Expand IRQ handling for CH32x00x models and add dual USART example

ch32fun/ch32fun.c

@@ -920,6 +920,7 @@ void I2C2_ER_IRQHandler( void )			__attribute__((section(VECTOR_HANDLER_SECTION)
 void SPI2_IRQHandler( void )			__attribute__((section(VECTOR_HANDLER_SECTION))) __attribute((weak,alias("DefaultIRQHandler"))) __attribute__((used));
 void USART1_IRQHandler( void )			__attribute__((section(VECTOR_HANDLER_SECTION))) __attribute((weak,alias("DefaultIRQHandler"))) __attribute__((used));
 void USART2_IRQHandler( void )			__attribute__((section(VECTOR_HANDLER_SECTION))) __attribute((weak,alias("DefaultIRQHandler"))) __attribute__((used));
+void OPCM_IRQHandler( void )			__attribute__((section(VECTOR_HANDLER_SECTION))) __attribute((weak,alias("DefaultIRQHandler"))) __attribute__((used));
 void USART3_IRQHandler( void )			__attribute__((section(VECTOR_HANDLER_SECTION))) __attribute((weak,alias("DefaultIRQHandler"))) __attribute__((used));
 void EXTI15_10_IRQHandler( void )		__attribute__((section(VECTOR_HANDLER_SECTION))) __attribute((weak,alias("DefaultIRQHandler"))) __attribute__((used));
 void RTCAlarm_IRQHandler( void )		__attribute__((section(VECTOR_HANDLER_SECTION))) __attribute((weak,alias("DefaultIRQHandler"))) __attribute__((used));

ch32fun/ch32x00xhw.h

@@ -95,7 +95,9 @@ typedef enum IRQn
 	.word   TIM1_TRG_COM_IRQHandler   /* TIM1 Trigger and Commutation */   \n\
 	.word   TIM1_CC_IRQHandler        /* TIM1 Capture Compare */           \n\
 	.word   TIM2_IRQHandler           /* TIM2 */                           \n\
-	.option   pop;\n"
+	.word   USART2_IRQHandler         /* USART2 */                         \n\
+    .word   OPCM_IRQHandler           /* OPCM */                           \n\
+    .option   pop;\n"
 
 
 /* memory mapped structure for SysTick */

examples_x00x/Readme.md

@@ -1,3 +1,7 @@
 # Examples for the CH32V002/4/5/6/7 and CH32M007 chips
 
 Examples which are different from the default CH32V003 examples will be here.  Each example may only work on a subset of the chips as they may depend on features not available in all members.  Examples should target the chip with the lowest feature set which support the given example.  Examples *should* work on all higher members even if the target is a lower member of the family.
+
+## dual_usart
+
+Demonstrates simultaneous use of USART1 and USART2 on CH32V00x parts with configurable pin remap, frame format, and baud-rate macros.

examples_x00x/dual_usart/Makefile

@@ -0,0 +1,9 @@
+all : flash
+
+TARGET:=dual_usart
+
+TARGET_MCU?=CH32V006
+include ../../ch32fun/ch32fun.mk
+
+flash : cv_flash
+clean : cv_clean

