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Update gdma_lcd_parallel16.cpp

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This commit is contained in:
mrfaptastic 2023-04-03 09:58:53 +01:00
parent 7c2d527dd8
commit 921392ce47
1 changed files with 46 additions and 82 deletions
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128
src/platforms/esp32s3/gdma_lcd_parallel16.cpp
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@ -1,4 +1,4 @@
/*
/*********************************************************************************************
Simple example of using the ESP32-S3's LCD peripheral for general-purpose
(non-LCD) parallel data output with DMA. Connect 8 LEDs (or logic analyzer),
cycles through a pattern among them at about 1 Hz.
@ -15,33 +15,30 @@
PLEASE SUPPORT THEM!
*/
********************************************************************************************/
#if __has_include (<hal/lcd_ll.h>)
// Stop compile errors: /src/platforms/esp32s3/gdma_lcd_parallel16.hpp:64:10: fatal error: hal/lcd_ll.h: No such file or directory
#ifdef ARDUINO_ARCH_ESP32
#include <Arduino.h>
#endif
#ifdef ARDUINO_ARCH_ESP32
#include <Arduino.h>
#endif
#include "gdma_lcd_parallel16.hpp"
#include "esp_attr.h"
//#if (CORE_DEBUG_LEVEL > ARDUHAL_LOG_LEVEL_NONE) || (ARDUHAL_LOG_LEVEL > ARDUHAL_LOG_LEVEL_NONE)
// static const char* TAG = "gdma_lcd_parallel16";
//#endif
//static int _dmadesc_a_idx = 0;
//static int _dmadesc_b_idx = 0;
dma_descriptor_t desc; // DMA descriptor for testing
/*
dma_descriptor_t desc; // DMA descriptor for testing
uint8_t data[8][312]; // Transmit buffer (2496 bytes total)
uint16_t* dmabuff2;
*/
DRAM_ATTR volatile bool previousBufferFree = true;
// End-of-DMA-transfer callback
IRAM_ATTR bool dma_callback(gdma_channel_handle_t dma_chan,
IRAM_ATTR bool gdma_on_trans_eof_callback(gdma_channel_handle_t dma_chan,
gdma_event_data_t *event_data, void *user_data) {
// This DMA callback seems to trigger a moment before the last data has
// issued (buffering between DMA & LCD peripheral?), so pause a moment
// before stopping LCD data out. The ideal delay may depend on the LCD
@ -53,7 +50,10 @@
// the transfer has finished, and the same flag is set later to trigger
// the next transfer.
LCD_CAM.lcd_user.lcd_start = 0;
//LCD_CAM.lcd_user.lcd_start = 0;
previousBufferFree = true;
return true;
}
@ -116,28 +116,26 @@
}
else
{
auto freq = (_cfg.bus_freq);
auto _div_num = 8; // 20Mhz
if (freq < 20000000L)
{
_div_num = 12; // 13Mhz
auto freq = (_cfg.bus_freq);
auto _div_num = 8; // 20Mhz
if (freq < 20000000L) {
_div_num = 12; // 13Mhz
}
else if (freq > 20000000L)
{
_div_num = 6; // 26Mhz --- likely to have noise without a good connection
else if (freq > 20000000L) {
_div_num = 6; // 26Mhz --- likely to have noise without a good connection
}
//LCD_CAM.lcd_clock.lcd_clkm_div_num = lcd_clkm_div_num;
LCD_CAM.lcd_clock.lcd_clkm_div_num = _div_num; //3;
}
ESP_LOGI("S3", "Clock divider is %d", LCD_CAM.lcd_clock.lcd_clkm_div_num);
ESP_LOGD("S3", "Resulting output clock frequency: %ld Mhz", (160000000L/LCD_CAM.lcd_clock.lcd_clkm_div_num));
ESP_LOGI("S3", "Clock divider is %d", LCD_CAM.lcd_clock.lcd_clkm_div_num);
ESP_LOGD("S3", "Resulting output clock frequency: %ld Mhz", (160000000L/LCD_CAM.lcd_clock.lcd_clkm_div_num));
LCD_CAM.lcd_clock.lcd_clkm_div_a = 1; // 0/1 fractional divide
LCD_CAM.lcd_clock.lcd_clkm_div_b = 0;
@ -212,10 +210,11 @@
// in a single DMA descriptor (max 4095 bytes). Large transfers would
// require a linked list of descriptors, but here it's just one...
/*
desc.dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
desc.dw0.suc_eof = 0; // Last descriptor
desc.next = &desc; // No linked list
*/
// Remaining descriptor elements are initialized before each DMA transfer.
