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Date:   Mon, 12 Feb 2018 00:43:44 +0100
From:   Pavel Machek <pavel@ucw.cz>
To:     Oleksandr Shamray <oleksandrs@mellanox.com>
Cc:     gregkh@linuxfoundation.org, arnd@arndb.de,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
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        linux-serial@vger.kernel.org, vadimp@mellanox.com,
        system-sw-low-level@mellanox.com, robh+dt@kernel.org,
        openocd-devel-owner@lists.sourceforge.net,
        linux-api@vger.kernel.org, davem@davemloft.net, mchehab@kernel.org
Subject: Re: [patch v14 4/4] Documentation: jtag: Add ABI documentation
Message-ID: <20180211234344.GA3864@localhost>
References: <1513268971-13518-1-git-send-email-oleksandrs@mellanox.com>
 <1513268971-13518-5-git-send-email-oleksandrs@mellanox.com>
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Hi!

> @@ -0,0 +1,27 @@
> +What:		/dev/jtag[0-9]+
> +Date:		October 2017
> +KernelVersion:	4.15
> +Contact:	oleksandrs@mellanox.com
> +Description:
> +		The misc device files /dev/jtag* are the interface
> +		between JTAG master interface and userspace.
> +
> +		The ioctl(2)-based ABI is defined and documented in
> +		[include/uapi]<linux/jtag.h>.
> +
> +		The following file operations are supported:
> +
> +		open(2)
> +		The argument flag currently support only one access
> +		mode O_RDWR.
> +
> +		ioctl(2)
> +		Initiate various actions.
> +		See the inline documentation in [include/uapi]<linux/jtag.h>
> +		for descriptions of all ioctls.

I tried reading the jtag.h, and am still not sure how it works. Real docs
would be nice...

In particular, it seems to always specify read or write actiom. Sounds
like a job for read/write syscalls?
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html