From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762414Ab2KAWL2 (ORCPT ); Thu, 1 Nov 2012 18:11:28 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:42328 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761979Ab2KAWLZ (ORCPT ); Thu, 1 Nov 2012 18:11:25 -0400 Date: Fri, 2 Nov 2012 00:05:18 +0200 From: Felipe Balbi To: Pantelis Antoniou CC: Alan Cox , , "Cousson, Benoit" , Tony Lindgren , , Koen Kooi , Matt Porter , Russ Dill , , Kevin Hilman , Paul Walmsley Subject: Re: [PATCH 0/3] capebus moving omap_devices to mach-omap2 Message-ID: <20121101220518.GE14982@arwen.pp.htv.fi> Reply-To: References: <50924DA3.1060901@ti.com> <20121101110418.GF410@arwen.pp.htv.fi> <3AF5A6FC-61D9-40CA-85B3-81C2C788CB76@antoniou-consulting.com> <20121101124025.GA12489@arwen.pp.htv.fi> <20121101131609.GC12489@arwen.pp.htv.fi> <20121101135148.382aec00@pyramind.ukuu.org.uk> <9F25E89E-9194-4725-8A8C-053DCBADA1DB@antoniou-consulting.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ILuaRSyQpoVaJ1HG" Content-Disposition: inline In-Reply-To: <9F25E89E-9194-4725-8A8C-053DCBADA1DB@antoniou-consulting.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --ILuaRSyQpoVaJ1HG Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable HI, On Thu, Nov 01, 2012 at 03:59:50PM +0200, Pantelis Antoniou wrote: > Hi Alan, >=20 > On Nov 1, 2012, at 3:51 PM, Alan Cox wrote: >=20 > >> What they want, and what every user wants, is I plug this board in, and > >> the driver make sure everything is loaded and ready. No, the end users > >> don't want to see any of the implementation details of how the bitfile > >> is transported; the driver can handle it. > >=20 > > That doesn't necessarily make it a bus merely some kind of hotplug > > enumeration of devices. That should all work properly both for devices > > and busses with spi and i=B2c as the final bits needed for it got fixed > > some time ago. > >=20 > > In an ideal world you don't want to be writing custom drivers for stuff. > > If your cape routes an i=B2c serial device to the existing system i=B2c > > busses then you want to just create an instance of any existing driver = on > > the existing i=B2c bus not create a whole new layer of goop. > >=20 > > It does need to do the plumbing and resource management for the plumbing > > but thats not the same as being a bus. > >=20 > > Alan >=20 >=20 > Fair enough. But there's no such thing a 'hotplug enumeration > construct' in Linux yet, and a bus is the closest thing to it. It does > take advantage of the nice way device code matches drivers and devices > though. >=20 > I'm afraid that having the I2C/SPI drivers doing the detection won't > work. The capes can have arbitrary I2C/SPI devices (and even more > weird components). There is no way to assure for example that the I2C > device responding to address 'foo' in cape A is the same I2C device > responding to the same address in cape B. your ->detect() method should take care of that. --=20 balbi --ILuaRSyQpoVaJ1HG Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQkvIdAAoJEIaOsuA1yqREv2sP+wSsVcN17PpVBmV6Q5ybcvpP qZ8oHUmVjI6HjCoavqmHh6VPzPJ1OCh7S/RlWdVlLvqh0YQ8jnODU3jYlpwqEbfq KPe/occbJmAQLc6xAugIfTjA+2Vtl8RYx3vdxYC0q4eqrXHDys5JZ/HHgf8qU8Nb u0ePE2KsO4Th9I/Ahnlw4I/szgqwrQrV0+gOt5eVK5JhEywbOUslEGyoiXsPXSm/ RlDVKRda9P/HLDWmV/3UPfTUFLkFGO9JcY7pYJIzV4OiwEQ4Yfr3ToaBQ3vK6Q0+ Tpr6daM/8cR8MIfW530fVIoHEbR0J9QJGbBRhU7WhyJ3k/kf/ZWMvxy4r9/0kd15 HWE/4lFSd1vIyAk1DQEqvpFUAjbmfpxQlGp1RnvfWEFCGp4H0g46YpBpv+6wLqn0 AyNCxIUcjrIuQ4aSq3za76VS3vCgNSELs4C8wEv6qktSRWUs/3i3DH6VcrJT9HfT 9AxYKf3p8eB99ZWSL4FiFg8FoywSYh3JFhyzN6w3XD88nULu2quq2/EIm7BYKr5y T/lIDReu2D2PunzPwL8RBBJuR+ZC7XxanC/Zz9I01Ry6ZyK+R4NPpdYcA7Yf9T9+ jPxJdUXSJFMW6/E4VQ6703MossZy3HlLpC023wnkkdv07ZpmmSQOiOk8ufcoDR1G 