X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fmedia%2FIR%2Fir-nec-decoder.c;h=02682e617fae886daab93441fe301c5f443feb40;hb=724e2495502a98aaa3f93c404472a991da8ff857;hp=0b50060ffbafae18cb5e76af93f477943fe71f93;hpb=a374fef4437abd0a1ee27afe0cca7a55425c1c3c;p=safe%2Fjmp%2Flinux-2.6

diff --git a/drivers/media/IR/ir-nec-decoder.c b/drivers/media/IR/ir-nec-decoder.c
index 0b50060..02682e6 100644
--- a/drivers/media/IR/ir-nec-decoder.c
+++ b/drivers/media/IR/ir-nec-decoder.c
@@ -13,40 +13,39 @@
  */
 
 #include <media/ir-core.h>
+#include <linux/bitrev.h>
 
-/* Start time: 4.5 ms + 560 us of the next pulse */
-#define MIN_START_TIME	(3900000 + 560000)
-#define MAX_START_TIME	(5100000 + 560000)
-
-/* Bit 1 time: 2.25ms us */
-#define MIN_BIT1_TIME	2050000
-#define MAX_BIT1_TIME	2450000
-
-/* Bit 0 time: 1.12ms us */
-#define MIN_BIT0_TIME	920000
-#define MAX_BIT0_TIME	1320000
-
-/* Total IR code is 110 ms, including the 9 ms for the start pulse */
-#define MAX_NEC_TIME	4000000
-
-/* Total IR code is 110 ms, including the 9 ms for the start pulse */
-#define MIN_REPEAT_TIME	99000000
-#define MAX_REPEAT_TIME	112000000
-
-/* Repeat time: 2.25ms us */
-#define MIN_REPEAT_START_TIME	2050000
-#define MAX_REPEAT_START_TIME	3000000
-
-#define REPEAT_TIME	240 /* ms */
+#define NEC_NBITS		32
+#define NEC_UNIT		562500  /* ns */
+#define NEC_HEADER_PULSE	PULSE(16)
+#define NEC_HEADER_SPACE	SPACE(8)
+#define NEC_REPEAT_SPACE	SPACE(4)
+#define NEC_BIT_PULSE		PULSE(1)
+#define NEC_BIT_0_SPACE		SPACE(1)
+#define NEC_BIT_1_SPACE		SPACE(3)
 
 /* Used to register nec_decoder clients */
 static LIST_HEAD(decoder_list);
-static spinlock_t decoder_lock;
+static DEFINE_SPINLOCK(decoder_lock);
+
+enum nec_state {
+	STATE_INACTIVE,
+	STATE_HEADER_SPACE,
+	STATE_BIT_PULSE,
+	STATE_BIT_SPACE,
+	STATE_TRAILER_PULSE,
+	STATE_TRAILER_SPACE,
+};
 
 struct decoder_data {
 	struct list_head	list;
 	struct ir_input_dev	*ir_dev;
 	int			enabled:1;
+
+	/* State machine control */
+	enum nec_state		state;
+	u32			nec_bits;
+	unsigned		count;
 };
 
 
@@ -56,7 +55,6 @@ struct decoder_data {
  *
  * Returns the struct decoder_data that corresponds to a device
  */
-
 static struct decoder_data *get_decoder_data(struct  ir_input_dev *ir_dev)
 {
 	struct decoder_data *data = NULL;
@@ -117,163 +115,130 @@ static struct attribute_group decoder_attribute_group = {
 	.attrs	= decoder_attributes,
 };
 
-
-/** is_repeat - Check if it is a NEC repeat event
+/**
+ * ir_nec_decode() - Decode one NEC pulse or space
  * @input_dev:	the struct input_dev descriptor of the device
- * @pos:	the position of the first event
- * @len:	the length of the buffer
+ * @duration:	duration in ns of pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
  */
-static int is_repeat(struct ir_raw_event *evs, int len, int pos)
+static int ir_nec_decode(struct input_dev *input_dev, s64 duration)
 {
-	if ((evs[pos].delta.tv_nsec < MIN_REPEAT_START_TIME) ||
-	    (evs[pos].delta.tv_nsec > MAX_REPEAT_START_TIME))
-		return 0;
+	struct decoder_data *data;
+	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+	int u;
+	u32 scancode;
+	u8 address, not_address, command, not_command;
 
