From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932212AbbFOMZW (ORCPT ); Mon, 15 Jun 2015 08:25:22 -0400 Received: from mail-wg0-f52.google.com ([74.125.82.52]:36680 "EHLO mail-wg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755193AbbFOMZM (ORCPT ); Mon, 15 Jun 2015 08:25:12 -0400 Date: Mon, 15 Jun 2015 13:25:05 +0100 From: Lee Jones To: Javier Martinez Canillas Cc: Samuel Ortiz , Olof Johansson , Doug Anderson , Bill Richardson , Simon Glass , Gwendal Grignou , Stephen Barber , Filipe Brandenburger , Todd Broch , Alexandru M Stan , Heiko Stuebner , linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Chris Zhong Subject: Re: [PATCH v7 7/8] mfd: cros_ec: spi: Add a DT property to delay asserting the CS Message-ID: <20150615122505.GG3266@x1> References: <1433847889-7220-1-git-send-email-javier.martinez@collabora.co.uk> <1433847889-7220-8-git-send-email-javier.martinez@collabora.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1433847889-7220-8-git-send-email-javier.martinez@collabora.co.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 09 Jun 2015, Javier Martinez Canillas wrote: > From: Alexandru M Stan > > Some ECs need a little time for waking up before they can accept > SPI data at a high speed. Add a "google,cros-ec-spi-pre-delay" > property to the DT binding to configure this. > > If this property isn't set, then no delay will be added. However, > if set it will cause a delay equal to the value passed to it to > be inserted at the beginning of a transaction. > > Signed-off-by: Alexandru M Stan > Reviewed-by: Doug Anderson > Signed-off-by: Chris Zhong > Signed-off-by: Javier Martinez Canillas > Tested-by: Heiko Stuebner > Acked-by: Lee Jones > Acked-by: Olof Johansson Applied, thanks. > --- > > Changes since v6: > - Add Olof Johansson Acked-by tag > > Changes since v5: None. > > Changes since v4: None. > > Changes since v3: > - Split DT binding and driver change as suggested by Lee Jones. > - Add tested-by tag from Heiko Stuebner > - Add acked-by tag from Lee Jones. > > Changes since v2: None > > Changes since v1: None, new patch > --- > Documentation/devicetree/bindings/mfd/cros-ec.txt | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mfd/cros-ec.txt b/Documentation/devicetree/bindings/mfd/cros-ec.txt > index 8009c3d87f33..1777916e9e28 100644 > --- a/Documentation/devicetree/bindings/mfd/cros-ec.txt > +++ b/Documentation/devicetree/bindings/mfd/cros-ec.txt > @@ -18,6 +18,10 @@ Required properties (SPI): > - reg: SPI chip select > > Optional properties (SPI): > +- google,cros-ec-spi-pre-delay: Some implementations of the EC need a little > + time to wake up from sleep before they can receive SPI transfers at a high > + clock rate. This property specifies the delay, in usecs, between the > + assertion of the CS to the start of the first clock pulse. > - google,cros-ec-spi-msg-delay: Some implementations of the EC require some > additional processing time in order to accept new transactions. If the delay > between transactions is not long enough the EC may not be able to respond -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog