Subject: [Patch v5 08/13] ARM: imx6q: add config-on-boot gpios

From: [email-masked] (Rob Herring)
Date: Wed, 13 Jun 2012 10:09:54 -0500

On 06/13/2012 07:34 AM, Richard Zhao wrote:
> Sometimes, boards have gpios that don't own by any driver or owner
> by a generic driver that don't like hacks. Such gpios is normally
> output and need setup once on boot. So I introduce the config-on-boot
> gpios.
> 
> Signed-off-by: Richard Zhao <[email-masked]>
> Cc: Shawn Guo <[email-masked]>
> Cc: Rob Herring <[email-masked]>
> Cc: Grant Likely <[email-masked]>
> ---
>  .../devicetree/bindings/arm/config-on-boot.txt     |   12 +++++++
>  arch/arm/boot/dts/imx6q-sabrelite.dts              |    7 ++++
>  arch/arm/mach-imx/mach-imx6q.c                     |   35 ++++++++++++++++++++
>  3 files changed, 54 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/config-on-boot.txt
> 
> diff --git a/Documentation/devicetree/bindings/arm/config-on-boot.txt b/Documentation/devicetree/bindings/arm/config-on-boot.txt
> new file mode 100644
> index 0000000..f98ed74
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/config-on-boot.txt
> @@ -0,0 +1,12 @@
> +* Configure on Boot
> +
> +Node name: config-on-boot
> +  It must be in root node. config-on-boot means to describe settings that needs
> +  to be set one time on boot but aren't owned by any driver, or the owned driver
> +  is too generic to handle such settings. For example, usb hub uses generic
> +  driver in usb core code, a on-board usb may need deassert reset pin.

NAK. This is not a h/w description and should be solved within the
kernel or bootloader. Either fix this in u-boot, the platform code, or
make the generic driver support this in a generic way.

Rob

> +
> +Optional properties:
> +- output-gpios: Output gpio array that needs to set.
> +- output-gpio-values: This property is required if output-gpios is set.
> +  The value is a array of 0 or 1. Total count eaquals the number of gpios.
> diff --git a/arch/arm/boot/dts/imx6q-sabrelite.dts b/arch/arm/boot/dts/imx6q-sabrelite.dts
> index e0ec929..1dd2261 100644
> --- a/arch/arm/boot/dts/imx6q-sabrelite.dts
> +++ b/arch/arm/boot/dts/imx6q-sabrelite.dts
> @@ -17,6 +17,13 @@
>  	model = "Freescale i.MX6 Quad SABRE Lite Board";
>  	compatible = "fsl,imx6q-sabrelite", "fsl,imx6q";
>  
> +	config-on-boot {
> +		output-gpios = <
> +				&gpio3 22 0>;	/* vbus reset */
> +		output-gpio-values = <
> +				1>;		/* vbus reset */
> +	};
> +
>  	memory {
>  		reg = <0x10000000 0x40000000>;
>  	};
> diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
> index b47e98b..577cf19 100644
> --- a/arch/arm/mach-imx/mach-imx6q.c
> +++ b/arch/arm/mach-imx/mach-imx6q.c
> @@ -19,6 +19,7 @@
>  #include <linux/irqdomain.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
> +#include <linux/of_gpio.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/pinctrl/machine.h>
> @@ -113,6 +114,38 @@ static void __init imx6q_sabrelite_init(void)
>  	imx6q_sabrelite_cko1_setup();
>  }
>  
> +static void __init imx6q_config_on_boot(void)
> +{
> +	struct device_node *np;
> +	struct property *pp;
> +	int cnt, len, i;
> +	int gpio;
> +
> +	np = of_find_node_by_path("/config-on-boot");
> +	if (!np)
> +		return;
> +	cnt = of_gpio_named_count(np, "output-gpios");
> +	pp = of_find_property(np, "output-gpio-values", &len);
> +	if (!pp || cnt != len / sizeof(u32)) {
> +		pr_err("Invalid config-on-boot gpios!\n");
> +		of_node_put(np);
> +		return;
> +	}
> +	for (i = 0; i < cnt; i++) {
> +		gpio = of_get_named_gpio(np, "output-gpios", i);
> +		if (gpio_is_valid(gpio))
> +			gpio_request_one(gpio, GPIOF_OUT_INIT_HIGH,
> +					"config-on-boot");
> +	}
> +
> +	of_node_put(np);
> +}
> +
> +static void __init imx6q_post_populate(void)
> +{
> +	imx6q_config_on_boot();
> +}
> +
>  static void __init imx6q_init_machine(void)
>  {
>  	/*
> @@ -126,6 +159,8 @@ static void __init imx6q_init_machine(void)
>  
>  	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
>  
> +	imx6q_post_populate();
> +
>  	imx6q_pm_init();
>  }
>