1 /* $NetBSD: com.c,v 1.1 2011/03/03 05:59:37 kiyohara Exp $ */ 2 3 /*- 4 * Copyright (c) 2008 Izumi Tsutsui. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 /*- 27 * Copyright (c) 1993, 1994, 1995, 1996, 1997 28 * Charles M. Hannum. All rights reserved. 29 * 30 * Interrupt processing and hardware flow control partly based on code from 31 * Onno van der Linden and Gordon Ross. 32 * 33 * Redistribution and use in source and binary forms, with or without 34 * modification, are permitted provided that the following conditions 35 * are met: 36 * 1. Redistributions of source code must retain the above copyright 37 * notice, this list of conditions and the following disclaimer. 38 * 2. Redistributions in binary form must reproduce the above copyright 39 * notice, this list of conditions and the following disclaimer in the 40 * documentation and/or other materials provided with the distribution. 41 * 3. All advertising materials mentioning features or use of this software 42 * must display the following acknowledgement: 43 * This product includes software developed by Charles M. Hannum. 44 * 4. The name of the author may not be used to endorse or promote products 45 * derived from this software without specific prior written permission. 46 * 47 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 48 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 49 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 50 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 51 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 52 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 53 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 54 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 55 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 56 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 57 */ 58 59 /* 60 * Copyright (c) 1991 The Regents of the University of California. 61 * All rights reserved. 62 * 63 * Redistribution and use in source and binary forms, with or without 64 * modification, are permitted provided that the following conditions 65 * are met: 66 * 1. Redistributions of source code must retain the above copyright 67 * notice, this list of conditions and the following disclaimer. 68 * 2. Redistributions in binary form must reproduce the above copyright 69 * notice, this list of conditions and the following disclaimer in the 70 * documentation and/or other materials provided with the distribution. 71 * 3. Neither the name of the University nor the names of its contributors 72 * may be used to endorse or promote products derived from this software 73 * without specific prior written permission. 74 * 75 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 76 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 77 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 78 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 79 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 80 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 81 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 82 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 83 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 84 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 85 * SUCH DAMAGE. 86 * 87 * @(#)com.c 7.5 (Berkeley) 5/16/91 88 */ 89 90 #ifdef CONS_COM 91 92 #include <lib/libsa/stand.h> 93 #include <lib/libkern/libkern.h> 94 95 #include <dev/ic/comreg.h> 96 97 #include <machine/cpu.h> 98 99 #include "boot.h" 100 #include "ns16550.h" 101 102 #define CSR_READ(base, reg) (*(volatile uint8_t *)((base) + (reg))) 103 #define CSR_WRITE(base, reg, val) \ 104 do { \ 105 *(volatile uint8_t *)((base) + (reg)) = (val); \ 106 } while (/* CONSTCOND */ 0) 107 108 #define COM_FREQ 1843200 /* 16-bit baud rate divisor */ 109 #define COM_TOLERANCE 30 /* baud rate tolerance, in 0.1% units */ 110 111 static int comspeed(long); 112 113 static int 114 comspeed(long speed) 115 { 116 #define divrnd(n, q) (((n)*2/(q)+1)/2) /* divide and round off */ 117 118 int x, err; 119 long frequency = COM_FREQ * 10; 120 121 if (speed <= 0) 122 return -1; 123 x = divrnd((frequency / 16), speed); 124 if (x <= 0) 125 return -1; 126 err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000; 127 if (err < 0) 128 err = -err; 129 if (err > COM_TOLERANCE) 130 return -1; 131 return x; 132 133 #undef divrnd 134 } 135 136 void * 137 com_init(int addr, int speed) 138 { 139 uint8_t *com_port; 140 141 com_port = (void *)addr; 142 143 CSR_WRITE(com_port, com_lctl, LCR_DLAB); 144 speed = comspeed(speed); 145 CSR_WRITE(com_port, com_dlbl, speed); 146 CSR_WRITE(com_port, com_dlbh, speed >> 8); 147 148 CSR_WRITE(com_port, com_lctl, LCR_PNONE | LCR_8BITS); 149 CSR_WRITE(com_port, com_mcr, MCR_RTS | MCR_DTR); 150 CSR_WRITE(com_port, com_fifo, 151 FIFO_XMT_RST | FIFO_RCV_RST | FIFO_ENABLE); 152 CSR_WRITE(com_port, com_ier, 0); 153 154 return com_port; 155 } 156 157 void 158 com_putc(void *dev, int c) 159 { 160 volatile uint8_t *com_port = dev; 161 162 while ((CSR_READ(com_port, com_lsr) & LSR_TXRDY) == 0) 163 ; 164 165 CSR_WRITE(com_port, com_data, c); 166 } 167 168 int 169 com_getc(void *dev) 170 { 171 volatile uint8_t *com_port = dev; 172 173 while ((CSR_READ(com_port, com_lsr) & LSR_RXRDY) == 0) 174 ; 175 176 return CSR_READ(com_port, com_data); 177 } 178 179 int 180 com_scankbd(void *dev) 181 { 182 volatile uint8_t *com_port = dev; 183 184 if ((CSR_READ(com_port, com_lsr) & LSR_RXRDY) == 0) 185 return -1; 186 187 return CSR_READ(com_port, com_data); 188 } 189 #endif /* CONS_SERIAL */ 190
Indexes created Sun Oct 25 00:26:45 UTC 2026