David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 1 | /* ir-rc5-decoder.c - handle RC5(x) IR Pulse/Space protocol |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 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 | /* |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 16 | * This code handles 14 bits RC5 protocols and 20 bits RC5x protocols. |
| 17 | * There are other variants that use a different number of bits. |
| 18 | * This is currently unsupported. |
| 19 | * It considers a carrier of 36 kHz, with a total of 14/20 bits, where |
Mauro Carvalho Chehab | 9b09df5 | 2010-04-06 02:29:42 -0300 | [diff] [blame] | 20 | * the first two bits are start bits, and a third one is a filing bit |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 21 | */ |
| 22 | |
Mauro Carvalho Chehab | 3f113e3 | 2010-04-08 15:10:27 -0300 | [diff] [blame] | 23 | #include "ir-core-priv.h" |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 24 | |
| 25 | #define RC5_NBITS 14 |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 26 | #define RC5X_NBITS 20 |
| 27 | #define CHECK_RC5X_NBITS 8 |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 28 | #define RC5_UNIT 888888 /* ns */ |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 29 | #define RC5_BIT_START (1 * RC5_UNIT) |
| 30 | #define RC5_BIT_END (1 * RC5_UNIT) |
| 31 | #define RC5X_SPACE (4 * RC5_UNIT) |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 32 | |
| 33 | /* Used to register rc5_decoder clients */ |
| 34 | static LIST_HEAD(decoder_list); |
Mauro Carvalho Chehab | 6eb9435 | 2010-04-07 16:19:36 -0300 | [diff] [blame] | 35 | static DEFINE_SPINLOCK(decoder_lock); |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 36 | |
| 37 | enum rc5_state { |
| 38 | STATE_INACTIVE, |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 39 | STATE_BIT_START, |
| 40 | STATE_BIT_END, |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 41 | STATE_CHECK_RC5X, |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 42 | STATE_FINISHED, |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 43 | }; |
| 44 | |
| 45 | struct decoder_data { |
| 46 | struct list_head list; |
| 47 | struct ir_input_dev *ir_dev; |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 48 | |
| 49 | /* State machine control */ |
| 50 | enum rc5_state state; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 51 | u32 rc5_bits; |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 52 | struct ir_raw_event prev_ev; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 53 | unsigned count; |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 54 | unsigned wanted_bits; |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | |
| 58 | /** |
| 59 | * get_decoder_data() - gets decoder data |
| 60 | * @input_dev: input device |
| 61 | * |
| 62 | * Returns the struct decoder_data that corresponds to a device |
| 63 | */ |
| 64 | |
| 65 | static struct decoder_data *get_decoder_data(struct ir_input_dev *ir_dev) |
| 66 | { |
| 67 | struct decoder_data *data = NULL; |
| 68 | |
| 69 | spin_lock(&decoder_lock); |
| 70 | list_for_each_entry(data, &decoder_list, list) { |
| 71 | if (data->ir_dev == ir_dev) |
| 72 | break; |
| 73 | } |
| 74 | spin_unlock(&decoder_lock); |
| 75 | return data; |
| 76 | } |
| 77 | |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 78 | /** |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 79 | * ir_rc5_decode() - Decode one RC-5 pulse or space |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 80 | * @input_dev: the struct input_dev descriptor of the device |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 81 | * @ev: the struct ir_raw_event descriptor of the pulse/space |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 82 | * |
| 83 | * This function returns -EINVAL if the pulse violates the state machine |
| 84 | */ |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 85 | static int ir_rc5_decode(struct input_dev *input_dev, struct ir_raw_event ev) |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 86 | { |
| 87 | struct decoder_data *data; |
