On Fri, Oct 23, 2015 at 4:08 AM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > 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 ? Good point. If the intent is to eventually remove it from the driver, then yes. We probably need "required for new designs" as a category or maybe "recommended"? The wording is not so important here, but I'm thinking about as we try to standardize the naming. Rob -- 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
