This series adds a new devfreq driver for the MBUS/DRAM controller in some Allwinner SoCs, and enables it for the A64 and H5. The first four patches make some improvements to the devfreq core to support drivers without any OPPs in the DT. They could be merged independently. (Since this driver controls only a divider, and can only slow down the DRAM clock, it works with most any base DRAM frequency.) Then the binding and DTs are updated in patches 5-9. The MBUS nodes already existed, but were not bound to any driver before; they were only used for their dma-ranges property. Finally, the driver is added in patch 10. I am not 100% sure the best way to handle DRAM register access -- as a separate reg property, a separate node, or simply enlarging the MBUS register range. While the DRAM controller is a separate IP block, the MBUS hardware has the ability to double-buffer certain DRAM controller registers, and the hardware MDFS process writes to some DRAM controller registers as well. So they are rather tightly integrated. Like the patch 10 description says, this driver could support additional SoCs: at least A33, A83T, and H3. I can send follow-up patches for these, but I cannot test A33 or A83T. Samuel Holland (10): PM / devfreq: strengthen check for freq_table PM / devfreq: Do not require devices to have OPPs PM / devfreq: Drop code for descending freq_table PM / devfreq: Add a recommended frequency helper dt-bindings: clock: sunxi: Export CLK_DRAM for devfreq dt-bindings: arm: sunxi: Expand MBUS binding dt-bindings: arm: sunxi: Add H5 MBUS compatible ARM: dts: sunxi: h3/h5: Update MBUS node arm64: dts: allwinner: a64: Update MBUS node PM / devfreq: Add a driver for the sun8i/sun50i MBUS .../arm/sunxi/allwinner,sun4i-a10-mbus.yaml | 77 ++- arch/arm/boot/dts/sun8i-h3.dtsi | 4 + arch/arm/boot/dts/sunxi-h3-h5.dtsi | 11 +- arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 10 +- arch/arm64/boot/dts/allwinner/sun50i-h5.dtsi | 4 + drivers/clk/sunxi-ng/ccu-sun50i-a64.h | 2 - drivers/clk/sunxi-ng/ccu-sun8i-h3.h | 2 - drivers/devfreq/Kconfig | 8 + drivers/devfreq/Makefile | 1 + drivers/devfreq/devfreq.c | 77 ++- drivers/devfreq/sun8i-a33-mbus.c | 482 ++++++++++++++++++ include/dt-bindings/clock/sun50i-a64-ccu.h | 2 +- include/dt-bindings/clock/sun8i-h3-ccu.h | 2 +- include/linux/devfreq.h | 2 + 14 files changed, 644 insertions(+), 40 deletions(-) create mode 100644 drivers/devfreq/sun8i-a33-mbus.c -- 2.31.1
