On Thu, Mar 14, 2013 at 5:37 PM, Javier Martinez Canillas <martinez.javier@xxxxxxxxx> wrote: > On Thu, Mar 14, 2013 at 4:48 PM, Jon Hunter <jon-hunter@xxxxxx> wrote: >> Hi Javier, >> >> On 03/14/2013 10:09 AM, 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 <javier.martinez@xxxxxxxxxxxxxxx> >>> --- >>> Documentation/devicetree/bindings/net/gpmc-eth.txt | 90 ++++++++++++++++++++ >>> arch/arm/mach-omap2/gpmc.c | 8 ++ >>> 2 files changed, 98 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..c45363c >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/net/gpmc-eth.txt >>> @@ -0,0 +1,90 @@ >>> +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 >>> + >>> +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. >> >> I am wondering if we should use reg-io-width here. The smsc driver is >> using this to determine the width of the device. And so I am wondering >> if this could cause problems. >> >> Obviously this complicates gpmc_probe_generic_child() a little, but may >> be would could pass the name of the width property to >> gpmc_probe_generic_child() as well. What do you think? >> > > Hi Jon, > > Well now I'm confused. I thought that both were needed since a > combination of bank-width 16-bit / reg-io-width 32-bit is also > possible (in fact that is how I'm testing on my IGEPv2) and we have > talked about this before [1]. > > By reading both the OMAP3 TRM and the smsc LAN9221 data-sheet, it > seems that the reg-io-width is not about the data bus address width > but the CPU address width. The smsc data-sheet says: > Hi Jon, By the way, here is the smsc LAN9221 data-sheet if you don't have it and want to take it a look: http://www.smsc.com/Downloads/SMSC/Downloads_Public/Data_Sheets/9221.pdf Thanks a lot and best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
