Re: [PATCH 5/5] rc: img-ir: add philips rc6 decoder module

From: James Hogan
Date: Mon Dec 08 2014 - 12:45:25 EST

On 04/12/14 15:38, Sifan Naeem wrote:
> Add img-ir module for decoding Philips rc6 protocol.
>
> Signed-off-by: Sifan Naeem <sifan.naeem@xxxxxxxxxx>

Aside from the "Philips" thing:

Acked-by: James Hogan <james.hogan@xxxxxxxxxx>

(It's unpleasant having unexplained timings for RC-6, but it's better
than no RC-6 support, and hopefully in the future it can be improved).

Cheers
James

> ---
> drivers/media/rc/img-ir/Kconfig | 8 +++
> drivers/media/rc/img-ir/Makefile | 1 +
> drivers/media/rc/img-ir/img-ir-hw.c | 3 +
> drivers/media/rc/img-ir/img-ir-hw.h | 1 +
> drivers/media/rc/img-ir/img-ir-rc6.c | 117 ++++++++++++++++++++++++++++++++++
> 5 files changed, 130 insertions(+)
> create mode 100644 drivers/media/rc/img-ir/img-ir-rc6.c
>
> diff --git a/drivers/media/rc/img-ir/Kconfig b/drivers/media/rc/img-ir/Kconfig
> index b5b114f..4d3fca9 100644
> --- a/drivers/media/rc/img-ir/Kconfig
> +++ b/drivers/media/rc/img-ir/Kconfig
> @@ -66,3 +66,11 @@ 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 "Phillips 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 898b1b8..8e6d458 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 322cdf8..3b70dc2 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 f124ec5..c7b6e1a 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 0000000..bcd0822
> --- /dev/null
> +++ b/drivers/media/rc/img-ir/img-ir-rc6.c
> @@ -0,0 +1,117 @@
> +/*
> + * ImgTec IR Decoder setup for Phillips 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,
> +};
>

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