| 88 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 89 | u8 toggle; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 90 | u32 scancode; |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 91 | |
| 92 | data = get_decoder_data(ir_dev); |
| 93 | if (!data) |
| 94 | return -EINVAL; |
| 95 | |
David Härdeman | 667c9eb | 2010-06-13 17:29:31 -0300 | [diff] [blame^] | 96 | if (!(ir_dev->raw->enabled_protocols & IR_TYPE_RC5)) |
| 97 | return 0; |
Mauro Carvalho Chehab | 7f20d32 | 2010-04-04 14:45:04 -0300 | [diff] [blame] | 98 | |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 99 | if (IS_RESET(ev)) { |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 100 | data->state = STATE_INACTIVE; |
| 101 | return 0; |
| 102 | } |
| 103 | |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 104 | if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2)) |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 105 | goto out; |
| 106 | |
| 107 | again: |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 108 | IR_dprintk(2, "RC5(x) decode started at state %i (%uus %s)\n", |
| 109 | data->state, TO_US(ev.duration), TO_STR(ev.pulse)); |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 110 | |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 111 | if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2)) |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 112 | return 0; |
| 113 | |
| 114 | switch (data->state) { |
| 115 | |
| 116 | case STATE_INACTIVE: |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 117 | if (!ev.pulse) |
| 118 | break; |
| 119 | |
| 120 | data->state = STATE_BIT_START; |
| 121 | data->count = 1; |
| 122 | /* We just need enough bits to get to STATE_CHECK_RC5X */ |
| 123 | data->wanted_bits = RC5X_NBITS; |
| 124 | decrease_duration(&ev, RC5_BIT_START); |
| 125 | goto again; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 126 | |
| 127 | case STATE_BIT_START: |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 128 | if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2)) |
| 129 | break; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 130 | |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 131 | data->rc5_bits <<= 1; |
| 132 | if (!ev.pulse) |
| 133 | data->rc5_bits |= 1; |
| 134 | data->count++; |
| 135 | data->prev_ev = ev; |
| 136 | data->state = STATE_BIT_END; |
| 137 | return 0; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 138 | |
| 139 | case STATE_BIT_END: |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 140 | if (!is_transition(&ev, &data->prev_ev)) |
| 141 | break; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 142 | |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 143 | if (data->count == data->wanted_bits) |
| 144 | data->state = STATE_FINISHED; |
| 145 | else if (data->count == CHECK_RC5X_NBITS) |
| 146 | data->state = STATE_CHECK_RC5X; |
| 147 | else |
| 148 | data->state = STATE_BIT_START; |
| 149 | |
| 150 | decrease_duration(&ev, RC5_BIT_END); |
| 151 | goto again; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 152 | |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 153 | case STATE_CHECK_RC5X: |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 154 | if (!ev.pulse && geq_margin(ev.duration, RC5X_SPACE, RC5_UNIT / 2)) { |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 155 | /* RC5X */ |
| 156 | data->wanted_bits = RC5X_NBITS; |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 157 | decrease_duration(&ev, RC5X_SPACE); |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 158 | } else { |
| 159 | /* RC5 */ |
| 160 | data->wanted_bits = RC5_NBITS; |
| 161 | } |
| 162 | data->state = STATE_BIT_START; |
| 163 | goto again; |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 164 | |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 165 | case STATE_FINISHED: |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 166 | if (ev.pulse) |
| 167 | break; |
| 168 | |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 169 | if (data->wanted_bits == RC5X_NBITS) { |
| 170 | /* RC5X */ |
| 171 | u8 xdata, command, system; |
