Add the capability to encode NEC scancodes as raw events. The
scancode_to_raw is pretty much taken from the img-ir NEC filter()
callback, and modulation uses the pulse distance helper added in a
previous commit.
Signed-off-by: James Hogan <ja...@albanarts.com>
Cc: Mauro Carvalho Chehab <m.che...@samsung.com>
Cc: Antti Seppälä <a.sepp...@gmail.com>
Cc: David Härdeman <da...@hardeman.nu>
---
Changes in v2:
- Update kerneldoc return values to reflect new API with -ENOBUFS
return value when buffer is full and only a partial message was
encoded.
---
drivers/media/rc/ir-nec-decoder.c | 93 +++++++++++++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)
diff --git a/drivers/media/rc/ir-nec-decoder.c
b/drivers/media/rc/ir-nec-decoder.c
index 9de1791..813fa6b 100644
--- a/drivers/media/rc/ir-nec-decoder.c
+++ b/drivers/media/rc/ir-nec-decoder.c
@@ -203,9 +203,102 @@ static int ir_nec_decode(struct rc_dev *dev, struct
ir_raw_event ev)
return -EINVAL;
}
+/**
+ * ir_nec_scancode_to_raw() - encode an NEC scancode ready for modulation.
+ * @in: scancode filter describing a single NEC scancode.
+ * @raw: raw data to be modulated.
+ */
+static int ir_nec_scancode_to_raw(const struct rc_scancode_filter *in,
+ u32 *raw)
+{
+ unsigned int addr, addr_inv, data, data_inv;
+
+ data = in->data & 0xff;
+
+ if ((in->data | in->mask) & 0xff000000) {
+ /* 32-bit NEC (used by Apple and TiVo remotes) */
+ /* scan encoding: aaAAddDD */
+ if (in->mask != 0xffffffff)
+ return -EINVAL;
+ addr_inv = (in->data >> 24) & 0xff;
+ addr = (in->data >> 16) & 0xff;
+ data_inv = (in->data >> 8) & 0xff;
+ } else if ((in->data | in->mask) & 0x00ff0000) {
+ /* Extended NEC */
+ /* scan encoding AAaaDD */
+ if (in->mask != 0x00ffffff)
+ return -EINVAL;
+ addr = (in->data >> 16) & 0xff;
+ addr_inv = (in->data >> 8) & 0xff;
+ data_inv = data ^ 0xff;
+ } else {
+ /* Normal NEC */
+ /* scan encoding: AADD */
+ if (in->mask != 0x0000ffff)
+ return -EINVAL;
+ addr = (in->data >> 8) & 0xff;
+ addr_inv = addr ^ 0xff;
+ data_inv = data ^ 0xff;
+ }
+
+ /* raw encoding: ddDDaaAA */
+ *raw = data_inv << 24 |
+ data << 16 |
+ addr_inv << 8 |
+ addr;
+ return 0;
+}
+
+static struct ir_raw_timings_pd ir_nec_timings = {
+ .header_pulse = NEC_HEADER_PULSE,
+ .header_space = NEC_HEADER_SPACE,
+ .bit_pulse = NEC_BIT_PULSE,
+ .bit_space[0] = NEC_BIT_0_SPACE,
+ .bit_space[1] = NEC_BIT_1_SPACE,
+ .trailer_pulse = NEC_TRAILER_PULSE,
+ .trailer_space = NEC_TRAILER_SPACE,
+ .msb_first = 0,
+};
+
+/**
+ * ir_nec_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_nec_encode(u64 protocols,
+ const struct rc_scancode_filter *scancode,
+ struct ir_raw_event *events, unsigned int max)
+{
+ struct ir_raw_event *e = events;
+ int ret;
+ u32 raw;
+
+ /* Convert a NEC scancode to raw NEC data */
+ ret = ir_nec_scancode_to_raw(scancode, &raw);
+ if (ret < 0)
+ return ret;
+
+ /* Modulate the raw data using a pulse distance modulation */
+ ret = ir_raw_gen_pd(&e, max, &ir_nec_timings, NEC_NBITS, raw);
+ if (ret < 0)
+ return ret;
+
+ return e - events;
+}
+
static struct ir_raw_handler nec_handler = {
.protocols = RC_BIT_NEC,
.decode = ir_nec_decode,
+ .encode = ir_nec_encode,
};
static int __init ir_nec_decode_init(void)
--
1.8.3.2
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