@ -236,38 +235,18 @@
gdma_apply_strategy(dma_chan, &strategy_config);
gdma_transfer_ability_t ability = {
.sram_trans_align = 4,
.sram_trans_align = 32,
.psram_trans_align = 64,
};
gdma_set_transfer_ability(dma_chan, &ability);
// Enable DMA transfer callback
/*
static gdma_tx_event_callbacks_t tx_cbs = {
.on_trans_eof = dma_callback
// .on_trans_eof is literally the only gdma tx event type available
.on_trans_eof = gdma_on_trans_eof_callback
};
gdma_register_tx_event_callbacks(dma_chan, &tx_cbs, NULL);
*/
// As mentioned earlier, the slowest clock we can get to the LCD
// peripheral is 40 MHz / 250 / 64 = 2500 Hz. To make an even slower
// bit pattern that's perceptible, we just repeat each value many
// times over. The pattern here just counts through each of 8 bits
// (each LED lights in sequence)...so to get this to repeat at about
// 1 Hz, each LED is lit for 2500/8 or 312 cycles, hence the
// data[8][312] declaration at the start of this code (it's not
// precisely 1 Hz because reality is messy, but sufficient for demo).
// In actual use, say controlling an LED matrix or NeoPixels, such
// shenanigans aren't necessary, as these operate at multiple MHz
// with much smaller clock dividers and can use 1 byte per datum.
/*
for (int i = 0; i < (sizeof(data) / sizeof(data[0])); i++) { // 0 to 7
for (int j = 0; j < sizeof(data[0]); j++) { // 0 to 311
data[i][j] = 1 << i;
}
}
*/
// This uses a busy loop to wait for each DMA transfer to complete...
// but the whole point of DMA is that one's code can do other work in
@ -277,36 +256,12 @@
// After much experimentation, each of these steps is required to get
// a clean start on the next LCD transfer:
gdma_reset(dma_chan); // Reset DMA to known state
LCD_CAM.lcd_user.lcd_dout = 1; // Enable data out
LCD_CAM.lcd_user.lcd_update = 1; // Update registers
LCD_CAM.lcd_user.lcd_dout = 1; // Enable data out
LCD_CAM.lcd_user.lcd_update = 1; // Update registers
LCD_CAM.lcd_misc.lcd_afifo_reset = 1; // Reset LCD TX FIFO
// This program happens to send the same data over and over...but,
// if desired, one could fill the data buffer with a new bit pattern
// here, or point to a completely different buffer each time through.
// With two buffers, one can make best use of time by filling each
// with new data before the busy loop above, alternating between them.
// Reset elements of DMA descriptor. Just one in this code, long
// transfers would loop through a linked list.
/*
desc.dw0.size = desc.dw0.length = sizeof(data);
desc.buffer = dmabuff2; //data;
desc.next = &desc;
*/
/*
//gdma_start(dma_chan, (intptr_t)&desc); // Start DMA w/updated descriptor(s)
gdma_start(dma_chan, (intptr_t)&_dmadesc_a[0]); // Start DMA w/updated descriptor(s)
esp_rom_delay_us(100); // Must 'bake' a moment before...
LCD_CAM.lcd_user.lcd_start = 1; // Trigger LCD DMA transfer
*/
return true; // no return val = illegal instruction
}
@ -379,7 +334,8 @@
{
_dmadesc_b[_dmadesc_b_idx].dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
_dmadesc_b[_dmadesc_b_idx].dw0.suc_eof = 0;
//_dmadesc_b[_dmadesc_b_idx].dw0.suc_eof = 0;
_dmadesc_b[_dmadesc_b_idx].dw0.suc_eof = (_dmadesc_b_idx == (_dmadesc_count-1));
_dmadesc_b[_dmadesc_b_idx].dw0.size = _dmadesc_b[_dmadesc_b_idx].dw0.length = size; //sizeof(data);
_dmadesc_b[_dmadesc_b_idx].buffer = data; //data;
@ -404,7 +360,8 @@
}
_dmadesc_a[_dmadesc_a_idx].dw0.owner = DMA_DESCRIPTOR_BUFFER_OWNER_DMA;
_dmadesc_a[_dmadesc_a_idx].dw0.suc_eof = 0;
//_dmadesc_a[_dmadesc_a_idx].dw0.suc_eof = 0;
_dmadesc_a[_dmadesc_a_idx].dw0.suc_eof = (_dmadesc_a_idx == (_dmadesc_count-1));
_dmadesc_a[_dmadesc_a_idx].dw0.size = _dmadesc_a[_dmadesc_a_idx].dw0.length = size; //sizeof(data);
_dmadesc_a[_dmadesc_a_idx].buffer = data; //data;
@ -458,6 +415,13 @@
}
//current_back_buffer_id ^= 1;
previousBufferFree = false;
//while (i2s_parallel_is_previous_buffer_free() == false) {}
while (!previousBufferFree);
} // end flip