Merge pull request #657 from mrcodetastic/dev

Better align clocks across SoCs

3 files changed, 32 insertions, 60 deletions

diff --git a/src/platforms/esp32/esp32_i2s_parallel_dma.cpp b/src/platforms/esp32/esp32_i2s_parallel_dma.cpp
index 4cc4706..9ea6456 100644
--- a/src/platforms/esp32/esp32_i2s_parallel_dma.cpp
+++ b/src/platforms/esp32/esp32_i2s_parallel_dma.cpp
@@ -47,9 +47,6 @@ Modified heavily for the ESP32 HUB75 DMA library by:
 #include <esp_err.h>
 #include <esp_log.h>
 
-// Get current frequecny
-#include "esp_clk_tree.h"
-
 // Get CPU freq function.
 #include <soc/rtc.h>
 
@@ -238,8 +235,8 @@ Modified heavily for the ESP32 HUB75 DMA library by:
       dev->clkm_conf.clkm_div_a   = 1;      // Clock denominator 			
       dev->clkm_conf.clkm_div_b   = 0;      // Clock numerator
 
-		  unsigned int _div_num = (freq > 8000000) ? 3:5; // 8 mhz or 13mhz   (eventual output after factoring in tx_bck_div_num)   
-      // Divider of 2 works theoretically with SRAM (22mhz output rate!)
+      // Output Frequency = (160Mhz / clkm_div_num) / (tx_bck_div_num*2)
+		  unsigned int _div_num = (freq > 8000000) ? 2:4; // 20 mhz or 10mhz 
 
       /*
         Page 675 of ESP-S2 TRM.
@@ -258,7 +255,7 @@ Modified heavily for the ESP32 HUB75 DMA library by:
 
       */
 
-      dev->clkm_conf.clkm_div_num = _div_num;	
+      dev->clkm_conf.clkm_div_num = _div_num;	 
       dev->clkm_conf.clk_en  = 1;
 
       // Binary clock 
@@ -276,7 +273,7 @@ Modified heavily for the ESP32 HUB75 DMA library by:
       dev->sample_rate_conf.rx_bck_div_num = 2;
 
       // ESP32 and ESP32-S2 TRM clearly say that "Note that I2S_TX_BCK_DIV_NUM[5:0] must not be configured as 1." 
-      // Testing has revealed that setting it to 1 causes problems.      
+      // Testing has revealed that setting it to 1 causes problems on S2.      
       dev->sample_rate_conf.tx_bck_div_num = 2;   
 
       // Output Frequency is now
@@ -286,48 +283,29 @@ Modified heavily for the ESP32 HUB75 DMA library by:
     // Calculate clock divider for Original ESP32
     #else  
 
-    dev->sample_rate_conf.rx_bck_div_num = 1;
-
-    // ESP32 and ESP32-S2 TRM clearly say that "Note that I2S_TX_BCK_DIV_NUM[5:0] must not be configured as 1." 
-    // Testing has revealed that setting it to 1 causes problems.      
-    dev->sample_rate_conf.tx_bck_div_num = 1;   
-
-
-		// Note: clkm_div_num must only be set here AFTER clkm_div_b, clkm_div_a, etc. Or weird things happen!
-		// On original ESP32, max I2S DMA parallel speed is 20Mhz.  
-		
-		// 160Mhz is only assured when the CPU clock is 240Mhz on the ESP32...	
-		// [esp32-hal-cpu.c:244] setCpuFrequencyMhz(): PLL: 480 / 2 = 240 Mhz, APB: 80000000 Hz		
-		
-		//static uint32_t pll_d2_clock = (source_freq/2) * 1000 * 1000 >> 1;
-		
-		// I2S_CLKM_DIV_NUM 2=40MHz  /  3=27MHz  /  4=20MHz  /  5=16MHz  /  8=10MHz  /  10=8MHz
-		//auto _div_num = std::min(255u, 1 + ((pll_d2_clock) / (1 + freq)));
-		
     /*
-		unsigned int _div_num = (unsigned int) (80000000L / freq / i2s_parallel_get_memory_width(ESP32_I2S_DEVICE, 16)); // 16 bits in parallel
-		if(_div_num < 2 || _div_num > 0xFF) {
-		//	return ESP_ERR_INVALID_ARG;
-			_div_num = 4;
-		}
+      The clock configuration of the LCD master transmitting mode is identical to I2S’ clock configuration. 
+      In the LCD mode, the frequency of WS is half of f-bck
     */
-   
-		unsigned int _div_num = (freq > 8000000) ? 5:10; // 8 mhz or 16mhz
 
