On 06.12.2012 17:19, Jon Hunter wrote: > > On 12/05/2012 05:24 PM, Grant Likely wrote: >> On Wed, 5 Dec 2012 16:33:48 -0600, Jon Hunter <jon-hunter@xxxxxx> wrote: >>> Hi Grant, >>> >>> On 12/05/2012 04:22 PM, Grant Likely wrote: >>>> On Wed, 5 Dec 2012 20:09:31 +0100, Daniel Mack <zonque@xxxxxxxxx> wrote: >>>>> This patch adds basic DT bindings for OMAP GPMC. >>>>> >>>>> The actual peripherals are instantiated from child nodes within the GPMC >>>>> node, and the only type of device that is currently supported is NAND. >>>>> >>>>> Code was added to parse the generic GPMC timing parameters and some >>>>> documentation with examples on how to use them. >>>>> >>>>> Successfully tested on an AM33xx board. >>>>> >>>>> Signed-off-by: Daniel Mack <zonque@xxxxxxxxx> >>>>> --- >>>>> Documentation/devicetree/bindings/bus/ti-gpmc.txt | 77 ++++++++++ >>>>> .../devicetree/bindings/mtd/gpmc-nand.txt | 76 +++++++++ >>>>> arch/arm/mach-omap2/gpmc.c | 171 ++++++++++++++++++++- >>>>> 3 files changed, 323 insertions(+), 1 deletion(-) >>>>> create mode 100644 Documentation/devicetree/bindings/bus/ti-gpmc.txt >>>>> create mode 100644 Documentation/devicetree/bindings/mtd/gpmc-nand.txt >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/bus/ti-gpmc.txt b/Documentation/devicetree/bindings/bus/ti-gpmc.txt >>>>> new file mode 100644 >>>>> index 0000000..7d2a645 >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/bus/ti-gpmc.txt >>>>> @@ -0,0 +1,77 @@ >>>>> +Device tree bindings for OMAP general purpose memory controllers (GPMC) >>>>> + >>>>> +The actual devices are instantiated from the child nodes of a GPMC node. >>>>> + >>>>> +Required properties: >>>>> + >>>>> + - compatible: Should be set to "ti,gpmc" >>>> >>>> Please, be specific. Use something like "ti,am3340-gpmc" or >>>> "ti,omap3430-gpmc". The compatible property is a list so that new >>>> devices can claim compatibility with old. Compatible strings that are >>>> overly generic are a pet-peave of mine. >>> >>> We aim to use the binding for omap2,3,4,5 as well as the am33xx devices >>> (which are omap based). Would it be sufficient to have "ti,omap2-gpmc" >>> implying all omap2+ based devices or should we have a compatible string >>> for each device supported? >> >> Are they each register-level compatible with one another? > > They are not 100% register compatible. There are a couple fields in the > binding that are only applicable to OMAP3+ devices. > >> The general recommended approach here is to make subsequent silicon >> claim compatibility with the first compatible implementation. >> >> So, for an am3358 board: >> compatible = "ti,am3358-gpmc", "ti,omap2420-gpmc"; >> >> Essentially, what this means is that "ti,omap2420-gpmc" is the generic >> value instead of "omap2-gpmc". The reason for this is so that the value >> is anchored against a specific implementation, and not against something >> completely imaginary or idealized. If a newer version isn't quite >> compatible with the omap2420-gpmc, then it can drop the compatible claim >> and the driver really should be told about the new device. > > Ok, gotcha! I will do a register comparison and may be recommend to > Daniel which compatible strings we will need. Any idea yet how we want to continue on this? I'm asking because I'm leaving for a longer trip by the end of this week, and so anything I haven't finished until then will have to be postponed until February or be taken over by someone else :) Thanks, Daniel -- 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
