Messages in this thread | | | Date | Wed, 03 Jan 2018 22:56:16 +0100 | From | Paul Cercueil <> | Subject | Re: [PATCH v2 5/6] clocksource: Add a new timer-ingenic driver |
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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.
>> + >> +Example: >> + >> +/ { >> + regmap { >> + compatible = "simple-mfd", "syscon"; >> + reg = <0x10002000 0x1000>; >> + >> + tcu: timer { >> + compatible = "ingenic,jz4740-tcu"; >> + >> + clocks = <&tcu 0>, <&tcu 1>; >> + clock-names = "timer0", "timer1"; > > It's curious that you have timer0 and timer1 here and then channels 0 > and 1 below. Would your clocks change if you use channel 2 for > example? > The binding should be a list of clock connections in the h/w, not > just what the driver needs or what the used h/w configuration is. > > Rob
I only put these to simplify the example, but you're right, I should have all the timer clocks supplied there.
Thanks, -Paul
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