In the CCU of the Allwinner R40 SoC, there's a GMAC configuration register, which is intended to be accessed by the dwmac-sun8i driver. On SoCs already supported by the driver the register is placed in the syscon rather than the CCU.
As CCU is a critical part of the SoC, so write to it should be strictly limited. A regmap with restricted write permission is created by the R40 CCU driver, and can be get with dev_get_regmap. In order to tie the regmap to the CCU device, the R40 CCU is now a platform driver, so a platform device is created for it (and then tied with the regmap). The first patch does the conversion of the driver to a platform driver, and the second patch adds the regmap. Icenowy Zheng (2): clk: sunxi-ng: r40: rewrite init code to a platform driver clk: sunxi-ng: r40: export a regmap to access the GMAC register drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 69 ++++++++++++++++++++++++++++++------ 1 file changed, 59 insertions(+), 10 deletions(-) -- 2.13.6