Re: [PATCH v7 7/7] pinctrl: freescale: imx: imx7d iomuxc-lpsr devicetree bindings

[Shawn Guo <shawnguo@kernel.org>]

On Mon, Sep 28, 2015 at 04:56:41PM -0500, Adrian Alonso wrote:
> Add iomuxc-lpsr devicetree bindings documentation
> Provide documentation context as well an example on
> pheriperals that could use pad from either iomuxc controller
> supported by iMX7D SoC
> 
> Signed-off-by: Adrian Alonso <aalonso@freescale.com>
> ---
> Changes for V2: New patch on imx7d iomuxc-lpsr patch series
> Changes for V3: Add shared input select register notes
> Changes for V4: Resend
> Changes for V5:
> - Fix spell error
> - Remove references of SHARE_INPUT_SELECT_REG flag
> Changes for V6: Resend
> Changes for v7: Resend
> 
>  .../bindings/pinctrl/fsl,imx7d-pinctrl.txt         | 63 +++++++++++++++++++++-
>  1 file changed, 62 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
> index 8bbf25d..aae069f 100644
> --- a/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
> +++ b/Documentation/devicetree/bindings/pinctrl/fsl,imx7d-pinctrl.txt
> @@ -1,16 +1,42 @@
>  * Freescale i.MX7 Dual IOMUX Controller
>  
> +iMX7D supports two iomuxc controllers, fsl,imx7d-iomuxc controller is similar
> +as previous iMX SoC generation and fsl,imx7d-iomuxc-lpsr which provides low
> +power state retention capabilities on gpios that are part of iomuxc-lpsr
> +(GPIO1_IO7..GPIO1_IO0). While iomuxc-lpsr provides its own set of registers for
> +mux and pad control settings, it shares the input select register from main
> +iomuxc controller for daisy chain settings, the fsl,input-sel property extends
> +fsl,imx-pinctrl driver to support iomuxc-lpsr controller.
> +
> +iomuxc_lpsr: iomuxc-lpsr@302c0000 {
> +	compatible = "fsl,imx7d-iomuxc-lpsr";
> +	reg = <0x302c0000 0x10000>;
> +	fsl,input-sel = <&iomuxc>;
> +};
> +
> +iomuxc: iomuxc@30330000 {
> +	compatible = "fsl,imx7d-iomuxc";
> +	reg = <0x30330000 0x10000>;
> +};
> +
> +Pheriparials using pads from iomuxc-lpsr support low state retention power
> +state, under LPSR mode GPIO's state of pads are retain.
> +
>  Please refer to fsl,imx-pinctrl.txt in this directory for common binding part
>  and usage.
>  
>  Required properties:
> -- compatible: "fsl,imx7d-iomuxc"
> +- compatible: "fsl,imx7d-iomuxc" for main IOMUXC controller, or
> +  "fsl,imx7d-iomuxc-lpsr" for Low Power State Retention IOMUXC controller.
>  - fsl,pins: each entry consists of 6 integers and represents the mux and config
>    setting for one pin.  The first 5 integers <mux_reg conf_reg input_reg mux_val
>    input_val> are specified using a PIN_FUNC_ID macro, which can be found in
>    imx7d-pinfunc.h under device tree source folder.  The last integer CONFIG is
>    the pad setting value like pull-up on this pin.  Please refer to i.MX7 Dual
>    Reference Manual for detailed CONFIG settings.
> +- fsl,input-sel: required property for iomuxc-lpsr controller, this property is
> +  a phandle for main iomuxc controller which shares the input select register for
> +  daisy chain settings.
>  
>  CONFIG bits definition:
>  PAD_CTL_PUS_100K_DOWN           (0 << 5)
> @@ -25,3 +51,38 @@ PAD_CTL_DSE_X1                  (0 << 0)
>  PAD_CTL_DSE_X2                  (1 << 0)
>  PAD_CTL_DSE_X3                  (2 << 0)
>  PAD_CTL_DSE_X4                  (3 << 0)
> +
> +Examples:
> +While iomuxc-lpsr is intended to be used by dedicated peripherals to take
> +advantages of LPSR power mode, is also possible that an IP to use pads from
> +any of the iomux controllers. For example the I2C1 IP can use SCL pad from
> +iomuxc-lpsr controller and SDA pad from iomuxc controller as:
> +
> +i2c1: i2c@30a20000 {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pinctrl_i2c1_1 &pinctrl_i2c1_2>;
> +	status = "okay";
> +};
> +
> +iomuxc-lpsr@302c0000 {
> +	compatible = "fsl,imx7d-iomuxc-lpsr";
> +	reg = <0x302c0000 0x10000>;
> +	fsl,input-sel = <&iomuxc>;
> +
> +	pinctrl_i2c1_1: i2c1grp-1 {
> +		fsl,pins = <
> +			MX7D_PAD_GPIO1_IO04__I2C1_SCL 0x4000007f
> +		>;
> +	};
> +};
> +
> +iomuxc@30330000 {
> +	compatible = "fsl,imx7d-iomuxc";
> +	reg = <0x30330000 0x10000>;
> +
> +	pinctrl_i2c1_2: i2c1grp-2 {
> +		fsl,pins = <
> +			MX7D_PAD_I2C1_SCL__I2C1_SCL 0x4000007f

I'm not sure how many times I should repeat: you should set up a
I2C1_SDA instead of two I2C1_SCL in this example.

Shawn

> +		>;
> +	};
> +};
> -- 
> 2.1.4
>