[media] rc: img-ir: add philips rc6 decoder module

Add img-ir module for decoding Philips rc6 protocol.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

5 files changed, 130 insertions, 0 deletions

diff --git a/drivers/media/rc/img-ir/Kconfig b/drivers/media/rc/img-ir/Kconfig
index b20b3e9b441e..a896d3c83a1c 100644
--- a/drivers/media/rc/img-ir/Kconfig
+++ b/drivers/media/rc/img-ir/Kconfig
@@ -67,3 +67,11 @@ config IR_IMG_RC5
         help
            Say Y here to enable support for the RC5 protocol in the ImgTec
            infrared decoder block.
+
+config IR_IMG_RC6
+        bool "Philips RC6 protocol support"
+        depends on IR_IMG_HW
+        help
+           Say Y here to enable support for the RC6 protocol in the ImgTec
+           infrared decoder block.
+           Note: This version only supports mode 0.
diff --git a/drivers/media/rc/img-ir/Makefile b/drivers/media/rc/img-ir/Makefile
index 898b1b8086d0..8e6d458e66ad 100644
--- a/drivers/media/rc/img-ir/Makefile
+++ b/drivers/media/rc/img-ir/Makefile
@@ -7,6 +7,7 @@ img-ir-$(CONFIG_IR_IMG_SONY)	+= img-ir-sony.o
 img-ir-$(CONFIG_IR_IMG_SHARP)   += img-ir-sharp.o
 img-ir-$(CONFIG_IR_IMG_SANYO)   += img-ir-sanyo.o
 img-ir-$(CONFIG_IR_IMG_RC5)     += img-ir-rc5.o
+img-ir-$(CONFIG_IR_IMG_RC6)     += img-ir-rc6.o
 img-ir-objs                     := $(img-ir-y)
 
 obj-$(CONFIG_IR_IMG)            += img-ir.o
diff --git a/drivers/media/rc/img-ir/img-ir-hw.c b/drivers/media/rc/img-ir/img-ir-hw.c
index 13f0b1e0e211..7bb71bc9f534 100644
--- a/drivers/media/rc/img-ir/img-ir-hw.c
+++ b/drivers/media/rc/img-ir/img-ir-hw.c
@@ -45,6 +45,9 @@ static struct img_ir_decoder *img_ir_decoders[] = {
 #ifdef CONFIG_IR_IMG_RC5
         &img_ir_rc5,
 #endif
+#ifdef CONFIG_IR_IMG_RC6
+        &img_ir_rc6,
+#endif
         NULL
 };
 
diff --git a/drivers/media/rc/img-ir/img-ir-hw.h b/drivers/media/rc/img-ir/img-ir-hw.h
index b9e799d57d99..91a297731661 100644
--- a/drivers/media/rc/img-ir/img-ir-hw.h
+++ b/drivers/media/rc/img-ir/img-ir-hw.h
@@ -188,6 +188,7 @@ extern struct img_ir_decoder img_ir_sony;
 extern struct img_ir_decoder img_ir_sharp;
 extern struct img_ir_decoder img_ir_sanyo;
 extern struct img_ir_decoder img_ir_rc5;
+extern struct img_ir_decoder img_ir_rc6;
 
 /**
  * struct img_ir_reg_timings - Reg values for decoder timings at clock rate.
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 000000000000..de1e27534968
--- /dev/null
+++ b/drivers/media/rc/img-ir/img-ir-rc6.c
@@ -0,0 +1,117 @@
+/*
+ * ImgTec IR Decoder setup for Philips RC-6 protocol.
+ *
+ * Copyright 2012-2014 Imagination Technologies Ltd.
+ *
+ * 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; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#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_TYPE_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_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,
+};