examples_x00x/dual_usart/dual_usart.c

@@ -0,0 +1,212 @@
+/*
+ * Example for using USART1 and USART2 on CH32V00x parts.
+ * Default configuration uses:
+ *   USART1: PD5 TX, PD6 RX, remap value 0, 115200 8N1
+ *   USART2: PD2 TX, PD3 RX, remap value 3, 115200 8N1
+ *
+ * Intended user-tunable defines in this file are:
+ *   USE_USART1 / USE_USART2
+ *   USART1_TX_PIN / USART1_RX_PIN
+ *   USART2_TX_PIN / USART2_RX_PIN
+ *   USART1_BAUD / USART2_BAUD
+ *   USART1_CTLR1_FORMAT / USART1_CTLR2_FORMAT
+ *   USART2_CTLR1_FORMAT / USART2_CTLR2_FORMAT
+ *   USART1_RM_VALUE / USART2_RM_VALUE
+ *
+ * Do not change USART1_RM_SHIFT or USART2_RM_SHIFT. Those are fixed bit
+ * positions of the remap fields inside AFIO->PCFR1 on CH32V00x hardware.
+ */
+
+#include "ch32fun.h"
+#include <stdio.h>
+
+#ifndef USE_USART1
+#define USE_USART1         1
+#endif
+
+#ifndef USE_USART2
+#define USE_USART2         1
+#endif
+
+#if !USE_USART1 && !USE_USART2
+#error At least one of USE_USART1 or USE_USART2 must be enabled.
+#endif
+
+#ifndef USART1_TX_PIN
+#define USART1_TX_PIN       PD5
+#endif
+
+#ifndef USART1_RX_PIN
+#define USART1_RX_PIN       PD6
+#endif
+
+#ifndef USART2_TX_PIN
+#define USART2_TX_PIN       PD2
+#endif
+
+#ifndef USART2_RX_PIN
+#define USART2_RX_PIN       PD3
+#endif
+
+#ifndef USART1_BAUD
+#define USART1_BAUD         115200UL
+#endif
+
+#ifndef USART2_BAUD
+#define USART2_BAUD         115200UL
+#endif
+
+// These CTLR1/CTLR2 defaults implement 8N1 on each port:
+// - 8 data bits: no USART_CTLR1_M bit
+// - no parity: no USART_CTLR1_PCE bit
+// - 1 stop bit: USART_StopBits_1
+// Override these if you want a different framing such as 8E1.
+#ifndef USART1_CTLR1_FORMAT
+#define USART1_CTLR1_FORMAT (USART_Mode_Tx | USART_Mode_Rx)
+#endif
+
+#ifndef USART1_CTLR2_FORMAT
+#define USART1_CTLR2_FORMAT USART_StopBits_1
+#endif
+
+#ifndef USART2_CTLR1_FORMAT
+#define USART2_CTLR1_FORMAT (USART_Mode_Tx | USART_Mode_Rx)
+#endif
+
+#ifndef USART2_CTLR2_FORMAT
+#define USART2_CTLR2_FORMAT USART_StopBits_1
+#endif
+
+// Do not edit these shift constants. They are derived from the CH32V00x AFIO
+// register layout: USART1 remap lives in PCFR1 bits 9:6 and USART2 remap
+// lives in bits 22:20, so the remap values must be shifted into those exact
+// positions before writing the register.
+#define USART1_RM_SHIFT     6u
+#define USART2_RM_SHIFT     20u
+
+#ifndef USART1_RM_VALUE
+// This is user-configurable. Remap value 0 keeps USART1 on its default
+// routing, which for this example is TX on PD5 and RX on PD6.
+#define USART1_RM_VALUE     0u
+#endif
+
+#ifndef USART2_RM_VALUE
+// This is user-configurable. Remap value 3 selects the routing used by the
+// working CH32V006 dual-UART setup in this repository: USART2 TX on PD2 and
+// RX on PD3.
+#define USART2_RM_VALUE     3u
+#endif
+
+static void usart_write_byte(USART_TypeDef *usart, uint8_t byte)
+{
+	// TXE indicates that the transmit data register is empty and can accept
+	// the next byte.
+	while((usart->STATR & USART_STATR_TXE) == 0u)
+		;
+	usart->DATAR = byte;
+}
+
+static void usart_write_string(USART_TypeDef *usart, const char *text)
+{
+	// Keep the helper simple: send characters until the terminating '\0'.
