From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Mon, 12 Feb 2018 00:43:44 +0100 Subject: [patch v14 4/4] Documentation: jtag: Add ABI documentation In-Reply-To: <1513268971-13518-5-git-send-email-oleksandrs@mellanox.com> References: <1513268971-13518-1-git-send-email-oleksandrs@mellanox.com> <1513268971-13518-5-git-send-email-oleksandrs@mellanox.com> Message-ID: <20180211234344.GA3864@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi! > @@ -0,0 +1,27 @@ > +What: /dev/jtag[0-9]+ > +Date: October 2017 > +KernelVersion: 4.15 > +Contact: oleksandrs at 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]. > + > + 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] > + 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