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 <devices.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 #else 49 #define DCC_RBIT (1 << 0) 50 #define DCC_WBIT (1 << 1) 51 52 #define write_dcc(x) \ 53 __asm__ volatile ("mcr p14, 0, %0, c1, c0, 0\n" : : "r" (x)) 54 55 #define read_dcc(x) \ 56 __asm__ volatile ("mrc p14, 0, %0, c1, c0, 0\n" : "=r" (x)) 57 58 #define status_dcc(x) \ 59 __asm__ volatile ("mrc p14, 0, %0, c0, c0, 0\n" : "=r" (x)) 60 61 #endif 62 63 #define can_read_dcc(x) do { \ 64 status_dcc(x); \ 65 x &= DCC_RBIT; \ 66 } while (0); 67 68 #define can_write_dcc(x) do { \ 69 status_dcc(x); \ 70 x &= DCC_WBIT; \ 71 x = (x == 0); \ 72 } while (0); 73 74 #define TIMEOUT_COUNT 0x4000000 75 76 #ifndef CONFIG_ARM_DCC_MULTI 77 #define arm_dcc_init serial_init 78 void serial_setbrg(void) {} 79 #define arm_dcc_getc serial_getc 80 #define arm_dcc_putc serial_putc 81 #define arm_dcc_puts serial_puts 82 #define arm_dcc_tstc serial_tstc 83 #endif 84 85 int arm_dcc_init(void) 86 { 87 return 0; 88 } 89 90 int arm_dcc_getc(void) 91 { 92 int ch; 93 register unsigned int reg; 94 95 do { 96 can_read_dcc(reg); 97 } while (!reg); 98 read_dcc(ch); 99 100 return ch; 101 } 102 103 void arm_dcc_putc(char ch) 104 { 105 register unsigned int reg; 106 unsigned int timeout_count = TIMEOUT_COUNT; 107 108 while (--timeout_count) { 109 can_write_dcc(reg); 110 if (reg) 111 break; 112 } 113 if (timeout_count == 0) 114 return; 115 else 116 write_dcc(ch); 117 } 118 119 void arm_dcc_puts(const char *s) 120 { 121 while (*s) 122 arm_dcc_putc(*s++); 123 } 124 125 int arm_dcc_tstc(void) 126 { 127 register unsigned int reg; 128 129 can_read_dcc(reg); 130 131 return reg; 132 } 133 134 #ifdef CONFIG_ARM_DCC_MULTI 135 static device_t arm_dcc_dev; 136 137 int drv_arm_dcc_init(void) 138 { 139 int rc; 140 141 /* Device initialization */ 142 memset(&arm_dcc_dev, 0, sizeof(arm_dcc_dev)); 143 144 strcpy(arm_dcc_dev.name, "dcc"); 145 arm_dcc_dev.ext = 0; /* No extensions */ 146 arm_dcc_dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_OUTPUT; 147 arm_dcc_dev.tstc = arm_dcc_tstc; /* 'tstc' function */ 148 arm_dcc_dev.getc = arm_dcc_getc; /* 'getc' function */ 149 arm_dcc_dev.putc = arm_dcc_putc; /* 'putc' function */ 150 arm_dcc_dev.puts = arm_dcc_puts; /* 'puts' function */ 151 152 return device_register(&arm_dcc_dev); 153 } 154 #endif 155