Hi Sebastian,

Sebastian Reichel [off-list ref] hat am 28. Januar 2015 um 23:59
geschrieben:


Hi,

On Wed, Jan 28, 2015 at 11:22:05PM +0100, Stefan Wahren wrote:

quoted

quoted

Mark Brown [off-list ref] hat am 27. Januar 2015 um 20:43
geschrieben:
On Tue, Jan 27, 2015 at 07:35:09PM +0100, Stefan Wahren wrote:

changing the switching frequency is not a common feature for this IC. In
most
cases the clock for the DC-DC switching frequency runs at 24 MHz (ref_xtal).
Unfortunatelly this could cause interferences for example in UHF band. So
switching to ref_pll and changing clock divider is a option to avoid such
interferences without changing hardware.

I decided to implement it as a module parameter, because i see it's a
configuration option.

I think its best to use a DT property then. That way it can be set
appropiatly for boards known to use a band, which could have
interference problems.

So just add a simple property (without a subnode). If I understand
Mark correctly, there's a high chance more drivers will need to
describe the switching frequency, so I suggest to use a vendor
independent property name:

switching-frequency = <12345>;

i'm not sure. So here is the complete current state (power and regulator binding
from imx28.dtsi) including my suggestion for the new property:

	power: power at 80044000 {
		compatible = "fsl,imx28-power"; /* handled by mxs_power.c */
		#address-cells = <1>;
		#size-cells = <1>;
		reg = <0x80044000 0x2000>;
		interrupts = <6>;
		switching-frequency = <24000000>; /* new property */
		ranges;

		reg_vddd: regulator at 80044040 {
			reg = <0x80044040 0x10>,
			      <0x80044010 0x10>,
			      <0x800440c0 0x10>;
			reg-names = "base-address",
				    "v5ctrl-address",
				    "status-address";
			compatible = "fsl,imx28-vddd"; /* handled by mxs-regulator.c */
			regulator-name = "vddd";
			regulator-min-microvolt = <1350000>;
			regulator-max-microvolt = <1550000>;
			vddd-supply = <&reg_vdda>;
		};

		reg_vdda: regulator at 80044050 {
			reg = <0x80044050 0x10>,
			      <0x80044010 0x10>,
			      <0x800440c0 0x10>;
			reg-names = "base-address",
				    "v5ctrl-address",
				    "status-address";
			compatible = "fsl,imx28-vdda"; /* handled by mxs-regulator.c */
			regulator-name = "vdda";
			regulator-min-microvolt = <1725000>;
			regulator-max-microvolt = <1950000>;
			vdda-supply = <&reg_vddio>;
		};

		reg_vddio: regulator at 80044060 {
			reg = <0x80044060 0x10>,
			      <0x80044010 0x10>,
			      <0x800440c0 0x10>;
			reg-names = "base-address",
				    "v5ctrl-address",
				    "status-address";
			compatible = "fsl,imx28-vddio"; /* handled by mxs-regulator.c */
			regulator-name = "vddio";
			regulator-min-microvolt = <3000000>;
			regulator-max-microvolt = <3575000>;
			regulator-microvolt-offset = <80000>;
		};
	};

Please correct me if i'm wrong.

Stefan

-- Sebastian
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