[media] rc: Add support for decoding Sanyo protocol

This protocol is found on Sanyo/Aiwa remotes.

Tested with an Aiwa RC-7AS06 remote control.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 204 insertions, 0 deletions

diff --git a/drivers/media/rc/ir-sanyo-decoder.c b/drivers/media/rc/ir-sanyo-decoder.c
new file mode 100644
index 000000000000..164673071252
--- /dev/null
+++ b/drivers/media/rc/ir-sanyo-decoder.c
@@ -0,0 +1,204 @@
+/* ir-sanyo-decoder.c - handle SANYO IR Pulse/Space protocol
+ *
+ * Copyright (C) 2011 by Mauro Carvalho Chehab <mchehab@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ * This protocol uses the NEC protocol timings. However, data is formatted as:
+ *	13 bits Custom Code
+ *	13 bits NOT(Custom Code)
+ *	8 bits Key data
+ *	8 bits NOT(Key data)
+ *
+ * According with LIRC, this protocol is used on Sanyo, Aiwa and Chinon
+ * Information for this protocol is available at the Sanyo LC7461 datasheet.
+ */
+
+#include <linux/bitrev.h>
+#include "rc-core-priv.h"
+
+#define SANYO_NBITS		(13+13+8+8)
+#define SANYO_UNIT		562500  /* ns */
+#define SANYO_HEADER_PULSE	(16  * SANYO_UNIT)
+#define SANYO_HEADER_SPACE	(8   * SANYO_UNIT)
+#define SANYO_BIT_PULSE		(1   * SANYO_UNIT)
+#define SANYO_BIT_0_SPACE	(1   * SANYO_UNIT)
+#define SANYO_BIT_1_SPACE	(3   * SANYO_UNIT)
+#define SANYO_REPEAT_SPACE	(150 * SANYO_UNIT)
+#define	SANYO_TRAILER_PULSE	(1   * SANYO_UNIT)
+#define	SANYO_TRAILER_SPACE	(10  * SANYO_UNIT)	/* in fact, 42 */
+
+enum sanyo_state {
+	STATE_INACTIVE,
+	STATE_HEADER_SPACE,
+	STATE_BIT_PULSE,
+	STATE_BIT_SPACE,
+	STATE_TRAILER_PULSE,
+	STATE_TRAILER_SPACE,
+};
+
+/**
+ * ir_sanyo_decode() - Decode one SANYO pulse or space
+ * @dev:	the struct rc_dev descriptor of the device
+ * @duration:	the struct ir_raw_event descriptor of the pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
+ */
+static int ir_sanyo_decode(struct rc_dev *dev, struct ir_raw_event ev)
+{
+	struct sanyo_dec *data = &dev->raw->sanyo;
+	u32 scancode;
+	u8 address, not_address, command, not_command;
+
+	if (!(dev->raw->enabled_protocols & RC_TYPE_SANYO))
+		return 0;
+
+	if (!is_timing_event(ev)) {
+		if (ev.reset) {
+			IR_dprintk(1, "SANYO event reset received. reset to state 0\n");
+			data->state = STATE_INACTIVE;
+		}
+		return 0;
+	}
+
+	IR_dprintk(2, "SANYO decode started at state %d (%uus %s)\n",
+		   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+
+	switch (data->state) {
+
+	case STATE_INACTIVE:
+		if (!ev.pulse)
+			break;
+
+		if (eq_margin(ev.duration, SANYO_HEADER_PULSE, SANYO_UNIT / 2)) {
+			data->count = 0;
+			data->state = STATE_HEADER_SPACE;
+			return 0;
+		}
+		break;
+
+
+	case STATE_HEADER_SPACE:
+		if (ev.pulse)
+			break;
+
+		if (eq_margin(ev.duration, SANYO_HEADER_SPACE, SANYO_UNIT / 2)) {
+			data->state = STATE_BIT_PULSE;
+			return 0;
+		}
+
+		break;
+
+	case STATE_BIT_PULSE:
+		if (!ev.pulse)
+			break;
+
+		if (!eq_margin(ev.duration, SANYO_BIT_PULSE, SANYO_UNIT / 2))
+			break;
+
+		data->state = STATE_BIT_SPACE;
+		return 0;
+
+	case STATE_BIT_SPACE:
+		if (ev.pulse)
+			break;
+
+		if (!data->count && geq_margin(ev.duration, SANYO_REPEAT_SPACE, SANYO_UNIT / 2)) {
+			if (!dev->keypressed) {
+				IR_dprintk(1, "SANYO discarding last key repeat: event after key up\n");
+			} else {
+				rc_repeat(dev);
+				IR_dprintk(1, "SANYO repeat last key\n");
+				data->state = STATE_INACTIVE;
+			}
+			return 0;
+		}
+
+		data->bits <<= 1;
+		if (eq_margin(ev.duration, SANYO_BIT_1_SPACE, SANYO_UNIT / 2))
+			data->bits |= 1;
+		else if (!eq_margin(ev.duration, SANYO_BIT_0_SPACE, SANYO_UNIT / 2))
+			break;
+		data->count++;
+
+		if (data->count == SANYO_NBITS)
+			data->state = STATE_TRAILER_PULSE;
+		else
+			data->state = STATE_BIT_PULSE;
+
+		return 0;
+
+	case STATE_TRAILER_PULSE:
+		if (!ev.pulse)
+			break;
+
+		if (!eq_margin(ev.duration, SANYO_TRAILER_PULSE, SANYO_UNIT / 2))
+			break;
+
+		data->state = STATE_TRAILER_SPACE;
+		return 0;
+
+	case STATE_TRAILER_SPACE:
+		if (ev.pulse)
+			break;
+
+		if (!geq_margin(ev.duration, SANYO_TRAILER_SPACE, SANYO_UNIT / 2))
+			break;
+
+		address     = bitrev16((data->bits >> 29) & 0x1fff) >> 3;
+		not_address = bitrev16((data->bits >> 16) & 0x1fff) >> 3;
+		command	    = bitrev8((data->bits >>  8) & 0xff);
+		not_command = bitrev8((data->bits >>  0) & 0xff);
+
+		if ((command ^ not_command) != 0xff) {
+			IR_dprintk(1, "SANYO checksum error: received 0x%08Lx\n",
+				   data->bits);
+			data->state = STATE_INACTIVE;
+			return 0;
+		}
+
+		scancode = address << 8 | command;
+		IR_dprintk(1, "SANYO scancode: 0x%06x\n", scancode);
+		rc_keydown(dev, scancode, 0);
+		data->state = STATE_INACTIVE;
+		return 0;
+	}
+
+	IR_dprintk(1, "SANYO decode failed at count %d state %d (%uus %s)\n",
+		   data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+	data->state = STATE_INACTIVE;
+	return -EINVAL;
+}
+
+static struct ir_raw_handler sanyo_handler = {
+	.protocols	= RC_TYPE_SANYO,
+	.decode		= ir_sanyo_decode,
+};
+
+static int __init ir_sanyo_decode_init(void)
+{
+	ir_raw_handler_register(&sanyo_handler);
+
+	printk(KERN_INFO "IR SANYO protocol handler initialized\n");
+	return 0;
+}
+
+static void __exit ir_sanyo_decode_exit(void)
+{
+	ir_raw_handler_unregister(&sanyo_handler);
+}
+
+module_init(ir_sanyo_decode_init);
+module_exit(ir_sanyo_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
+MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
+MODULE_DESCRIPTION("SANYO IR protocol decoder");