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 #ifndef CONFIG_ARM_DCC_MULTI 93 #define arm_dcc_init serial_init 94 void serial_setbrg(void) {} 95 #define arm_dcc_getc serial_getc 96 #define arm_dcc_putc serial_putc 97 #define arm_dcc_puts serial_puts 98 #define arm_dcc_tstc serial_tstc 99 #endif 100 101 int arm_dcc_init(void) 102 { 103 return 0; 104 } 105 106 int arm_dcc_getc(void) 107 { 108 int ch; 109 register unsigned int reg; 110 111 do { 112 can_read_dcc(reg); 113 } while (!reg); 114 read_dcc(ch); 115 116 return ch; 117 } 118 119 void arm_dcc_putc(char ch) 120 { 121 register unsigned int reg; 122 unsigned int timeout_count = TIMEOUT_COUNT; 123 124 while (--timeout_count) { 125 can_write_dcc(reg); 126 if (reg) 127 break; 128 } 129 if (timeout_count == 0) 130 return; 131 else 132 write_dcc(ch); 133 } 134 135 void arm_dcc_puts(const char *s) 136 { 137 while (*s) 138 arm_dcc_putc(*s++); 139 } 140 141 int arm_dcc_tstc(void) 142 { 143 register unsigned int reg; 144 145 can_read_dcc(reg); 146 147 return reg; 148 } 149 150 #ifdef CONFIG_ARM_DCC_MULTI 151 static struct stdio_dev arm_dcc_dev; 152 153 int drv_arm_dcc_init(void) 154 { 155 int rc; 156 157 /* Device initialization */ 158 memset(&arm_dcc_dev, 0, sizeof(arm_dcc_dev)); 159 160 strcpy(arm_dcc_dev.name, "dcc"); 161 arm_dcc_dev.ext = 0; /* No extensions */ 162 arm_dcc_dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_OUTPUT; 163 arm_dcc_dev.tstc = arm_dcc_tstc; /* 'tstc' function */ 164 arm_dcc_dev.getc = arm_dcc_getc; /* 'getc' function */ 165 arm_dcc_dev.putc = arm_dcc_putc; /* 'putc' function */ 166 arm_dcc_dev.puts = arm_dcc_puts; /* 'puts' function */ 167 168 return stdio_register(&arm_dcc_dev); 169 } 170 #endif 171