1 /* 2 * Copyright (C) 2004-2007 ARM Limited. 3 * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License version 2 7 * as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 * 18 * As a special exception, if other files instantiate templates or use macros 19 * or inline functions from this file, or you compile this file and link it 20 * with other works to produce a work based on this file, this file does not 21 * by itself cause the resulting work to be covered by the GNU General Public 22 * License. However the source code for this file must still be made available 23 * in accordance with section (3) of the GNU General Public License. 24 25 * This exception does not invalidate any other reasons why a work based on 26 * this file might be covered by the GNU General Public License. 27 */ 28 29 #include <common.h> 30 #include <stdio_dev.h> 31 32 #if defined(CONFIG_CPU_V6) 33 /* 34 * ARMV6 35 */ 36 #define DCC_RBIT (1 << 30) 37 #define DCC_WBIT (1 << 29) 38 39 #define write_dcc(x) \ 40 __asm__ volatile ("mcr p14, 0, %0, c0, c5, 0\n" : : "r" (x)) 41 42 #define read_dcc(x) \ 43 __asm__ volatile ("mrc p14, 0, %0, c0, c5, 0\n" : "=r" (x)) 44 45 #define status_dcc(x) \ 46 __asm__ volatile ("mrc p14, 0, %0, c0, c1, 0\n" : "=r" (x)) 47 48 #elif defined(CONFIG_CPU_XSCALE) 49 /* 50 * XSCALE 51 */ 52 #define DCC_RBIT (1 << 31) 53 #define DCC_WBIT (1 << 28) 54 55 #define write_dcc(x) \ 56 __asm__ volatile ("mcr p14, 0, %0, c8, c0, 0\n" : : "r" (x)) 57 58 #define read_dcc(x) \ 59 __asm__ volatile ("mrc p14, 0, %0, c9, c0, 0\n" : "=r" (x)) 60 61 #define status_dcc(x) \ 62 __asm__ volatile ("mrc p14, 0, %0, c14, c0, 0\n" : "=r" (x)) 63 64 #else 65 #define DCC_RBIT (1 << 0) 66 #define DCC_WBIT (1 << 1) 67 68 #define write_dcc(x) \ 69 __asm__ volatile ("mcr p14, 0, %0, c1, c0, 0\n" : : "r" (x)) 70 71 #define read_dcc(x) \ 72 __asm__ volatile ("mrc p14, 0, %0, c1, c0, 0\n" : "=r" (x)) 73 74 #define status_dcc(x) \ 75 __asm__ volatile ("mrc p14, 0, %0, c0, c0, 0\n" : "=r" (x)) 76 77 #endif 78 79 #define can_read_dcc(x) do { \ 80 status_dcc(x); \ 81 x &= DCC_RBIT; \ 82 } while (0); 83 84 #define can_write_dcc(x) do { \ 85 status_dcc(x); \ 86 x &= DCC_WBIT; \ 87 x = (x == 0); \ 88 } while (0); 89 90 #define TIMEOUT_COUNT 0x4000000 91 92 int arm_dcc_init(void) 93 { 94 return 0; 95 } 96 97 int arm_dcc_getc(void) 98 { 99 int ch; 100 register unsigned int reg; 101 102 do { 103 can_read_dcc(reg); 104 } while (!reg); 105 read_dcc(ch); 106 107 return ch; 108 } 109 110 void arm_dcc_putc(char ch) 111 { 112 register unsigned int reg; 113 unsigned int timeout_count = TIMEOUT_COUNT; 114 115 while (--timeout_count) { 116 can_write_dcc(reg); 117 if (reg) 118 break; 119 } 120 if (timeout_count == 0) 121 return; 122 else 123 write_dcc(ch); 124 } 125 126 void arm_dcc_puts(const char *s) 127 { 128 while (*s) 129 arm_dcc_putc(*s++); 130 } 131 132 int arm_dcc_tstc(void) 133 { 134 register unsigned int reg; 135 136 can_read_dcc(reg); 137 138 return reg; 139 } 140 141 static struct stdio_dev arm_dcc_dev; 142 143 int drv_arm_dcc_init(void) 144 { 145 strcpy(arm_dcc_dev.name, "dcc"); 146 arm_dcc_dev.ext = 0; /* No extensions */ 147 arm_dcc_dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_OUTPUT; 148 arm_dcc_dev.tstc = arm_dcc_tstc; /* 'tstc' function */ 149 arm_dcc_dev.getc = arm_dcc_getc; /* 'getc' function */ 150 arm_dcc_dev.putc = arm_dcc_putc; /* 'putc' function */ 151 arm_dcc_dev.puts = arm_dcc_puts; /* 'puts' function */ 152 153 return stdio_register(&arm_dcc_dev); 154 } 155 156 __weak struct serial_device *default_serial_console(void) 157 { 158 return NULL; 159 } 160