How to implement common clk in multi function controller?
yamada.masahiro at socionext.com
Tue Nov 10 19:16:27 PST 2015
I am implementing clk and reset drivers for my SoCs.
(drivers/clk/uniphier/* and drivers/reset/uniphier/*)
In my SoCs, one hardware block contains various
registers for both clock and reset controlling.
(so, it is like a MFD system controller device).
I think it is a common case.
I am guessing my device tree would be like follows:
(one syscon device contains clk and rst devices under it)
compatible = "socionext,uniphier-syscon",
reg = <... ...>;
.compatible = "socionext,uniphier-clkctrl";
#clock-cells = <1>;
.compatible = "socionext,uniphier-rstctrl";
#reset-cells = <1>;
One problem I noticed was,
we are supposed to use regmap for register access
if we use syscon.
OTOH, common clk APIs such as clk-gate, clk-divider
expect simple register access via writel()/readl().
Is it a good idea to expand such APIs to regmap?
Of course, I could my own uniphier/clk-gate.c
to use regmap as other SoCs do.
But, I think regmap is general demand, so
I am wondering if it could be supported in common parts.
Or, any other good solution exists?
More information about the linux-arm-kernel