From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH 2/3] dt-bindings: add binding for at91-usart in spi mode Date: Tue, 17 Apr 2018 12:03:58 +0100 Message-ID: <20180417110358.GD8973@sirena.org.uk> References: <20180413161117.20274-1-radu.pirea@microchip.com> <20180413161117.20274-3-radu.pirea@microchip.com> <20180413162327.GE22187@piout.net> <8e6c447d-dce5-f9af-e5b2-8d1d863159d6@microchip.com> <20180413181251.GG22187@piout.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="KdquIMZPjGJQvRdI" Cc: Nicolas Ferre , Radu Pirea , robh+dt@kernel.org, mark.rutland@arm.com, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org To: Alexandre Belloni Return-path: Content-Disposition: inline In-Reply-To: <20180413181251.GG22187@piout.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org --KdquIMZPjGJQvRdI Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Apr 13, 2018 at 08:12:51PM +0200, Alexandre Belloni wrote: > On 13/04/2018 19:12:54+0200, Nicolas Ferre wrote: > > This layout of the hardware is completely different from the USART one and > > it seems to makes sense to address it with a different hardware description > > and so a different compatible string. > But then, you can end up with two drivers trying to use the same IP > because nothing prevents you from writing a DT with both a usart and an > spi node enabled for the same IP. request_mem_region() will not help > here because then the working driver will depend on the probing order. We don't really have too much in the way of better ideas for how to handle this though. Take a look at how the PXA SSP stuff handles this, though that's not really doing too much different it at least layers a mechanism on top to avoid collisions. --KdquIMZPjGJQvRdI Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlrV1J0ACgkQJNaLcl1U h9DCSQf+MvNTpltQosRGeLwGrJwao9U0bH049keLdBcKwW0YHwsyF27+3qgKSt2P o0yP3Kc0wpvXsg8nCA8i002IsP0TlMwfoK4iErmRsm3yrq9oW1OvLhQhmSQQPMGo nKCK5JnS9yRigDctPIHxBEypFSVz7yeEcISKO7A7xdhsZx9OZAsj+E/IN/msyur0 qq5dmuxkWEOpHBRVib82AZkiGT4mnKtI1++JyKvtUxPJkALV9/2oZ02zBmF0wP7B Xr4/E0ceAJ1dGNoCoDgE3buSyUn/4dPf/+0PnN4hnnAfT64Nr0jAogk8U4yVESEC M2sMuJONsvBSwQh9X6OWXvBtec/3Ig== =CaAS -----END PGP SIGNATURE----- --KdquIMZPjGJQvRdI--