On 02/02/2016 at 09:46:02 +0100, Oleksij Rempel wrote : > Am 01.02.2016 um 16:55 schrieb Alexandre Belloni: > > On 01/02/2016 at 09:27:50 -0600, Rob Herring wrote : > >> On Fri, Jan 29, 2016 at 09:40:02AM +0100, Oleksij Rempel wrote: > >>> Document Alphascale asm9260 RTC bindings > >>> > >>> Signed-off-by: Oleksij Rempel <linux@xxxxxxxxxxxxxxxx> > >>> --- > >>> .../bindings/rtc/alphascale,asm9260-rtc.txt | 25 ++++++++++++++++++++++ > >>> 1 file changed, 25 insertions(+) > >>> create mode 100644 Documentation/devicetree/bindings/rtc/alphascale,asm9260-rtc.txt > >>> > >>> diff --git a/Documentation/devicetree/bindings/rtc/alphascale,asm9260-rtc.txt b/Documentation/devicetree/bindings/rtc/alphascale,asm9260-rtc.txt > >>> new file mode 100644 > >>> index 0000000..2c0ff3c > >>> --- /dev/null > >>> +++ b/Documentation/devicetree/bindings/rtc/alphascale,asm9260-rtc.txt > >>> @@ -0,0 +1,25 @@ > >>> +* Alphascale asm9260 SoC Real Time Clock > >>> + > >>> +Required properties: > >>> +- compatible: Should be "alphascale,asm9260-rtc" > >>> +- reg: Physical base address of the controller and length > >>> + of memory mapped region. > >>> +- interrupts: IRQ line for the RTC. > >>> +- clocks: Reference to the clock entry. > >>> +- clock-names: should contain: > >>> + * "ahb" for the SoC RTC clock > >>> + > >>> +Optional: > >>> +- calibration: calibration value for 1 sec period. > >>> + Max value for forward calibration is 0x1ffff (131071), > >>> + Min value for backward calibration is 0xfffe0001 (-131071). > >> > >> This should be prefixed with 'alphascale,' > >> > >> How is this value determined? > >> > > > > I think this should stay in userspace, see that series: > > https://groups.google.com/forum/#!topic/rtc-linux/HGQqiHnMiuw > > > > It quite often depends on environmental things like temperature so it may be updated at runtime. > > > > I partially agree. IMO default configuration should work properly by > 20C. My devkit provide terrible results without default offset. > I'm not against having a sane default. What I would do is set a default hardcoded value from the driver at the time the RTC is reset (that is: it has never been set yet) then let the user adjust that calibration through sysfs. -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- 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
