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 NUM_PORTS 2
#define CONSOLE_PORT CONFIG_CONS_INDEX
#define baudRate CONFIG_BAUDRATE
static volatile unsigned char * const port[NUM_PORTS] = {(void*)(CFG_SERIAL0),
(void*)(CFG_SERIAL1)};
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))
*/
#ifdef CONFIG_VERSATILE
temp = 16 * baudRate;
divider = 24000000 / temp;
remainder = 24000000 % temp;
temp = (8 * remainder) / baudRate;
fraction = (temp >> 1) + (temp & 1);
#endif
#ifdef CONFIG_INTEGRATOR
temp = 16 * baudRate;
divider = 14745600 / temp;
remainder = 14745600 % temp;
temp = (8 * remainder) / baudRate;
fraction = (temp >> 1) + (temp & 1);
#endif
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