Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 1 | /* ir-raw-event.c - handle IR Pulse/Space event |
| 2 | * |
| 3 | * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation version 2 of the License. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | */ |
| 14 | |
| 15 | #include <media/ir-core.h> |
| 16 | |
| 17 | /* Start time: 4.5 ms */ |
| 18 | #define MIN_START_TIME 3900000 |
| 19 | #define MAX_START_TIME 5100000 |
| 20 | |
| 21 | /* Pulse time: 560 us */ |
| 22 | #define MIN_PULSE_TIME 460000 |
| 23 | #define MAX_PULSE_TIME 660000 |
| 24 | |
| 25 | /* Bit 1 space time: 2.25ms-560 us */ |
| 26 | #define MIN_BIT1_TIME 1490000 |
| 27 | #define MAX_BIT1_TIME 1890000 |
| 28 | |
| 29 | /* Bit 0 space time: 1.12ms-560 us */ |
| 30 | #define MIN_BIT0_TIME 360000 |
| 31 | #define MAX_BIT0_TIME 760000 |
| 32 | |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 33 | /** |
| 34 | * __ir_nec_decode() - Decode one NEC pulsecode |
| 35 | * @input_dev: the struct input_dev descriptor of the device |
| 36 | * @evs: event array with type/duration of pulse/space |
| 37 | * @len: length of the array |
| 38 | * @pos: position to start seeking for a code |
| 39 | * This function returns the decoded ircode or -EINVAL if no pulse got decoded |
| 40 | */ |
| 41 | static int __ir_nec_decode(struct input_dev *input_dev, |
| 42 | struct ir_raw_event *evs, |
| 43 | int len, int *pos) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 44 | { |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 45 | int count = -1; |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 46 | int ircode = 0, not_code = 0; |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 47 | |
| 48 | /* Be sure that the first event is an start one and is a pulse */ |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 49 | for (; *pos < len; (*pos)++) { |
| 50 | if (evs[*pos].type & (IR_START_EVENT | IR_PULSE)) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 51 | break; |
| 52 | } |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 53 | (*pos)++; /* First event doesn't contain data */ |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 54 | |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 55 | if (*pos >= len) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 56 | return 0; |
| 57 | |
| 58 | /* First space should have 4.5 ms otherwise is not NEC protocol */ |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 59 | if ((evs[*pos].delta.tv_nsec < MIN_START_TIME) | |
| 60 | (evs[*pos].delta.tv_nsec > MAX_START_TIME) | |
| 61 | (evs[*pos].type != IR_SPACE)) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 62 | goto err; |
| 63 | |
| 64 | /* |
| 65 | * FIXME: need to implement the repeat sequence |
| 66 | */ |
| 67 | |
| 68 | count = 0; |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 69 | for ((*pos)++; *pos < len; (*pos)++) { |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 70 | int bit; |
| 71 | |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 72 | if ((evs[*pos].delta.tv_nsec < MIN_PULSE_TIME) | |
| 73 | (evs[*pos].delta.tv_nsec > MAX_PULSE_TIME) | |
| 74 | (evs[*pos].type != IR_PULSE)) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 75 | goto err; |
| 76 | |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 77 | if (++*pos >= len) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 78 | goto err; |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 79 | if (evs[*pos].type != IR_SPACE) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 80 | goto err; |
| 81 | |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 82 | if ((evs[*pos].delta.tv_nsec > MIN_BIT1_TIME) && |
| 83 | (evs[*pos].delta.tv_nsec < MAX_BIT1_TIME)) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 84 | bit = 1; |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 85 | else if ((evs[*pos].delta.tv_nsec > MIN_BIT0_TIME) && |
| 86 | (evs[*pos].delta.tv_nsec < MAX_BIT0_TIME)) |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 87 | bit = 0; |
| 88 | else |
| 89 | goto err; |
| 90 | |
| 91 | if (bit) { |
| 92 | int shift = count; |
| 93 | /* Address first, then command */ |
| 94 | if (shift < 8) { |
| 95 | shift += 8; |
| 96 | ircode |= 1 << shift; |
| 97 | } else if (shift < 16) { |
| 98 | not_code |= 1 << shift; |
| 99 | } else if (shift < 24) { |
| 100 | shift -= 16; |
| 101 | ircode |= 1 << shift; |
| 102 | } else { |
| 103 | shift -= 24; |
| 104 | not_code |= 1 << shift; |
| 105 | } |
| 106 | } |
| 107 | if (++count == 32) |
| 108 | break; |
| 109 | } |
| 110 | |
| 111 | /* |
| 112 | * Fixme: may need to accept Extended NEC protocol? |
| 113 | */ |
| 114 | if ((ircode & ~not_code) != ircode) { |
| 115 | IR_dprintk(1, "NEC checksum error: code 0x%04x, not-code 0x%04x\n", |
| 116 | ircode, not_code); |
| 117 | return -EINVAL; |
| 118 | } |
| 119 | |
| 120 | IR_dprintk(1, "NEC scancode 0x%04x\n", ircode); |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 121 | ir_keydown(input_dev, ircode); |
| 122 | ir_keyup(input_dev); |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 123 | |
| 124 | return ircode; |
| 125 | err: |
| 126 | IR_dprintk(1, "NEC decoded failed at bit %d while decoding %luus time\n", |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 127 | count, (evs[*pos].delta.tv_nsec + 500) / 1000); |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 128 | |
| 129 | return -EINVAL; |
| 130 | } |
Mauro Carvalho Chehab | ada3963 | 2010-03-21 12:24:24 -0300 | [diff] [blame^] | 131 | |
| 132 | /** |
| 133 | * __ir_nec_decode() - Decodes all NEC pulsecodes on a given array |
| 134 | * @input_dev: the struct input_dev descriptor of the device |
| 135 | * @evs: event array with type/duration of pulse/space |
| 136 | * @len: length of the array |
| 137 | * This function returns the number of decoded pulses or -EINVAL if no |
| 138 | * pulse got decoded |
| 139 | */ |
| 140 | int ir_nec_decode(struct input_dev *input_dev, |
| 141 | struct ir_raw_event *evs, |
| 142 | int len) |
| 143 | { |
| 144 | int pos = 0; |
| 145 | int rc = 0; |
| 146 | |
| 147 | while (pos < len) { |
| 148 | if (__ir_nec_decode(input_dev, evs, len, &pos) >= 0) |
| 149 | rc++; |
| 150 | } |
| 151 | |
| 152 | if (!rc) |
| 153 | return -EINVAL; |
| 154 | return rc; |
| 155 | } |
| 156 | |
Mauro Carvalho Chehab | a3572c3 | 2010-03-20 20:59:44 -0300 | [diff] [blame] | 157 | EXPORT_SYMBOL_GPL(ir_nec_decode); |