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Diffstat (limited to 'arch/mips/cpu/au1x00_serial.c')
-rw-r--r--arch/mips/cpu/au1x00_serial.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/arch/mips/cpu/au1x00_serial.c b/arch/mips/cpu/au1x00_serial.c
new file mode 100644
index 0000000..c25ba5a
--- /dev/null
+++ b/arch/mips/cpu/au1x00_serial.c
@@ -0,0 +1,131 @@
+/*
+ * AU1X00 UART support
+ *
+ * Hardcoded to UART 0 for now
+ * Speed and options also hardcoded to 115200 8N1
+ *
+ * Copyright (c) 2003 Thomas.Lange@corelatus.se
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <config.h>
+#include <common.h>
+#include <asm/au1x00.h>
+
+/******************************************************************************
+*
+* serial_init - initialize a channel
+*
+* This routine initializes the number of data bits, parity
+* and set the selected baud rate. Interrupts are disabled.
+* Set the modem control signals if the option is selected.
+*
+* RETURNS: N/A
+*/
+
+int serial_init (void)
+{
+ volatile u32 *uart_fifoctl = (volatile u32*)(UART0_ADDR+UART_FCR);
+ volatile u32 *uart_enable = (volatile u32*)(UART0_ADDR+UART_ENABLE);
+
+ /* Enable clocks first */
+ *uart_enable = UART_EN_CE;
+
+ /* Then release reset */
+ /* Must release reset before setting other regs */
+ *uart_enable = UART_EN_CE|UART_EN_E;
+
+ /* Activate fifos, reset tx and rx */
+ /* Set tx trigger level to 12 */
+ *uart_fifoctl = UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|
+ UART_FCR_CLEAR_XMIT|UART_FCR_T_TRIGGER_12;
+
+ serial_setbrg();
+
+ return 0;
+}
+
+
+void serial_setbrg (void)
+{
+ volatile u32 *uart_clk = (volatile u32*)(UART0_ADDR+UART_CLK);
+ volatile u32 *uart_lcr = (volatile u32*)(UART0_ADDR+UART_LCR);
+ volatile u32 *sys_powerctrl = (u32 *)SYS_POWERCTRL;
+ int sd;
+ int divisorx2;
+
+ /* sd is system clock divisor */
+ /* see section 10.4.5 in au1550 datasheet */
+ sd = (*sys_powerctrl & 0x03) + 2;
+
+ /* calulate 2x baudrate and round */
+ divisorx2 = ((CONFIG_SYS_MIPS_TIMER_FREQ/(sd * 16 * CONFIG_BAUDRATE)));
+
+ if (divisorx2 & 0x01)
+ divisorx2 = divisorx2 + 1;
+
+ *uart_clk = divisorx2 / 2;
+
+ /* Set parity, stop bits and word length to 8N1 */
+ *uart_lcr = UART_LCR_WLEN8;
+}
+
+void serial_putc (const char c)
+{
+ volatile u32 *uart_lsr = (volatile u32*)(UART0_ADDR+UART_LSR);
+ volatile u32 *uart_tx = (volatile u32*)(UART0_ADDR+UART_TX);
+
+ if (c == '\n') serial_putc ('\r');
+
+ /* Wait for fifo to shift out some bytes */
+ while((*uart_lsr&UART_LSR_THRE)==0);
+
+ *uart_tx = (u32)c;
+}
+
+void serial_puts (const char *s)
+{
+ while (*s)
+ {
+ serial_putc (*s++);
+ }
+}
+
+int serial_getc (void)
+{
+ volatile u32 *uart_rx = (volatile u32*)(UART0_ADDR+UART_RX);
+ char c;
+
+ while (!serial_tstc());
+
+ c = (*uart_rx&0xFF);
+ return c;
+}
+
+int serial_tstc (void)
+{
+ volatile u32 *uart_lsr = (volatile u32*)(UART0_ADDR+UART_LSR);
+
+ if(*uart_lsr&UART_LSR_DR){
+ /* Data in rfifo */
+ return(1);
+ }
+ return 0;
+}