1 /* 2 * Copyright (c) 2008 Travis Geiselbrecht 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining 5 * a copy of this software and associated documentation files 6 * (the "Software"), to deal in the Software without restriction, 7 * including without limitation the rights to use, copy, modify, merge, 8 * publish, distribute, sublicense, and/or sell copies of the Software, 9 * and to permit persons to whom the Software is furnished to do so, 10 * subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice shall be 13 * included in all copies or substantial portions of the Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 22 */ 23 24 25 #include <debug.h> 26 #include <arch/generic/debug_uart_8250.h> 27 28 29 DebugUART8250::DebugUART8250(addr_t base, int64 clock) 30 : 31 DebugUART(base, clock) 32 { 33 } 34 35 36 DebugUART8250::~DebugUART8250() 37 { 38 } 39 40 41 #define UART_RHR 0 42 #define UART_THR 0 43 #define UART_DLL 0 44 #define UART_IER 1 45 #define UART_DLH 1 46 #define UART_IIR 2 47 #define UART_FCR 2 48 #define UART_EFR 2 49 #define UART_LCR 3 50 #define UART_MCR 4 51 #define UART_LSR 5 52 #define UART_MSR 6 53 #define UART_TCR 6 54 #define UART_SPR 7 55 #define UART_TLR 7 56 57 #define LCR_8N1 0x03 58 59 #define FCR_FIFO_EN 0x01 /* Fifo enable */ 60 #define FCR_RXSR 0x02 /* Receiver soft reset */ 61 #define FCR_TXSR 0x04 /* Transmitter soft reset */ 62 63 #define MCR_DTR 0x01 64 #define MCR_RTS 0x02 65 #define MCR_DMA_EN 0x04 66 #define MCR_TX_DFR 0x08 67 68 #define LCR_WLS_MSK 0x03 /* character length select mask */ 69 #define LCR_WLS_5 0x00 /* 5 bit character length */ 70 #define LCR_WLS_6 0x01 /* 6 bit character length */ 71 #define LCR_WLS_7 0x02 /* 7 bit character length */ 72 #define LCR_WLS_8 0x03 /* 8 bit character length */ 73 #define LCR_STB 0x04 /* Number of stop Bits, off = 1, on = 1.5 or 2) */ 74 #define LCR_PEN 0x08 /* Parity eneble */ 75 #define LCR_EPS 0x10 /* Even Parity Select */ 76 #define LCR_STKP 0x20 /* Stick Parity */ 77 #define LCR_SBRK 0x40 /* Set Break */ 78 #define LCR_BKSE 0x80 /* Bank select enable */ 79 80 #define LSR_DR 0x01 /* Data ready */ 81 #define LSR_OE 0x02 /* Overrun */ 82 #define LSR_PE 0x04 /* Parity error */ 83 #define LSR_FE 0x08 /* Framing error */ 84 #define LSR_BI 0x10 /* Break */ 85 #define LSR_THRE 0x20 /* Xmit holding register empty */ 86 #define LSR_TEMT 0x40 /* Xmitter empty */ 87 #define LSR_ERR 0x80 /* Error */ 88 89 90 void 91 DebugUART8250::InitPort(uint32 baud) 92 { 93 Disable(); 94 95 uint16 baudDivisor = Clock() / (16 * baud); 96 97 // Write standard uart settings 98 Out8(UART_LCR, LCR_8N1); 99 // 8N1 100 Out8(UART_IER, 0); 101 // Disable interrupt 102 Out8(UART_FCR, 0); 103 // Disable FIFO 104 Out8(UART_MCR, MCR_DTR | MCR_RTS); 105 // DTR / RTS 106 107 // Gain access to, and program baud divisor 108 unsigned char buffer = In8(UART_LCR); 109 Out8(UART_LCR, buffer | LCR_BKSE); 110 Out8(UART_DLL, baudDivisor & 0xff); 111 Out8(UART_DLH, (baudDivisor >> 8) & 0xff); 112 Out8(UART_LCR, buffer & ~LCR_BKSE); 113 114 // Out8(UART_MDR1, 0); // UART 16x mode 115 // Out8(UART_LCR, 0xBF); // config mode B 116 // Out8(UART_EFR, (1<<7)|(1<<6)); // hw flow control 117 // Out8(UART_LCR, LCR_8N1); // operational mode 118 119 Enable(); 120 } 121 122 123 void 124 DebugUART8250::InitEarly() 125 { 126 } 127 128 129 void 130 DebugUART8250::Init() 131 { 132 } 133 134 135 int 136 DebugUART8250::PutChar(char c) 137 { 138 while (!(In8(UART_LSR) & (1<<6))); 139 // wait for the last char to get out 140 Out8(UART_THR, c); 141 return 0; 142 } 143 144 145 /* returns -1 if no data available */ 146 int 147 DebugUART8250::GetChar(bool wait) 148 { 149 if (wait) { 150 while (!(In8(UART_LSR) & (1<<0))); 151 // wait for data to show up in the rx fifo 152 } else { 153 if (!(In8(UART_LSR) & (1<<0))) 154 return -1; 155 } 156 return In8(UART_RHR); 157 } 158 159 160 void 161 DebugUART8250::FlushTx() 162 { 163 while (!(In8(UART_LSR) & (1<<6))); 164 // wait for the last char to get out 165 } 166 167 168 void 169 DebugUART8250::FlushRx() 170 { 171 // empty the rx fifo 172 while (In8(UART_LSR) & (1<<0)) { 173 volatile char c = In8(UART_RHR); 174 (void)c; 175 } 176 } 177