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Diffstat (limited to 'drivers/media/rc/img-ir/img-ir-rc6.c')
-rw-r--r--drivers/media/rc/img-ir/img-ir-rc6.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/media/rc/img-ir/img-ir-rc6.c b/drivers/media/rc/img-ir/img-ir-rc6.c
new file mode 100644
index 0000000000..b2bf468864
--- /dev/null
+++ b/drivers/media/rc/img-ir/img-ir-rc6.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ImgTec IR Decoder setup for Philips RC-6 protocol.
+ *
+ * Copyright 2012-2014 Imagination Technologies Ltd.
+ */
+
+#include "img-ir-hw.h"
+
+/* Convert RC6 data to a scancode */
+static int img_ir_rc6_scancode(int len, u64 raw, u64 enabled_protocols,
+ struct img_ir_scancode_req *request)
+{
+ unsigned int addr, cmd, mode, trl1, trl2;
+
+ /*
+ * Due to a side effect of the decoder handling the double length
+ * Trailer bit, the header information is a bit scrambled, and the
+ * raw data is shifted incorrectly.
+ * This workaround effectively recovers the header bits.
+ *
+ * The Header field should look like this:
+ *
+ * StartBit ModeBit2 ModeBit1 ModeBit0 TrailerBit
+ *
+ * But what we get is:
+ *
+ * ModeBit2 ModeBit1 ModeBit0 TrailerBit1 TrailerBit2
+ *
+ * The start bit is not important to recover the scancode.
+ */
+
+ raw >>= 27;
+
+ trl1 = (raw >> 17) & 0x01;
+ trl2 = (raw >> 16) & 0x01;
+
+ mode = (raw >> 18) & 0x07;
+ addr = (raw >> 8) & 0xff;
+ cmd = raw & 0xff;
+
+ /*
+ * Due to the above explained irregularity the trailer bits cannot
+ * have the same value.
+ */
+ if (trl1 == trl2)
+ return -EINVAL;
+
+ /* Only mode 0 supported for now */
+ if (mode)
+ return -EINVAL;
+
+ request->protocol = RC_PROTO_RC6_0;
+ request->scancode = addr << 8 | cmd;
+ request->toggle = trl2;
+ return IMG_IR_SCANCODE;
+}
+
+/* Convert RC6 scancode to RC6 data filter */
+static int img_ir_rc6_filter(const struct rc_scancode_filter *in,
+ struct img_ir_filter *out, u64 protocols)
+{
+ /* Not supported by the hw. */
+ return -EINVAL;
+}
+
+/*
+ * RC-6 decoder
+ * see http://www.sbprojects.com/knowledge/ir/rc6.php
+ */
+struct img_ir_decoder img_ir_rc6 = {
+ .type = RC_PROTO_BIT_RC6_0,
+ .control = {
+ .bitorien = 1,
+ .code_type = IMG_IR_CODETYPE_BIPHASE,
+ .decoden = 1,
+ .decodinpol = 1,
+ },
+ /* main timings */
+ .tolerance = 20,
+ /*
+ * Due to a quirk in the img-ir decoder, default header values do
+ * not work, the values described below were extracted from
+ * successful RTL test cases.
+ */
+ .timings = {
+ /* leader symbol */
+ .ldr = {
+ .pulse = { 650 },
+ .space = { 660 },
+ },
+ /* 0 symbol */
+ .s00 = {
+ .pulse = { 370 },
+ .space = { 370 },
+ },
+ /* 01 symbol */
+ .s01 = {
+ .pulse = { 370 },
+ .space = { 370 },
+ },
+ /* free time */
+ .ft = {
+ .minlen = 21,
+ .maxlen = 21,
+ .ft_min = 2666, /* 2.666 ms */
+ },
+ },
+
+ /* scancode logic */
+ .scancode = img_ir_rc6_scancode,
+ .filter = img_ir_rc6_filter,
+};