feat(rgb_lcd): use gdma_link driver

This commit is contained in:
morris 2024-09-23 23:28:00 +08:00
parent 1193e26c88
commit dd82222dd9
5 changed files with 203 additions and 180 deletions

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@ -4,6 +4,7 @@ entries:
if LCD_RGB_ISR_IRAM_SAFE = y:
gdma: gdma_reset (noflash)
gdma: gdma_start (noflash)
gdma_link: gdma_link_get_head_addr (noflash)
[mapping:esp_lcd_hal]
archive: libhal.a

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@ -1,5 +1,5 @@
/*
* SPDX-FileCopyrightText: 2021-2023 Espressif Systems (Shanghai) CO LTD
* SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
@ -60,15 +60,6 @@ int lcd_com_register_device(lcd_com_device_type_t device_type, void *device_obj)
void lcd_com_remove_device(lcd_com_device_type_t device_type, int member_id);
#endif // SOC_LCDCAM_SUPPORTED
/**
* @brief Mount data to DMA descriptors
*
* @param desc_head Point to the head of DMA descriptor chain
* @param buffer Data buffer
* @param len Size of the data buffer, in bytes
*/
void lcd_com_mount_dma_data(dma_descriptor_t *desc_head, const void *buffer, size_t len);
/**
* @brief Reverse the bytes in the buffer
*

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@ -17,7 +17,6 @@
#endif
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "esp_attr.h"
#include "esp_check.h"
#include "esp_pm.h"
@ -28,14 +27,16 @@
#include "soc/soc_caps.h"
#include "esp_clk_tree.h"
#include "hal/dma_types.h"
#include "esp_private/gdma.h"
#include "driver/gpio.h"
#include "esp_bit_defs.h"
#include "esp_private/esp_clk_tree_common.h"
#include "esp_private/gdma.h"
#include "esp_private/gdma_link.h"
#include "esp_private/periph_ctrl.h"
#include "esp_private/gpio.h"
#include "esp_psram.h"
#include "esp_lcd_common.h"
#include "esp_cache.h"
#include "esp_memory_utils.h"
#include "soc/lcd_periph.h"
#include "soc/io_mux_reg.h"
@ -43,18 +44,27 @@
#include "hal/lcd_ll.h"
#include "hal/cache_hal.h"
#include "hal/cache_ll.h"
#include "rom/cache.h"
#include "esp_cache.h"
#if CONFIG_LCD_RGB_ISR_IRAM_SAFE
#define LCD_RGB_INTR_ALLOC_FLAGS (ESP_INTR_FLAG_IRAM | ESP_INTR_FLAG_INTRDISABLED)
#define LCD_RGB_MEM_ALLOC_CAPS (MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT)
#else
#define LCD_RGB_INTR_ALLOC_FLAGS ESP_INTR_FLAG_INTRDISABLED
#define LCD_RGB_MEM_ALLOC_CAPS MALLOC_CAP_DEFAULT
#endif
#if defined(SOC_GDMA_TRIG_PERIPH_LCD0_BUS) && (SOC_GDMA_TRIG_PERIPH_LCD0_BUS == SOC_GDMA_BUS_AHB)
#define LCD_GDMA_NEW_CHANNEL gdma_new_ahb_channel
#define LCD_GDMA_DESCRIPTOR_ALIGN 4
#elif defined(SOC_GDMA_TRIG_PERIPH_LCD0_BUS) && (SOC_GDMA_TRIG_PERIPH_LCD0_BUS == SOC_GDMA_BUS_AXI)
#define LCD_GDMA_NEW_CHANNEL gdma_new_axi_channel
#define LCD_GDMA_DESCRIPTOR_ALIGN 8
#else
#error "Unsupported GDMA bus type for RGB LCD"
#endif
#define RGB_LCD_PANEL_MAX_FB_NUM 3 // maximum supported frame buffer number
#define RGB_LCD_PANEL_BOUNCE_BUF_NUM 2 // bounce buffer number
#define RGB_LCD_PANEL_DMA_LINKS_REPLICA MAX(RGB_LCD_PANEL_MAX_FB_NUM, RGB_LCD_PANEL_BOUNCE_BUF_NUM)
#define RGB_PANEL_SWAP_XY 0
#define RGB_PANEL_MIRROR_Y 1
@ -80,8 +90,8 @@ static esp_err_t rgb_panel_swap_xy(esp_lcd_panel_t *panel, bool swap_axes);
static esp_err_t rgb_panel_set_gap(esp_lcd_panel_t *panel, int x_gap, int y_gap);
static esp_err_t rgb_panel_disp_on_off(esp_lcd_panel_t *panel, bool off);
static esp_err_t lcd_rgb_panel_select_clock_src(esp_rgb_panel_t *panel, lcd_clock_source_t clk_src);
