Active Display Area / / / /| | * | | | |/ / / / / / / / / / / / / / / / / / / /| | * | | | |/ / / / / / / / / / / / / / / / / / / /| | * | | | |/ / / / / / / / / / / / / / / / / / / /| | * | | | |/ / / / / / / / / / / / / / / / / / / /| | * | | | |/ / / / / / / / / / / / / / / / / / / /| | * | \|/_____|_________|_______________________________________| | * | /|\ | | * | VFP | | | * \|/ \|/_____|______________________________________________________| * @endverbatim */ typedef struct { unsigned int pclk_hz; /*!< Frequency of pixel clock */ unsigned int h_res; /*!< Horizontal resolution, i.e. the number of pixels in a line */ unsigned int v_res; /*!< Vertical resolution, i.e. the number of lines in the frame */ unsigned int hsync_pulse_width; /*!< Horizontal sync width, unit: PCLK period */ unsigned int hsync_back_porch; /*!< Horizontal back porch, number of PCLK between hsync and start of line active data */ unsigned int hsync_front_porch; /*!< Horizontal front porch, number of PCLK between the end of active data and the next hsync */ unsigned int vsync_pulse_width; /*!< Vertical sync width, unit: number of lines */ unsigned int vsync_back_porch; /*!< Vertical back porch, number of invalid lines between vsync and start of frame */ unsigned int vsync_front_porch; /*!< Vertical front porch, number of invalid lines between the end of frame and the next vsync */ struct { unsigned int hsync_idle_low: 1; /*!< The hsync signal is low in IDLE state */ unsigned int vsync_idle_low: 1; /*!< The vsync signal is low in IDLE state */ unsigned int de_idle_high: 1; /*!< The de signal is high in IDLE state */ unsigned int pclk_active_neg: 1; /*!< Whether the display data is clocked out on the falling edge of PCLK */ unsigned int pclk_idle_high: 1; /*!< The PCLK stays at high level in IDLE phase */ } flags; /*!< LCD RGB timing flags */ } esp_lcd_rgb_timing_t; /** * @brief Type of RGB LCD panel event data */ typedef struct { } esp_lcd_rgb_panel_event_data_t; /** * @brief Declare the prototype of the function that will be invoked when panel IO finishes transferring color data * * @param[in] panel LCD panel handle, returned from `esp_lcd_new_rgb_panel()` * @param[in] edata Panel event data, fed by driver * @param[in] user_ctx User data, passed from `esp_lcd_rgb_panel_config_t` * @return Whether a high priority task has been waken up by this function */ typedef bool (*esp_lcd_rgb_panel_frame_trans_done_cb_t)(esp_lcd_panel_handle_t panel, esp_lcd_rgb_panel_event_data_t *edata, void *user_ctx); /** * @brief Prototype for function to re-fill a bounce buffer. Note this is called in ISR context. * * @param bounce_buf Bounce buffer to write data into * @param pos_px How many pixels already were sent to the display this frame, in other words, at what pixel * the routine should start putting data into bounce_buf * @param len_bytes Length, in bytes, of the bounce buffer. Routine should fill this length fully. * @param user_ctx Opaque pointer that was passed as bounce_buffer_cb_user_ctx to esp_lcd_new_rgb_panel * @return True if the callback woke up a higher-priority task, false otherwise. */ typedef bool (*esp_lcd_rgb_panel_bounce_buf_fill_cb_t)(void *bounce_buf, int pos_px, int len_bytes, void *user_ctx); /** * @brief LCD RGB framebuffer operation modes * * With regards to how the framebuffer is accessed and where it is located, the RGB LCD panel driver can * operate in four modes: * * - Framebuffer in internal memory. * - Framebuffer in PSRAM, accessed using EDMA * - Framebuffer in PSRAM, smaller bounce buffers in internal memory. * - No framebuffer in driver, bounce buffers in internal memory filled by callback. * * The first option (framebuffer in internal memory) is the default and simplest. There is a framebuffer in * internal memory that is read out once a frame using DMA and the data is sent out to the LCD verbatim. It * needs no CPU intervention to function, but it has the downside that it uses up a fair bit of the limited * amount of internal memory. This is the default if you do not specify flags or bounce buffer options. * * The second option is useful if you have PSRAM and want to store the framebuffer there rather than in the * limited internal memory. The LCD peripheral will use EDMA to fetch frame data directly from the PSRAM, * bypassing the internal cache. If you use this, after writing to the framebuffer, make sure to use e.g. * Cache_WriteBack_Addr to make sure the framebuffer is actually written back to the PSRAM. Not doing this * will lead to image corruption. * The downside of this is that when both the CPU as well as peripherals need access to the EDMA, the * bandwidth will be shared between the two, that is, EDMA gets half and the CPUs the other half. If * there's other peripherals using EDMA as well, with a high enough pixel clock this can lead to starvation * of the LCD peripheral, leading to display corruption. However, if the pixel clock is low enough for this * not to be an issue, this is a solution that uses almost no CPU intervention. This option can be enabled * by setting the ``fb_in_psram`` flag. * * The third option makes use of two so-called 'bounce buffers' in internal memory, but a main framebuffer that * is still in PSRAM. These bounce buffers are buffers large enough to hold e.g. a few lines of display data, * but still significantly less than the main framebuffer. The LCD peripheral will use DMA to read data from * one of the bounce buffers, and meanwhile an interrupt routine will use the CPU to copy data from the main * PSRAM framebuffer into the other bounce buffer. Once the LCD peripheral has finished