[U-Boot] [linux-sunxi] [PATCH v2 0/4] sunxi: SPI: Add SUN6I generation SPI support

[Jagan Teki]

On Tue, Feb 12, 2019 at 4:11 PM Andre Przywara <andre.przywara at arm.com> wrote:
>
> We already have a driver for the SPI devices in older Allwinner CPUs.
> Newer SoCs (SUN6I generation) have a similar, but improved IP block.
> This series adds support for that, so we can access the SPI flash that
> some newer boards come with.
> This series gathers some patches that have appeared on the list in one
> form or another before (hence the v2 tag), but brings them all together
> and updates them.
>
> The SUN4I/SUN6I SPI devices share a very similar architecure, but differ
> annoyingly in quite some details, to a point where a shared driver
> would look unnecessarily complicated. So we use an #ifdef based approach,
> which keeps the driver simple, at the cost of not being able to access
> both types of device in one binary build. But since there are no SoCs
> which feature both types, this is a theoretical disadvantage.
>
> Patch 1/4 moves the clock toggling from the probe/remove to the
> claim/release-bus stage.
> Patch 2/4 adds the SPI gate clocks and reset gates to the clock drivers,
> also describes at least the enable bit for the SPI mod clock. This is used
> in patch 3/4, which uses the new DM clock framework in the driver, helping
> to abstract differences between the SUN4I/SUN6I types.
> Patch 4/4 eventually adds support for the new SUN6I generation SPI device.
> The actual device support is determined at compile time, based on the
> CONFIG_SUNXI_GEN_SUN6I symbol.
>
> What's left out of this series is the config bits needed to actually
> activate the support for a board. At the moment this is unnecessarily
> verbose, so that Oskari is looking at simplifying this at the Kconfig
> level, which would complement this series.
>
> This has been briefly tested on the Pine64-LTS and the OrangePi PC2 board.
> Please test them if you have other devices with a SUN6I SPI generation.

I have new series for this which I sent two days back [1]. which uses
same sun4i driver and implement enum reg set to avoid ifdef.

[1] https://patchwork.ozlabs.org/cover/1039178/