From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Kocialkowski Date: Sun, 05 Apr 2015 22:59:40 +0200 Subject: [U-Boot] [PATCH v3 0/3] i2c: sunxi: Support every i2c controller on each supported platform In-Reply-To: <5520F5E0.80406@redhat.com> References: <1428220288-3829-1-git-send-email-contact@paulk.fr> <5520F5E0.80406@redhat.com> Message-ID: <1428267580.2501.22.camel@collins> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Hans, Le dimanche 05 avril 2015 ? 10:44 +0200, Hans de Goede a ?crit : > Hi, > > On 05-04-15 09:51, Paul Kocialkowski wrote: > > Changes since v2: > > * I2C/TWI busses enable for Cubietruck as well > > > > Changes since v1: > > * Kconfig option to enable I2C/TWI controllers 1-4 (when applicable) > > * Following patch to enable exposed busses on a few community-supported > > single-board-computers > > > > This series adds support for every i2c controller found on > > sun4i/sun5i/sun6i/sun7i/sun8i platforms and shouldn't break support for Marvell > > platforms (orion5x, kirkwood, armada xp) the driver was originally written for. > > > > Regarding sunxi, I double-checked that this doesn't conflict with > > VIDEO_LCD_PANEL_I2C. > > > > I would be interested in having this tested on sun8i (A23), since I changed TWI0 > > muxing (to PH2-PH3 instead of PB0-PB1), according to the user manual and what > > is being done on the upstream Linux kernel. I2C was either not working before, > > or it was being muxed correctly by the bootrom, probably to communicate with the > > AXP, which luckily made it work in U-Boot too, since the I/O base address was > > already correct. > > > > My use case here is that I'm writing a slave-side bitbang i2c implementation > > (with an Arduino) for a school project, using a Cubieboard2 as master and > > U-Boot as POC. However, only TWI1 was available through the expansion pins, > > hence the need for this series. > > > > Thanks for your work on this, may I request one more change ? For sunxi I would > like to also see a CONFIG_I2C0_ENABLE, the reason for this is that on sun6i / sun8i > we do not really use i2c0 as we use p2wi resp. rsb to talk to the axp pmic there. > > This way we will not end up messing with the muxing of the PH14/15 (sun6i) resp. > PH2/3 (sun8i) which may be used in some other fashion. > > This also means making a small change to the first patch to also make registering > of twsi0 #ifdef CONFIG_I2C_MVTWSI_BASE0 . > > Can you please make the default for CONFIG_I2C0_ENABLE y on sun4i / sun5i / sun7i and n > on others? Ack that, it makes sense to me. > Also I'm not entirely convinced that patch 3/3 is a good idea, on the olimex boards > which have a i2c eeprom enabling the attached i2c controller makes sense, but on the > other boards the i2c pins are really just gpio pins, any daughter board can be connected > including one which uses them differently. I believe that in the defconfig the i2c > controllers should thus be left off. It is after all a default config, users with > a daughter board which they want to use in u-boot can easily change the config after > running make foo_defconfig. I think the right bargain here would be to enable i2c lines that already have something useful for U-Boot attached (e.g. not an accelerometer sensor). I concur to your point otherwise. -- Paul Kocialkowski, Replicant developer Replicant is a fully free Android distribution running on several devices, a free software mobile operating system putting the emphasis on freedom and privacy/security. Website: http://www.replicant.us/ Blog: http://blog.replicant.us/ Wiki/tracker/forums: http://redmine.replicant.us/ -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: This is a digitally signed message part URL: