forgotten files

[rpikern] / src / serial.c

diff --git a/src/serial.c b/src/serial.c
new file mode 100644 (file)
index 0000000..ddd5923
--- /dev/null
+++ b/src/serial.c
@@ -0,0 +1,54 @@
+#include <stdint.h>
+#include "serial.h"
+#include "uart.h"
+#include "gpio.h"
+
+/* baud rate: BAUDDIV = (UART_CLK / (16 * baud)) */
+#define UART_CLK       3000000
+
+void init_serial(int baud)
+{
+       uint32_t bdiv_fp6;
+
+       REG_CR = 0;             /* disable UART */
+
+       /* disable pullups for GPIO 14 & 15 */
+       gpio_pullups(0xc000, 0, PUD_DISABLE);
+
+       REG_ICR = 0;    /* clear pending interrupts */
+
+       /* calculate baud rate divisor */
+       bdiv_fp6 = (UART_CLK << 6) / (16 * baud);
+       REG_IBRD = (bdiv_fp6 >> 6) & 0xffff;    /* 16 bits integer part */
+       REG_FBRD = bdiv_fp6 & 0x3f;             /* 6 bits fractional precision */
+
+       /* line control: fifo enable, 8n1 */
+       REG_LCRH = LCRH_FIFOEN | LCRH_8BITS;
+       /* mask all interrupts */
+       REG_IMSC = I_CTS | I_RX | I_TX | I_RTIME | I_FRM | I_PAR | I_BRK | I_OVR;
+
+       /* enable UART RX&TX */
+       REG_CR = CR_UARTEN | CR_TXEN | CR_RXEN;
+}
+
+void ser_putchar(int c)
+{
+       while(REG_FR & FR_TXFF);
+       REG_DR = c & 0xff;
+}
+
+int ser_getchar(void)
+{
+       while(REG_FR & FR_RXFE);
+       return REG_DR & 0xff;
+}
+
+void ser_printstr(const char *s)
+{
+       while(*s) {
+               if(*s == '\n') {
+                       ser_putchar('\r');
+               }
+               ser_putchar(*s++);
+       }
+}