1 /* 2 * ImgTec IR Decoder setup for NEC protocol. 3 * 4 * Copyright 2010-2014 Imagination Technologies Ltd. 5 */ 6 7 #include "img-ir-hw.h" 8 #include <linux/bitrev.h> 9 10 /* Convert NEC data to a scancode */ 11 static int img_ir_nec_scancode(int len, u64 raw, int *scancode, u64 protocols) 12 { 13 unsigned int addr, addr_inv, data, data_inv; 14 /* a repeat code has no data */ 15 if (!len) 16 return IMG_IR_REPEATCODE; 17 if (len != 32) 18 return -EINVAL; 19 /* raw encoding: ddDDaaAA */ 20 addr = (raw >> 0) & 0xff; 21 addr_inv = (raw >> 8) & 0xff; 22 data = (raw >> 16) & 0xff; 23 data_inv = (raw >> 24) & 0xff; 24 if ((data_inv ^ data) != 0xff) { 25 /* 32-bit NEC (used by Apple and TiVo remotes) */ 26 /* scan encoding: as transmitted, MSBit = first received bit */ 27 *scancode = bitrev8(addr) << 24 | 28 bitrev8(addr_inv) << 16 | 29 bitrev8(data) << 8 | 30 bitrev8(data_inv); 31 } else if ((addr_inv ^ addr) != 0xff) { 32 /* Extended NEC */ 33 /* scan encoding: AAaaDD */ 34 *scancode = addr << 16 | 35 addr_inv << 8 | 36 data; 37 } else { 38 /* Normal NEC */ 39 /* scan encoding: AADD */ 40 *scancode = addr << 8 | 41 data; 42 } 43 return IMG_IR_SCANCODE; 44 } 45 46 /* Convert NEC scancode to NEC data filter */ 47 static int img_ir_nec_filter(const struct rc_scancode_filter *in, 48 struct img_ir_filter *out, u64 protocols) 49 { 50 unsigned int addr, addr_inv, data, data_inv; 51 unsigned int addr_m, addr_inv_m, data_m, data_inv_m; 52 53 data = in->data & 0xff; 54 data_m = in->mask & 0xff; 55 56 if ((in->data | in->mask) & 0xff000000) { 57 /* 32-bit NEC (used by Apple and TiVo remotes) */ 58 /* scan encoding: as transmitted, MSBit = first received bit */ 59 addr = bitrev8(in->data >> 24); 60 addr_m = bitrev8(in->mask >> 24); 61 addr_inv = bitrev8(in->data >> 16); 62 addr_inv_m = bitrev8(in->mask >> 16); 63 data = bitrev8(in->data >> 8); 64 data_m = bitrev8(in->mask >> 8); 65 data_inv = bitrev8(in->data >> 0); 66 data_inv_m = bitrev8(in->mask >> 0); 67 } else if ((in->data | in->mask) & 0x00ff0000) { 68 /* Extended NEC */ 69 /* scan encoding AAaaDD */ 70 addr = (in->data >> 16) & 0xff; 71 addr_m = (in->mask >> 16) & 0xff; 72 addr_inv = (in->data >> 8) & 0xff; 73 addr_inv_m = (in->mask >> 8) & 0xff; 74 data_inv = data ^ 0xff; 75 data_inv_m = data_m; 76 } else { 77 /* Normal NEC */ 78 /* scan encoding: AADD */ 79 addr = (in->data >> 8) & 0xff; 80 addr_m = (in->mask >> 8) & 0xff; 81 addr_inv = addr ^ 0xff; 82 addr_inv_m = addr_m; 83 data_inv = data ^ 0xff; 84 data_inv_m = data_m; 85 } 86 87 /* raw encoding: ddDDaaAA */ 88 out->data = data_inv << 24 | 89 data << 16 | 90 addr_inv << 8 | 91 addr; 92 out->mask = data_inv_m << 24 | 93 data_m << 16 | 94 addr_inv_m << 8 | 95 addr_m; 96 return 0; 97 } 98 99 /* 100 * NEC decoder 101 * See also http://www.sbprojects.com/knowledge/ir/nec.php 102 * http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol 103 */ 104 struct img_ir_decoder img_ir_nec = { 105 .type = RC_BIT_NEC, 106 .control = { 107 .decoden = 1, 108 .code_type = IMG_IR_CODETYPE_PULSEDIST, 109 }, 110 /* main timings */ 111 .unit = 562500, /* 562.5 us */ 112 .timings = { 113 /* leader symbol */ 114 .ldr = { 115 .pulse = { 16 /* 9ms */ }, 116 .space = { 8 /* 4.5ms */ }, 117 }, 118 /* 0 symbol */ 119 .s00 = { 120 .pulse = { 1 /* 562.5 us */ }, 121 .space = { 1 /* 562.5 us */ }, 122 }, 123 /* 1 symbol */ 124 .s01 = { 125 .pulse = { 1 /* 562.5 us */ }, 126 .space = { 3 /* 1687.5 us */ }, 127 }, 128 /* free time */ 129 .ft = { 130 .minlen = 32, 131 .maxlen = 32, 132 .ft_min = 10, /* 5.625 ms */ 133 }, 134 }, 135 /* repeat codes */ 136 .repeat = 108, /* 108 ms */ 137 .rtimings = { 138 /* leader symbol */ 139 .ldr = { 140 .space = { 4 /* 2.25 ms */ }, 141 }, 142 /* free time */ 143 .ft = { 144 .minlen = 0, /* repeat code has no data */ 145 .maxlen = 0, 146 }, 147 }, 148 /* scancode logic */ 149 .scancode = img_ir_nec_scancode, 150 .filter = img_ir_nec_filter, 151 }; 152