static esp_err_t lcd_rgb_create_dma_channel(esp_rgb_panel_t *panel);
static void lcd_rgb_panel_init_trans_link(esp_rgb_panel_t *panel);
static esp_err_t lcd_rgb_create_dma_channel(esp_rgb_panel_t *rgb_panel);
static esp_err_t lcd_rgb_panel_init_trans_link(esp_rgb_panel_t *rgb_panel);
static esp_err_t lcd_rgb_panel_configure_gpio(esp_rgb_panel_t *panel, const esp_lcd_rgb_panel_config_t *panel_config);
static void lcd_rgb_panel_start_transmission(esp_rgb_panel_t *rgb_panel);
static void rgb_lcd_default_isr_handler(void *args);
@ -99,19 +109,24 @@ struct esp_rgb_panel_t {
intr_handle_t intr; // LCD peripheral interrupt handle
esp_pm_lock_handle_t pm_lock; // Power management lock
size_t num_dma_nodes; // Number of DMA descriptors that used to carry the frame buffer
gdma_channel_handle_t dma_chan; // DMA channel handle
gdma_link_list_handle_t dma_fb_links[RGB_LCD_PANEL_MAX_FB_NUM]; // DMA link lists for multiple frame buffers
gdma_link_list_handle_t dma_bb_link; // DMA link list for bounce buffer
gdma_link_list_handle_t dma_restart_link; // DMA link list for restarting the DMA
uint8_t *fbs[RGB_LCD_PANEL_MAX_FB_NUM]; // Frame buffers
uint8_t *bounce_buffer[RGB_LCD_PANEL_BOUNCE_BUF_NUM]; // Pointer to the bounce buffers
size_t fb_size; // Size of frame buffer, in bytes
size_t bb_size; // Size of the bounce buffer, in bytes. If not-zero, the driver uses two bounce buffers allocated from internal memory
uint8_t cur_fb_index; // Current frame buffer index
uint8_t bb_fb_index; // Current frame buffer index which used by bounce buffer
size_t fb_size; // Size of frame buffer, in bytes
size_t int_mem_align; // DMA buffer alignment for internal memory
size_t ext_mem_align; // DMA buffer alignment for external memory
int data_gpio_nums[SOC_LCD_RGB_DATA_WIDTH]; // GPIOs used for data lines, we keep these GPIOs for action like "invert_color"
uint32_t src_clk_hz; // Peripheral source clock resolution
esp_lcd_rgb_timing_t timings; // RGB timing parameters (e.g. pclk, sync pulse, porch width)
size_t bb_size; // Size of the bounce buffer, in bytes. If not-zero, the driver uses two bounce buffers allocated from internal memory
int bounce_pos_px; // Position in whatever source material is used for the bounce buffer, in pixels
uint8_t *bounce_buffer[RGB_LCD_PANEL_BOUNCE_BUF_NUM]; // Pointer to the bounce buffers
size_t bb_eof_count; // record the number we received the DMA EOF event, compare with `expect_eof_count` in the VSYNC_END ISR
size_t expect_eof_count; // record the number of DMA EOF event we expected to receive
gdma_channel_handle_t dma_chan; // DMA channel handle
esp_lcd_rgb_panel_vsync_cb_t on_vsync; // VSYNC event callback
esp_lcd_rgb_panel_bounce_buf_fill_cb_t on_bounce_empty; // callback used to fill a bounce buffer rather than copying from the frame buffer
esp_lcd_rgb_panel_bounce_buf_finish_cb_t on_bounce_frame_finish; // callback used to notify when the bounce buffer finish copying the entire frame
@ -128,66 +143,55 @@ struct esp_rgb_panel_t {
uint32_t need_update_pclk: 1; // Whether to update the PCLK before start a new transaction
uint32_t need_restart: 1; // Whether to restart the LCD controller and the DMA
uint32_t bb_invalidate_cache: 1; // Whether to do cache invalidation in bounce buffer mode
uint32_t fb_behind_cache: 1; // Whether the frame buffer is behind the cache