0FjCvvcrQwUa5elKGjFh =JdqB -----END PGP SIGNATURE----- --ILuaRSyQpoVaJ1HG-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH 0/3] capebus moving omap_devices to mach-omap2 Date: Fri, 2 Nov 2012 00:05:18 +0200 Message-ID: <20121101220518.GE14982@arwen.pp.htv.fi> References: <50924DA3.1060901@ti.com> <20121101110418.GF410@arwen.pp.htv.fi> <3AF5A6FC-61D9-40CA-85B3-81C2C788CB76@antoniou-consulting.com> <20121101124025.GA12489@arwen.pp.htv.fi> <20121101131609.GC12489@arwen.pp.htv.fi> <20121101135148.382aec00@pyramind.ukuu.org.uk> <9F25E89E-9194-4725-8A8C-053DCBADA1DB@antoniou-consulting.com> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ILuaRSyQpoVaJ1HG" Return-path: Content-Disposition: inline In-Reply-To: <9F25E89E-9194-4725-8A8C-053DCBADA1DB@antoniou-consulting.com> Sender: linux-kernel-owner@vger.kernel.org To: Pantelis Antoniou Cc: Alan Cox , balbi@ti.com, "Cousson, Benoit" , Tony Lindgren , linux-kernel@vger.kernel.org, Koen Kooi , Matt Porter , Russ Dill , linux-omap@vger.kernel.org, Kevin Hilman , Paul Walmsley List-Id: linux-omap@vger.kernel.org --ILuaRSyQpoVaJ1HG Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable HI, On Thu, Nov 01, 2012 at 03:59:50PM +0200, Pantelis Antoniou wrote: > Hi Alan, >=20 > On Nov 1, 2012, at 3:51 PM, Alan Cox wrote: >=20 > >> What they want, and what every user wants, is I plug this board in, and > >> the driver make sure everything is loaded and ready. No, the end users > >> don't want to see any of the implementation details of how the bitfile > >> is transported; the driver can handle it. > >=20 > > That doesn't necessarily make it a bus merely some kind of hotplug > > enumeration of devices. That should all work properly both for devices > > and busses with spi and i=B2c as the final bits needed for it got fixed > > some time ago. > >=20 > > In an ideal world you don't want to be writing custom drivers for stuff. > > If your cape routes an i=B2c serial device to the existing system i=B2c > > busses then you want to just create an instance of any existing driver = on > > the existing i=B2c bus not create a whole new layer of goop. > >=20 > > It does need to do the plumbing and resource management for the plumbing > > but thats not the same as being a bus. > >=20 > > Alan >=20 >=20 > Fair enough. But there's no such thing a 'hotplug enumeration > construct' in Linux yet, and a bus is the closest thing to it. It does > take advantage of the nice way device code matches drivers and devices > though. >=20 > I'm afraid that having the I2C/SPI drivers doing the detection won't > work. The capes can have arbitrary I2C/SPI devices (and even more > weird components). There is no way to assure for example that the I2C > device responding to address 'foo' in cape A is the same I2C device > responding to the same address in cape B. your ->detect() method should take care of that. --=20 balbi --ILuaRSyQpoVaJ1HG Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQkvIdAAoJEIaOsuA1yqREv2sP+wSsVcN17PpVBmV6Q5ybcvpP qZ8oHUmVjI6HjCoavqmHh6VPzPJ1OCh7S/RlWdVlLvqh0YQ8jnODU3jYlpwqEbfq KPe/occbJmAQLc6xAugIfTjA+2Vtl8RYx3vdxYC0q4eqrXHDys5JZ/HHgf8qU8Nb u0ePE2KsO4Th9I/Ahnlw4I/szgqwrQrV0+gOt5eVK5JhEywbOUslEGyoiXsPXSm/ RlDVKRda9P/HLDWmV/3UPfTUFLkFGO9JcY7pYJIzV4OiwEQ4Yfr3ToaBQ3vK6Q0+ Tpr6daM/8cR8MIfW530fVIoHEbR0J9QJGbBRhU7WhyJ3k/kf/ZWMvxy4r9/0kd15 HWE/4lFSd1vIyAk1DQEqvpFUAjbmfpxQlGp1RnvfWEFCGp4H0g46YpBpv+6wLqn0 AyNCxIUcjrIuQ4aSq3za76VS3vCgNSELs4C8wEv6qktSRWUs/3i3DH6VcrJT9HfT 9AxYKf3p8eB99ZWSL4FiFg8FoywSYh3JFhyzN6w3XD88nULu2quq2/EIm7BYKr5y T/lIDReu2D2PunzPwL8RBBJuR+ZC7XxanC/Zz9I01Ry6ZyK+R4NPpdYcA7Yf9T9+ jPxJdUXSJFMW6/E4VQ6703MossZy3HlLpC023wnkkdv07ZpmmSQOiOk8ufcoDR1G 0FjCvvcrQwUa5elKGjFh =JdqB -----END PGP SIGNATURE----- --ILuaRSyQpoVaJ1HG--