From: Chen-Yu Tsai wenst@chromium.org
[ Upstream commit ce8a06b5bac75ccce99c0cf91b96b767d64f28a7 ]
The systimer block derives its 13 MHz clock by dividing the main 26 MHz oscillator clock by 2 internally, not through the TOPCKGEN clock controller.
On the MT8183 this divider is set either by power-on-reset or by the bootloader. The bootloader may then make the divider unconfigurable to, but can be read out by, the operating system.
Making the systimer block take the 26 MHz clock directly requires changing the implementations. As an ABI compatible fix, change the input clock of the systimer block a fixed factor divide-by-2 clock that takes the 26 MHz oscillator as its input.
Fixes: 5bc8e2875ffb ("arm64: dts: mt8183: add systimer0 device node") Signed-off-by: Chen-Yu Tsai wenst@chromium.org Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Link: https://lore.kernel.org/r/20221201084229.3464449-2-wenst@chromium.org Signed-off-by: Matthias Brugger matthias.bgg@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/boot/dts/mediatek/mt8183.dtsi | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/boot/dts/mediatek/mt8183.dtsi b/arch/arm64/boot/dts/mediatek/mt8183.dtsi index f4e0bea8ddcb6..81fde34ffd52a 100644 --- a/arch/arm64/boot/dts/mediatek/mt8183.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt8183.dtsi @@ -299,6 +299,15 @@ psci { method = "smc"; };
+ clk13m: fixed-factor-clock-13m { + compatible = "fixed-factor-clock"; + #clock-cells = <0>; + clocks = <&clk26m>; + clock-div = <2>; + clock-mult = <1>; + clock-output-names = "clk13m"; + }; + clk26m: oscillator { compatible = "fixed-clock"; #clock-cells = <0>; @@ -610,8 +619,7 @@ systimer: timer@10017000 { "mediatek,mt6765-timer"; reg = <0 0x10017000 0 0x1000>; interrupts = <GIC_SPI 200 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&topckgen CLK_TOP_CLK13M>; - clock-names = "clk13m"; + clocks = <&clk13m>; };
iommu: iommu@10205000 {