From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joshua Clayton Subject: [PATCH v12 2/6] doc: dt: document altera-passive-serial binding Date: Fri, 2 Jun 2017 13:30:48 -0700 Message-ID: <4945d90535e701e4e0207c08a7543a7623b94aeb.1496434383.git.stillcompiling@gmail.com> References: <684ea151ba9aa2c6555a299daf56552ddc11f596.1496434383.git.stillcompiling@gmail.com> Return-path: In-Reply-To: <684ea151ba9aa2c6555a299daf56552ddc11f596.1496434383.git.stillcompiling@gmail.com> In-Reply-To: <20170525172911.11467-1-stillcompiling@gmail.com> References: <20170525172911.11467-1-stillcompiling@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Alan Tull , Moritz Fischer , Anatolij Gustschin , Bastian Stender , Shawn Guo , Joshua Clayton Cc: Rob Herring , Mark Rutland , Sascha Hauer , Fabio Estevam , Russell King , linux-fpga@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org Describe an altera-passive-serial devicetree entry, required features Signed-off-by: Joshua Clayton Acked-by: Rob Herring --- .../bindings/fpga/altera-passive-serial.txt | 29 ++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 Documentation/devicetree/bindings/fpga/altera-passive-serial.txt diff --git a/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt b/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt new file mode 100644 index 000000000000..48478bc07e29 --- /dev/null +++ b/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt @@ -0,0 +1,29 @@ +Altera Passive Serial SPI FPGA Manager + +Altera FPGAs support a method of loading the bitstream over what is +referred to as "passive serial". +The passive serial link is not technically SPI, and might require extra +circuits in order to play nicely with other SPI slaves on the same bus. + +See https://www.altera.com/literature/hb/cyc/cyc_c51013.pdf + +Required properties: +- compatible: Must be one of the following: + "altr,fpga-passive-serial", + "altr,fpga-arria10-passive-serial" +- reg: SPI chip select of the FPGA +- nconfig-gpios: config pin (referred to as nCONFIG in the manual) +- nstat-gpios: status pin (referred to as nSTATUS in the manual) + +Optional properties: +- confd-gpios: confd pin (referred to as CONF_DONE in the manual) + +Example: + fpga: fpga@0 { + compatible = "altr,fpga-passive-serial"; + spi-max-frequency = <20000000>; + reg = <0>; + nconfig-gpios = <&gpio4 9 GPIO_ACTIVE_LOW>; + nstat-gpios = <&gpio4 11 GPIO_ACTIVE_LOW>; + confd-gpios = <&gpio4 12 GPIO_ACTIVE_LOW>; + }; -- 2.11.0