From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4E42C196.7030708@freescale.com> Date: Wed, 10 Aug 2011 12:36:22 -0500 From: Scott Wood MIME-Version: 1.0 To: Robin Holt Subject: Re: [PATCH v11 5/5] powerpc: Fix up fsl-flexcan device tree binding. References: <1312993670-23999-1-git-send-email-holt@sgi.com> <1312993670-23999-6-git-send-email-holt@sgi.com> <4E42B83C.2040705@freescale.com> <20110810171933.GW4926@sgi.com> In-Reply-To: <20110810171933.GW4926@sgi.com> Content-Type: text/plain; charset="ISO-8859-1" Cc: socketcan-core@lists.berlios.de, netdev@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, U Bhaskar-B22300 , PPC list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 08/10/2011 12:19 PM, Robin Holt wrote: > On Wed, Aug 10, 2011 at 11:56:28AM -0500, Scott Wood wrote: >> On 08/10/2011 11:27 AM, Robin Holt wrote: >>> -CPI Clock- Can Protocol Interface Clock >>> - This CLK_SRC bit of CTRL(control register) selects the clock source to >>> - the CAN Protocol Interface(CPI) to be either the peripheral clock >>> - (driven by the PLL) or the crystal oscillator clock. The selected clock >>> - is the one fed to the prescaler to generate the Serial Clock (Sclock). >>> - The PRESDIV field of CTRL(control register) controls a prescaler that >>> - generates the Serial Clock (Sclock), whose period defines the >>> - time quantum used to compose the CAN waveform. >>> +- compatible : Should be "fsl,flexcan" and optionally >>> + "fsl,flexcan-" >> >> fsl,-flexcan, and it should not be optional, and should come >> before "fsl,flexcan". >> >> Also may want to list fsl,p1010-rdb as a "canonical compatible" for >> anything which is backwards compatible with p1010's implementation. > > How do I specify 'canonical compatible'? Something like: compatible: Should be "fsl,-flexcan" and "fsl,flexcan". An implementation should also claim any of the following compatibles that it is fully backwards compatible with: - fsl,p1010-rdb > What would be the use of it in that implementation? It limits the number of compatibles a driver has to care about, so you don't need a huge ID table just to be able to figure out whether this is a p1010-style flexcan or ARM-style. -Scott