reading the bounce * buffer, the two buffers change place and the CPU can fill the others. Note that as the CPU reads the * framebuffer data through the cache, it's not needed to call Cache_WriteBack_Addr() anymore. * The advantage here is that, as it's easier to control CPU memory bandwith use than EDMA memory bandwith * use, doing this can lead to higher pixel clocks being supported. As the bounce buffers are larger than * the FIFOs in the EDMA path, this method is also more robust against short bandwidth spikes. The * downside is a major increase in CPU use. This mode is selected by setting the ``fb_in_psram`` flag and * additionally specifying a (non-zero) bounce_buffer_size_px value. This value is dependent on your use * case, but a suggested initial value would be e.g. 8 times the amount of pixels in one LCD line. * * Note that this third option also allows for a ``bb_do_cache_invalidate`` flag to be set. Enabling this * frees up the cache lines after they're used to read out the framebuffer data from PSRAM, but it may lead * to slight corruption if the other core writes data to the framebuffer at the exact time the cache lines * are freed up. (Technically, a write to the framebuffer can be ignored if it falls between the cache * writeback and the cache invalidate calls.) * * Finally, the fourth option is the same as the third option, but there is no PSRAM frame buffer initialized * by the LCD driver. Instead, the user supplies a callback function that is responsible for filling the * bounce buffers. As this driver does not care where the written pixels come from, this allows for * the callback doing e.g. on-the-fly conversion from a smaller, 8-bit-per-pixel PSRAM framebuffer to * an 16-bit LCD, or even procedurally-generated framebuffer-less graphics. This option is selected * by not setting the ``fb_in_psram`` flag but supplying both a ``bounce_buffer_size_px`` value as well * as a ``on_bounce_empty`` callback. */ /** * @brief LCD RGB panel configuration structure */ typedef struct { lcd_clock_source_t clk_src; /*!< Clock source for the RGB LCD peripheral */ esp_lcd_rgb_timing_t timings; /*!< RGB timing parameters */ size_t data_width; /*!< Number of data lines */ size_t sram_trans_align; /*!< Alignment for framebuffer that allocated in SRAM */ size_t psram_trans_align; /*!< Alignment for framebuffer that allocated in PSRAM */ int hsync_gpio_num; /*!< GPIO used for HSYNC signal */ int vsync_gpio_num; /*!< GPIO used for VSYNC signal */ int de_gpio_num; /*!< GPIO used for DE signal, set to -1 if it's not used */ int pclk_gpio_num; /*!< GPIO used for PCLK signal */ int data_gpio_nums[SOC_LCD_RGB_DATA_WIDTH]; /*!< GPIOs used for data lines */ int disp_gpio_num; /*!< GPIO used for display control signal, set to -1 if it's not used */ esp_lcd_rgb_panel_frame_trans_done_cb_t on_frame_trans_done; /*!< Callback invoked when one frame buffer has transferred done */ int bounce_buffer_size_px; /*!< If not-zero, the driver uses a bounce buffer in internal memory to DMA from. Value is in pixels. */ esp_lcd_rgb_panel_bounce_buf_fill_cb_t on_bounce_empty; /*!< If we use a bounce buffer, this function gets called to fill that, rather than copying from the framebuffer */ void *bounce_buffer_cb_user_ctx; /*!< Opaque parameter to pass to the on_bounce_empty function */ void *user_ctx; /*!< User data which would be passed to on_frame_trans_done's user_ctx */ struct { unsigned int disp_active_low: 1; /*!< If this flag is enabled, a low level of display control signal can turn the screen on; vice versa */ unsigned int relax_on_idle: 1; /*!< If this flag is enabled, the host won't refresh the LCD if nothing changed in host's frame buffer (this is usefull for LCD with built-in GRAM) */ unsigned int fb_in_psram: 1; /*!< If this flag is enabled, the frame buffer will be allocated from PSRAM preferentially */ unsigned int bb_do_cache_invalidate:1; /*!< If this flag is enabled, in bounceback mode we'll do a cache invalidate on the read data, freeing the cache. Can be dangerous if data is written from other core. */ } flags; /*!< LCD RGB panel configuration flags */ } esp_lcd_rgb_panel_config_t; /** * @brief Create RGB LCD panel * * @param rgb_panel_config RGB panel configuration * @param ret_panel Returned LCD panel handle * @return * - ESP_ERR_INVALID_ARG if parameter is invalid * - ESP_ERR_NO_MEM if out of memory * - ESP_ERR_NOT_FOUND if no free RGB panel is available * - ESP_OK on success */ esp_err_t esp_lcd_new_rgb_panel(const esp_lcd_rgb_panel_config_t *rgb_panel_config, esp_lcd_panel_handle_t *ret_panel); /** * @brief Set frequency of PCLK for RGB LCD panel * * @note The PCLK frequency is set in the `esp_lcd_rgb_timing_t` and gets configured during LCD panel initialization. * Usually you don't need to call this function to set the PCLK again, but in some cases, you may need to change the PCLK frequency. * e.g. to slow down the PCLK frequency to reduce power consumption or to reduce the memory throughput. * @note This function doesn't cause the hardware to update the PCLK immediately but to record the new frequency and set a flag internally. * Next time when start a new transaction, the driver will update the PCLK automatically. * * @param panel LCD panel handle, returned from `esp_lcd_new_rgb_panel()` * @param freq_hz Frequency of pixel clock, in Hz * @return * - ESP_ERR_NOT_SUPPORTED if frequency is unreachable * - ESP_ERR_INVALID_ARG if parameter panel is invalid * - ESP_OK on success */ esp_err_t esp_rgb_panel_set_pclk(esp_lcd_panel_handle_t panel, uint32_t freq_hz); #endif // SOC_LCD_RGB_SUPPORTED #ifdef __cplusplus } #endif