From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH] can: grcan: Add device driver for GRCAN and GRHCAN cores Date: Thu, 11 Oct 2012 13:28:37 +0200 Message-ID: <5076AD65.6080909@pengutronix.de> References: <1349188730-11434-1-git-send-email-andreas@gaisler.com> <506D5AA4.5080704@pengutronix.de> <5076999F.6070302@pengutronix.de> <5076AC0C.6090306@gaisler.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig063952DB4A3CEBD074FF2666" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:39364 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758398Ab2JKL2q (ORCPT ); Thu, 11 Oct 2012 07:28:46 -0400 In-Reply-To: <5076AC0C.6090306@gaisler.com> Sender: linux-can-owner@vger.kernel.org List-ID: To: Andreas Larsson Cc: linux-can@vger.kernel.org, software@gaisler.com This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig063952DB4A3CEBD074FF2666 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 10/11/2012 01:22 PM, Andreas Larsson wrote: > On 2012-10-11 12:04, Marc Kleine-Budde wrote: >> On 10/04/2012 11:45 AM, Marc Kleine-Budde wrote: >>> Hello, >>> >>> On 10/02/2012 04:38 PM, Andreas Larsson wrote: >>>> This driver supports GRCAN and CRHCAN CAN controllers available in >>>> the GRLIB >>>> VHDL IP core library. >>>> >>>> Signed-off-by: Andreas Larsson >>>> --- >>>> drivers/net/can/Kconfig | 6 + >>>> drivers/net/can/Makefile | 1 + >>>> drivers/net/can/grcan.c | 1283 >>>> ++++++++++++++++++++++++++++++++++++++++++++++ >>>> drivers/net/can/grcan.h | 273 ++++++++++ >>>> 4 files changed, 1563 insertions(+), 0 deletions(-) >>>> create mode 100644 drivers/net/can/grcan.c >>>> create mode 100644 drivers/net/can/grcan.h >>> >>> Some general remarks while scrolling though the driver: >>> - please provide a device tree binding documentation >>> Documentation/devicetree/bindings/net/can/grcan.txt >>> and add devicetree-discuss@lists.ozlabs.org on Cc >>> - please provide a documentation for the sysfs entries: >>> Documentation/ABI/testing/sys-XXX-grcan.txt >>> - please implement a NAPI >>> - please include the .h file into the C code, >>> as the C code is the one and only user of the .h file >>> - please give every macro a GRCAN_ prefix >> >> Your driver should work on little as well as on big endian systems. Yo= u >> need probably two implementations of the grcan_{read,write}_reg >> functions, you can take the flexcan driver [1] as an example. >=20 > Adding that is easy of course, but that gives the impression of support= > for little endian systems. If the core would be instantiated in a littl= e > endian fashion in a little endian environment, the DMA accessing parts > of the hardware would still not work in a little endian system without > modifications to the hardware design. Can you add this to the Kconfig help text. > From the driver point of view either way works for me, but I am not sur= e > what is best. In this case you should limit the driver to big endian systems via kconfi= g. Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --------------enig063952DB4A3CEBD074FF2666 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iEYEARECAAYFAlB2rWUACgkQjTAFq1RaXHMOzwCglYaJrGy6UICZrW8y8fAHM7nn jCcAn3+8ffRpAAKB9eJRKFiaxdln+Uhz =lOtv -----END PGP SIGNATURE----- --------------enig063952DB4A3CEBD074FF2666--