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arm_dcc.c

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  • Forked from Reform / reform-boundary-uboot
    29231 commits behind the upstream repository.
    arm_dcc.c 3.56 KiB
    /*
     * Copyright (C) 2004-2007 ARM Limited.
     * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
     *
     * This program is free software; you can redistribute it and/or
     * modify it under the terms of the GNU General Public License version 2
     * as published by the Free Software Foundation.
     *
     * 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
     *
     * As a special exception, if other files instantiate templates or use macros
     * or inline functions from this file, or you compile this file and link it
     * with other works to produce a work based on this file, this file does not
     * by itself cause the resulting work to be covered by the GNU General Public
     * License. However the source code for this file must still be made available
     * in accordance with section (3) of the GNU General Public License.
    
     * This exception does not invalidate any other reasons why a work based on
     * this file might be covered by the GNU General Public License.
     */
    
    #include <common.h>
    #include <serial.h>
    
    #if defined(CONFIG_CPU_V6)
    /*
     * ARMV6
     */
    #define DCC_RBIT	(1 << 30)
    #define DCC_WBIT	(1 << 29)
    
    #define write_dcc(x)	\
    		__asm__ volatile ("mcr p14, 0, %0, c0, c5, 0\n" : : "r" (x))
    
    #define read_dcc(x)	\
    		__asm__ volatile ("mrc p14, 0, %0, c0, c5, 0\n" : "=r" (x))
    
    #define status_dcc(x)	\
    		__asm__ volatile ("mrc p14, 0, %0, c0, c1, 0\n" : "=r" (x))
    
    #elif defined(CONFIG_CPU_XSCALE)
    /*
     * XSCALE
     */
    #define DCC_RBIT	(1 << 31)
    #define DCC_WBIT	(1 << 28)
    
    #define write_dcc(x)	\
    		__asm__ volatile ("mcr p14, 0, %0, c8, c0, 0\n" : : "r" (x))
    
    #define read_dcc(x)	\
    		__asm__ volatile ("mrc p14, 0, %0, c9, c0, 0\n" : "=r" (x))
    
    #define status_dcc(x)	\
    		__asm__ volatile ("mrc p14, 0, %0, c14, c0, 0\n" : "=r" (x))
    
    #else
    #define DCC_RBIT	(1 << 0)
    #define DCC_WBIT	(1 << 1)
    
    #define write_dcc(x)	\
    		__asm__ volatile ("mcr p14, 0, %0, c1, c0, 0\n" : : "r" (x))
    
    #define read_dcc(x)	\
    		__asm__ volatile ("mrc p14, 0, %0, c1, c0, 0\n" : "=r" (x))
    
    #define status_dcc(x)	\
    		__asm__ volatile ("mrc p14, 0, %0, c0, c0, 0\n" : "=r" (x))
    
    #endif
    
    #define can_read_dcc(x)	do {	\
    		status_dcc(x);	\
    		x &= DCC_RBIT;	\
    		} while (0);
    
    #define can_write_dcc(x) do {	\
    		status_dcc(x);	\
    		x &= DCC_WBIT;	\
    		x = (x == 0);	\
    		} while (0);
    
    #define TIMEOUT_COUNT 0x4000000
    
    static int arm_dcc_init(void)
    {
    	return 0;
    }
    
    static int arm_dcc_getc(void)
    {
    	int ch;
    	register unsigned int reg;
    
    	do {
    		can_read_dcc(reg);
    	} while (!reg);
    	read_dcc(ch);
    
    	return ch;
    }
    
    static void arm_dcc_putc(char ch)
    {
    	register unsigned int reg;
    	unsigned int timeout_count = TIMEOUT_COUNT;
    
    	while (--timeout_count) {
    		can_write_dcc(reg);
    		if (reg)
    			break;
    	}
    	if (timeout_count == 0)
    		return;
    	else
    		write_dcc(ch);
    }
    
    static int arm_dcc_tstc(void)
    {
    	register unsigned int reg;
    
    	can_read_dcc(reg);
    
    	return reg;
    }
    
    static void arm_dcc_setbrg(void)
    {
    }
    
    static struct serial_device arm_dcc_drv = {
    	.name	= "arm_dcc",
    	.start	= arm_dcc_init,
    	.stop	= NULL,
    	.setbrg	= arm_dcc_setbrg,
    	.putc	= arm_dcc_putc,
    	.puts	= default_serial_puts,
    	.getc	= arm_dcc_getc,
    	.tstc	= arm_dcc_tstc,
    };
    
    void arm_dcc_initialize(void)
    {
    	serial_register(&arm_dcc_drv);
    }
    
    __weak struct serial_device *default_serial_console(void)
    {
    	return &arm_dcc_drv;
    }