[PATCH v3 5/5] ARM: dts: Alpine platform devicetree

[Tsahee Zidenberg]

Thank you for your review!

On 2 February 2015 at 15:40, Mark Rutland <mark.rutland at arm.com> wrote:
> On Mon, Feb 02, 2015 at 11:20:44AM +0000, Tsahee Zidenberg wrote:
>> +             arch-timer {
>> +                     compatible = "arm,cortex-a15-timer",
>> +                                  "arm,armv7-timer";
>> +                     interrupts =
>> +                             <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
>> +                             <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
>> +                             <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
>> +                             <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>;
>> +                     clock-frequency = <0>; /* Filled by loader */
>
> Your loader doesn't configure CNTFRQ?
>

Not currently. setting CNTFRQ must be done in the firmware, to be
valid across all CPUs and through power-cycles. This isn't supported
on current firmware, which is used in currently available devices. I
will add this as a required feature from next-gen firmware.
clock-frequency property is read by linux-kernel before attempting to
read CNTFRQ.


>> +             /* North Bridge Service Registers */
>> +             sysfabric-service at fb070000 {
>> +                     compatible = "al,alpine-sysfabric-service", "syscon", "simple-bus";
>> +                     reg = <0x0 0xfb070000 0x0 0x10000>;
>> +             };
>
> That compatible list makes no sense whatsoever.
>
> Why is "simple-bus" on the end?
>

Nodes that are used with "syscon_regmap_lookup_by_compatible" appear
both with and without compatibility to "simple-bus" in the
device-trees.
examples with: "fsl,imx6q-anatop", "xlnx,zynq-slcr"
examples without: "fsl,imx6q-iomuxc-gpr", "rockchip,rk3066-pmu"
Both ways work, I'm not if there is reasoning behind this difference
in current device-trees or which is the better example to follow. I
have no problem working either way. Is there a consensus on this?

> Mark.