-		ESP_LOGD("ESP32", "i2s pll_d2_clock clkm_div_num is: %u", _div_num);    		
+    // ESP32 and ESP32-S2 TRM clearly say that "Note that I2S_TX_BCK_DIV_NUM[5:0] must not be configured as 1." 
+    dev->sample_rate_conf.tx_bck_div_num = 2;   
+    dev->sample_rate_conf.rx_bck_div_num = 2;
 
-		dev->clkm_conf.clka_en=0;           // Use the 80mhz system clock (PLL_D2_CLK) when '0'
+  	dev->clkm_conf.clka_en    = 0;           // Use the 80mhz system clock (PLL_D2_CLK) when '0'
 		dev->clkm_conf.clkm_div_a = 1;      // Clock denominator 
 		dev->clkm_conf.clkm_div_b = 0;      // Clock numerator
+
+    unsigned int _div_num = (freq > 8000000) ? 2:4; // 20 mhz or 10mhz
+		ESP_LOGD("ESP32", "i2s pll_d2_clock clkm_div_num is: %u", _div_num);    		
+
+    // Frequency will be (80Mhz / clkm_div_num / tx_bck_div_num (2))
 		dev->clkm_conf.clkm_div_num = _div_num;  
-   // dev->clkm_conf.clk_en=1;
 
    // Note tx_bck_div_num value of 2 will further divide clock rate
 		
     #endif
- 
-
-  
+   
     ////////////////////////////// END CLOCK CONFIGURATION /////////////////////////////////
 
     // I2S conf2 reg
diff --git a/src/platforms/esp32c6/dma_parallel_io.cpp b/src/platforms/esp32c6/dma_parallel_io.cpp
index 930c29e..fa53cca 100644
--- a/src/platforms/esp32c6/dma_parallel_io.cpp
+++ b/src/platforms/esp32c6/dma_parallel_io.cpp
@@ -1,7 +1,10 @@
 #include "dma_parallel_io.hpp"
+#include <Arduino.h>
 
 #ifdef CONFIG_IDF_TARGET_ESP32C6
 
+#pragma message "Compiling for ESP32-C6"
+
 //First implementation might have a lot of bugs, especially on deleting and reloading
 
 //major test setup:
@@ -33,8 +36,6 @@
 //     for a view clocks
 
 
-
-
 // limitation of parlio interface
 // PARLIO_LL_TX_MAX_BITS_PER_FRAME = (PARLIO_LL_TX_MAX_BYTES_PER_FRAME * 8)
 // PARLIO_LL_TX_MAX_BYTES_PER_FRAME = 0xFFFF
@@ -53,8 +54,6 @@
 //                                                                              I don't get it
 
 
-
-
 #pragma message "Compiling for ESP32-C6"
 
 #ifdef ARDUINO_ARCH_ESP32
@@ -81,22 +80,17 @@ DRAM_ATTR volatile bool previousBufferFree = true;
 IRAM_ATTR bool gdma_on_trans_eof_callback(gdma_channel_handle_t dma_chan,
                                           gdma_event_data_t *event_data, void *user_data)
 {
-
     //esp_rom_delay_us(100);
-
     previousBufferFree = true;
 
-
     //parlio_ll_tx_reset_fifo(&PARL_IO);
     parlio_ll_tx_reset_clock(&PARL_IO);
     
     //gdma_start(dma_chan, (intptr_t)&_dmadesc_a[0]);
-    
     //while (parlio_ll_tx_is_ready(&PARL_IO) == false);
-
     //parlio_ll_tx_start(&PARL_IO, true);
     //parlio_ll_tx_enable_clock(&PARL_IO, true);
-    
+
     return true;
 }
 
