On Thursday 22 October 2015 18:41:05 Rob Herring wrote: > On Thu, Oct 22, 2015 at 1:52 PM, Ray Jui wrote: > > On 10/22/2015 11:43 AM, Rob Herring wrote: > >> On Mon, Oct 19, 2015 at 12:43 AM, Pramod Kumar wrote: > >>> Add ngpios property to the gpio controller's DT node so that controller > >>> driver extracts total number of gpio lines present in controller > >>> from DT and removes dependency on driver. > >>> > >>> Signed-off-by: Pramod Kumar <pramodku@xxxxxxxxxxxx> > >>> Reviewed-by: Ray Jui <rjui@xxxxxxxxxxxx> > >>> Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx> > >>> --- > >>> > >>> Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt | 5 +++ > >>> 1 file changed, 5 insertions(+) > >>> > >>> diff --git > >>> a/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt > >>> b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt > >>> index f92b833..655a8d7 100644 > >>> --- a/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt > >>> +++ b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt > >>> > >>> @@ -10,6 +10,9 @@ Required properties: > >>> Define the base and range of the I/O address space that contains > >>> the Cygnus > >>> GPIO/PINCONF controller registers > >>> > >>> +- ngpios: > >>> + Total number of GPIOs the controller provides > >> > >> This must be optional for compatibility and the driver needs to handle > >> it not present. > > > > You meant to be compatible with existing Cygnus devices, correct? > > > > Just to clarify, here you suggest we still leave the existing hard coded > > ngpios in the driver, in order to be compatible with all existing Cygnus > > devices (while the Cygnus device tree changes to use ngpio is still being > > merged and through different maintainer), and have all new iProc SoCs > > switch to use ngpios from device tree, right? > > Yes, an existing dtb should continue to work with a new kernel. You > can add the DT property to the older devices too and then eventually > remove the hard coded values some time in the future. That could be > immediately (don't care about compatibility at all), a couple of > kernel cycles, never... It all depends on users of the impacted > platforms. But shouldn't the property still be documented as required to ensure that new DTs always include it ? -- Regards, Laurent Pinchart -- 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
