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linux/include/asm-arm/arch-at91/uncompress.h
Guennadi Liakhovetski fa3218d859 [ARM] 4660/3: at91: allow selecting UART for early kernel messages
Currently early kernel messages, i.e., those from uncompression, go to the
debugging UART. And if it is enabled in the platform configuration, but
not initialized by the bootloader, the machine hangs, waiting for UART
status change. Besides, having those messages on another UART - typically
the console UART - may be preferrable. This patch allows selecting the
UART in kernel configuration.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-02-04 13:16:39 +00:00

77 lines
2.2 KiB
C

/*
* include/asm-arm/arch-at91/uncompress.h
*
* Copyright (C) 2003 SAN People
*
* 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
*/
#ifndef __ASM_ARCH_UNCOMPRESS_H
#define __ASM_ARCH_UNCOMPRESS_H
#include <asm/io.h>
#include <linux/atmel_serial.h>
#if defined(CONFIG_AT91_EARLY_DBGU)
#define UART_OFFSET (AT91_DBGU + AT91_BASE_SYS)
#elif defined(CONFIG_AT91_EARLY_USART0)
#define UART_OFFSET AT91_USART0
#elif defined(CONFIG_AT91_EARLY_USART1)
#define UART_OFFSET AT91_USART1
#elif defined(CONFIG_AT91_EARLY_USART2)
#define UART_OFFSET AT91_USART2
#elif defined(CONFIG_AT91_EARLY_USART3)
#define UART_OFFSET AT91_USART3
#elif defined(CONFIG_AT91_EARLY_USART4)
#define UART_OFFSET AT91_USART4
#elif defined(CONFIG_AT91_EARLY_USART5)
#define UART_OFFSET AT91_USART5
#endif
/*
* The following code assumes the serial port has already been
* initialized by the bootloader. If you didn't setup a port in
* your bootloader then nothing will appear (which might be desired).
*
* This does not append a newline
*/
static void putc(int c)
{
#ifdef UART_OFFSET
void __iomem *sys = (void __iomem *) UART_OFFSET; /* physical address */
while (!(__raw_readl(sys + ATMEL_US_CSR) & ATMEL_US_TXRDY))
barrier();
__raw_writel(c, sys + ATMEL_US_THR);
#endif
}
static inline void flush(void)
{
#ifdef UART_OFFSET
void __iomem *sys = (void __iomem *) UART_OFFSET; /* physical address */
/* wait for transmission to complete */
while (!(__raw_readl(sys + ATMEL_US_CSR) & ATMEL_US_TXEMPTY))
barrier();
#endif
}
#define arch_decomp_setup()
#define arch_decomp_wdog()
#endif