xisb.c (5174B)
1 /* 2 * Copyright (c) 1997 Metro Link Incorporated 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be included in 12 * all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 17 * THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 18 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF 19 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 20 * SOFTWARE. 21 * 22 * Except as contained in this notice, the name of the Metro Link shall not be 23 * used in advertising or otherwise to promote the sale, use or other dealings 24 * in this Software without prior written authorization from Metro Link. 25 * 26 */ 27 28 /* 29 X Input Serial Buffer routines for use in any XInput driver that accesses 30 a serial device. 31 */ 32 33 /***************************************************************************** 34 * Standard Headers 35 ****************************************************************************/ 36 37 #ifdef HAVE_XORG_CONFIG_H 38 #include <xorg-config.h> 39 #endif 40 41 #include <misc.h> 42 #include <xf86.h> 43 #include <xf86_OSproc.h> 44 #include <xf86_OSlib.h> 45 #include <xf86Xinput.h> 46 #include "xisb.h" 47 48 /***************************************************************************** 49 * Local Headers 50 ****************************************************************************/ 51 52 /***************************************************************************** 53 * Variables without includable headers 54 ****************************************************************************/ 55 56 /***************************************************************************** 57 * Local Variables 58 ****************************************************************************/ 59 60 /***************************************************************************** 61 * Function Definitions 62 ****************************************************************************/ 63 64 XISBuffer * 65 XisbNew(int fd, ssize_t size) 66 { 67 XISBuffer *b; 68 69 b = malloc(sizeof(XISBuffer)); 70 if (!b) 71 return NULL; 72 b->buf = malloc((sizeof(unsigned char) * size)); 73 if (!b->buf) { 74 free(b); 75 return NULL; 76 } 77 78 b->fd = fd; 79 b->trace = 0; 80 b->block_duration = 0; 81 b->current = 1; /* force it to be past the end to trigger initial read */ 82 b->end = 0; 83 b->buffer_size = size; 84 return b; 85 } 86 87 void 88 XisbFree(XISBuffer * b) 89 { 90 free(b->buf); 91 free(b); 92 } 93 94 int 95 XisbRead(XISBuffer * b) 96 { 97 int ret; 98 99 if (b->current >= b->end) { 100 if (b->block_duration >= 0) { 101 if (xf86WaitForInput(b->fd, b->block_duration) < 1) 102 return -1; 103 } 104 else { 105 /* 106 * automatically clear it so if XisbRead is called in a loop 107 * the next call will make sure there is data with select and 108 * thus prevent a blocking read 109 */ 110 b->block_duration = 0; 111 } 112 113 ret = xf86ReadSerial(b->fd, b->buf, b->buffer_size); 114 switch (ret) { 115 case 0: 116 return -1; /* timeout */ 117 case -1: 118 return -2; /* error */ 119 default: 120 b->end = ret; 121 b->current = 0; 122 break; 123 } 124 } 125 if (b->trace) 126 ErrorF("read 0x%02x (%c)\n", b->buf[b->current], 127 isprint(b->buf[b->current]) ? b->buf[b->current] : '.'); 128 129 return b->buf[b->current++]; 130 } 131 132 /* the only purpose of this function is to provide output tracing */ 133 ssize_t 134 XisbWrite(XISBuffer * b, unsigned char *msg, ssize_t len) 135 { 136 if (b->trace) { 137 int i = 0; 138 139 for (i = 0; i < len; i++) 140 ErrorF("\t\twrote 0x%02x (%c)\n", msg[i], msg[i]); 141 } 142 return (xf86WriteSerial(b->fd, msg, len)); 143 } 144 145 /* turn tracing of this buffer on (1) or off (0) */ 146 void 147 XisbTrace(XISBuffer * b, int trace) 148 { 149 b->trace = trace; 150 } 151 152 /* 153 * specify a block_duration of -1 when you know the buffer's fd is ready to 154 * read. After a read, it is automatically set to 0 so that the next read 155 * will use check to select for data and prevent a block. 156 * It is the caller's responsibility to set the block_duration to -1 if it 157 * knows that there is data to read (because the main select loop triggered 158 * the read) and wants to avoid the unnecessary overhead of the select call 159 * 160 * a zero or positive block duration will cause the select to block for the 161 * give duration in usecs. 162 */ 163 164 void 165 XisbBlockDuration(XISBuffer * b, int block_duration) 166 { 167 b->block_duration = block_duration; 168 }