Commit 8d023a57 authored by Sean Young's avatar Sean Young Committed by Mauro Carvalho Chehab
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media: rc: imon_raw: use fls rather than loop per bit 



Previously, the code would loop for each of the 40 bits. Now it will
branch for each edge in the IR, which will be much less.

Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent cea1c41d

drivers/media/rc/imon_raw.c

+23 −24
Original line number Diff line number Diff line
@@ -14,51 +14,50 @@ struct imon { 
	struct device *dev;

	struct urb *ir_urb;

	struct rc_dev *rcdev;

	u8 ir_buf[8];

	u8 ir_buf[8] __aligned(__alignof__(u64));

	char phys[64];

};



/*

 * ffs/find_next_bit() searches in the wrong direction, so open-code our own.

 * The first 5 bytes of data represent IR pulse or space. Each bit, starting

 * from highest bit in the first byte, represents 250µs of data. It is 1

 * for space and 0 for pulse.

 *

 * The station sends 10 packets, and the 7th byte will be number 1 to 10, so

 * when we receive 10 we assume all the data has arrived.

 */

static inline int is_bit_set(const u8 *buf, int bit)

{

	return buf[bit / 8] & (0x80 >> (bit & 7));

}



static void imon_ir_data(struct imon *imon)

{

	struct ir_raw_event rawir = {};

	int offset = 0, size = 5 * 8;

	u64 d = be64_to_cpup((__be64 *)imon->ir_buf) >> 24;

	int offset = 40;

	int bit;



	dev_dbg(imon->dev, "data: %*ph", 8, imon->ir_buf);



	while (offset < size) {

		bit = offset;

		while (!is_bit_set(imon->ir_buf, bit) && bit < size)

			bit++;

		dev_dbg(imon->dev, "pulse: %d bits", bit - offset);

		if (bit > offset) {

	do {

		bit = fls64(d & (BIT_ULL(offset) - 1));

		if (bit < offset) {

			dev_dbg(imon->dev, "pulse: %d bits", offset - bit);

			rawir.pulse = true;

			rawir.duration = (bit - offset) * BIT_DURATION;

			rawir.duration = (offset - bit) * BIT_DURATION;

			ir_raw_event_store_with_filter(imon->rcdev, &rawir);

		}



		if (bit >= size)

			if (bit == 0)

				break;



			offset = bit;

		while (is_bit_set(imon->ir_buf, bit) && bit < size)

			bit++;

		dev_dbg(imon->dev, "space: %d bits", bit - offset);

		}



		bit = fls64(~d & (BIT_ULL(offset) - 1));

		dev_dbg(imon->dev, "space: %d bits", offset - bit);



		rawir.pulse = false;

		rawir.duration = (bit - offset) * BIT_DURATION;

		rawir.duration = (offset - bit) * BIT_DURATION;

		ir_raw_event_store_with_filter(imon->rcdev, &rawir);



		offset = bit;

	}

	} while (offset > 0);



	if (imon->ir_buf[7] == 0x0a) {

		ir_raw_event_set_idle(imon->rcdev, true);