uint32_t bb_behind_cache: 1; // Whether the bounce buffer is behind the cache
} flags;
dma_descriptor_t *dma_links[RGB_LCD_PANEL_DMA_LINKS_REPLICA]; // fbs[0] <-> dma_links[0], fbs[1] <-> dma_links[1], etc
dma_descriptor_t dma_restart_node; // DMA descriptor used to restart the transfer
dma_descriptor_t dma_nodes[]; // DMA descriptors pool
};
static esp_err_t lcd_rgb_panel_alloc_frame_buffers(const esp_lcd_rgb_panel_config_t *rgb_panel_config, esp_rgb_panel_t *rgb_panel)
static esp_err_t lcd_rgb_panel_alloc_frame_buffers(esp_rgb_panel_t *rgb_panel)
{
bool fb_in_psram = false;
size_t ext_mem_align = 0;
size_t int_mem_align = 0;
gdma_get_alignment_constraints(rgb_panel->dma_chan, &int_mem_align, &ext_mem_align);
bool fb_in_psram = rgb_panel->flags.fb_in_psram;
// also take the cache line size into account when allocating the frame buffer
uint32_t ext_mem_cache_line_size = cache_hal_get_cache_line_size(CACHE_LL_LEVEL_EXT_MEM, CACHE_TYPE_DATA);
// read the cache line size of internal and external memory, we use this information to check if the allocated memory is behind the cache
uint32_t int_mem_cache_line_size = cache_hal_get_cache_line_size(CACHE_LL_LEVEL_INT_MEM, CACHE_TYPE_DATA);
// The buffer must be aligned to the cache line size
if (ext_mem_cache_line_size) {
ext_mem_align = MAX(ext_mem_align, ext_mem_cache_line_size);
}
if (int_mem_cache_line_size) {
int_mem_align = MAX(int_mem_align, int_mem_cache_line_size);
}
uint32_t ext_mem_cache_line_size = cache_hal_get_cache_line_size(CACHE_LL_LEVEL_EXT_MEM, CACHE_TYPE_DATA);
// alloc frame buffer
if (rgb_panel->num_fbs > 0) {
// fb_in_psram is only an option, if there's no PSRAM on board, we fallback to alloc from SRAM
if (rgb_panel_config->flags.fb_in_psram) {
#if CONFIG_SPIRAM_USE_MALLOC || CONFIG_SPIRAM_USE_CAPS_ALLOC
if (esp_psram_is_initialized()) {
fb_in_psram = true;
}
#endif
for (int i = 0; i < rgb_panel->num_fbs; i++) {
if (fb_in_psram) {
// the allocated buffer is also aligned to the cache line size
rgb_panel->fbs[i] = heap_caps_aligned_calloc(rgb_panel->ext_mem_align, 1, rgb_panel->fb_size,
MALLOC_CAP_SPIRAM | MALLOC_CAP_DMA | MALLOC_CAP_8BIT);
ESP_RETURN_ON_FALSE(rgb_panel->fbs[i], ESP_ERR_NO_MEM, TAG, "no mem for frame buffer");
rgb_panel->flags.fb_behind_cache = ext_mem_cache_line_size > 0;
} else {
rgb_panel->fbs[i] = heap_caps_aligned_calloc(rgb_panel->int_mem_align, 1, rgb_panel->fb_size,
MALLOC_CAP_INTERNAL | MALLOC_CAP_DMA | MALLOC_CAP_8BIT);
ESP_RETURN_ON_FALSE(rgb_panel->fbs[i], ESP_ERR_NO_MEM, TAG, "no mem for frame buffer");
rgb_panel->flags.fb_behind_cache = int_mem_cache_line_size > 0;
}
for (int i = 0; i < rgb_panel->num_fbs; i++) {
if (fb_in_psram) {
// the low level malloc function will help check the validation of alignment
rgb_panel->fbs[i] = heap_caps_aligned_calloc(ext_mem_align, 1, rgb_panel->fb_size, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
ESP_RETURN_ON_FALSE(rgb_panel->fbs[i], ESP_ERR_NO_MEM, TAG, "no mem for frame buffer");
// calloc not only allocates but also zero's the buffer. We have to make sure this is
// properly committed to the PSRAM, otherwise all sorts of visual corruption will happen.
ESP_RETURN_ON_ERROR(esp_cache_msync(rgb_panel->fbs[i], rgb_panel->fb_size, ESP_CACHE_MSYNC_FLAG_DIR_C2M), TAG, "cache write back failed");
} else {
rgb_panel->fbs[i] = heap_caps_aligned_calloc(int_mem_align, 1, rgb_panel->fb_size, MALLOC_CAP_INTERNAL | MALLOC_CAP_DMA);
