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Rev | Author | Line No. | Line |
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538 | mauro | 1 | /* |
2 | * Project: S.Ha.R.K. |
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3 | * |
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4 | * Coordinators: |
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5 | * Giorgio Buttazzo <giorgio@sssup.it> |
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6 | * Paolo Gai <pj@gandalf.sssup.it> |
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7 | * |
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8 | * Authors : |
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9 | * Paolo Gai <pj@gandalf.sssup.it> |
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10 | * Massimiliano Giorgi <massy@gandalf.sssup.it> |
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11 | * Luca Abeni <luca@gandalf.sssup.it> |
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1035 | tullio | 12 | * Tullio Facchinetti <tullio.facchinetti@unipv.it> |
538 | mauro | 13 | * (see the web pages for full authors list) |
14 | * |
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15 | * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy) |
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16 | * |
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17 | * http://www.sssup.it |
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18 | * http://retis.sssup.it |
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19 | * http://shark.sssup.it |
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20 | */ |
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21 | |||
22 | /* |
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23 | * Copyright (C) 2000 Paolo Gai |
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24 | * |
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25 | * This program is free software; you can redistribute it and/or modify |
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26 | * it under the terms of the GNU General Public License as published by |
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27 | * the Free Software Foundation; either version 2 of the License, or |
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28 | * (at your option) any later version. |
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29 | * |
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30 | * This program is distributed in the hope that it will be useful, |
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31 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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32 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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33 | * GNU General Public License for more details. |
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34 | * |
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35 | * You should have received a copy of the GNU General Public License |
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36 | * along with this program; if not, write to the Free Software |
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37 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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38 | * |
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39 | */ |
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40 | |||
41 | /* Serial communication device */ |
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42 | /* This implementation is capable of handling 4 distinct COM ports */ |
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43 | /* The COM port settings are the standard PC settings: */ |
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44 | /* PORT ADDRESS IRQ */ |
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45 | /* 1 0x3F8 4 */ |
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46 | /* 2 0x2F8 3 */ |
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47 | /* 3 0x3E8 4 */ |
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48 | /* 4 0x2E8 2 */ |
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49 | |||
50 | /* By Massy |
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51 | * I have modified the fast handler routines to support serial |
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52 | * mouse better (see below) |
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53 | */ |
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54 | |||
55 | #include <kernel/kern.h> |
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56 | #include <drivers/scom.h> |
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57 | |||
58 | /* Base address for each standard COM link */ |
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59 | static unsigned com_base[] = {0x03F8,0x02F8,0x03E8,0x02E8}; |
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60 | |||
61 | /* Used for decoding the IIR status */ |
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62 | const int IIRbits[] = {MS_CHANGED,TX_EMPTY,RX_FULL,LS_CHANGED}; |
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63 | |||
1035 | tullio | 64 | int serial_initialized[4] = {0, 0, 0, 0}; |
538 | mauro | 65 | |
1035 | tullio | 66 | /** |
67 | * Register level access functions. |
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68 | */ |
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69 | unsigned com_read(unsigned port, unsigned reg) { |
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538 | mauro | 70 | unsigned b; |
1035 | tullio | 71 | if (port > 3 || reg > 7 || (!serial_initialized[port])) return(0); |
538 | mauro | 72 | b = ll_in(com_base[port]+reg); |
73 | return(b); |
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74 | } |
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75 | |||
1035 | tullio | 76 | void com_write(unsigned port, unsigned reg, unsigned value) { |
77 | if (port > 3 || reg > 7 || (!serial_initialized[port])) return; |
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538 | mauro | 78 | ll_out(com_base[port]+reg,value); |
79 | } |
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80 | |||
1035 | tullio | 81 | /** |
82 | * Write the character "b" to the port "port". |
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83 | * If wait is 0 then a busy port makes the fuction to return immediately. |
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84 | * If wait is 1 loops until the port become free. |
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85 | * Return 0 if the byte has been sent. Return 1 otherwise. |
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86 | */ |
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87 | unsigned com_send(unsigned port, BYTE b, unsigned wait) { |
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88 | if (wait) { |
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89 | while ((com_read(port,LSR) & 32) == 0); |
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90 | } else { |
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91 | if ((com_read(port,LSR) & 32) == 0) return(1); |
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92 | } |
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538 | mauro | 93 | com_write(port,THR,b); |
1035 | tullio | 94 | return(0); |
538 | mauro | 95 | } |
96 | |||
1035 | tullio | 97 | /** |
98 | * Read a character from the port "port". |
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99 | * Polls the port until a character is ready to be read. |
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100 | */ |
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101 | unsigned com_receive(unsigned port) { |
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538 | mauro | 102 | while ((com_read(port,LSR) & 1) == 0); |
103 | return(com_read(port,RBR)); |
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104 | } |
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105 | |||
1035 | tullio | 106 | /** |
107 | * Initialize a serial channel. |
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108 | * Do not do anything if the port has been already initialized. |
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109 | */ |
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110 | int com_open(unsigned port,DWORD speed,BYTE parity,BYTE len,BYTE stop) { |
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538 | mauro | 111 | unsigned long div,b_mask; |
714 | giacomo | 112 | SYS_FLAGS f; |
113 | |||
114 | f = kern_fsave(); |
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1035 | tullio | 115 | |
116 | if (serial_initialized[port]) { |
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117 | kern_frestore(f); |
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118 | return(0); |
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119 | } |
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714 | giacomo | 120 | |
1060 | tullio | 121 | serial_initialized[port] = 1; |
122 | |||
538 | mauro | 123 | /* Now set up the serial link */ |
1055 | tullio | 124 | b_mask = (parity & 3) * 8 + ((stop - 1) & 1) * 4 + ((len - 5) & 3); |
538 | mauro | 125 | div = 115200L / speed; |
126 | /* Clear serial interrupt enable register */ |
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127 | com_write(port,IER,0); |
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128 | /* Empty input buffer */ |
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129 | com_read(port,RBR); |
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130 | /* Activate DLAB bit for speed setting */ |
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131 | com_write(port,LCR,0x80); |
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132 | /* Load baud divisor */ |
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133 | com_write(port,0,div & 0x00FF); |
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134 | div >>= 8; |
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135 | com_write(port,1,div & 0x00FF); |
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136 | /* Load control word (parity,stop bit,bit len) */ |
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137 | com_write(port,LCR,b_mask); |
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138 | /* Attiva OUT1 & OUT2 */ |
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139 | com_write(port,MCR,0x0C); |
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140 | |||
714 | giacomo | 141 | kern_frestore(f); |
538 | mauro | 142 | |
714 | giacomo | 143 | return(0); |
144 | |||
538 | mauro | 145 | } |
146 | |||
1035 | tullio | 147 | /** |
148 | * Close port channel & release the server. |
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149 | */ |
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538 | mauro | 150 | int com_close(unsigned port) |
151 | { |
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714 | giacomo | 152 | SYS_FLAGS f; |
538 | mauro | 153 | |
714 | giacomo | 154 | f = kern_fsave(); |
538 | mauro | 155 | |
714 | giacomo | 156 | com_write(port,IER,0); |
157 | com_read(port,IIR); |
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158 | com_read(port,RBR); |
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538 | mauro | 159 | |
1035 | tullio | 160 | serial_initialized[port] = 0; |
161 | |||
714 | giacomo | 162 | kern_frestore(f); |
538 | mauro | 163 | |
714 | giacomo | 164 | return(0); |
538 | mauro | 165 | } |
166 |