Messages in this thread | | | Date | Sat, 06 Jan 2018 00:48:25 +0100 | From | Paul Cercueil <> | Subject | Re: [PATCH v2 5/6] clocksource: Add a new timer-ingenic driver |
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Hi Rob,
Le sam. 6 janv. 2018 à 0:27, Rob Herring <robh@kernel.org> a écrit : > On Wed, Jan 3, 2018 at 3:56 PM, Paul Cercueil <paul@crapouillou.net> > wrote: >> Hi, >> >> Le mer. 3 janv. 2018 à 22:08, Rob Herring <robh@kernel.org> a >> écrit : >>> >>> On Mon, Jan 01, 2018 at 03:33:43PM +0100, Paul Cercueil wrote: >>>> >>>> This driver will use the TCU (Timer Counter Unit) present on the >>>> Ingenic >>>> JZ47xx SoCs to provide the kernel with a clocksource and timers. >>>> >>>> Signed-off-by: Paul Cercueil <paul@crapouillou.net> >>>> --- >>>> .../devicetree/bindings/timer/ingenic,tcu.txt | 35 +++ >>> >>> >>> Separate patch please. >> >> >> OK. >> >> >>>> drivers/clocksource/Kconfig | 8 + >>>> drivers/clocksource/Makefile | 1 + >>>> drivers/clocksource/timer-ingenic.c | 256 >>>> +++++++++++++++++++++ >>>> 4 files changed, 300 insertions(+) >>>> create mode 100644 >>>> Documentation/devicetree/bindings/timer/ingenic,tcu.txt >>>> create mode 100644 drivers/clocksource/timer-ingenic.c >>>> >>>> v2: Use SPDX identifier for the license >>>> >>>> diff --git >>>> a/Documentation/devicetree/bindings/timer/ingenic,tcu.txt >>>> b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt >>>> new file mode 100644 >>>> index 000000000000..e4944972ea53 >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt >>>> @@ -0,0 +1,35 @@ >>>> +Ingenic JZ47xx SoCs Timer/Counter Unit driver >>>> +--------------------------------------------- >>>> + >>>> +Required properties: >>>> + >>>> +- compatible : should be "ingenic,<socname>-tcu". Valid strings >>>> are: >>>> + * ingenic,jz4740-tcu >>>> + * ingenic,jz4770-tcu >>>> + * ingenic,jz4780-tcu >>>> +- interrupt-parent : phandle of the TCU interrupt controller. >>>> +- interrupts : Specifies the interrupts the controller is >>>> connected to. >>>> +- clocks : List of phandle & clock specifiers for the TCU >>>> clocks. >>>> +- clock-names : List of name strings for the TCU clocks. >>>> +- ingenic,channels: a list of TCU channels to be used as timers. >>> >>> >>> Why is this needed? This looks like you are trying to assign >>> certain >>> timers to clocksource and clockevent. A common problem, but one >>> that >>> should be decided by describing h/w features. There must be some >>> property present or missing to make you decide to use a given >>> channel or >>> not. >> >> >> Well, it's not easy; some TCU channels will be used as PWM, and >> there's no >> way >> to know that when the clocksource driver probes. And which ones are >> PWM / >> which >> ones are not, is board-specific. If you have a better solution >> though, I >> take it. > > Aren't the PWMs connected to something? Describe those in DT and then > you can find the free ones. > > Rob
The ingenic PWM driver just creates a PWM chip with 8 channels. Then it's up to the various clients (backlight, rumble...) to request a channel using the PWM API, from their own driver node or pdata. Besides you can also request PWM channels from sysfs... I can't detect all of that...
Paul
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