@@ -110,9 +104,10 @@ void Bus_Parallel16::config(const config_t &cfg)
 
 bool Bus_Parallel16::init(void)
 {
+    ESP_LOGI("ESP32-C6", "Performing DMA bus init() for ESP-C6");
 
     periph_module_enable(PERIPH_PARLIO_MODULE);
-    periph_module_reset(PERIPH_PARLIO_MODULE);
+    periph_module_reset (PERIPH_PARLIO_MODULE);
 
     // Reset LCD bus
     parlio_ll_tx_reset_fifo(&PARL_IO);
@@ -120,18 +115,17 @@ bool Bus_Parallel16::init(void)
 
     parlio_ll_clock_source_t clk_src = (parlio_ll_clock_source_t)PARLIO_CLK_SRC_DEFAULT;
     uint32_t periph_src_clk_hz = 0;
+
     esp_clk_tree_src_get_freq_hz((soc_module_clk_t)clk_src, ESP_CLK_TREE_SRC_FREQ_PRECISION_CACHED, &periph_src_clk_hz);
     parlio_ll_tx_set_clock_source(&PARL_IO, clk_src);
+
     uint32_t div = (periph_src_clk_hz + _cfg.bus_freq - 1) / _cfg.bus_freq;
     parlio_ll_tx_set_clock_div(&PARL_IO, div);
     _cfg.bus_freq = periph_src_clk_hz / div;
 
-
     ESP_LOGI("C6", "Clock divider is %d", (int)div);
     ESP_LOGD("C6", "Resulting output clock frequency: %d Mhz", (int)(160000000L /  _cfg.bus_freq));
 
-    
-
 
     // Allocate DMA channel and connect it to the LCD peripheral
     static gdma_channel_alloc_config_t dma_chan_config = {
diff --git a/src/platforms/esp32s3/gdma_lcd_parallel16.cpp b/src/platforms/esp32s3/gdma_lcd_parallel16.cpp
index f8c0667..fb647a3 100644
--- a/src/platforms/esp32s3/gdma_lcd_parallel16.cpp
+++ b/src/platforms/esp32s3/gdma_lcd_parallel16.cpp
@@ -99,7 +99,7 @@
     //LCD_CAM.lcd_clock.clk_en = 0;             // Enable peripheral clock
 
     // LCD_CAM_LCD_CLK_SEL Select LCD module source clock. 0: clock source is disabled. 1: XTAL_CLK. 2: PLL_D2_CLK. 3: PLL_F160M_CLK. (R/W)
-    LCD_CAM.lcd_clock.lcd_clk_sel = 3;        // Use 160Mhz Clock Source
+    LCD_CAM.lcd_clock.lcd_clk_sel = 3;        // Use 160Mhz Clock Source -> PLL_F160M_CLK
     
     LCD_CAM.lcd_clock.lcd_ck_out_edge = 0;    // PCLK low in 1st half cycle
     LCD_CAM.lcd_clock.lcd_ck_idle_edge = 0;   // PCLK low idle
@@ -127,20 +127,20 @@
         //LCD_CAM.lcd_clock.lcd_clkm_div_num = 10; //16mhz is the fasted the Octal PSRAM can support it seems from faptastic's testing using an N8R8 variant (Octal SPI PSRAM).
         
         // https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-DMA/issues/441#issuecomment-1513631890
-        LCD_CAM.lcd_clock.lcd_clkm_div_num = 12; // 13Mhz is the fastest when the DMA memory is needed to service other peripherals as well.
+        LCD_CAM.lcd_clock.lcd_clkm_div_num = 12; // 13Mhz is about the fastest output from PSRAM if we want to be able to service other peripherals as well.
     }
     else
     {
 
       auto  freq     = (_cfg.bus_freq);
-
-      auto  _div_num = 8; // 20Mhz 
+      auto  _div_num = 20; // 8Mhzhz 
       if (freq < 20000000L) {
-            _div_num = 12; // 13Mhz
-      }
-      else if (freq > 20000000L) {
-            _div_num = 6; // 26Mhz --- likely to have noise without a good connection         
+            _div_num = 10; // 16Mhz
+      } else {
+            _div_num = 7; // 22Mhz --- likely to have noise without a good connection         
       }
+      
+      _div_num = 6;
 
       //LCD_CAM.lcd_clock.lcd_clkm_div_num = lcd_clkm_div_num;      
       LCD_CAM.lcd_clock.lcd_clkm_div_num = _div_num; //3;