-	if (++pos >= len)
-		return 0;
+	data = get_decoder_data(ir_dev);
+	if (!data)
+		return -EINVAL;
 
-	if ((evs[pos].delta.tv_nsec < MIN_REPEAT_TIME) ||
-	    (evs[pos].delta.tv_nsec > MAX_REPEAT_TIME))
+	if (!data->enabled)
 		return 0;
 
-	return 1;
-}
+	if (IS_RESET(duration)) {
+		data->state = STATE_INACTIVE;
+		return 0;
+	}
 
-/**
- * __ir_nec_decode() - Decode one NEC pulsecode
- * @input_dev:	the struct input_dev descriptor of the device
- * @evs:	event array with type/duration of pulse/space
- * @len:	length of the array
- * @pos:	position to start seeking for a code
- * This function returns -EINVAL if no pulse got decoded,
- * 0 if buffer is empty and 1 if one keycode were handled.
- */
-static int __ir_nec_decode(struct input_dev *input_dev,
-			   struct ir_raw_event *evs,
-			   int len, int *pos)
-{
-	struct ir_input_dev *ir = input_get_drvdata(input_dev);
-	int count = -1;
-	int ircode = 0, not_code = 0;
-
-	/* Be sure that the first event is an start one and is a pulse */
-	for (; *pos < len; (*pos)++) {
-		/* Very long delays are considered as start events */
-		if (evs[*pos].delta.tv_nsec > MAX_NEC_TIME)
-			break;
-		if (evs[*pos].type & IR_START_EVENT)
-			break;
-		IR_dprintk(1, "%luus: Spurious NEC %s\n",
-			   (evs[*pos].delta.tv_nsec + 500) / 1000,
-			   (evs[*pos].type & IR_SPACE) ? "space" : "pulse");
+	u = TO_UNITS(duration, NEC_UNIT);
+	if (DURATION(u) == 0)
+		goto out;
 
-	}
-	if (*pos >= len)
-		return 0;
+	IR_dprintk(2, "NEC decode started at state %d (%i units, %ius)\n",
+		   data->state, u, TO_US(duration));
 
-	(*pos)++;	/* First event doesn't contain data */
+	switch (data->state) {
 
-	if (evs[*pos].type != IR_PULSE)
-		goto err;
+	case STATE_INACTIVE:
+		if (u == NEC_HEADER_PULSE) {
+			data->count = 0;
+			data->state = STATE_HEADER_SPACE;
+		}
+		return 0;
 
-	/* Check if it is a NEC repeat event */
-	if (is_repeat(evs, len, *pos)) {
-		*pos += 2;
-		if (ir->keypressed) {
+	case STATE_HEADER_SPACE:
+		if (u == NEC_HEADER_SPACE) {
+			data->state = STATE_BIT_PULSE;
+			return 0;
+		} else if (u == NEC_REPEAT_SPACE) {
 			ir_repeat(input_dev);
-			IR_dprintk(1, "NEC repeat event\n");
-			return 1;
-		} else {
-			IR_dprintk(1, "missing NEC repeat event\n");
+			IR_dprintk(1, "Repeat last key\n");
+			data->state = STATE_TRAILER_PULSE;
 			return 0;
 		}
-	}
+		break;
 
