From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olof Johansson Subject: Re: [PATCH V2 2/9] Documentation: devicetree: Add DT bindings for UFS host controller Date: Mon, 27 May 2013 22:31:40 -0700 Message-ID: <20130528053140.GA18476@quad.lixom.net> References: <1368515328-31535-1-git-send-email-draviv@codeaurora.org> <1368515328-31535-3-git-send-email-draviv@codeaurora.org> <51933768.20107@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <51933768.20107-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Sujit Reddy Thumma Cc: linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, DOCUMENTATION , linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "moderated list:OPEN FIRMWARE AND..." , open list , Dolev Raviv List-Id: devicetree@vger.kernel.org On Wed, May 15, 2013 at 12:51:12PM +0530, Sujit Reddy Thumma wrote: > On 5/14/2013 11:38 PM, Olof Johansson wrote: > >On Tue, May 14, 2013 at 12:08 AM, Dolev Raviv wrote: > >>Compatible list is used in commit 03b1781 but is not documented. > >>Add necessary device tree bindings to describe on-chip UFS host > >>controllers. > >> > >>Signed-off-by: Sujit Reddy Thumma > >> > >>diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > >>new file mode 100644 > >>index 0000000..20468b2 > >>--- /dev/null > >>+++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > >>@@ -0,0 +1,16 @@ > >>+* Universal Flash Storage (UFS) Host Controller > >>+ > >>+UFSHC nodes are defined to describe on-chip UFS host controllers. > >>+Each UFS controller instance should have its own node. > >>+ > >>+Required properties: > >>+- compatible : compatible list, contains "jedec,ufs-1.1" > >>+- interrupts : > >>+- reg : > >>+ > >>+Example: > >>+ ufshc@0xfc598000 { > >>+ compatible = "jedec,ufs-1.1"; > > > >Hmm. > > > >Does jedec really specify the programming interface of this type of > >device, register layout and meaning? It seems to be more about the > >command set and electrical/connectivity specifications, no? > > That's true with UFS device specification. For UFS Host Controller > specification Jedec indeed standardized the hardware registers, > memory structures and register programming sequence to talk to UFS > device. Ok, fair enough. However, I think "jedec,ufshc-1.1" would be more appropriate to avoid ambiguities. Compare to SD where "sdhci" is the only compatible string used for the standard interface. -Olof