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Diffstat (limited to 'drivers/serial/serial_pl011.c')
-rw-r--r--drivers/serial/serial_pl011.c161
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/serial/serial_pl011.c b/drivers/serial/serial_pl011.c
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+++ b/drivers/serial/serial_pl011.c
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+/*
+ * (C) Copyright 2000
+ * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
+ *
+ * (C) Copyright 2004
+ * ARM Ltd.
+ * Philippe Robin, <philippe.robin@arm.com>
+ *
+ * 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
+ */
+
+/* Simple U-Boot driver for the PrimeCell PL011 UARTs on the IntegratorCP */
+/* Should be fairly simple to make it work with the PL010 as well */
+
+#include <common.h>
+
+#ifdef CFG_PL011_SERIAL
+
+#include "serial_pl011.h"
+
+#define IO_WRITE(addr, val) (*(volatile unsigned int *)(addr) = (val))
+#define IO_READ(addr) (*(volatile unsigned int *)(addr))
+
+/*
+ * IntegratorCP has two UARTs, use the first one, at 38400-8-N-1
+ * Versatile PB has four UARTs.
+ */
+
+#define CONSOLE_PORT CONFIG_CONS_INDEX
+#define baudRate CONFIG_BAUDRATE
+static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
+#define NUM_PORTS (sizeof(port)/sizeof(port[0]))
+
+static void pl011_putc (int portnum, char c);
+static int pl011_getc (int portnum);
+static int pl011_tstc (int portnum);
+
+
+int serial_init (void)
+{
+ unsigned int temp;
+ unsigned int divider;
+ unsigned int remainder;
+ unsigned int fraction;
+
+ /*
+ ** First, disable everything.
+ */
+ IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR, 0x0);
+
+ /*
+ ** Set baud rate
+ **
+ ** IBRD = UART_CLK / (16 * BAUD_RATE)
+ ** FBRD = ROUND((64 * MOD(UART_CLK,(16 * BAUD_RATE))) / (16 * BAUD_RATE))
+ */
+ temp = 16 * baudRate;
+ divider = CONFIG_PL011_CLOCK / temp;
+ remainder = CONFIG_PL011_CLOCK % temp;
+ temp = (8 * remainder) / baudRate;
+ fraction = (temp >> 1) + (temp & 1);
+
+ IO_WRITE (port[CONSOLE_PORT] + UART_PL011_IBRD, divider);
+ IO_WRITE (port[CONSOLE_PORT] + UART_PL011_FBRD, fraction);
+
+ /*
+ ** Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled.
+ */
+ IO_WRITE (port[CONSOLE_PORT] + UART_PL011_LCRH,
+ (UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN));
+
+ /*
+ ** Finally, enable the UART
+ */
+ IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR,
+ (UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
+ UART_PL011_CR_RXE));
+
+ return 0;
+}
+
+void serial_putc (const char c)
+{
+ if (c == '\n')
+ pl011_putc (CONSOLE_PORT, '\r');
+
+ pl011_putc (CONSOLE_PORT, c);
+}
+
+void serial_puts (const char *s)
+{
+ while (*s) {
+ serial_putc (*s++);
+ }
+}
+
+int serial_getc (void)
+{
+ return pl011_getc (CONSOLE_PORT);
+}
+
+int serial_tstc (void)
+{
+ return pl011_tstc (CONSOLE_PORT);
+}
+
+void serial_setbrg (void)
+{
+}
+
+static void pl011_putc (int portnum, char c)
+{
+ /* Wait until there is space in the FIFO */
+ while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_TXFF);
+
+ /* Send the character */
+ IO_WRITE (port[portnum] + UART_PL01x_DR, c);
+}
+
+static int pl011_getc (int portnum)
+{
+ unsigned int data;
+
+ /* Wait until there is data in the FIFO */
+ while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_RXFE);
+
+ data = IO_READ (port[portnum] + UART_PL01x_DR);
+
+ /* Check for an error flag */
+ if (data & 0xFFFFFF00) {
+ /* Clear the error */
+ IO_WRITE (port[portnum] + UART_PL01x_ECR, 0xFFFFFFFF);
+ return -1;
+ }
+
+ return (int) data;
+}
+
+static int pl011_tstc (int portnum)
+{
+ return !(IO_READ (port[portnum] + UART_PL01x_FR) &
+ UART_PL01x_FR_RXFE);
+}
+
+#endif