ESP_RETURN_ON_FALSE(rgb_panel->fbs[i], ESP_ERR_NO_MEM, TAG, "no mem for frame buffer");
}
// flush data from cache to the physical memory
if (rgb_panel->flags.fb_behind_cache) {
esp_cache_msync(rgb_panel->fbs[i], rgb_panel->fb_size, ESP_CACHE_MSYNC_FLAG_DIR_C2M | ESP_CACHE_MSYNC_FLAG_UNALIGNED);
}
}
// alloc bounce buffer
if (rgb_panel->bb_size) {
for (int i = 0; i < RGB_LCD_PANEL_BOUNCE_BUF_NUM; i++) {
// bounce buffer must come from SRAM
rgb_panel->bounce_buffer[i] = heap_caps_aligned_calloc(int_mem_align, 1, rgb_panel->bb_size, MALLOC_CAP_INTERNAL | MALLOC_CAP_DMA);
// bounce buffer must be allocated from internal memory for performance
rgb_panel->bounce_buffer[i] = heap_caps_aligned_calloc(rgb_panel->int_mem_align, 1, rgb_panel->bb_size,
MALLOC_CAP_INTERNAL | MALLOC_CAP_DMA | MALLOC_CAP_8BIT);
ESP_RETURN_ON_FALSE(rgb_panel->bounce_buffer[i], ESP_ERR_NO_MEM, TAG, "no mem for bounce buffer");
if (int_mem_cache_line_size > 0) {
// flush data from cache to the physical memory
esp_cache_msync(rgb_panel->bounce_buffer[i], rgb_panel->bb_size, ESP_CACHE_MSYNC_FLAG_DIR_C2M | ESP_CACHE_MSYNC_FLAG_UNALIGNED);
rgb_panel->flags.bb_behind_cache = true;
}
}
}
rgb_panel->cur_fb_index = 0;
rgb_panel->bb_fb_index = 0;
rgb_panel->flags.fb_in_psram = fb_in_psram;
return ESP_OK;
}
@ -205,21 +209,29 @@ static esp_err_t lcd_rgb_panel_destroy(esp_rgb_panel_t *rgb_panel)
}
lcd_com_remove_device(LCD_COM_DEVICE_TYPE_RGB, rgb_panel->panel_id);
}
for (size_t i = 0; i < rgb_panel->num_fbs; i++) {
if (rgb_panel->fbs[i]) {
free(rgb_panel->fbs[i]);
}
}
if (rgb_panel->bounce_buffer[0]) {
free(rgb_panel->bounce_buffer[0]);
}
if (rgb_panel->bounce_buffer[1]) {
free(rgb_panel->bounce_buffer[1]);
}
if (rgb_panel->dma_chan) {
gdma_disconnect(rgb_panel->dma_chan);
gdma_del_channel(rgb_panel->dma_chan);
}
for (size_t i = 0; i < RGB_LCD_PANEL_MAX_FB_NUM; i++) {
if (rgb_panel->fbs[i]) {
free(rgb_panel->fbs[i]);
}
if (rgb_panel->dma_fb_links[i]) {
gdma_del_link_list(rgb_panel->dma_fb_links[i]);
}
}
for (int i = 0; i < RGB_LCD_PANEL_BOUNCE_BUF_NUM; i++) {
if (rgb_panel->bounce_buffer[i]) {
free(rgb_panel->bounce_buffer[i]);
}
}
if (rgb_panel->dma_bb_link) {
gdma_del_link_list(rgb_panel->dma_bb_link);
}
if (rgb_panel->dma_restart_link) {
gdma_del_link_list(rgb_panel->dma_restart_link);
}
if (rgb_panel->intr) {
esp_intr_free(rgb_panel->intr);
}
@ -240,7 +252,7 @@ esp_err_t esp_lcd_new_rgb_panel(const esp_lcd_rgb_panel_config_t *rgb_panel_conf
esp_rgb_panel_t *rgb_panel = NULL;
ESP_RETURN_ON_FALSE(rgb_panel_config && ret_panel, ESP_ERR_INVALID_ARG, TAG, "invalid parameter");
size_t data_width = rgb_panel_config->data_width;
ESP_RETURN_ON_FALSE((data_width >= 8) && (data_width <= SOC_LCD_RGB_DATA_WIDTH) && ((data_width & (data_width - 1)) == 0), ESP_ERR_INVALID_ARG,
ESP_RETURN_ON_FALSE((data_width > 0) && (data_width <= SOC_LCDCAM_RGB_DATA_WIDTH) && ((data_width % 8) == 0), ESP_ERR_INVALID_ARG,
TAG, "unsupported data width %d", data_width);
ESP_RETURN_ON_FALSE(!(rgb_panel_config->flags.double_fb && rgb_panel_config->flags.no_fb),
ESP_ERR_INVALID_ARG, TAG, "double_fb conflicts with no_fb");
@ -283,25 +295,16 @@ esp_err_t esp_lcd_new_rgb_panel(const esp_lcd_rgb_panel_config_t *rgb_panel_conf
// calculate the number of DMA descriptors
size_t num_dma_nodes = 0;
if (bb_size) {
// in bounce buffer mode, DMA is used to convey the bounce buffer, not the frame buffer.
