[RFC v2: PATCH 1/2] dt-bindings: Document the hi3660 reset bindings

[Philipp Zabel]

Am Donnerstag, den 24.11.2016, 17:40 +0800 schrieb zhangfei:
> 
> On 2016年11月24日 17:26, Philipp Zabel wrote:
> > Am Mittwoch, den 23.11.2016, 16:07 +0800 schrieb Zhangfei Gao:
> >> Add DT bindings documentation for hi3660 SoC reset controller.
> >>
> >> Signed-off-by: Zhangfei Gao <zhangfei.gao at linaro.org>
> >> ---
> >>   .../bindings/reset/hisilicon,hi3660-reset.txt      | 51 ++++++++++++++++++++++
> >>   1 file changed, 51 insertions(+)
> >>   create mode 100644 Documentation/devicetree/bindings/reset/hisilicon,hi3660-reset.txt
> >>
> >> diff --git a/Documentation/devicetree/bindings/reset/hisilicon,hi3660-reset.txt b/Documentation/devicetree/bindings/reset/hisilicon,hi3660-reset.txt
> >> new file mode 100644
> >> index 0000000..250daf2
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/reset/hisilicon,hi3660-reset.txt
> >> @@ -0,0 +1,51 @@
> >> +Hisilicon System Reset Controller
> >> +======================================
> >> +
> >> +Please also refer to reset.txt in this directory for common reset
> >> +controller binding usage.
> >> +
> >> +The reset controller registers are part of the system-ctl block on
> >> +hi3660 SoC.
> >> +
> >> +Required properties:
> >> +- compatible: should be
> >> +		 "hisilicon,hi3660-reset"
> >> +- #reset-cells: 1, see below
> >> +- hisi,rst-syscon: phandle of the reset's syscon.
> >> +- hisi,reset-bits: Contains the reset control register information
> >> +		  Should contain 2 cells for each reset exposed to
> >> +		  consumers, defined as:
> >> +			Cell #1 : offset from the syscon register base
> >> +			Cell #2 : bits position of the control register
> >> +
> >> +Example:
> >> +	iomcu: iomcu at ffd7e000 {
> >> +		compatible = "hisilicon,hi3660-iomcu", "syscon";
> >> +		reg = <0x0 0xffd7e000 0x0 0x1000>;
> >> +	};
> >> +
> >> +	iomcu_rst: iomcu_rst_controller {
> > This should be
> > 	iomcu_rst: reset-controller {
> >
> >> +		compatible = "hisilicon,hi3660-reset";
> >> +		#reset-cells = <1>;
> >> +		hisi,rst-syscon = <&iomcu>;
> >> +		hisi,reset-bits = <0x20 0x8		/* 0: i2c0 */
> >> +				   0x20 0x10		/* 1: i2c1 */
> >> +				   0x20 0x20		/* 2: i2c2 */
> >> +				   0x20 0x8000000>;	/* 3: i2c6 */
> >> +	};
> > The reset lines are controlled through iomcu bits, is there a reason not
> > to put the iomcu_rst node inside the iomcu node? That way the
> > hisi,rst-syscon property could be removed and the syscon could be
> > retrieved via the reset-controller parent node.
> iomcu is common registers, controls clock and reset, etc.
> So we use syscon, without mapping the registers everywhere.
> It is common case in hisilicon, same in hi6220.
>
> Also the #clock-cells and #reset-cells can not be put in the same node,
> if they are both using probe, since reset_probe will not be called.
> 
> So we use hisi,rst-syscon as a general solution.

What I meant is this:

	iomcu: iomcu at ffd7e000 {
		compatible = "hisilicon,hi3660-iomcu", "syscon", "simple-mfd";
		reg = <0x0 0xffd7e000 0x0 0x1000>;

		iomcu_rst: reset-controller {
			compatible = "hisilicon,hi3660-reset";
			#reset-cells = <1>;
			hisi,reset-bits = <0x20 0x8		/* 0: i2c0 */
					   0x20 0x10		/* 1: i2c1 */
					   0x20 0x20		/* 2: i2c2 */
					   0x20 0x8000000>;	/* 3: i2c6 */
		};
	};

regards
Philipp