diff options
Diffstat (limited to 'drivers/media/rc/ir-rc5-decoder.c')
| -rw-r--r-- | drivers/media/rc/ir-rc5-decoder.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-rc5-decoder.c b/drivers/media/rc/ir-rc5-decoder.c index 84fa6e9b59a1..8939ebd74391 100644 --- a/drivers/media/rc/ir-rc5-decoder.c +++ b/drivers/media/rc/ir-rc5-decoder.c @@ -184,9 +184,125 @@ out: return -EINVAL; } +static struct ir_raw_timings_manchester ir_rc5_timings = { + .leader = RC5_UNIT, + .pulse_space_start = 0, + .clock = RC5_UNIT, + .trailer_space = RC5_UNIT * 10, +}; + +static struct ir_raw_timings_manchester ir_rc5x_timings[2] = { + { + .leader = RC5_UNIT, + .pulse_space_start = 0, + .clock = RC5_UNIT, + .trailer_space = RC5X_SPACE, + }, + { + .clock = RC5_UNIT, + .trailer_space = RC5_UNIT * 10, + }, +}; + +static struct ir_raw_timings_manchester ir_rc5_sz_timings = { + .leader = RC5_UNIT, + .pulse_space_start = 0, + .clock = RC5_UNIT, + .trailer_space = RC5_UNIT * 10, +}; + +static int ir_rc5_validate_filter(const struct rc_scancode_filter *scancode, + unsigned int important_bits) +{ + /* all important bits of scancode should be set in mask */ + if (~scancode->mask & important_bits) + return -EINVAL; + /* extra bits in mask should be zero in data */ + if (scancode->mask & scancode->data & ~important_bits) + return -EINVAL; + return 0; +} + +/** + * ir_rc5_encode() - Encode a scancode as a stream of raw events + * + * @protocols: allowed protocols + * @scancode: scancode filter describing scancode (helps distinguish between + * protocol subtypes when scancode is ambiguous) + * @events: array of raw ir events to write into + * @max: maximum size of @events + * + * Returns: The number of events written. + * -ENOBUFS if there isn't enough space in the array to fit the + * encoding. In this case all @max events will have been written. + * -EINVAL if the scancode is ambiguous or invalid. + */ +static int ir_rc5_encode(u64 protocols, + const struct rc_scancode_filter *scancode, + struct ir_raw_event *events, unsigned int max) +{ + int ret; + struct ir_raw_event *e = events; + unsigned int data, xdata, command, commandx, system; + + /* Detect protocol and convert scancode to raw data */ + if (protocols & RC_BIT_RC5 && + !ir_rc5_validate_filter(scancode, 0x1f7f)) { + /* decode scancode */ + command = (scancode->data & 0x003f) >> 0; + commandx = (scancode->data & 0x0040) >> 6; + system = (scancode->data & 0x1f00) >> 8; + /* encode data */ + data = !commandx << 12 | system << 6 | command; + + /* Modulate the data */ + ret = ir_raw_gen_manchester(&e, max, &ir_rc5_timings, RC5_NBITS, + data); + if (ret < 0) + return ret; + } else if (protocols & RC_BIT_RC5X && + !ir_rc5_validate_filter(scancode, 0x1f7f3f)) { + /* decode scancode */ + xdata = (scancode->data & 0x00003f) >> 0; + command = (scancode->data & 0x003f00) >> 8; + commandx = (scancode->data & 0x004000) >> 14; + system = (scancode->data & 0x1f0000) >> 16; + /* commandx and system overlap, bits must match when encoded */ + if (commandx == (system & 0x1)) + return -EINVAL; + /* encode data */ + data = 1 << 18 | system << 12 | command << 6 | xdata; + + /* Modulate the data */ + ret = ir_raw_gen_manchester(&e, max, &ir_rc5x_timings[0], + CHECK_RC5X_NBITS, + data >> (RC5X_NBITS-CHECK_RC5X_NBITS)); + if (ret < 0) + return ret; + ret = ir_raw_gen_manchester(&e, max - (e - events), + &ir_rc5x_timings[1], + RC5X_NBITS - CHECK_RC5X_NBITS, + data); + if (ret < 0) + return ret; + } else if (protocols & RC_BIT_RC5_SZ && + !ir_rc5_validate_filter(scancode, 0x2fff)) { + /* RC5-SZ scancode is raw enough for Manchester as it is */ + ret = ir_raw_gen_manchester(&e, max, &ir_rc5_sz_timings, + RC5_SZ_NBITS, scancode->data & 0x2fff); + if (ret < 0) + return ret; + } else { + return -EINVAL; + } + + return e - events; +} + static struct ir_raw_handler rc5_handler = { .protocols = RC_BIT_RC5 | RC_BIT_RC5X | RC_BIT_RC5_SZ, .decode = ir_rc5_decode, + .encode = ir_rc5_encode, }; static int __init ir_rc5_decode_init(void) |