From 9d71a62a71b6bf1e790adb04fb087b1482b366b3 Mon Sep 17 00:00:00 2001
From: cnlohr <lohr85@gmail.com>
Date: Wed, 2 Aug 2023 13:58:39 -0400
Subject: [PATCH] * Add code to modify INTSYSCR to ch32v003fun * Allow
interrupt preemption in WS2812B driver. * Add simple driver for ws2812b's.
---
ch32v003fun/ch32v003fun.h | 12 ++++
extralibs/ws2812b_dma_spi_led_driver.h | 12 +++-
extralibs/ws2812b_simple.h | 88 ++++++++++++++++++++++++++
3 files changed, 111 insertions(+), 1 deletion(-)
create mode 100644 extralibs/ws2812b_simple.h
diff --git a/ch32v003fun/ch32v003fun.h b/ch32v003fun/ch32v003fun.h
index 3e07c24..bea67b2 100644
--- a/ch32v003fun/ch32v003fun.h
+++ b/ch32v003fun/ch32v003fun.h
@@ -4789,6 +4789,18 @@ RV_STATIC_INLINE void NVIC_SystemReset(void)
NVIC->CFGR = NVIC_KEY3|(1<<7);
}
+// For configuring INTSYSCR, for interrupt nesting + hardware stack enable.
+static inline uint32_t __get_INTSYSCR(void)
+{
+ uint32_t result;
+ asm volatile("csrr %0, 0x804": "=r"(result));
+ return (result);
+}
+
+static inline void __set_INTSYSCR( uint32_t value )
+{
+ asm volatile("csrw 0x804, %0" : : "r"(value));
+}
/*********************************************************************
diff --git a/extralibs/ws2812b_dma_spi_led_driver.h b/extralibs/ws2812b_dma_spi_led_driver.h
index 433fff7..115fea5 100644
--- a/extralibs/ws2812b_dma_spi_led_driver.h
+++ b/extralibs/ws2812b_dma_spi_led_driver.h
@@ -3,13 +3,18 @@
to generate outputs very efficiently. So, for now, SPI Port. Additionally, it uses FAR less
internal bus resources than to do the same thing with timers.
- For the CH32V003 this means output will be on PORTC Pin 6
+ **For the CH32V003 this means output will be on PORTC Pin 6**
Copyright 2023 <>< Charles Lohr, under the MIT-x11 or NewBSD License, you choose!
If you are including this in main, simply
#define WS2812DMA_IMPLEMENTATION
+ Other defines inclue:
+ #define WSRBG
+ #define WSGRB
+ #define ALLOW_INTERRUPT_NESTING
+
You will need to implement the following two functions, as callbacks from the ISR.
uint32_t WS2812BLEDCallback( int ledno );
@@ -219,6 +224,11 @@ void WS2812BDMAInit( )
// NVIC_SetPriority( DMA1_Channel3_IRQn, 0<<4 ); //We don't need to tweak priority.
NVIC_EnableIRQ( DMA1_Channel3_IRQn );
DMA1_Channel3->CFGR |= DMA_CFGR1_EN;
+
+#ifdef ALLOW_INTERRUPT_NESTING
+ __set_INTSYSCR( 2 ); // Enable interrupt nesting.
+ PFIC->IPRIOR[24] = 0b10000000; // Turn on preemption for DMA1Ch3
+#endif
}
#endif
diff --git a/extralibs/ws2812b_simple.h b/extralibs/ws2812b_simple.h
new file mode 100644
index 0000000..8c569fe
--- /dev/null
+++ b/extralibs/ws2812b_simple.h
@@ -0,0 +1,88 @@
+/* Single-File-Header for using asynchronous LEDs with the CH32V003 using DMA to the SPI port.
+ I may write another version of this to use DMA to timer ports, but, the SPI port can be used
+ to generate outputs very efficiently. So, for now, SPI Port. Additionally, it uses FAR less
+ internal bus resources than to do the same thing with timers.
+
+ For the CH32V003 this means output will be on PORTC Pin 6
+
+ Copyright 2023 <>< Charles Lohr, under the MIT-x11 or NewBSD License, you choose!
+
+ If you are including this in main, simply
+ #define WS2812BSIMPLE_IMPLEMENTATION
+
+ You may also want to define
+ #define WS2812BSIMPLE_NO_IRQ_TWEAKING
+
+*/
+
+#ifndef _WS2812B_SIMPLE
+#define _WS2812B_SIMPLE
+
+#include <stdint.h>
+
+void WS2812BSimpleSend( GPIO_TypeDef * port, int pin, uint8_t * data, int len_in_bytes );
+
+#ifdef WS2812BSIMPLE_IMPLEMENTATION
+
+#include "funconfig.h"
+
+#if FUNCONF_SYSTICK_USE_HCLK != 1
+#error WS2812B Driver Requires FUNCONF_SYSTICK_USE_HCLK
+#endif
+
+void WS2812BSimpleSend( GPIO_TypeDef * port, int pin, uint8_t * data, int len_in_bytes )
+{
+ int port_id = (((intptr_t)port-(intptr_t)GPIOA)>>10);
+ RCC->APB2PCENR |= (RCC_APB2Periph_GPIOA<<port_id); // Make sure port is enabled.
+
+ int poffset = (pin*4);
+ port->CFGLR = ( port->CFGLR & (~(0xf<<poffset))) | ((GPIO_Speed_2MHz | GPIO_CNF_OUT_PP)<<(poffset));
+
+ int maskon = 1<<pin;
+ int maskoff = 1<<(16+pin);
+
+ port->BSHR = maskoff;
+
+ uint8_t * end = data + len_in_bytes;
+ while( data != end )
+ {
+ uint8_t byte = *data;
+
+ int i;
+ for( i = 0; i < 8; i++ )
+ {
+ if( byte & 0x80 )
+ {
+ // WS2812B's need AT LEAST 625ns for a logical "1"
+ port->BSHR = maskon;
+ DelaySysTick(25);
+ port->BSHR = maskoff;
+ DelaySysTick(1);
+ }
+ else
+ {
+ // WS2812B's need BETWEEN 62.5 to about 500 ns for a logical "0"
+#ifndef WS2812BSIMPLE_NO_IRQ_TWEAKING
+ __disable_irq();
+#endif
+ port->BSHR = maskon;
+ asm volatile( "nop\nnop\nnop\nnop" );
+ port->BSHR = maskoff;
+#ifndef WS2812BSIMPLE_NO_IRQ_TWEAKING
+ __enable_irq();
+#endif
+ DelaySysTick(15);
+ }
+ byte <<= 1;
+ }
+
+ data++;
+ }
+
+ port->BSHR = maskoff;
+}
+
+#endif
+
+#endif
+
--
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