Re: [PATCH 1/4] pinctrl: Broadcom Cygnus pinctrl device tree binding

[Belisko Marek <marek.belisko@gmail.com>]

On Thu, Dec 4, 2014 at 10:56 PM, Ray Jui <rjui@broadcom.com> wrote:
> Device tree binding documentation for Broadcom Cygnus pinctrl driver
>
> Signed-off-by: Ray Jui <rjui@broadcom.com>
> Reviewed-by: Scott Branden <sbranden@broadcom.com>
> ---
>  .../bindings/pinctrl/brcm,cygnus-pinctrl.txt       |   92 ++++++++++++++++++++
>  1 file changed, 92 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt
> new file mode 100644
> index 0000000..86e4579
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-pinctrl.txt
> @@ -0,0 +1,92 @@
> +Broadcom Cygnus Pin Controller
> +
> +The Cygnus pin controller supports setting the alternate functions of groups
> +of pins. Pinmux configuration on individual pins is not supported by the
> +Cygnus A0 SoC.
> +
> +Required properties:
> +
> +- compatible:
> +    Must be "brcm,cygnus-pinctrl"
> +
> +- reg:
> +    Define the base and range of the I/O address space that contain the Cygnus
> +pin control registers
> +
> +- brcm,groups:
> +    This can be strings of one or more group names. This defines the group(s)
> +that one wants to configure
> +
> +- brcm,function:
> +    This is the alternate function that one wants to configure to. Valid
> +alternate functions are "alt1", "alt2", "alt3", "alt4"
> +
> +Each child node represents a configuration. Client devices reference the the
> +child node to enable the mux configuration.
> +
> +For example:
> +
> +       pinctrl: pinctrl@0x0301d0c8 {
> +               compatible = "brcm,cygnus-pinctrl";
> +               reg = <0x0301d0c8 0x2c>;
> +
> +               i2s_0: i2s_0 {
> +                       brcm,groups = "smart_card0", "smart_card0_fcb";
> +                       brcm,function = "alt2";
> +               };
> +
> +               i2s_1: i2s_1 {
> +                       brcm,groups = "smart_card1", "smart_card1_fcb";
> +                       brcm,function = "alt2";
> +               };
> +
> +               spi_0: spi_0 {
> +                       brcm,groups = "spi0";
> +                       brcm,function = "alt1";
> +               };
> +       }
> +
> +       spi0@18028000 {
> +                       compatible = "arm,pl022", "arm,primecell";
> +                       reg = <0x18028000 0x1000>;
> +                       #address-cells = <1>;
> +                       #size-cells = <0>;
> +                       interrupts = <GIC_SPI 78 IRQ_TYPE_LEVEL_HIGH>;
> +                       pinctrl-0 = <&spi_0>;
> +                       clocks = <&axi81_clk>;
> +                       clock-names = "apb_pclk";
> +       };
> +
> +Consider the following snapshot of Cygnus pinmux table:
> +
> +number    pin            group              alt1             alt2        alt3        alt4
> +------    ---            ----               ----             ----        ----        ----
> +42        sc0_clk        smart_card0        SMART CARD0      I2S_0       N/A         chip_gpio24
> +43        sc0_cmdvcc_l   smart_card0        SMART CARD0      I2S_0       N/A         STRAP
> +44        sc0_detect     smart_card0        SMART CARD0      I2S_0       N/A         chip_gpio25
> +45        sc0_fcb        smart_card0_fcb    SMART CARD0_FCB  I2S_0       N/A         chip_gpio26
> +46        sc0_io         smart_card0        SMART CARD0      I2S_0       N/A         chip_gpio27
> +47        sc0_rst_l      smart_card0        SMART CARD0      SPDIF       N/A         STRAP
> +
> +Note due to limitation of the Cygnus hardware, pinmux configuration can only
> +be group based. To enable I2S_0 function, one needs the following child node
> +configuration:
> +
> +       i2s_0: i2s_0 {
> +               brcm,groups = "smart_card0", "smart_card0_fcb";
> +               brcm,function = "alt2";
> +       };
> +
> +This tells the Cygnus pin controller to configure groups "smart_card0" and
> +"smart_card0_fcb" to I2S_0. With this configuration, pins 42, 43, 44, 45, 46
> +become I2C_0, and pin 47 becomes SPDIF
                  ^^^^ typo - should be I2S_0
> +
> +Consider another example, that one wants to configure the above pins as GPIO:
> +
> +       gpio_24_27: gpio_24_27 {
> +               brcm,groups = "smart_card0", "smart_card0_fcb";
> +               brcm,function = "alt4";
> +       };
> +
> +With the above configuration, pins 42, 44, 45, 46 become GPIO, and 43 and 47
> +become reserved for STRAP
> --
> 1.7.9.5
>
>
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BR,

marek

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