+	while(*text != '\0')
+		usart_write_byte(usart, (uint8_t)*text++);
+}
+
+static void usart_init(USART_TypeDef *usart, uint32_t baud, uint32_t ctlr1_format, uint32_t ctlr2_format)
+{
+	// Reset the control registers to a known state before programming the
+	// framing and baud rate.
+	usart->CTLR1 = 0;
+	usart->CTLR2 = ctlr2_format;
+	usart->CTLR3 = 0;
+	usart->BRR = (FUNCONF_SYSTEM_CORE_CLOCK + (baud / 2u)) / baud;
+
+	// The caller provides the frame format bits for this port. UE is added
+	// here so every configuration path still enables the peripheral.
+	usart->CTLR1 = ctlr1_format | USART_CTLR1_UE;
+}
+
+static void configure_dual_usart_remap(void)
+{
+	uint32_t pcfr1 = AFIO->PCFR1;
+
+	// Clear the existing USART remap fields first so the example can be
+	// retargeted by changing only USART1_RM_VALUE / USART2_RM_VALUE.
+	pcfr1 &= ~(AFIO_PCFR1_USART1_RM | AFIO_PCFR1_USART2_RM);
+#if USE_USART1
+	pcfr1 |= (USART1_RM_VALUE << USART1_RM_SHIFT);
+#endif
+#if USE_USART2
+	pcfr1 |= (USART2_RM_VALUE << USART2_RM_SHIFT);
+#endif
+	AFIO->PCFR1 = pcfr1;
+}
+
+static void gpio_setup(void)
+{
+	// AFIO must be enabled before changing remap settings. GPIOD carries the
+	// default example UART pins for both serial ports.
+	RCC->APB2PCENR |= RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOD;
+	configure_dual_usart_remap();
+
+	// TX pins use alternate-function push-pull. RX pins are plain inputs.
+#if USE_USART1
+	funPinMode(USART1_TX_PIN, GPIO_CFGLR_OUT_10Mhz_AF_PP);
+	funPinMode(USART1_RX_PIN, GPIO_CFGLR_IN_FLOAT);
+#endif
+#if USE_USART2
+	funPinMode(USART2_TX_PIN, GPIO_CFGLR_OUT_10Mhz_AF_PP);
+	funPinMode(USART2_RX_PIN, GPIO_CFGLR_IN_FLOAT);
+#endif
+}
+
+static void usart_setup(void)
+{
+	// Enable only the UART clocks that are actually used by this build.
+#if USE_USART1
+	RCC->APB2PCENR |= RCC_APB2Periph_USART1;
+	usart_init(USART1, USART1_BAUD, USART1_CTLR1_FORMAT, USART1_CTLR2_FORMAT);
+#endif
+#if USE_USART2
+	RCC->APB2PCENR |= RCC_APB2Periph_USART2;
+	usart_init(USART2, USART2_BAUD, USART2_CTLR1_FORMAT, USART2_CTLR2_FORMAT);
+#endif
+}
+
+int main(void)
+{
+	uint32_t counter = 0;
+	char message[80];
+
+	SystemInit();
+	gpio_setup();
+	usart_setup();
+
+	// Send a startup banner on each enabled port so it is immediately obvious
+	// which UARTs are active in the current build.
+#if USE_USART1
+	usart_write_string(USART1, "\r\nCH32V00x dual_usart example\r\n");
+	usart_write_string(USART1, "USART1 ready\r\n");
+#endif
+#if USE_USART2
+	usart_write_string(USART2, "\r\nCH32V00x dual_usart example\r\n");
+	usart_write_string(USART2, "USART2 ready\r\n");
+#endif
+
+	while(1)
+	{
+#if USE_USART1
+		snprintf(message, sizeof(message), "tick %lu via USART1\r\n", counter);
+		usart_write_string(USART1, message);
+#endif
+
+#if USE_USART2
+		snprintf(message, sizeof(message), "tick %lu via USART2\r\n", counter);
+		usart_write_string(USART2, message);
+#endif
+
+		counter++;
+		Delay_Ms(1000);
+	}
+}

examples_x00x/dual_usart/funconfig.h

@@ -0,0 +1,7 @@
+#ifndef _FUNCONFIG_H
+#define _FUNCONFIG_H
+
+// Place configuration items here, you can see a full list in ch32fun/ch32fun.h
+// To reconfigure to a different processor, update TARGET_MCU in the  Makefile
+
+#endif