// frame buffer is copied to bounce buffer by CPU
num_dma_nodes = (bb_size + DMA_DESCRIPTOR_BUFFER_MAX_SIZE - 1) / DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
} else {
// Not bounce buffer mode, DMA descriptors need to fit the entire frame buffer
num_dma_nodes = (fb_size + DMA_DESCRIPTOR_BUFFER_MAX_SIZE - 1) / DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
}
// DMA descriptors must be placed in internal SRAM (requested by DMA)
rgb_panel = heap_caps_calloc(1, sizeof(esp_rgb_panel_t) + num_dma_nodes * sizeof(dma_descriptor_t) * RGB_LCD_PANEL_DMA_LINKS_REPLICA,
MALLOC_CAP_DMA | MALLOC_CAP_INTERNAL);
// allocate memory for rgb panel
rgb_panel = heap_caps_calloc(1, sizeof(esp_rgb_panel_t), LCD_RGB_MEM_ALLOC_CAPS);
ESP_GOTO_ON_FALSE(rgb_panel, ESP_ERR_NO_MEM, err, TAG, "no mem for rgb panel");
rgb_panel->panel_id = -1;
rgb_panel->num_dma_nodes = num_dma_nodes;
rgb_panel->num_fbs = num_fbs;
rgb_panel->fb_size = fb_size;
rgb_panel->bb_size = bb_size;
rgb_panel->fb_bits_per_pixel = fb_bits_per_pixel;
rgb_panel->expect_eof_count = expect_bb_eof_count;
rgb_panel->panel_id = -1;
// register to platform
int panel_id = lcd_com_register_device(LCD_COM_DEVICE_TYPE_RGB, rgb_panel);
ESP_GOTO_ON_FALSE(panel_id >= 0, ESP_ERR_NOT_FOUND, err, TAG, "no free rgb panel slot");
@ -343,13 +346,13 @@ esp_err_t esp_lcd_new_rgb_panel(const esp_lcd_rgb_panel_config_t *rgb_panel_conf
// install DMA service
rgb_panel->flags.stream_mode = !rgb_panel_config->flags.refresh_on_demand;
rgb_panel->fb_bits_per_pixel = fb_bits_per_pixel;
rgb_panel->dma_burst_size = rgb_panel_config->dma_burst_size ? rgb_panel_config->dma_burst_size : 64;
rgb_panel->flags.fb_in_psram = rgb_panel_config->flags.fb_in_psram;
ESP_GOTO_ON_ERROR(lcd_rgb_create_dma_channel(rgb_panel), err, TAG, "install DMA failed");
// allocate frame buffers + bounce buffers
ESP_GOTO_ON_ERROR(lcd_rgb_panel_alloc_frame_buffers(rgb_panel_config, rgb_panel), err, TAG, "alloc frame buffers failed");
ESP_GOTO_ON_ERROR(lcd_rgb_panel_alloc_frame_buffers(rgb_panel), err, TAG, "alloc frame buffers failed");
// initialize DMA descriptor link
lcd_rgb_panel_init_trans_link(rgb_panel);
ESP_GOTO_ON_ERROR(lcd_rgb_panel_init_trans_link(rgb_panel), err, TAG, "init DMA link failed");
// configure GPIO
ret = lcd_rgb_panel_configure_gpio(rgb_panel, rgb_panel_config);
@ -786,13 +789,14 @@ static esp_err_t rgb_panel_draw_bitmap(esp_lcd_panel_t *panel, int x_start, int
if (!rgb_panel->bb_size) {
if (rgb_panel->flags.stream_mode) {
// the DMA will convey the new frame buffer next time
for (int i = 0; i < RGB_LCD_PANEL_DMA_LINKS_REPLICA; i++) {
rgb_panel->dma_nodes[rgb_panel->num_dma_nodes * (i + 1) - 1].next = rgb_panel->dma_links[rgb_panel->cur_fb_index];
for (int i = 0; i < rgb_panel->num_fbs; i++) {
// Note, because of DMA prefetch, there's possibility that the old frame buffer might be sent out again
// it's hard to know the time when the new frame buffer starts
gdma_link_concat(rgb_panel->dma_fb_links[i], -1, rgb_panel->dma_fb_links[rgb_panel->cur_fb_index], 0);
}
}
}
return ESP_OK;
}
@ -959,95 +963,144 @@ static IRAM_ATTR bool lcd_rgb_panel_fill_bounce_buffer(esp_rgb_panel_t *panel, u
static IRAM_ATTR bool lcd_rgb_panel_eof_handler(gdma_channel_handle_t dma_chan, gdma_event_data_t *event_data, void *user_data)
{
esp_rgb_panel_t *panel = (esp_rgb_panel_t *)user_data;
dma_descriptor_t *desc = (dma_descriptor_t *)event_data->tx_eof_desc_addr;
// Figure out which bounce buffer to write to.
// Note: what we receive is the *last* descriptor of this bounce buffer.
