1 /* ir-sony-decoder.c - handle Sony IR Pulse/Space protocol 2 * 3 * Copyright (C) 2010 by David Härdeman <david@hardeman.nu> 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 <linux/bitrev.h> 16 #include "rc-core-priv.h" 17 18 #define SONY_UNIT 600000 /* ns */ 19 #define SONY_HEADER_PULSE (4 * SONY_UNIT) 20 #define SONY_HEADER_SPACE (1 * SONY_UNIT) 21 #define SONY_BIT_0_PULSE (1 * SONY_UNIT) 22 #define SONY_BIT_1_PULSE (2 * SONY_UNIT) 23 #define SONY_BIT_SPACE (1 * SONY_UNIT) 24 #define SONY_TRAILER_SPACE (10 * SONY_UNIT) /* minimum */ 25 26 enum sony_state { 27 STATE_INACTIVE, 28 STATE_HEADER_SPACE, 29 STATE_BIT_PULSE, 30 STATE_BIT_SPACE, 31 STATE_FINISHED, 32 }; 33 34 /** 35 * ir_sony_decode() - Decode one Sony pulse or space 36 * @dev: the struct rc_dev descriptor of the device 37 * @ev: the struct ir_raw_event descriptor of the pulse/space 38 * 39 * This function returns -EINVAL if the pulse violates the state machine 40 */ 41 static int ir_sony_decode(struct rc_dev *dev, struct ir_raw_event ev) 42 { 43 struct sony_dec *data = &dev->raw->sony; 44 u32 scancode; 45 u8 device, subdevice, function; 46 47 if (!(dev->raw->enabled_protocols & RC_TYPE_SONY)) 48 return 0; 49 50 if (!is_timing_event(ev)) { 51 if (ev.reset) 52 data->state = STATE_INACTIVE; 53 return 0; 54 } 55 56 if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2)) 57 goto out; 58 59 IR_dprintk(2, "Sony decode started at state %d (%uus %s)\n", 60 data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 61 62 switch (data->state) { 63 64 case STATE_INACTIVE: 65 if (!ev.pulse) 66 break; 67 68 if (!eq_margin(ev.duration, SONY_HEADER_PULSE, SONY_UNIT / 2)) 69 break; 70 71 data->count = 0; 72 data->state = STATE_HEADER_SPACE; 73 return 0; 74 75 case STATE_HEADER_SPACE: 76 if (ev.pulse) 77 break; 78 79 if (!eq_margin(ev.duration, SONY_HEADER_SPACE, SONY_UNIT / 2)) 80 break; 81 82 data->state = STATE_BIT_PULSE; 83 return 0; 84 85 case STATE_BIT_PULSE: 86 if (!ev.pulse) 87 break; 88 89 data->bits <<= 1; 90 if (eq_margin(ev.duration, SONY_BIT_1_PULSE, SONY_UNIT / 2)) 91 data->bits |= 1; 92 else if (!eq_margin(ev.duration, SONY_BIT_0_PULSE, SONY_UNIT / 2)) 93 break; 94 95 data->count++; 96 data->state = STATE_BIT_SPACE; 97 return 0; 98 99 case STATE_BIT_SPACE: 100 if (ev.pulse) 101 break; 102 103 if (!geq_margin(ev.duration, SONY_BIT_SPACE, SONY_UNIT / 2)) 104 break; 105 106 decrease_duration(&ev, SONY_BIT_SPACE); 107 108 if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2)) { 109 data->state = STATE_BIT_PULSE; 110 return 0; 111 } 112 113 data->state = STATE_FINISHED; 114 /* Fall through */ 115 116 case STATE_FINISHED: 117 if (ev.pulse) 118 break; 119 120 if (!geq_margin(ev.duration, SONY_TRAILER_SPACE, SONY_UNIT / 2)) 121 break; 122 123 switch (data->count) { 124 case 12: 125 device = bitrev8((data->bits << 3) & 0xF8); 126 subdevice = 0; 127 function = bitrev8((data->bits >> 4) & 0xFE); 128 break; 129 case 15: 130 device = bitrev8((data->bits >> 0) & 0xFF); 131 subdevice = 0; 132 function = bitrev8((data->bits >> 7) & 0xFD); 133 break; 134 case 20: 135 device = bitrev8((data->bits >> 5) & 0xF8); 136 subdevice = bitrev8((data->bits >> 0) & 0xFF); 137 function = bitrev8((data->bits >> 12) & 0xFE); 138 break; 139 default: 140 IR_dprintk(1, "Sony invalid bitcount %u\n", data->count); 141 goto out; 142 } 143 144 scancode = device << 16 | subdevice << 8 | function; 145 IR_dprintk(1, "Sony(%u) scancode 0x%05x\n", data->count, scancode); 146 rc_keydown(dev, scancode, 0); 147 data->state = STATE_INACTIVE; 148 return 0; 149 } 150 151 out: 152 IR_dprintk(1, "Sony decode failed at state %d (%uus %s)\n", 153 data->state, TO_US(ev.duration), TO_STR(ev.pulse)); 154 data->state = STATE_INACTIVE; 155 return -EINVAL; 156 } 157 158 static struct ir_raw_handler sony_handler = { 159 .protocols = RC_TYPE_SONY, 160 .decode = ir_sony_decode, 161 }; 162 163 static int __init ir_sony_decode_init(void) 164 { 165 ir_raw_handler_register(&sony_handler); 166 167 printk(KERN_INFO "IR Sony protocol handler initialized\n"); 168 return 0; 169 } 170 171 static void __exit ir_sony_decode_exit(void) 172 { 173 ir_raw_handler_unregister(&sony_handler); 174 } 175 176 module_init(ir_sony_decode_init); 177 module_exit(ir_sony_decode_exit); 178 179 MODULE_LICENSE("GPL"); 180 MODULE_AUTHOR("David Härdeman <david@hardeman.nu>"); 181 MODULE_DESCRIPTION("Sony IR protocol decoder"); 182