mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-16 01:38:22 +00:00
2956532625
It can be optimised out by the compiler otherwise resulting in obscure errors like a board not booting. This has been documented in README since 2006 when these were first fixed up for GCC 4.x. Signed-off-by: John Rigby <john.rigby@linaro.org> Fix some additional places. Signed-off-by: Wolfgang Denk <wd@denx.de> Acked-By: Albert ARIBAUD <albert.aribaud@free.fr>
173 lines
3.5 KiB
C
173 lines
3.5 KiB
C
/*
|
|
* (C) Copyright 2002
|
|
* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
|
|
*
|
|
* (C) Copyright 2008
|
|
* Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
|
|
*
|
|
* 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 <common.h>
|
|
|
|
#include <asm/arch/s3c6400.h>
|
|
|
|
DECLARE_GLOBAL_DATA_PTR;
|
|
|
|
#ifdef CONFIG_SERIAL1
|
|
#define UART_NR S3C64XX_UART0
|
|
|
|
#elif defined(CONFIG_SERIAL2)
|
|
#define UART_NR S3C64XX_UART1
|
|
|
|
#elif defined(CONFIG_SERIAL3)
|
|
#define UART_NR S3C64XX_UART2
|
|
|
|
#else
|
|
#error "Bad: you didn't configure serial ..."
|
|
#endif
|
|
|
|
#define barrier() asm volatile("" ::: "memory")
|
|
|
|
/*
|
|
* The coefficient, used to calculate the baudrate on S3C6400 UARTs is
|
|
* calculated as
|
|
* C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
|
|
* however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
|
|
* 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
|
|
*/
|
|
static const int udivslot[] = {
|
|
0,
|
|
0x0080,
|
|
0x0808,
|
|
0x0888,
|
|
0x2222,
|
|
0x4924,
|
|
0x4a52,
|
|
0x54aa,
|
|
0x5555,
|
|
0xd555,
|
|
0xd5d5,
|
|
0xddd5,
|
|
0xdddd,
|
|
0xdfdd,
|
|
0xdfdf,
|
|
0xffdf,
|
|
};
|
|
|
|
void serial_setbrg(void)
|
|
{
|
|
s3c64xx_uart *const uart = s3c64xx_get_base_uart(UART_NR);
|
|
u32 pclk = get_PCLK();
|
|
u32 baudrate = gd->baudrate;
|
|
int i;
|
|
|
|
i = (pclk / baudrate) % 16;
|
|
|
|
uart->UBRDIV = pclk / baudrate / 16 - 1;
|
|
uart->UDIVSLOT = udivslot[i];
|
|
|
|
for (i = 0; i < 100; i++)
|
|
barrier();
|
|
}
|
|
|
|
/*
|
|
* Initialise the serial port with the given baudrate. The settings
|
|
* are always 8 data bits, no parity, 1 stop bit, no start bits.
|
|
*/
|
|
int serial_init(void)
|
|
{
|
|
s3c64xx_uart *const uart = s3c64xx_get_base_uart(UART_NR);
|
|
|
|
/* reset and enable FIFOs, set triggers to the maximum */
|
|
uart->UFCON = 0xff;
|
|
uart->UMCON = 0;
|
|
/* 8N1 */
|
|
uart->ULCON = 3;
|
|
/* No interrupts, no DMA, pure polling */
|
|
uart->UCON = 5;
|
|
|
|
serial_setbrg();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Read a single byte from the serial port. Returns 1 on success, 0
|
|
* otherwise. When the function is succesfull, the character read is
|
|
* written into its argument c.
|
|
*/
|
|
int serial_getc(void)
|
|
{
|
|
s3c64xx_uart *const uart = s3c64xx_get_base_uart(UART_NR);
|
|
|
|
/* wait for character to arrive */
|
|
while (!(uart->UTRSTAT & 0x1));
|
|
|
|
return uart->URXH & 0xff;
|
|
}
|
|
|
|
#ifdef CONFIG_MODEM_SUPPORT
|
|
static int be_quiet;
|
|
void disable_putc(void)
|
|
{
|
|
be_quiet = 1;
|
|
}
|
|
|
|
void enable_putc(void)
|
|
{
|
|
be_quiet = 0;
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* Output a single byte to the serial port.
|
|
*/
|
|
void serial_putc(const char c)
|
|
{
|
|
s3c64xx_uart *const uart = s3c64xx_get_base_uart(UART_NR);
|
|
|
|
#ifdef CONFIG_MODEM_SUPPORT
|
|
if (be_quiet)
|
|
return;
|
|
#endif
|
|
|
|
/* wait for room in the tx FIFO */
|
|
while (!(uart->UTRSTAT & 0x2));
|
|
|
|
uart->UTXH = c;
|
|
|
|
/* If \n, also do \r */
|
|
if (c == '\n')
|
|
serial_putc('\r');
|
|
}
|
|
|
|
/*
|
|
* Test whether a character is in the RX buffer
|
|
*/
|
|
int serial_tstc(void)
|
|
{
|
|
s3c64xx_uart *const uart = s3c64xx_get_base_uart(UART_NR);
|
|
|
|
return uart->UTRSTAT & 0x1;
|
|
}
|
|
|
|
void serial_puts(const char *s)
|
|
{
|
|
while (*s)
|
|
serial_putc(*s++);
|
|
}
|