On 6/30/21 9:58 AM, Michal Simek wrote: > > > On 6/30/21 3:47 PM, Michal Simek wrote: >> >> >> On 5/28/21 11:45 PM, Sean Anderson wrote: >>> This adds a binding for the Xilinx LogiCORE IP AXI Timer. This device is >>> a "soft" block, so it has many parameters which would not be >>> configurable in most hardware. This binding is usually automatically >>> generated by Xilinx's tools, so the names and values of some properties >>> must be kept as they are. Replacement properties have been provided for >>> new device trees. >>> >>> Because we need to init timer devices so early in boot, the easiest way >>> to configure things is to use a device tree property. For the moment >>> this is 'xlnx,pwm', but this could be extended/renamed/etc. in the >>> future if these is a need for a generic property. >>> >>> Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxx> >>> --- >>> >>> Changes in v4: >>> - Remove references to generate polarity so this can get merged >>> - Predicate PWM driver on the presence of #pwm-cells >>> - Make some properties optional for clocksource drivers >>> >>> Changes in v3: >>> - Mark all boolean-as-int properties as deprecated >>> - Add xlnx,pwm and xlnx,gen?-active-low properties. >>> - Make newer replacement properties mutually-exclusive with what they >>> replace >>> - Add an example with non-deprecated properties only. >>> >>> Changes in v2: >>> - Use 32-bit addresses for example binding >>> >>> .../bindings/pwm/xlnx,axi-timer.yaml | 85 +++++++++++++++++++ >>> 1 file changed, 85 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/pwm/xlnx,axi-timer.yaml >>> >>> diff --git a/Documentation/devicetree/bindings/pwm/xlnx,axi-timer.yaml b/Documentation/devicetree/bindings/pwm/xlnx,axi-timer.yaml >>> new file mode 100644 >>> index 000000000000..48a280f96e63 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/pwm/xlnx,axi-timer.yaml >> >> I don't think this is the right location for this. >> >> I have done some grepping and I think this should be done in a different >> way. I pretty much like solution around "ti,omap3430-timer" which is >> calling dmtimer_systimer_select_best() and later dmtimer_is_preferred() >> which in this case would allow us to get rid of cases which are not >> suitable for clocksource and clockevent. >> >> And there is drivers/pwm/pwm-omap-dmtimer.c which has link to timer >> which is providing functions for it's functionality. >> >> I have also looked at >> Documentation/devicetree/bindings/timer/nxp,tpm-timer.yaml which is also >> the same device. >> >> And sort of curious if you look at >> https://www.xilinx.com/support/documentation/ip_documentation/axi_timer/v2_0/pg079-axi-timer.pdf >> ( Figure 1-1) >> that PWM is taking input from generate out 0 and generate out 1 which is >> maybe can be modeled is any output and pwm driver can register inputs >> for pwm driver. >> >> >>> @@ -0,0 +1,85 @@ >>> +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause >>> +%YAML 1.2 >>> +--- >>> +$id: http://devicetree.org/schemas/pwm/xlnx,axi-timer.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> + >>> +title: Xilinx LogiCORE IP AXI Timer Device Tree Binding >>> + >>> +maintainers: >>> + - Sean Anderson <sean.anderson@xxxxxxxx> >>> + >>> +properties: >>> + compatible: >>> + oneOf: >>> + - items: >>> + - const: xlnx,axi-timer-2.0 > > I am not quite sure if make sense also to list 2.0 version. > There were likely also 1.0 version which is compatible with origin xps > version which IIRC was PLB based. And the same driver was using in past > with OPB bus. It's required to list all compatible properties which may be used in a binding. And AFAIK it is good practice to add a new compatible string for new releases of an IP, in case incompatibilities are discovered. --Sean
