From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH V1 21/26] DT bindings: spi: add tx/rx clock delay SPI client properties Date: Sun, 31 Mar 2019 01:42:28 -0500 Message-ID: <5ca06155.1c69fb81.60281.9b59@mx.google.com> References: <1553666207-11414-1-git-send-email-skomatineni@nvidia.com> <1553666207-11414-21-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: thierry.reding@gmail.com, jonathanh@nvidia.com, talho@nvidia.com, broonie@kernel.org, mark.rutland@arm.com, kyarlagadda@nvidia.com, ldewangan@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org To: Sowjanya Komatineni Return-path: Content-Disposition: inline In-Reply-To: <1553666207-11414-21-git-send-email-skomatineni@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org On Tue, Mar 26, 2019 at 10:56:42PM -0700, Sowjanya Komatineni wrote: > This patch adds Tegra SPI master tx and rx clock delay properties. > > TX/RX clock delays may vary depending on the platform design trace lengths > for each client on the Tegra SPI bus. These properties helps to tune the > clock delays. > > Signed-off-by: Sowjanya Komatineni > --- > .../devicetree/bindings/spi/nvidia,tegra114-spi.txt | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) Just combine this with patch 19. > diff --git a/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt b/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt > index 6167c5234b64..2b84b7b726ce 100644 > --- a/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt > +++ b/Documentation/devicetree/bindings/spi/nvidia,tegra114-spi.txt > @@ -29,6 +29,12 @@ spi-client device controller properties: > - nvidia,cs-hold-clk-count: CS hold timing parameter. > - nvidia,cs-inactive-cycles: CS inactive delay in terms of clock between > transfers. > +- nvidia,tx-clk-tap-delay: Delays the clock going out to the external device > + with this tap value. This property is used to tune the outgoing data from > + Tegra SPI master with respect to outgoing Tegra SPI master clock. > +- nvidia,rx-clk-tap-delay: Delays the clock coming in from the external device > + with this tap value. This property is used to adjust the Tegra SPI master > + clock with respect to the data from the SPI slave device. Are there units? What's the range of values. > > Example: > > @@ -45,4 +51,14 @@ spi@7000d600 { > reset-names = "spi"; > dmas = <&apbdma 16>, <&apbdma 16>; > dma-names = "rx", "tx"; > + > + @ { > + ... > + ... > + nvidia,cs-setup-clk-count = <10>; > + nvidia,cs-hold-clk-count = <10>; > + nvidia,rx-clk-tap-delay = <0>; > + nvidia,tx-clk-tap-delay = <16>; > + ... > + }; > }; > -- > 2.7.4 >