V4L/DVB: ir-rc5-decoder: fix state machine (9b09df51) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/media/IR/ir-rc5-decoder.c

+52 −109

Original line number	Original line	Diff line number	Diff line
	@@ -15,19 +15,17 @@
	/*		/*
	* This code only handles 14 bits RC-5 protocols. There are other variants		* This code only handles 14 bits RC-5 protocols. There are other variants
	* that use a different number of bits. This is currently unsupported		* that use a different number of bits. This is currently unsupported
			* It considers a carrier of 36 kHz, with a total of 14 bits, where
			* the first two bits are start bits, and a third one is a filing bit
	*/		*/

	#include <media/ir-core.h>		#include <media/ir-core.h>

	#define RC5_NBITS 14		static unsigned int ir_rc5_remote_gap = 888888;
	#define RC5_HALFBIT 888888 /* ns */
	#define RC5_BIT (RC5_HALFBIT * 2)
	#define RC5_DURATION (RC5_BIT * RC5_NBITS)

	#define is_rc5_halfbit(nsec) ((ev->delta.tv_nsec >= RC5_HALFBIT / 2) && \
	(ev->delta.tv_nsec < RC5_HALFBIT + RC5_HALFBIT / 2))

	#define n_half(nsec) ((ev->delta.tv_nsec + RC5_HALFBIT / 2) / RC5_HALFBIT)		#define RC5_NBITS 14
			#define RC5_BIT (ir_rc5_remote_gap * 2)
			#define RC5_DURATION (ir_rc5_remote_gap * RC5_NBITS)

	/* Used to register rc5_decoder clients */		/* Used to register rc5_decoder clients */
	static LIST_HEAD(decoder_list);		static LIST_HEAD(decoder_list);
	@@ -35,19 +33,8 @@ static spinlock_t decoder_lock;

	enum rc5_state {		enum rc5_state {
	STATE_INACTIVE,		STATE_INACTIVE,
	STATE_START2_SPACE,
	STATE_START2_MARK,
	STATE_MARKSPACE,		STATE_MARKSPACE,
	STATE_TRAILER_MARK,		STATE_TRAILER,
	};

	static char *st_name[] = {
	"Inactive",
	"start2 sapce",
	"start2 mark",
	"mark",
	"space",
	"trailer"
	};		};

	struct rc5_code {		struct rc5_code {
	@@ -63,8 +50,7 @@ struct decoder_data {
	/* State machine control */		/* State machine control */
	enum rc5_state state;		enum rc5_state state;
	struct rc5_code rc5_code;		struct rc5_code rc5_code;
	unsigned n_half;		unsigned code, elapsed, last_bit, last_code;
	unsigned count;
	};		};


	@@ -147,7 +133,7 @@ static int ir_rc5_decode(struct input_dev *input_dev,
	{		{
	struct decoder_data *data;		struct decoder_data *data;
	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);		struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
	int bit, last_bit, n_half;		int is_pulse, scancode, delta, toggle;

	data = get_decoder_data(ir_dev);		data = get_decoder_data(ir_dev);
	if (!data)		if (!data)
	@@ -156,122 +142,79 @@ static int ir_rc5_decode(struct input_dev *input_dev,
	if (!data->enabled)		if (!data->enabled)
	return 0;		return 0;

	/* Except for the initial event, what matters is the previous bit */		delta = DIV_ROUND_CLOSEST(ev->delta.tv_nsec, ir_rc5_remote_gap);
	bit = (ev->type & IR_PULSE) ? 1 : 0;

	last_bit = !bit;		/* The duration time refers to the last bit time */
			is_pulse = (ev->type & IR_PULSE) ? 1 : 0;
	/* Discards spurious space last_bits when inactive */

	/* Very long delays are considered as start events */		/* Very long delays are considered as start events */
	if (ev->delta.tv_nsec > RC5_DURATION + RC5_HALFBIT / 2)		if (delta > RC5_DURATION \|\| (ev->type & IR_START_EVENT))
	data->state = STATE_INACTIVE;

	if (ev->type & IR_START_EVENT)
	data->state = STATE_INACTIVE;		data->state = STATE_INACTIVE;

	switch (data->state) {		switch (data->state) {
	case STATE_INACTIVE:		case STATE_INACTIVE:
	IR_dprintk(1, "currently inative. Received bit (%s) @%luus\n",		IR_dprintk(2, "currently inative. Start bit (%s) @%uus\n",
	last_bit ? "pulse" : "space",		is_pulse ? "pulse" : "space",
	(ev->delta.tv_nsec + 500) / 1000);		(unsigned)(ev->delta.tv_nsec + 500) / 1000);

	/* Discards the initial start space */		/* Discards the initial start space */
	if (bit)		if (!is_pulse)
	return 0;
	data->count = 0;
	data->n_half = 0;
	memset (&data->rc5_code, 0, sizeof(data->rc5_code));

	data->state = STATE_START2_SPACE;
	return 0;
	case STATE_START2_SPACE:
	if (last_bit)
	goto err;
	if (!is_rc5_halfbit(ev->delta.tv_nsec))
	goto err;
	data->state = STATE_START2_MARK;
	return 0;
	case STATE_START2_MARK:
	if (!last_bit)
	goto err;

	if (!is_rc5_halfbit(ev->delta.tv_nsec))
	goto err;		goto err;
			data->code = 1;
			data->last_bit = 1;
			data->elapsed = 0;
			memset(&data->rc5_code, 0, sizeof(data->rc5_code));
	data->state = STATE_MARKSPACE;		data->state = STATE_MARKSPACE;
	return 0;		return 0;
	case STATE_MARKSPACE:		case STATE_MARKSPACE:
	n_half = n_half(ev->delta.tv_nsec);		if (delta != 1)
	if (n_half < 1 \|\| n_half > 3) {		data->last_bit = data->last_bit ? 0 : 1;
	IR_dprintk(1, "Decode failed at %d-th bit (%s) @%luus\n",
	data->count,
	last_bit ? "pulse" : "space",
	(ev->delta.tv_nsec + 500) / 1000);
	printk("%d halves\n", n_half);
	goto err2;
	}
	data->n_half += n_half;

	if (!last_bit)		data->elapsed += delta;
	return 0;

	/* Got one complete mark/space cycle */		if ((data->elapsed % 2) == 1)
			return 0;

	bit = ((data->count + 1) * 2)/ data->n_half;		data->code <<= 1;
			data->code \|= data->last_bit;

	printk("%d halves, %d bits\n", n_half, bit);		/* Fill the 2 unused bits at the command with 0 */
			if (data->elapsed / 2 == 6)
			data->code <<= 2;

	#if 1 /* SANITY check - while testing the decoder */		if (data->elapsed >= (RC5_NBITS - 1) * 2) {
	if (bit > 1) {		scancode = data->code;
	IR_dprintk(1, "Decoder HAS failed at %d-th bit (%s) @%luus\n",
	data->count,
	last_bit ? "pulse" : "space",
	(ev->delta.tv_nsec + 500) / 1000);

	goto err2;		/* Check for the start bits */
			if ((scancode & 0xc000) != 0xc000) {
			IR_dprintk(1, "Code 0x%04x doesn't have two start bits. It is not RC-5\n", scancode);
			goto err;
	}		}
	#endif
	/* Ok, we've got a valid bit. proccess it */
	if (bit) {
	int shift = data->count;

	/*		toggle = (scancode & 0x2000) ? 1 : 0;
	* RC-5 transmit bytes on this temporal order:
	* address \| not address \| command \| not command		if (scancode == data->last_code) {
	*/		IR_dprintk(1, "RC-5 repeat\n");
	if (shift < 8) {		ir_repeat(input_dev);
	data->rc5_code.address \|= 1 << shift;
	} else {		} else {
	data->rc5_code.command \|= 1 << (shift - 8);		data->last_code = scancode;
	}		scancode &= 0x1fff;
	}
	IR_dprintk(1, "RC-5: bit #%d: %d (%d)\n",
	data->count, bit, data->n_half);
	if (++data->count >= RC5_NBITS) {
	u32 scancode;
	scancode = data->rc5_code.address << 8 \|
	data->rc5_code.command;
	IR_dprintk(1, "RC-5 scancode 0x%04x\n", scancode);		IR_dprintk(1, "RC-5 scancode 0x%04x\n", scancode);

	ir_keydown(input_dev, scancode, 0);		ir_keydown(input_dev, scancode, 0);
			}
	data->state = STATE_TRAILER_MARK;		data->state = STATE_TRAILER;
	}		}
	return 0;		return 0;
	case STATE_TRAILER_MARK:		case STATE_TRAILER:
	if (!last_bit)
	goto err;
	data->state = STATE_INACTIVE;		data->state = STATE_INACTIVE;
	return 0;		return 0;
	}		}

	err:		err:
	IR_dprintk(1, "RC-5 decoded failed at state %s (%s) @ %luus\n",		IR_dprintk(1, "RC-5 decoded failed at %s @ %luus\n",
	st_name[data->state],		is_pulse ? "pulse" : "space",
	bit ? "pulse" : "space",
	(ev->delta.tv_nsec + 500) / 1000);		(ev->delta.tv_nsec + 500) / 1000);
	err2:
	data->state = STATE_INACTIVE;		data->state = STATE_INACTIVE;
	return -EINVAL;		return -EINVAL;
	}		}