X-Git-Url: https://robinkrens.nl/gitweb/?a=blobdiff_plain;f=uart.c;h=86bf9fee596f202a9fed48fc9ab4b3aa09e8fb5b;hb=a4ce13373a288b4496299396e26c2608852b713f;hp=a3905c4e0cd4f0e1eb1533a16baf02ee9d1cc41b;hpb=3f9ee85c250250580f0ceb38525ddb99ebc6d36e;p=cortex-from-scratch

diff --git a/uart.c b/uart.c
index a3905c4..86bf9fe 100644
--- a/uart.c
+++ b/uart.c
@@ -4,14 +4,40 @@
 #include <stm32.h>
 #include <mmap.h>
 
+#define RXNE ((*USART1_SR >> 5) & 0x1)
+
+#define O_WRITE 0x01
+#define SET 0x02
+#define CLEAR 0x03
+
+void * uart_handler() {
+
+	uart_puts("echo: ");
+ 	while (RXNE) {
+		char echochar = *USART1_DR;
+		//regw_u32(USART1_DR, echochar, 0, O_WRITE);
+		uart_putc(echochar);
+	}
+	uart_putc('\n');
+      		
+
+}
 void uart_init() {
 
+	// global interrupt setup
+//	regw_u32(EXTI_IMR, 0x000FFFFF, 0, O_WRITE);
+//	regw_u32(EXTI_RTSR, 0x000FFFFF, 0, O_WRITE);
+
+		
+	regw_u32(RCC_APB2ENR, 0x4005, 0, SET);// enable clock to UART1, AFIO and GPIOA
 	
-	*RCC_APB2ENR = 0x4005; // enable clock to UART1, AFIO and GPIOA
-	*GPIOA_CRH = 0x444444D4; // (after enable GPIOA), on PA9&PA10 and set mode to alternative output
-	*AFIO_EVCR = 0x89; // (after enable) set event control register, output on PA, Pin 9
+	/* (after enable GPIOA), on PA9&PA10 and set mode
+	 *  to alternative output */
+	regw_u32(GPIOA_CRH, 0x444444D4, 0, O_WRITE);
+	regw_u8(AFIO_EVCR, 0x89, 0, O_WRITE);// set event control register, output on PA, Pin 9
 
-	*USART1_CR1 = (0 << 13); // disable temporarily to set values
+	//disable temporarily to set values
+	regw_u8(USART1_CR1, 0x0, 13, SET);
 
 	/* baud rate 115200,  8MHz / (16 * USARTDIV)
 	 * USARTDIV = 4.34
@@ -19,28 +45,17 @@ void uart_init() {
 	 * MANTISSA: 0d4.34 0d4 -> 0x4 
 	 * USART_BRR = 0x45*/
 
-	/* baud rate 2400 
-	 * 
-	 * 16 * 0.33 -> 0x5
-	 * 208 -> 0x34 */
-
-	*USART1_BRR = (volatile uint32_t) 0x00000045;
+	regw_u32(USART1_BRR, 0x00000045, 0, O_WRITE);
+	regw_u32(USART1_CR2, 0x0000, 0, O_WRITE); //set stop bit, default is 1 stop bit 0x00
 	
-	*USART1_CR2 = (volatile uint32_t) 0x0000; // set stop bit, default is 1 stop bit 0x00
-	// enable DMA 
-	// *USART1_CR3 = 0x0C0; 
 	/* parity = 8 bit, UART1 enabled,
 	 * TX and RX enabled, interrupts enabled */
-	*USART1_CR1 = (volatile uint32_t) 0x000030AC; 
-
-/* 
- * Configure UART0:
-	1. Disable the UART by clearing the UARTEN bit in the UARTCTL register.
-	2. Write the integer portion of the BRD to the UARTIBRD register.
-	3. Write the fractional portion of the BRD to the UARTFBRD register.
-	4. Write the desired serial parameters to the UARTLCRH register
-	5. Enable the UART by setting the UARTEN bit in the UARTCTL register.
-*/
+	//regw_u32(USART1_CR1, 0x000030AC, 0, O_WRITE);
+	regw_u32(USART1_CR1, 0x0000302C, 0, O_WRITE);
+
+	ivt_set_gate(53, uart_handler, 0);
+	
+	*NVIC_ISER1 = (1 << 5); // Enable UART interrupt at NVIC
 }
 
 void wait() {
@@ -51,34 +66,33 @@ extern void uart_putc(unsigned char ch) {
 	
   	if (ch == '\n') {
 		while (*USART1_SR & 0x0C) { } // transmit data register empty and complete
-		*USART1_DR = 0x0D; // return line
+		regw_u8(USART1_DR, 0x0D, 0, O_WRITE); // return line
 	}
 
-
 	while (*USART1_SR & 0x0C) {} 
-		*USART1_DR = ch;
-
+		regw_u8(USART1_DR, ch, 0, O_WRITE);
 
-	
 	wait();
 }
 
-extern void uart_puts(unsigned char *str)
-{
-
+extern void uart_puts(unsigned char *str) {
     int i;
-
-    for (i = 0; i < strlen(str); i++)
-    {
+    for (i = 0; i < strlen(str); i++)     {
         uart_putc(str[i]);
     }
 }
 
 
 
-char * uart_read() {
+char uart_read() { 
 
-	return NULL;
+	/* while (buffer not empty)
+	 * 	read()
+	 * 	uart_putc(ch) // echo
+	 * 		if ch = enter
+	 * 		process inquiry.
+	 */
+	
 }