| 172 | xdata = (data->rc5_bits & 0x0003F) >> 0; |
| 173 | command = (data->rc5_bits & 0x00FC0) >> 6; |
| 174 | system = (data->rc5_bits & 0x1F000) >> 12; |
| 175 | toggle = (data->rc5_bits & 0x20000) ? 1 : 0; |
| 176 | command += (data->rc5_bits & 0x01000) ? 0 : 0x40; |
| 177 | scancode = system << 16 | command << 8 | xdata; |
| 178 | |
| 179 | IR_dprintk(1, "RC5X scancode 0x%06x (toggle: %u)\n", |
| 180 | scancode, toggle); |
| 181 | |
| 182 | } else { |
| 183 | /* RC5 */ |
| 184 | u8 command, system; |
| 185 | command = (data->rc5_bits & 0x0003F) >> 0; |
| 186 | system = (data->rc5_bits & 0x007C0) >> 6; |
| 187 | toggle = (data->rc5_bits & 0x00800) ? 1 : 0; |
| 188 | command += (data->rc5_bits & 0x01000) ? 0 : 0x40; |
| 189 | scancode = system << 8 | command; |
| 190 | |
| 191 | IR_dprintk(1, "RC5 scancode 0x%04x (toggle: %u)\n", |
| 192 | scancode, toggle); |
| 193 | } |
| 194 | |
David Härdeman | 724e249 | 2010-04-08 13:10:00 -0300 | [diff] [blame] | 195 | ir_keydown(input_dev, scancode, toggle); |
| 196 | data->state = STATE_INACTIVE; |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | out: |
David Härdeman | e40b112 | 2010-04-15 18:46:00 -0300 | [diff] [blame] | 201 | IR_dprintk(1, "RC5(x) decode failed at state %i (%uus %s)\n", |
| 202 | data->state, TO_US(ev.duration), TO_STR(ev.pulse)); |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 203 | data->state = STATE_INACTIVE; |
| 204 | return -EINVAL; |
| 205 | } |
| 206 | |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 207 | static int ir_rc5_register(struct input_dev *input_dev) |
| 208 | { |
| 209 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); |
| 210 | struct decoder_data *data; |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 211 | |
| 212 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
David Härdeman | 667c9eb | 2010-06-13 17:29:31 -0300 | [diff] [blame^] | 213 | if (!data) |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 214 | return -ENOMEM; |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 215 | |
| 216 | data->ir_dev = ir_dev; |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 217 | |
| 218 | spin_lock(&decoder_lock); |
| 219 | list_add_tail(&data->list, &decoder_list); |
| 220 | spin_unlock(&decoder_lock); |
| 221 | |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | static int ir_rc5_unregister(struct input_dev *input_dev) |
| 226 | { |
| 227 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); |
| 228 | static struct decoder_data *data; |
| 229 | |
| 230 | data = get_decoder_data(ir_dev); |
| 231 | if (!data) |
| 232 | return 0; |
| 233 | |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 234 | spin_lock(&decoder_lock); |
| 235 | list_del(&data->list); |
| 236 | spin_unlock(&decoder_lock); |
| 237 | |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static struct ir_raw_handler rc5_handler = { |
David Härdeman | 667c9eb | 2010-06-13 17:29:31 -0300 | [diff] [blame^] | 242 | .protocols = IR_TYPE_RC5, |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 243 | .decode = ir_rc5_decode, |
| 244 | .raw_register = ir_rc5_register, |
| 245 | .raw_unregister = ir_rc5_unregister, |
| 246 | }; |
| 247 | |
| 248 | static int __init ir_rc5_decode_init(void) |
| 249 | { |
| 250 | ir_raw_handler_register(&rc5_handler); |
| 251 | |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 252 | printk(KERN_INFO "IR RC5(x) protocol handler initialized\n"); |
Mauro Carvalho Chehab | db1423a | 2010-04-04 10:27:20 -0300 | [diff] [blame] | 253 | return 0; |
| 254 | } |
| 255 | |
| 256 | static void __exit ir_rc5_decode_exit(void) |
| 257 | { |
| 258 | ir_raw_handler_unregister(&rc5_handler); |
| 259 | } |
| 260 | |
| 261 | module_init(ir_rc5_decode_init); |
| 262 | module_exit(ir_rc5_decode_exit); |
| 263 | |
| 264 | MODULE_LICENSE("GPL"); |
| 265 | MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); |
| 266 | MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); |
David Härdeman | 733419b | 2010-04-08 20:04:30 -0300 | [diff] [blame] | 267 | MODULE_DESCRIPTION("RC5(x) IR protocol decoder"); |