On 03/14/2013 03:33 PM, Javier Martinez Canillas wrote: > Besides being used to interface with external memory devices, > the General-Purpose Memory Controller can be used to connect > Pseudo-SRAM devices such as ethernet controllers to OMAP2+ > processors using the TI GPMC as a data bus. > > This patch allows an ethernet chip to be defined as an GPMC > child device node. > > Signed-off-by: Javier Martinez Canillas <[email protected]> > --- > > Changes since v1: > - Improve the DT binding documentation explaining that even when the GPMC > maximum bus address width is 16-bit, it supports devices with 32-bit > registers address width and the device property especifying this has to > be set accordingly; suggested by Jon Hunter. > > > Documentation/devicetree/bindings/net/gpmc-eth.txt | 101 > ++++++++++++++++++++ > arch/arm/mach-omap2/gpmc.c | 8 ++ > 2 files changed, 109 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/net/gpmc-eth.txt > > diff --git a/Documentation/devicetree/bindings/net/gpmc-eth.txt > b/Documentation/devicetree/bindings/net/gpmc-eth.txt > new file mode 100644 > index 0000000..8c8be58 > --- /dev/null > +++ b/Documentation/devicetree/bindings/net/gpmc-eth.txt > @@ -0,0 +1,101 @@ > +Device tree bindings for Ethernet chip connected to TI GPMC > + > +Besides being used to interface with external memory devices, the > +General-Purpose Memory Controller can be used to connect Pseudo-SRAM devices > +such as ethernet controllers to processors using the TI GPMC as a data bus. > + > +Ethernet controllers connected to TI GPMC are represented as child nodes of > +the GPMC controller with an "ethernet" name. > + > +All timing relevant properties as well as generic GPMC child properties are > +explained in a separate documents. Please refer to > +Documentation/devicetree/bindings/bus/ti-gpmc.txt > + > +For the properties relevant to the ethernet controller connected to the GPMC > +refer to the binding documentation of the device. For example, the > documentation > +for the SMSC 911x is Documentation/devicetree/bindings/net/smsc911x.txt > + > +Child nodes need to specify the GPMC bus address width using the "bank-width" > +property but is possible that an ethernet controller also has a property to > +specify the I/O registers address width. Even when the GPMC has a maximum > 16-bit > +address width, it supports devices with 32-bit word registers. > +For example with an SMSC LAN911x/912x controller connected to the TI GPMC on > an > +OMAP2+ board, "bank-width = <2>;" and "reg-io-width = <4>;". > + > +Required properties: > +- bank-width: Address width of the device in bytes. GPMC > supports 8-bit > + and 16-bit devices and so must be either 1 or 2 bytes. > +- compatible: Compatible string property for the ethernet > child device. > +- gpmc,cs-on: Chip-select assertion time > +- gpmc,cs-rd-off: Chip-select de-assertion time for reads > +- gpmc,cs-wr-off: Chip-select de-assertion time for writes > +- gpmc,oe-on: Output-enable assertion time > +- gpmc,oe-off Output-enable de-assertion time > +- gpmc,we-on: Write-enable assertion time > +- gpmc,we-off: Write-enable de-assertion time > +- gpmc,access: Start cycle to first data capture (read access) > +- gpmc,rd-cycle: Total read cycle time > +- gpmc,wr-cycle: Total write cycle time > +- reg: Chip-select, base address (relative to > chip-select) > + and size of the memory mapped for the device. > + Note that base address will be typically 0 as this > + is the start of the chip-select. > + > +Optional properties: > +- gpmc,XXX Additional GPMC timings and settings parameters. See > + Documentation/devicetree/bindings/bus/ti-gpmc.txt
Should we add "reg-io-width" here and say can be 2 or 4 and to refer to the above description? > + > +Optional properties for partiton table parsing: > +- #address-cells: should be set to 1 > +- #size-cells: should be set to 1 Sorry should have caught this earlier. The above is not relevant for ethernet. Otherwise looks good. Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