-	/* First space should have 4.5 ms otherwise is not NEC protocol */
-	if ((evs[*pos].delta.tv_nsec < MIN_START_TIME) ||
-	    (evs[*pos].delta.tv_nsec > MAX_START_TIME))
-		goto err;
-
-	count = 0;
-	for ((*pos)++; *pos < len; (*pos)++) {
-		int bit;
-		if ((evs[*pos].delta.tv_nsec > MIN_BIT1_TIME) &&
-		    (evs[*pos].delta.tv_nsec < MAX_BIT1_TIME))
-			bit = 1;
-		else if ((evs[*pos].delta.tv_nsec > MIN_BIT0_TIME) &&
-			 (evs[*pos].delta.tv_nsec < MAX_BIT0_TIME))
-			bit = 0;
-		else
-			goto err;
-
-		if (bit) {
-			int shift = count;
-			/* Address first, then command */
-			if (shift < 8) {
-				shift += 8;
-				ircode |= 1 << shift;
-			} else if (shift < 16) {
-				not_code |= 1 << shift;
-			} else if (shift < 24) {
-				shift -= 16;
-				ircode |= 1 << shift;
-			} else {
-				shift -= 24;
-				not_code |= 1 << shift;
-			}
+	case STATE_BIT_PULSE:
+		if (u == NEC_BIT_PULSE) {
+			data->state = STATE_BIT_SPACE;
+			return 0;
 		}
-		if (++count == 32)
+		break;
+
+	case STATE_BIT_SPACE:
+		if (u != NEC_BIT_0_SPACE && u != NEC_BIT_1_SPACE)
 			break;
-	}
-	(*pos)++;
-
-	/*
-	 * Fixme: may need to accept Extended NEC protocol?
-	 */
-	if ((ircode & ~not_code) != ircode) {
-		IR_dprintk(1, "NEC checksum error: code 0x%04x, not-code 0x%04x\n",
-			   ircode, not_code);
-		return -EINVAL;
-	}
 
-	IR_dprintk(1, "NEC scancode 0x%04x\n", ircode);
-	ir_keydown(input_dev, ircode, 0);
+		data->nec_bits <<= 1;
+		if (u == NEC_BIT_1_SPACE)
+			data->nec_bits |= 1;
+		data->count++;
 
-	return 1;
-err:
-	IR_dprintk(1, "NEC decoded failed at bit %d (%s) while decoding %luus time\n",
-		   count,
-		   (evs[*pos].type & IR_SPACE) ? "space" : "pulse",
-		   (evs[*pos].delta.tv_nsec + 500) / 1000);
+		if (data->count != NEC_NBITS) {
+			data->state = STATE_BIT_PULSE;
+			return 0;
+		}
 
-	return -EINVAL;
-}
+		address     = bitrev8((data->nec_bits >> 24) & 0xff);
+		not_address = bitrev8((data->nec_bits >> 16) & 0xff);
+		command	    = bitrev8((data->nec_bits >>  8) & 0xff);
+		not_command = bitrev8((data->nec_bits >>  0) & 0xff);
 
-/**
- * __ir_nec_decode() - Decodes all NEC pulsecodes on a given array
- * @input_dev:	the struct input_dev descriptor of the device
- * @evs:	event array with type/duration of pulse/space
- * @len:	length of the array
- * This function returns the number of decoded pulses
- */
-static int ir_nec_decode(struct input_dev *input_dev,
-			 struct ir_raw_event *evs,
-			 int len)
-{
-	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
-	struct decoder_data *data;
-	int pos = 0;
-	int rc = 0;
+		if ((command ^ not_command) != 0xff) {
+			IR_dprintk(1, "NEC checksum error: received 0x%08x\n",
+				   data->nec_bits);
+			break;
+		}
 
-	data = get_decoder_data(ir_dev);
-	if (!data || !data->enabled)
+		if ((address ^ not_address) != 0xff) {
+			/* Extended NEC */
+			scancode = address     << 16 |
+				   not_address <<  8 |
+				   command;
+			IR_dprintk(1, "NEC (Ext) scancode 0x%06x\n", scancode);
+		} else {
+			/* normal NEC */
+			scancode = address << 8 | command;
+			IR_dprintk(1, "NEC scancode 0x%04x\n", scancode);
+		}
+
+		ir_keydown(input_dev, scancode, 0);
+		data->state = STATE_TRAILER_PULSE;
 		return 0;
 
-	while (pos < len) {
-		if (__ir_nec_decode(input_dev, evs, len, &pos) > 0)
-			rc++;
+	case STATE_TRAILER_PULSE:
+		if (u > 0) {
+			data->state = STATE_TRAILER_SPACE;
+			return 0;
+		}
+		break;
+
+	case STATE_TRAILER_SPACE:
+		if (u < 0) {
+			data->state = STATE_INACTIVE;
+			return 0;
+		}
+
+		break;
 	}
-	return rc;
+
+out:
+	IR_dprintk(1, "NEC decode failed at state %d (%i units, %ius)\n",
+		   data->state, u, TO_US(duration));
+	data->state = STATE_INACTIVE;
+	return -EINVAL;
 }
 
 static int ir_nec_register(struct input_dev *input_dev)