altos/lpc: Get USART running

[fw/altos] / src / lpc / ao_serial_lpc.c

diff --git a/src/lpc/ao_serial_lpc.c b/src/lpc/ao_serial_lpc.c
index e47f743eec43ff9b73e751f226b256d06f9f81be..4ecaa175f0cc69f6da06bab4330bed758ee5d3d3 100644 (file)
--- a/src/lpc/ao_serial_lpc.c
+++ b/src/lpc/ao_serial_lpc.c
@@ -27,10 +27,9 @@ ao_debug_out(char c)
 {
        if (c == '\n')
                ao_debug_out('\r');
-#if 0
-       while (!(stm_usart1.sr & (1 << STM_USART_SR_TXE)));
-       stm_usart1.dr = c;
-#endif
+       while (!(lpc_usart.lsr & (1 << LPC_USART_LSR_TEMT)))
+               ;
+       lpc_usart.rbr_thr = c;
 }
 
 static void
@@ -39,35 +38,28 @@ _ao_serial_tx_start(void)
        if (!ao_fifo_empty(ao_usart_tx_fifo) & !ao_usart_tx_started)
        {
                ao_usart_tx_started = 1;
-#if 0
-               ao_fifo_remove(ao_usart_tx_fifo, usart->reg->dr);
-#endif
+               ao_fifo_remove(ao_usart_tx_fifo, lpc_usart.rbr_thr);
        }
 }
 
 void
 lpc_usart_isr(void)
 {
-#if 0
-       uint32_t        sr;
-
-       sr = usart->reg->sr;
-       usart->reg->sr = 0;
+       (void) lpc_usart.iir_fcr;
 
-       if (sr & (1 << STM_USART_SR_RXNE)) {
-               char c = usart->reg->dr;
+       while (lpc_usart.lsr & (1 << LPC_USART_LSR_RDR)) {
+               char c = lpc_usart.rbr_thr;
                if (!ao_fifo_full(ao_usart_rx_fifo))
                        ao_fifo_insert(ao_usart_rx_fifo, c);
-               ao_wakeup(ao_usart_rx_fifo);
+               ao_wakeup(&ao_usart_rx_fifo);
                if (stdin)
                        ao_wakeup(&ao_stdin_ready);
        }
-       if (sr & (1 << STM_USART_SR_TC)) {
+       if (lpc_usart.lsr & (1 << LPC_USART_LSR_THRE)) {
                ao_usart_tx_started = 0;
-               _ao_usart_tx_start(usart);
-               ao_wakeup(ao_usart_tx_fifo);
+               _ao_serial_tx_start();
+               ao_wakeup(&ao_usart_tx_fifo);
        }
-#endif
 }
 
 int
@@ -116,24 +108,33 @@ ao_serial_drain(void)
        ao_arch_release_interrupts();
 }
 
+#include "ao_serial_lpc.h"
+
 void
 ao_serial_set_speed(uint8_t speed)
 {
        if (speed > AO_SERIAL_SPEED_115200)
                return;
-#if 0
-       usart->reg->brr = ao_usart_speeds[speed].brr;
-#endif
-}
 
-#include "ao_serial_lpc.h"
+       /* Flip to allow access to divisor latches */
+       lpc_usart.lcr |= (1 << LPC_USART_LCR_DLAB);
+
+       /* DL LSB */
+       lpc_usart.rbr_thr = ao_usart_speeds[speed].dl & 0xff;
+       
+       /* DL MSB */
+       lpc_usart.ier = (ao_usart_speeds[speed].dl >> 8) & 0xff;
+
+       lpc_usart.fdr = ((ao_usart_speeds[speed].divaddval << LPC_USART_FDR_DIVADDVAL) |
+                        (ao_usart_speeds[speed].mulval << LPC_USART_FDR_MULVAL));
+
+       /* Turn access to divisor latches back off */
+       lpc_usart.lcr &= ~(1 << LPC_USART_LCR_DLAB);
+}
 
 void
 ao_serial_init(void)
 {
-       /* Turn on the USART clock */
-       lpc_scb.uartclkdiv = 1;
-
 #if SERIAL_0_18_19
        lpc_ioconf.pio0_18 = ((LPC_IOCONF_FUNC_PIO0_18_RXD << LPC_IOCONF_FUNC) |
                              (LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
@@ -149,6 +150,53 @@ ao_serial_init(void)
 
        /* Turn on the USART */
        lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_USART);
-}
-
 
+       /* Turn on the USART clock */
+       lpc_scb.uartclkdiv = AO_LPC_CLKOUT / AO_LPC_USARTCLK;
+
+       /* Configure USART */
+
+       /* Enable FIFOs, reset fifo contents, interrupt on 1 received char */
+       lpc_usart.iir_fcr = ((1 << LPC_USART_FCR_FIFOEN) |
+                        (1 << LPC_USART_FCR_RXFIFORES) |
+                        (1 << LPC_USART_FCR_TXFIFORES) |
+                        (LPC_USART_FCR_RXTL_1 << LPC_USART_FCR_RXTL));
+
+       /* 8 n 1 */
+       lpc_usart.lcr = ((LPC_USART_LCR_WLS_8 << LPC_USART_LCR_WLS) |
+                        (LPC_USART_LCR_SBS_1 << LPC_USART_LCR_SBS) |
+                        (0 << LPC_USART_LCR_PE) |
+                        (LPC_USART_LCR_PS_ODD << LPC_USART_LCR_PS) |
+                        (0 << LPC_USART_LCR_BC) |
+                        (0 << LPC_USART_LCR_DLAB));
+
+       /* Disable flow control */
+       lpc_usart.mcr = ((0 << LPC_USART_MCR_DTRCTRL) |
+                        (0 << LPC_USART_MCR_RTSCTRL) |
+                        (0 << LPC_USART_MCR_LMS) |
+                        (0 << LPC_USART_MCR_RTSEN) |
+                        (0 << LPC_USART_MCR_CTSEN));
+
+       /* 16x oversampling */
+       lpc_usart.osr = ((0 << LPC_USART_OSR_OSFRAC) |
+                        ((16 - 1) << LPC_USART_OSR_OSINT) |
+                        (0 << LPC_USART_OSR_FDINT));
+
+       /* Full duplex */
+       lpc_usart.hden = ((0 << LPC_USART_HDEN_HDEN));
+
+       /* Set baud rate */
+       ao_serial_set_speed(AO_SERIAL_SPEED_9600);
+
+       /* Enable interrupts */
+       lpc_usart.ier = ((1 << LPC_USART_IER_RBRINTEN) |
+                        (1 << LPC_USART_IER_THREINTEN));
+
+       lpc_nvic_set_enable(LPC_ISR_USART_POS);
+       lpc_nvic_set_priority(LPC_ISR_USART_POS, 0);
+#if USE_SERIAL_0_STDIN
+       ao_add_stdio(_ao_serial_pollchar,
+                    ao_serial_putchar,
+                    NULL);
+#endif
+}