From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: Re: [PATCH 2/5] ARM: dts: sun4i: Add support for mmc Date: Mon, 16 Dec 2013 13:34:42 +0100 Message-ID: <52AEF362.7080804@redhat.com> References: <1387058295-20641-1-git-send-email-hdegoede@redhat.com> <1387058295-20641-3-git-send-email-hdegoede@redhat.com> <20131215135854.GF3651@lukather> <52ADBD41.4050104@redhat.com> <20131216100253.GC3037@lukather> Reply-To: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Return-path: In-Reply-To: <20131216100253.GC3037@lukather> List-Post: , List-Help: , List-Archive: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org List-Subscribe: , List-Unsubscribe: , To: Maxime Ripard Cc: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Chris Ball , =?ISO-8859-1?Q?David_Lanzend=F6rfer?= , linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-mmc@vger.kernel.org Hi, On 12/16/2013 11:02 AM, Maxime Ripard wrote: > Hi Hans, > > Damn google-groups removed me from Cc :) > > On Sun, Dec 15, 2013 at 03:31:29PM +0100, Hans de Goede wrote: >>>> @@ -376,6 +385,13 @@ >>>> allwinner,drive = <0>; >>>> allwinner,pull = <0>; >>>> }; >>>> + >>>> + sdc0_pins_a: sdc0@0 { >>>> + allwinner,pins = "PF0","PF1","PF2","PF3","PF4","PF5"; >>>> + allwinner,function = "mmc0"; >>>> + allwinner,drive = <3>; >>>> + allwinner,pull = <1>; >>> >>> Wow, you need both the pullups and a 40mA output? >> >> Yes and no. The pullups are enabled by uboot and the allwinner >> sources, most of my testing has been done without them, which >> seems to work fine. I've enabled them to be consisten with the >> allwinner sources and u-boot. > > Henrik was suggesting that in most boards it's not required to set up > the internal pullups. Maybe we can just disable them by default, and > we will always be able to enable them at the board level if needed. Ok, I'm fine with disabling the pull-ups by default. >> As for drive = <3>, we need drive = <2> for normal modes, >> and drive = <3> for ddr mode. I simply picked <3> to keep >> things KISS. It should not matter much in power usage, as >> it will only make the flanks of the signal more steep. Once the >> desired output level is reached the current will drop off. It will >> use more current when changing the level, but for half the time, >> so the effective power usage (current * time) is the same. > > Ok, let's keep it to 40mA then. It will indeed be simpler :) Ack. > >>> Ideally, I'd like this patch to be splitted into three: >>> - One that adds the MMC controller nodes to the DTSI >>> - One that adds the muxing options you need to the pinctrl node >>> - One that enables the controller on the boards >> >> Sounds like a good job for David. Note I've a lot more boards for >> which I would like to add mmc support or dts files in general >> (will do so as time permits). >> >> For those boards which already have a dts I'll send mmc adding dts >> patches to David for now so he can add the changes to the patch-set. >> >> How do you want to deal with new boards ? Send the addition of the >> base board to you (and CC David as he will need them in his tree too), >> and then send a patch to add mmc to the dts to David ? > > I don't really like having a variable-sweep patch serie. Just send > your DT additions to me, saying that you depend on the MMC serie from > David. Ok will do if / when I've dts files for new boards. Regards, Hans