From mboxrd@z Thu Jan 1 00:00:00 1970 From: icenowy@aosc.io (icenowy at aosc.io) Date: Thu, 19 Oct 2017 16:18:04 +0800 Subject: [linux-sunxi] [PATCH v2 6/8] ARM: dts: sun8i: a83t: Move mmc1 pinctrl setting to dtsi file In-Reply-To: References: <20171018083138.14517-1-wens@csie.org> <20171018083138.14517-7-wens@csie.org> Message-ID: <0e934ef6b4254fc94f613d1305c06cde@aosc.io> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org ? 2017-10-19 14:48?Chen-Yu Tsai ??? > On Wed, Oct 18, 2017 at 11:00 PM, Joonas Kylm?l? > wrote: >> Hi, >> >> Chen-Yu Tsai: >>> mmc1 only has 1 possible pinmux setting. >> >> What if someone is using the MMC with bus width 1 and then using the >> remaining 3 pins for something else? > > I would very much like to see such a design. Currently the devices > we see all follow Allwinner's reference design, with only minor > modifications. As such, mmc1 is used exclusively for connecting > SDIO-based WiFi modules. > > If such a radical(?) design is done, the vendor can always add > a "mmc1-1bit-pins" setting and override the default. I think this kind of thing happened on A13 -- the MMC2 of A13 is 8-bit, but Lichee Pi One wires it to a SD card slot (4-bit); then the remaining 4 data lines are wired out as GPIO. (Lichee Pi's do not like obeying reference design ;-) ) But I think a MMC/SDIO device under 1-bit mode is too slow that maybe no one will use such a setup. > > ChenYu