Re: [linux-sunxi] [PATCH 00/15] rtc: sun6i: clock rework and pre-H6 SoC support

From: Corentin Labbe
Date: Wed Nov 28 2018 - 13:45:38 EST

On Wed, Nov 28, 2018 at 05:29:57PM +0800, Chen-Yu Tsai wrote:
> Hi everyone,
> This series was started as part of enabling Bluetooth on various
> Allwinner SBCs. The bluetooth controller requires a precise 32.768 kHz
> clock fed to it to correctly detect the frequency of its main oscillator.
> This clock signal is provided by the RTC, either directly from a special
> pin on the SoC, or some clock output function from the clock controllers.
> I found that the clock-related properties of the RTC on later SoCs were
> incorrect or missing.
> This series reworks the compatible strings and clock parts of the device
> tree bindings for sun6i-rtc. Currently we assume most Allwinner SoCs use
> the same sun6i-rtc variant, when in fact they do not. The differences
> that matter with regards to clocks are a) the A31 does not have an extra
> external output for the RTC 32K clock, while most of the others do;
> b) the clock frequency of the internal RC oscillator is different on
> some SoCs; c) on the H6 the RTC also handles the 24 MHz DCXO, which
> feeds the system HOSC. The last difference, and by extension the H6, are
> not covered in this series.
> Patch 1 cleans up the clock-related section of the RTC device tree
> binding. This would make it easier to read and easier to add additional
> clocks.
> Patch 2 adds compatible strings for all identified variants introduced
> prior to the H6.
> Patch 3 deprecates the external clock output for the A31. The A31 does
> not have this output, so it's introduction and usage was an error.
> Patch 4 adds a clock output for the RTC's internal oscillator to the
> device tree binding. This feeds the PRCM in some SoCs.
> Patch 5 adds a default clock name for the LOSC to the RTC driver.
> Patch 6 adds support for different hardware variants to the RTC driver.
> Patch 7 adds support for all known pre-H6 variants.
> Patch 8 exposes the RTC's internal oscillator through the device tree.
> Patch 9 makes the R40's CCU use the LOSC from the RTC module, instead of
> its own internal oscillator.
> Patch 10 through 15 adds an RTC node or fixes up the RTC device node
> address ranges, clock properties, names of existing clocks, and adds
> accuracy properties for the external fixed oscillators.
> The clock names require fixing because the sunxi clock driver implicitly
> depends on the HOSC and LOSC being named "osc24M" and "osc32k". The
> "fixes" to the clock hierarchy introduced in this series means the names
> must also be shuffled around or the in kernel representation would be
> incorrect. This has been the case since the sunxi-ng drivers were
> introduced. There are plans to address this, but the code is still in its
> early stages.
> Please have a look.
> Thanks
> ChenYu
> Chen-Yu Tsai (15):
> dt-bindings: rtc: sun6i-rtc: Rewrite clock outputs as a list
> dt-bindings: rtc: sun6i-rtc: Add compatible strings for pre-H6
> variants
> dt-bindings: rtc: sun6i-rtc: Deprecate external clock output for A31
> dt-bindings: rtc: sun6i-rtc: Export internal RC oscillator
> rtc: sun6i: Add default clock name for LOSC
> rtc: sun6i: Add support for different variants
> rtc: sun6i: Add support for all known pre-H6 variants
> rtc: sun6i: Expose internal oscillator through device tree
> clk: sunxi-ng: r40: Force LOSC parent to RTC LOSC output
> ARM: dts: sun8i: a23/a33: Fix up RTC device node
> ARM: dts: sunxi: h3/h5: Add clock accuracy for external oscillators
> ARM: dts: sunxi: h3/h5: Fix up RTC device node and clock references
> ARM: dts: sun8i: r40: Add clock accuracy for external oscillators
> ARM: dts: sun8i: r40: Add RTC device node
> arm64: dts: allwinner: a64: Fix up RTC device node and clock
> references
> .../devicetree/bindings/rtc/sun6i-rtc.txt | 31 ++++-
> arch/arm/boot/dts/sun8i-a23-a33.dtsi | 6 +-
> arch/arm/boot/dts/sun8i-h3.dtsi | 4 +
> arch/arm/boot/dts/sun8i-r40.dtsi | 18 ++-
> arch/arm/boot/dts/sunxi-h3-h5.dtsi | 28 ++---
> arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 22 ++--
> arch/arm64/boot/dts/allwinner/sun50i-h5.dtsi | 4 +
> drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 11 ++
> drivers/rtc/rtc-sun6i.c | 117 ++++++++++++++++--
> 9 files changed, 188 insertions(+), 53 deletions(-)
> --


Tested-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
Tested-on: sun8i-r40-bananapi-m2-ultra
Tested-on: sun50i-h5-nanopi-neo-plus2