From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCHv4 0/9] Add I2C support for Allwinner SoCs Date: Wed, 12 Jun 2013 14:44:32 +0200 Message-ID: <20130612124432.GH16699@lukather> References: <1371024438-16631-1-git-send-email-maxime.ripard@free-electrons.com> <3315236.ZNXhyxmCRd@wuerfel> <20130612113849.GG16699@lukather> <201306121438.12549.arnd@arndb.de> Reply-To: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: <201306121438.12549.arnd-r2nGTMty4D4@public.gmane.org> List-Post: , List-Help: , List-Archive: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org List-Subscribe: , List-Unsubscribe: , Content-Disposition: inline To: Arnd Bergmann Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Wolfram Sang , Jason Cooper , Andrew Lunn , Emilio Lopez , Tomasz Figa , linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, sunny-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org, shuge-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org, kevin-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Wed, Jun 12, 2013 at 02:38:12PM +0200, Arnd Bergmann wrote: > On Wednesday 12 June 2013, Maxime Ripard wrote: > > The Marvell and Allwinner controllers share the exact same logic (which > > is definitely not trivial), based on a finite state machine that > > triggers interrupts at each change of state, each state being a state in > > the I2C protocol (like address sent, data received with an ACK, etc.). > > > > The weird thing is that the only difference between the two controllers > > is the register offsets, and that's it. The state numbers, bit index, > > etc, are exactly the same. > > Ok, cool. Great someone noticed! Kudos to Wolfram :) > > So yes, I think they both licensed the same IP. > > I wonder if it's the Mentor Graphics Inventra mi2c block, which > would make sense given that Allwinner also uses musb. The only datasheet or manual I have been able to find is http://www.mentor.com/products/ip/peripheral/ip_interface/upload/mi2c_pd.pdf which doesn't give a lot of details. Yet, from what is shown and explained in the second page, it looks like it could be this IP. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com