From mboxrd@z Thu Jan 1 00:00:00 1970 From: vinod.koul@intel.com (Vinod Koul) Date: Wed, 13 Apr 2016 21:51:25 +0530 Subject: [PATCH v2 3/4] fsl-imx-sdma.txt: Document 'fsl, sdma-event-remap' property In-Reply-To: <1459554737-19684-3-git-send-email-festevam@gmail.com> References: <1459554737-19684-1-git-send-email-festevam@gmail.com> <1459554737-19684-3-git-send-email-festevam@gmail.com> Message-ID: <20160413162125.GV2274@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Apr 01, 2016 at 08:52:16PM -0300, Fabio Estevam wrote: > From: Fabio Estevam > > Document the 'fsl,sdma-event-remap' property and provide an example of > its usage. just 2/3 patch so I have no idea of the series. Whats going on? > > Cc: Vinod Koul > Signed-off-by: Fabio Estevam > --- > Changes since v1: > - Newly introduced in this series > > .../devicetree/bindings/dma/fsl-imx-sdma.txt | 27 ++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt > index dc8d3aa..175f0e4 100644 > --- a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt > +++ b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt > @@ -58,6 +58,15 @@ The third cell specifies the transfer priority as below. > 1 Medium > 2 Low > > +Optional properties: > + > +- gpr : The phandle to the General Purpose Register (GPR) node. > +- fsl,sdma-event-remap : Register bits of sdma event remap, the format is > + . > + reg is the GPR register offset. > + shift is the bit position inside the GPR register. > + val is the value of the bit (0 or 1). > + > Examples: > > sdma at 83fb0000 { > @@ -83,3 +92,21 @@ ssi2: ssi at 70014000 { > dma-names = "rx", "tx"; > fsl,fifo-depth = <15>; > }; > + > +Using the fsl,sdma-event-remap property: > + > +If we want to use SDMA on the SAI1 port on a MX6SX: > + > +&sdma { > + gpr = <&gpr>; > + /* SDMA events remap for SAI1_RX and SAI1_TX */ > + fsl,sdma-event-remap = <0 15 1>, <0 16 1>; > +}; > + > +The fsl,sdma-event-remap property in this case has two values: > +- <0 15 1> means that the offset is 0, so GPR0 is the register of the > +SDMA remap. Bit 15 of GPR0 selects between UART4_RX and SAI1_RX. > +Setting bit 15 to 1 selects SAI1_RX. > +- <0 16 1> means that the offset is 0, so GPR0 is the register of the > +SDMA remap. Bit 16 of GPR0 selects between UART4_TX and SAI1_TX. > +Setting bit 16 to 1 selects SAI1_TX. > -- > 1.9.1 > -- ~Vinod