int bb = (desc == &panel->dma_nodes[panel->num_dma_nodes - 1]) ? 0 : 1;
portENTER_CRITICAL_ISR(&panel->spinlock);
int bb = panel->bb_eof_count % RGB_LCD_PANEL_BOUNCE_BUF_NUM;
panel->bb_eof_count++;
portEXIT_CRITICAL_ISR(&panel->spinlock);
return lcd_rgb_panel_fill_bounce_buffer(panel, panel->bounce_buffer[bb]);
}
static esp_err_t lcd_rgb_create_dma_channel(esp_rgb_panel_t *panel)
static esp_err_t lcd_rgb_create_dma_channel(esp_rgb_panel_t *rgb_panel)
{
// alloc DMA channel and connect to LCD peripheral
gdma_channel_alloc_config_t dma_chan_config = {
.direction = GDMA_CHANNEL_DIRECTION_TX,
};
#if SOC_GDMA_TRIG_PERIPH_LCD0_BUS == SOC_GDMA_BUS_AHB
ESP_RETURN_ON_ERROR(gdma_new_ahb_channel(&dma_chan_config, &panel->dma_chan), TAG, "alloc DMA channel failed");
#elif SOC_GDMA_TRIG_PERIPH_LCD0_BUS == SOC_GDMA_BUS_AXI
ESP_RETURN_ON_ERROR(gdma_new_axi_channel(&dma_chan_config, &panel->dma_chan), TAG, "alloc DMA channel failed");
#endif
gdma_connect(panel->dma_chan, GDMA_MAKE_TRIGGER(GDMA_TRIG_PERIPH_LCD, 0));
ESP_RETURN_ON_ERROR(LCD_GDMA_NEW_CHANNEL(&dma_chan_config, &rgb_panel->dma_chan), TAG, "alloc DMA channel failed");
gdma_connect(rgb_panel->dma_chan, GDMA_MAKE_TRIGGER(GDMA_TRIG_PERIPH_LCD, 0));
// configure DMA transfer parameters
gdma_transfer_config_t trans_cfg = {
.max_data_burst_size = panel->dma_burst_size,
.access_ext_mem = true, // frame buffer was allocated from external memory
// configure DMA strategy
gdma_strategy_config_t dma_strategy = {
.eof_till_data_popped = false,
};
ESP_RETURN_ON_ERROR(gdma_config_transfer(panel->dma_chan, &trans_cfg), TAG, "config DMA transfer failed");
gdma_apply_strategy(rgb_panel->dma_chan, &dma_strategy);
// configure DMA transfer
gdma_transfer_config_t trans_cfg = {
.max_data_burst_size = rgb_panel->dma_burst_size,
.access_ext_mem = rgb_panel->flags.fb_in_psram,
};
ESP_RETURN_ON_ERROR(gdma_config_transfer(rgb_panel->dma_chan, &trans_cfg), TAG, "config DMA transfer failed");
// get the memory alignment required by the DMA
gdma_get_alignment_constraints(rgb_panel->dma_chan, &rgb_panel->int_mem_align, &rgb_panel->ext_mem_align);
// we need to refill the bounce buffer in the DMA EOF interrupt, so only register the callback for bounce buffer mode
if (panel->bb_size) {
if (rgb_panel->bb_size) {
gdma_tx_event_callbacks_t cbs = {
.on_trans_eof = lcd_rgb_panel_eof_handler,
};
gdma_register_tx_event_callbacks(panel->dma_chan, &cbs, panel);
gdma_register_tx_event_callbacks(rgb_panel->dma_chan, &cbs, rgb_panel);
}
return ESP_OK;
}
// If we restart GDMA, many pixels already have been transferred to the LCD peripheral.
// Looks like that has 16 pixels of FIFO plus one holding register.
// If we restart GDMA, the data sent to the LCD peripheral needs to start LCD_FIFO_PRESERVE_SIZE_PX pixels after the FB start
// so we use a dedicated DMA link (called restart link) to restart the transaction
#define LCD_FIFO_PRESERVE_SIZE_PX (LCD_LL_FIFO_DEPTH + 1)
static void lcd_rgb_panel_init_trans_link(esp_rgb_panel_t *panel)
static esp_err_t lcd_rgb_panel_init_trans_link(esp_rgb_panel_t *rgb_panel)
{
for (int i = 0; i < RGB_LCD_PANEL_DMA_LINKS_REPLICA; i++) {
panel->dma_links[i] = &panel->dma_nodes[panel->num_dma_nodes * i];
}
// chain DMA descriptors
for (int i = 0; i < panel->num_dma_nodes * RGB_LCD_PANEL_DMA_LINKS_REPLICA; i++) {
panel->dma_nodes[i].dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_CPU;
panel->dma_nodes[i].next = &panel->dma_nodes[i + 1];
}
// the restart link shares the same buffer with the frame/bounce buffer but start from a different offset
int restart_skip_bytes = LCD_FIFO_PRESERVE_SIZE_PX * (rgb_panel->fb_bits_per_pixel / 8);
if (rgb_panel->bb_size) {
// DMA is used to convey the bounce buffer
size_t num_dma_nodes_per_bounce_buffer = (rgb_panel->bb_size + LCD_DMA_DESCRIPTOR_BUFFER_MAX_SIZE - 1) / LCD_DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
gdma_link_list_config_t link_cfg = {
.buffer_alignment = rgb_panel->int_mem_align,
.item_alignment = LCD_GDMA_DESCRIPTOR_ALIGN,
