V4L/DVB: Add RC5x support to ir-core

This patch adds RC5x support to drivers/media/IR/ir-rc5-decoder.c
Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

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

-/* ir-rc5-decoder.c - handle RC-5 IR Pulse/Space protocol
+/* ir-rc5-decoder.c - handle RC5(x) IR Pulse/Space protocol
  *
  * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
  *
@@ -13,15 +13,19 @@
  */
 
 /*
- * This code only handles 14 bits RC-5 protocols. There are other variants
- * 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
+ * This code handles 14 bits RC5 protocols and 20 bits RC5x protocols.
+ * There are other variants that use a different number of bits.
+ * This is currently unsupported.
+ * It considers a carrier of 36 kHz, with a total of 14/20 bits, where
  * the first two bits are start bits, and a third one is a filing bit
  */
 
 #include "ir-core-priv.h"
 
 #define RC5_NBITS		14
+#define RC5X_NBITS		20
+#define CHECK_RC5X_NBITS	8
+#define RC5X_SPACE		SPACE(4)
 #define RC5_UNIT		888888 /* ns */
 
 /* Used to register rc5_decoder clients */
@@ -32,6 +36,7 @@ enum rc5_state {
 	STATE_INACTIVE,
 	STATE_BIT_START,
 	STATE_BIT_END,
+	STATE_CHECK_RC5X,
 	STATE_FINISHED,
 };
 
@@ -45,6 +50,7 @@ struct decoder_data {
 	u32			rc5_bits;
 	int			last_unit;
 	unsigned		count;
+	unsigned		wanted_bits;
 };
 
 
@@ -126,7 +132,7 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 {
 	struct decoder_data *data;
 	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
-	u8 command, system, toggle;
+	u8 toggle;
 	u32 scancode;
 	int u;
 
@@ -147,7 +153,7 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 		goto out;
 
 again:
-	IR_dprintk(2, "RC5 decode started at state %i (%i units, %ius)\n",
+	IR_dprintk(2, "RC5(x) decode started at state %i (%i units, %ius)\n",
 		   data->state, u, TO_US(duration));
 
 	if (DURATION(u) == 0 && data->state != STATE_FINISHED)
@@ -159,6 +165,8 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 		if (IS_PULSE(u)) {
 			data->state = STATE_BIT_START;
 			data->count = 1;
+			/* We just need enough bits to get to STATE_CHECK_RC5X */
+			data->wanted_bits = RC5X_NBITS;
 			DECREASE_DURATION(u, 1);
 			goto again;
 		}
@@ -176,7 +184,7 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 			 * If the last bit is zero, a space will merge
 			 * with the silence after the command.
 			 */
-			if (IS_PULSE(u) && data->count == RC5_NBITS) {
+			if (IS_PULSE(u) && data->count == data->wanted_bits) {
 				data->state = STATE_FINISHED;
 				goto again;
 			}
@@ -188,8 +196,10 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 
 	case STATE_BIT_END:
 		if (IS_TRANSITION(u, data->last_unit)) {
-			if (data->count == RC5_NBITS)
+			if (data->count == data->wanted_bits)
 				data->state = STATE_FINISHED;
+			else if (data->count == CHECK_RC5X_NBITS)
+				data->state = STATE_CHECK_RC5X;
 			else
 				data->state = STATE_BIT_START;
 
@@ -198,7 +208,35 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 		}
 		break;
 
+	case STATE_CHECK_RC5X:
+		if (IS_SPACE(u) && DURATION(u) >= DURATION(RC5X_SPACE)) {
+			/* RC5X */
+			data->wanted_bits = RC5X_NBITS;
+			DECREASE_DURATION(u, DURATION(RC5X_SPACE));
+		} else {
+			/* RC5 */
+			data->wanted_bits = RC5_NBITS;
+		}
+		data->state = STATE_BIT_START;
+		goto again;
+
 	case STATE_FINISHED:
+		if (data->wanted_bits == RC5X_NBITS) {
+			/* RC5X */
+			u8 xdata, command, system;
+			xdata    = (data->rc5_bits & 0x0003F) >> 0;
+			command  = (data->rc5_bits & 0x00FC0) >> 6;
+			system   = (data->rc5_bits & 0x1F000) >> 12;
+			toggle   = (data->rc5_bits & 0x20000) ? 1 : 0;
+			command += (data->rc5_bits & 0x01000) ? 0 : 0x40;
+			scancode = system << 16 | command << 8 | xdata;
+
+			IR_dprintk(1, "RC5X scancode 0x%06x (toggle: %u)\n",
+				   scancode, toggle);
+
+		} else {
+			/* RC5 */
+			u8 command, system;
 			command  = (data->rc5_bits & 0x0003F) >> 0;
 			system   = (data->rc5_bits & 0x007C0) >> 6;
 			toggle   = (data->rc5_bits & 0x00800) ? 1 : 0;
@@ -207,13 +245,15 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 
 			IR_dprintk(1, "RC5 scancode 0x%04x (toggle: %u)\n",
 				   scancode, toggle);
+		}
+
 		ir_keydown(input_dev, scancode, toggle);
 		data->state = STATE_INACTIVE;
 		return 0;
 	}
 
 out:
-	IR_dprintk(1, "RC5 decode failed at state %i (%i units, %ius)\n",
+	IR_dprintk(1, "RC5(x) decode failed at state %i (%i units, %ius)\n",
 		   data->state, u, TO_US(duration));
 	data->state = STATE_INACTIVE;
 	return -EINVAL;
@@ -273,7 +313,7 @@ static int __init ir_rc5_decode_init(void)
 {
 	ir_raw_handler_register(&rc5_handler);
 
-	printk(KERN_INFO "IR RC-5 protocol handler initialized\n");
+	printk(KERN_INFO "IR RC5(x) protocol handler initialized\n");
 	return 0;
 }
 
@@ -288,4 +328,4 @@ module_exit(ir_rc5_decode_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
-MODULE_DESCRIPTION("RC-5 IR protocol decoder");
+MODULE_DESCRIPTION("RC5(x) IR protocol decoder");