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/*
* Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/** @file
*
* 16550-compatible UART
*
*/
#include <errno.h>
#include <ipxe/uart.h>
/** UART port bases */
static uint16_t uart_base[] = {
[COM1] = 0x3f8,
[COM2] = 0x2f8,
[COM3] = 0x3e8,
[COM4] = 0x2e8,
};
/**
* Select UART port
*
* @v uart UART
* @v port Port number, or 0 to disable
* @ret rc Return status code
*/
int uart_select ( struct uart *uart, unsigned int port ) {
int rc;
/* Set new UART base */
if ( port >= ( sizeof ( uart_base ) / sizeof ( uart_base[0] ) ) ) {
rc = -ENODEV;
goto err;
}
uart->base = ( ( void * ) ( intptr_t ) uart_base[port] );
/* Check that UART exists */
if ( ( rc = uart_exists ( uart ) ) != 0 )
goto err;
return 0;
err:
uart->base = NULL;
return rc;
}
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