Re: [PATCH 6/6] rc-core: add protocol to EVIOC[GS]KEYCODE_V2 ioctl

From: Sean Young <sean@mess.org>
To: "David Härdeman" <david@hardeman.nu>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>,
	linux-media@vger.kernel.org
Subject: Re: [PATCH 6/6] rc-core: add protocol to EVIOC[GS]KEYCODE_V2 ioctl
Date: Sun, 11 Jun 2017 17:17:40 +0100	[thread overview]
Message-ID: <20170611161740.GB16107@gofer.mess.org> (raw)
In-Reply-To: <20170429084458.rwoty4bdce6iqftr@hardeman.nu>

On Sat, Apr 29, 2017 at 10:44:58AM +0200, David Härdeman wrote:
> >This can be implemented without breaking userspace.
> 
> How?

The current keymaps we have do not specify the protocol variant, only
the protocol (rc6 vs rc6-mce). So to support this, we have to be able
to specify multiple protocols at the same time. So I think the protocol
should be a bitmask.

Also, in your example you re-used RC_TYPE_OTHER to match any protocol;
I don't think that is a good solution since there are already keymaps
which use other.

So if we have an "struct rc_scancode" which looks like:

struct rc_scancode {
	u64 protocol;
	u64 scancode;
};

Then if the keymap protocol is rc6, ir-keytable should set the protocol
to RC_BIT_RC6_0 | RC_BIT_RC6_6A_20 | RC_BIT_RC6_6A_24 | RC_BIT_RC6_6A_32
 | RC_BIT_RC6_MCE.

If the old ioctl is used, then the protocol should be set to RC_BIT_ALL.

I can't think of anything what would break with this scheme.

Thanks
Sean