drivers/media/rc/ir-sanyo-decoder.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // ir-sanyo-decoder.c - handle SANYO IR Pulse/Space protocol
   3 //
   4 // Copyright (C) 2011 by Mauro Carvalho Chehab
   5 //
   6 // This protocol uses the NEC protocol timings. However, data is formatted as:
   7 //      13 bits Custom Code
   8 //      13 bits NOT(Custom Code)
   9 //      8 bits Key data
  10 //      8 bits NOT(Key data)
  11 //
  12 // According with LIRC, this protocol is used on Sanyo, Aiwa and Chinon
  13 // Information for this protocol is available at the Sanyo LC7461 datasheet.
  14
  15 #include <linux/module.h>
  16 #include <linux/bitrev.h>
  17 #include "rc-core-priv.h"
  18
  19 #define SANYO_NBITS             (13+13+8+8)
  20 #define SANYO_UNIT              562500  /* ns */
  21 #define SANYO_HEADER_PULSE      (16  * SANYO_UNIT)
  22 #define SANYO_HEADER_SPACE      (8   * SANYO_UNIT)
  23 #define SANYO_BIT_PULSE         (1   * SANYO_UNIT)
  24 #define SANYO_BIT_0_SPACE       (1   * SANYO_UNIT)
  25 #define SANYO_BIT_1_SPACE       (3   * SANYO_UNIT)
  26 #define SANYO_REPEAT_SPACE      (150 * SANYO_UNIT)
  27 #define SANYO_TRAILER_PULSE     (1   * SANYO_UNIT)
  28 #define SANYO_TRAILER_SPACE     (10  * SANYO_UNIT)      /* in fact, 42 */
  29
  30 enum sanyo_state {
  31         STATE_INACTIVE,
  32         STATE_HEADER_SPACE,
  33         STATE_BIT_PULSE,
  34         STATE_BIT_SPACE,
  35         STATE_TRAILER_PULSE,
  36         STATE_TRAILER_SPACE,
  37 };
  38
  39 /**
  40  * ir_sanyo_decode() - Decode one SANYO pulse or space
  41  * @dev:        the struct rc_dev descriptor of the device
  42  * @ev:         the struct ir_raw_event descriptor of the pulse/space
  43  *
  44  * This function returns -EINVAL if the pulse violates the state machine
  45  */
  46 static int ir_sanyo_decode(struct rc_dev *dev, struct ir_raw_event ev)
  47 {
  48         struct sanyo_dec *data = &dev->raw->sanyo;
  49         u32 scancode;
  50         u16 address;
  51         u8 command, not_command;
  52
  53         if (!is_timing_event(ev)) {
  54                 if (ev.reset) {
  55                         dev_dbg(&dev->dev, "SANYO event reset received. reset to state 0\n");
  56                         data->state = STATE_INACTIVE;
  57                 }
  58                 return 0;
  59         }
  60
  61         dev_dbg(&dev->dev, "SANYO decode started at state %d (%uus %s)\n",
  62                 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
  63
  64         switch (data->state) {
  65
  66         case STATE_INACTIVE:
  67                 if (!ev.pulse)
  68                         break;
  69
  70                 if (eq_margin(ev.duration, SANYO_HEADER_PULSE, SANYO_UNIT / 2)) {
  71                         data->count = 0;
  72                         data->state = STATE_HEADER_SPACE;
  73                         return 0;
  74                 }
  75                 break;
  76
  77
  78         case STATE_HEADER_SPACE:
  79                 if (ev.pulse)
  80                         break;
  81
  82                 if (eq_margin(ev.duration, SANYO_HEADER_SPACE, SANYO_UNIT / 2)) {
  83                         data->state = STATE_BIT_PULSE;
  84                         return 0;
  85                 }
  86
  87                 break;
  88
  89         case STATE_BIT_PULSE:
  90                 if (!ev.pulse)
  91                         break;
  92
  93                 if (!eq_margin(ev.duration, SANYO_BIT_PULSE, SANYO_UNIT / 2))
  94                         break;
  95
  96                 data->state = STATE_BIT_SPACE;
  97                 return 0;
  98
  99         case STATE_BIT_SPACE:
 100                 if (ev.pulse)
 101                         break;
 102
 103                 if (!data->count && geq_margin(ev.duration, SANYO_REPEAT_SPACE, SANYO_UNIT / 2)) {
 104                         rc_repeat(dev);
 105                         dev_dbg(&dev->dev, "SANYO repeat last key\n");
 106                         data->state = STATE_INACTIVE;
 107                         return 0;
 108                 }
 109
 110                 data->bits <<= 1;
 111                 if (eq_margin(ev.duration, SANYO_BIT_1_SPACE, SANYO_UNIT / 2))
 112                         data->bits |= 1;
 113                 else if (!eq_margin(ev.duration, SANYO_BIT_0_SPACE, SANYO_UNIT / 2))
 114                         break;
 115                 data->count++;
 116
 117                 if (data->count == SANYO_NBITS)
 118                         data->state = STATE_TRAILER_PULSE;
