From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Mon, 1 Aug 2016 16:30:19 +0100 Subject: [PATCH v2] mmc: sunxi: Handle the 'New Timings' In-Reply-To: References: Message-ID: <20160801153016.GB17146@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Aug 01, 2016 at 03:10:29PM +0200, Jean-Francois Moine wrote: > Some MMC devices as mmc2 in the A83T or mmc1 and mmc2 in the H3 have > a 'New Timings' mode. > Set this capacity in the DT and use it when possible. What exactly is this "New Timings" mode? Why do we wnat to set it? Improved performance, power? Is it *necessary* to use it? > Signed-off-by: Jean-Francois Moine > --- > I don't know if this mode works or is needed at 25MHz. > --- > Documentation/devicetree/bindings/mmc/sunxi-mmc.txt | 1 + > drivers/mmc/host/sunxi-mmc.c | 21 +++++++++++++++++++-- > 2 files changed, 20 insertions(+), 2 deletions(-) > > diff --git a/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt b/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt > index 4bf41d8..a541bf4 100644 > --- a/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt > +++ b/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt > @@ -19,6 +19,7 @@ Optional properties: > - reset-names : must contain "ahb" > - for cd, bus-width and additional generic mmc parameters > please refer to mmc.txt within this directory > + - allwinner,new-timings: the controller may accept the "New Timings" mode It's not at all clear to me what this means. This needs a better description. Which devices have this? Can we determine this based on compatible string? Mark.