.num_items = num_dma_nodes_per_bounce_buffer * RGB_LCD_PANEL_BOUNCE_BUF_NUM,
.flags = {
.check_owner = true,
}
};
ESP_RETURN_ON_ERROR(gdma_new_link_list(&link_cfg, &rgb_panel->dma_bb_link), TAG, "create bounce buffer DMA link failed");
// mount bounce buffers to the DMA link list
gdma_buffer_mount_config_t mount_cfgs[RGB_LCD_PANEL_BOUNCE_BUF_NUM] = {0};
for (int i = 0; i < RGB_LCD_PANEL_BOUNCE_BUF_NUM; i++) {
mount_cfgs[i].buffer = rgb_panel->bounce_buffer[i];
mount_cfgs[i].length = rgb_panel->bb_size;
mount_cfgs[i].flags.mark_eof = true; // we use the DMA EOF interrupt to copy the frame buffer (partially) to the bounce buffer
}
ESP_RETURN_ON_ERROR(gdma_link_mount_buffers(rgb_panel->dma_bb_link, 0, mount_cfgs, RGB_LCD_PANEL_BOUNCE_BUF_NUM, NULL),
TAG, "mount DMA bounce buffers failed");
// create restart link
gdma_link_list_config_t restart_link_cfg = {
.buffer_alignment = rgb_panel->int_mem_align,
.item_alignment = LCD_GDMA_DESCRIPTOR_ALIGN,
.num_items = 1, // the restart link only contains one node
.flags = {
.check_owner = true,
}
};
ESP_RETURN_ON_ERROR(gdma_new_link_list(&restart_link_cfg, &rgb_panel->dma_restart_link), TAG, "create DMA restart link list failed");
gdma_buffer_mount_config_t restart_buffer_mount_cfg = {
.buffer = rgb_panel->bounce_buffer[0] + restart_skip_bytes,
.length = MIN(LCD_DMA_DESCRIPTOR_BUFFER_MAX_SIZE, rgb_panel->bb_size) - restart_skip_bytes,
};
ESP_RETURN_ON_ERROR(gdma_link_mount_buffers(rgb_panel->dma_restart_link, 0, &restart_buffer_mount_cfg, 1, NULL),
TAG, "mount DMA restart buffer failed");
if (panel->bb_size) {
// loop end back to start
panel->dma_nodes[panel->num_dma_nodes * RGB_LCD_PANEL_BOUNCE_BUF_NUM - 1].next = &panel->dma_nodes[0];
// mount the bounce buffers to the DMA descriptors
lcd_com_mount_dma_data(panel->dma_links[0], panel->bounce_buffer[0], panel->bb_size);
lcd_com_mount_dma_data(panel->dma_links[1], panel->bounce_buffer[1], panel->bb_size);
// Magic here: we use the restart link to restart the bounce buffer link list, so concat them
gdma_link_concat(rgb_panel->dma_restart_link, 0, rgb_panel->dma_bb_link, 1);
} else {
if (panel->flags.stream_mode) {
// circle DMA descriptors chain for each frame buffer
for (int i = 0; i < RGB_LCD_PANEL_DMA_LINKS_REPLICA; i++) {
panel->dma_nodes[panel->num_dma_nodes * (i + 1) - 1].next = &panel->dma_nodes[panel->num_dma_nodes * i];
}
} else {
// one-off DMA descriptors chain
for (int i = 0; i < RGB_LCD_PANEL_DMA_LINKS_REPLICA; i++) {
panel->dma_nodes[panel->num_dma_nodes * (i + 1) - 1].next = NULL;
}
}
// mount the frame buffer to the DMA descriptors
for (size_t i = 0; i < panel->num_fbs; i++) {
lcd_com_mount_dma_data(panel->dma_links[i], panel->fbs[i], panel->fb_size);
// DMA is used to convey the frame buffer
size_t num_dma_nodes = (rgb_panel->fb_size + LCD_DMA_DESCRIPTOR_BUFFER_MAX_SIZE - 1) / LCD_DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
gdma_link_list_config_t link_cfg = {
.buffer_alignment = rgb_panel->flags.fb_in_psram ? rgb_panel->ext_mem_align : rgb_panel->int_mem_align,
.item_alignment = LCD_GDMA_DESCRIPTOR_ALIGN,
.num_items = num_dma_nodes,
.flags = {
.check_owner = true,
},
};
gdma_buffer_mount_config_t mount_cfg = {
.length = rgb_panel->fb_size,
.flags = {
.mark_final = rgb_panel->flags.stream_mode ? false : true,
.mark_eof = true,
},
};
for (size_t i = 0; i < rgb_panel->num_fbs; i++) {
ESP_RETURN_ON_ERROR(gdma_new_link_list(&link_cfg, &rgb_panel->dma_fb_links[i]), TAG, "create frame buffer DMA link failed");
// mount bounce buffers to the DMA link list
mount_cfg.buffer = rgb_panel->fbs[i];
ESP_RETURN_ON_ERROR(gdma_link_mount_buffers(rgb_panel->dma_fb_links[i], 0, &mount_cfg, 1, NULL),
TAG, "mount DMA frame buffer failed");
}
// create restart link
gdma_link_list_config_t restart_link_cfg = {
.buffer_alignment = rgb_panel->flags.fb_in_psram ? rgb_panel->ext_mem_align : rgb_panel->int_mem_align,
.item_alignment = LCD_GDMA_DESCRIPTOR_ALIGN,
.num_items = 1, // the restart link only contains one node