 119                 else
 120                         data->state = STATE_BIT_PULSE;
 121
 122                 return 0;
 123
 124         case STATE_TRAILER_PULSE:
 125                 if (!ev.pulse)
 126                         break;
 127
 128                 if (!eq_margin(ev.duration, SANYO_TRAILER_PULSE, SANYO_UNIT / 2))
 129                         break;
 130
 131                 data->state = STATE_TRAILER_SPACE;
 132                 return 0;
 133
 134         case STATE_TRAILER_SPACE:
 135                 if (ev.pulse)
 136                         break;
 137
 138                 if (!geq_margin(ev.duration, SANYO_TRAILER_SPACE, SANYO_UNIT / 2))
 139                         break;
 140
 141                 address     = bitrev16((data->bits >> 29) & 0x1fff) >> 3;
 142                 /* not_address = bitrev16((data->bits >> 16) & 0x1fff) >> 3; */
 143                 command     = bitrev8((data->bits >>  8) & 0xff);
 144                 not_command = bitrev8((data->bits >>  0) & 0xff);
 145
 146                 if ((command ^ not_command) != 0xff) {
 147                         dev_dbg(&dev->dev, "SANYO checksum error: received 0x%08llx\n",
 148                                 data->bits);
 149                         data->state = STATE_INACTIVE;
 150                         return 0;
 151                 }
 152
 153                 scancode = address << 8 | command;
 154                 dev_dbg(&dev->dev, "SANYO scancode: 0x%06x\n", scancode);
 155                 rc_keydown(dev, RC_PROTO_SANYO, scancode, 0);
 156                 data->state = STATE_INACTIVE;
 157                 return 0;
 158         }
 159
 160         dev_dbg(&dev->dev, "SANYO decode failed at count %d state %d (%uus %s)\n",
 161                 data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 162         data->state = STATE_INACTIVE;
 163         return -EINVAL;
 164 }
 165
 166 static const struct ir_raw_timings_pd ir_sanyo_timings = {
 167         .header_pulse  = SANYO_HEADER_PULSE,
 168         .header_space  = SANYO_HEADER_SPACE,
 169         .bit_pulse     = SANYO_BIT_PULSE,
 170         .bit_space[0]  = SANYO_BIT_0_SPACE,
 171         .bit_space[1]  = SANYO_BIT_1_SPACE,
 172         .trailer_pulse = SANYO_TRAILER_PULSE,
 173         .trailer_space = SANYO_TRAILER_SPACE,
 174         .msb_first     = 1,
 175 };
 176
 177 /**
 178  * ir_sanyo_encode() - Encode a scancode as a stream of raw events
 179  *
 180  * @protocol:   protocol to encode
 181  * @scancode:   scancode to encode
 182  * @events:     array of raw ir events to write into
 183  * @max:        maximum size of @events
 184  *
 185  * Returns:     The number of events written.
 186  *              -ENOBUFS if there isn't enough space in the array to fit the
 187  *              encoding. In this case all @max events will have been written.
 188  */
 189 static int ir_sanyo_encode(enum rc_proto protocol, u32 scancode,
 190                            struct ir_raw_event *events, unsigned int max)
 191 {
 192         struct ir_raw_event *e = events;
 193         int ret;
 194         u64 raw;
 195
 196         raw = ((u64)(bitrev16(scancode >> 8) & 0xfff8) << (8 + 8 + 13 - 3)) |
 197               ((u64)(bitrev16(~scancode >> 8) & 0xfff8) << (8 + 8 +  0 - 3)) |
 198               ((bitrev8(scancode) & 0xff) << 8) |
 199               (bitrev8(~scancode) & 0xff);
 200
 201         ret = ir_raw_gen_pd(&e, max, &ir_sanyo_timings, SANYO_NBITS, raw);
 202         if (ret < 0)
 203                 return ret;
 204
 205         return e - events;
 206 }
 207
 208 static struct ir_raw_handler sanyo_handler = {
 209         .protocols      = RC_PROTO_BIT_SANYO,
 210         .decode         = ir_sanyo_decode,
 211         .encode         = ir_sanyo_encode,
 212         .carrier        = 38000,
 213         .min_timeout    = SANYO_TRAILER_SPACE,
 214 };
 215
 216 static int __init ir_sanyo_decode_init(void)
 217 {
 218         ir_raw_handler_register(&sanyo_handler);
 219
 220         printk(KERN_INFO "IR SANYO protocol handler initialized\n");
 221         return 0;
 222 }
 223
 224 static void __exit ir_sanyo_decode_exit(void)
 225 {
 226         ir_raw_handler_unregister(&sanyo_handler);
 227 }
 228
 229 module_init(ir_sanyo_decode_init);
 230 module_exit(ir_sanyo_decode_exit);
 231
 232 MODULE_LICENSE("GPL v2");
 233 MODULE_AUTHOR("Mauro Carvalho Chehab");
 234 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 235 MODULE_DESCRIPTION("SANYO IR protocol decoder");