On Thursday, August 27, 2015 at 07:44:34 PM, vikas wrote: > Hi, > > On 08/21/2015 02:20 AM, Marek Vasut wrote: > > From: Graham Moore <grmoore@xxxxxxxxxxxxxxxxxxxxx> > > > > Add binding document for the Cadence QSPI controller. > > > > Signed-off-by: Graham Moore <grmoore@xxxxxxxxxxxxxxxxxxxxx> > > Signed-off-by: Marek Vasut <marex@xxxxxxx> > > Cc: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> > > Cc: Brian Norris <computersforpeace@xxxxxxxxx> > > Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx> > > Cc: Dinh Nguyen <dinguyen@xxxxxxxxxxxxxxxxxxxxx> > > Cc: Graham Moore <grmoore@xxxxxxxxxxxxxxxxxxxxx> > > Cc: Vikas MANOCHA <vikas.manocha@xxxxxx> > > Cc: Yves Vandervennet <yvanderv@xxxxxxxxxxxxxxxxxxxxx> > > Cc: devicetree@xxxxxxxxxxxxxxx > > --- > > > > .../devicetree/bindings/mtd/cadence-quadspi.txt | 56 > > ++++++++++++++++++++++ 1 file changed, 56 insertions(+) > > create mode 100644 > > Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > > > > V2: Add cdns prefix to driver-specific bindings. > > V3: Use existing property "is-decoded-cs" instead of creating a > > > > duplicate, "ext-decoder". Timing parameters are in nanoseconds, > > not master reference clocks. Remove bus-num completely. > > > > V4: Add new properties fifo-width and trigger-address > > V7: - Prefix all of the Cadence-specific properties with cdns prefix, > > > > those are in particular "cdns,is-decoded-cs", "cdns,fifo-depth", > > "cdns,fifo-width", "cdns,trigger-address". > > > > - Drop bogus properties which were not used and were incorrect. > > > > V8: Align lines to 80 chars. > > > > diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > > b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt new file > > mode 100644 > > index 0000000..f248056 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > > @@ -0,0 +1,56 @@ > > +* Cadence Quad SPI controller > > + > > +Required properties: > > +- compatible : Should be "cdns,qspi-nor". > > +- reg : Contains two entries, each of which is a tuple consisting of a > > + physical address and length. The first entry is the address and > > + length of the controller register set. The second entry is the > > + address and length of the QSPI Controller data area. > > still hooked up with "Controller data area", it is ambiguous. > Use something which is more clear: Nor Flash memory mapped address. I have to disagree, I will call it whatever it is called in the datasheet and it is called "controller data area". > > +- interrupts : Unit interrupt specifier for the controller interrupt. > > +- clocks : phandle to the Quad SPI clock. > > +- cdns,fifo-depth : Size of the data FIFO in words. > > +- cdns,fifo-width : Bus width of the data FIFO in bytes. > > +- cdns,trigger-address : 32-bit indirect AHB trigger address. > > + > > > +Optional properties: > again, is it optional ? can the driver be used without these properties ? Why wouldn't it be possible to use the driver with no SPI NOR attached to it? It's a cornercase, but still a valid one. > > +- cdns,is-decoded-cs : Flag to indicate whether decoder is used or not. > > again, add info what the decoder is for ? This is something Graham has to clarify. Based on the code (I'm sure you did check the code), it's a 4:16 demuxer. > > + > > +Optional subnodes: > > +Subnodes of the Cadence Quad SPI controller are spi slave nodes with > > additional +custom properties: > > +- cdns,read-delay : Delay for read capture logic, in clock cycles > > +- cdns,tshsl-ns : Delay in nanoseconds for the length that the master > > + mode chip select outputs are de-asserted between > > + transactions. > > +- cdns,tsd2d-ns : Delay in nanoseconds between one chip select being > > + de-activated and the activation of another. > > +- cdns,tchsh-ns : Delay in nanoseconds between last bit of current > > + transaction and deasserting the device chip select > > + (qspi_n_ss_out). > > +- cdns,tslch-ns : Delay in nanoseconds between setting qspi_n_ss_out low > > + and first bit transfer. > > + > > +Example: > > + > > + qspi: spi@ff705000 { > > + compatible = "cdns,qspi-nor"; > > + #address-cells = <1>; > > + #size-cells = <0>; > > + reg = <0xff705000 0x1000>, > > + <0xffa00000 0x1000>; > > + interrupts = <0 151 4>; > > + clocks = <&qspi_clk>; > > + cdns,is-decoded-cs; > > flag value ? Sorry, I don't quite understand the question. If you mean why there is no value, it's because this is a boolean OF node, which just does't need to have a value ; it's either present or not. Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html