From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Linus Walleij Subject: [PATCH 3/4] spi: Add a DT binding for high impedance turnaround Date: Mon, 3 Sep 2018 23:50:34 +0200 Message-Id: <20180903215035.17265-4-linus.walleij@linaro.org> In-Reply-To: <20180903215035.17265-1-linus.walleij@linaro.org> References: <20180903215035.17265-1-linus.walleij@linaro.org> To: Mark Brown , linux-spi@vger.kernel.org, Andrzej Hajda , Lorenzo Bianconi Cc: linux-gpio@vger.kernel.org, Rob Herring , Linus Walleij , devicetree@vger.kernel.org List-ID: Some 3WIRE SPI devices require the host to insert a "high impedance turnaround" essentially a clock pulse after switching the one line from output to input. This is needed to support the TPO TPG110 panel to use the 3WIRE SPI bindings. Cc: devicetree@vger.kernel.org Cc: Andrzej Hajda Cc: Lorenzo Bianconi Signed-off-by: Linus Walleij --- Documentation/devicetree/bindings/spi/spi-bus.txt | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt index 1f6e86f787ef..ee08be2894eb 100644 --- a/Documentation/devicetree/bindings/spi/spi-bus.txt +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt @@ -70,6 +70,10 @@ All slave nodes can contain the following optional properties: - spi-cs-high - Empty property indicating device requires chip select active high. - spi-3wire - Empty property indicating device requires 3-wire mode. +- spi-3wire-high-impedance-turnaround - Empty property indicating that a + 3wire host need to insert a high impedance turn-around + clock cycle after turning the one output line into an + input line. - spi-lsb-first - Empty property indicating device requires LSB first mode. - spi-tx-bus-width - The bus width (number of data wires) that is used for MOSI. Defaults to 1 if not present. -- 2.17.1