.flags = {
.check_owner = true,
}
};
ESP_RETURN_ON_ERROR(gdma_new_link_list(&restart_link_cfg, &rgb_panel->dma_restart_link), TAG, "create DMA restart link list failed");
gdma_buffer_mount_config_t restart_buffer_mount_cfg = {
.buffer = rgb_panel->fbs[0] + restart_skip_bytes,
.length = MIN(LCD_DMA_DESCRIPTOR_BUFFER_MAX_SIZE, rgb_panel->fb_size) - restart_skip_bytes,
};
ESP_RETURN_ON_ERROR(gdma_link_mount_buffers(rgb_panel->dma_restart_link, 0, &restart_buffer_mount_cfg, 1, NULL),
TAG, "mount DMA restart buffer failed");
// Magic here: we use the restart link to restart the frame buffer link list, so concat them
gdma_link_concat(rgb_panel->dma_restart_link, 0, rgb_panel->dma_fb_links[0], 1);
}
// On restart, the data sent to the LCD peripheral needs to start LCD_FIFO_PRESERVE_SIZE_PX pixels after the FB start
// so we use a dedicated DMA node to restart the DMA transaction
// see also `lcd_rgb_panel_try_restart_transmission`
memcpy(&panel->dma_restart_node, &panel->dma_nodes[0], sizeof(panel->dma_restart_node));
int restart_skip_bytes = LCD_FIFO_PRESERVE_SIZE_PX * (panel->fb_bits_per_pixel / 8);
uint8_t *p = (uint8_t *)panel->dma_restart_node.buffer;
panel->dma_restart_node.buffer = &p[restart_skip_bytes];
panel->dma_restart_node.dw0.length -= restart_skip_bytes;
panel->dma_restart_node.dw0.size -= restart_skip_bytes;
return ESP_OK;
}
// reset the GDMA channel every VBlank to stop permanent desyncs from happening.
@ -1093,7 +1146,7 @@ static IRAM_ATTR void lcd_rgb_panel_try_restart_transmission(esp_rgb_panel_t *pa
gdma_reset(panel->dma_chan);
// restart the DMA by a special DMA node
gdma_start(panel->dma_chan, (intptr_t)&panel->dma_restart_node);
gdma_start(panel->dma_chan, gdma_link_get_head_addr(panel->dma_restart_link));
if (panel->bb_size) {
// Fill 2nd bounce buffer while 1st is being sent out, if needed.
@ -1119,7 +1172,11 @@ static void lcd_rgb_panel_start_transmission(esp_rgb_panel_t *rgb_panel)
}
// the start of DMA should be prior to the start of LCD engine
gdma_start(rgb_panel->dma_chan, (intptr_t)rgb_panel->dma_links[rgb_panel->cur_fb_index]);
if (rgb_panel->bb_size) {
gdma_start(rgb_panel->dma_chan, gdma_link_get_head_addr(rgb_panel->dma_bb_link));
} else {
gdma_start(rgb_panel->dma_chan, gdma_link_get_head_addr(rgb_panel->dma_fb_links[rgb_panel->cur_fb_index]));
}
// delay 1us is sufficient for DMA to pass data to LCD FIFO
// in fact, this is only needed when LCD pixel clock is set too high
esp_rom_delay_us(1);

View File

@ -78,29 +78,3 @@ void lcd_com_remove_device(lcd_com_device_type_t device_type, int member_id)
}
}
#endif // SOC_LCDCAM_SUPPORTED
void lcd_com_mount_dma_data(dma_descriptor_t *desc_head, const void *buffer, size_t len)
{
size_t prepared_length = 0;
uint8_t *data = (uint8_t *)buffer;
dma_descriptor_t *desc = desc_head;
while (len > DMA_DESCRIPTOR_BUFFER_MAX_SIZE) {
desc->dw0.suc_eof = 0; // not the end of the transaction
desc->dw0.size = DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
desc->dw0.length = DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
desc->dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
desc->buffer = &data[prepared_length];
desc = desc->next; // move to next descriptor
prepared_length += DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
len -= DMA_DESCRIPTOR_BUFFER_MAX_SIZE;
}
if (len) {
desc->dw0.suc_eof = 1; // end of the transaction
desc->dw0.size = len;
desc->dw0.length = len;
desc->dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
desc->buffer = &data[prepared_length];
desc = desc->next; // move to next descriptor
prepared_length += len;
}
}

View File

@ -1,5 +1,5 @@
/*
* SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
* SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
@ -34,7 +34,7 @@ extern "C" {
#define TEST_LCD_DATA15_GPIO 40 // R4
#define TEST_LCD_DISP_EN_GPIO -1
#define TEST_LCD_PIXEL_CLOCK_HZ (10 * 1000 * 1000)
#define TEST_LCD_PIXEL_CLOCK_HZ (18 * 1000 * 1000)
#ifdef __cplusplus
}