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

[Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>]

Dear Rob Herring,

> 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 <richard.zhao-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
> > Cc: Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> > Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
> > Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
> > ---
> > 
> >  .../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

I don't want to be the bastard here, but this shouldn't go into uboot.

> the platform code

Yes, it should be here. But then, it's some usb reset, so maybe the PHY should 
somehow handle it?

> , or
> make the generic driver support this in a generic way.

Well, this is platform specific stuff, so it shouldn't be in any way part of the 
driver.

> 
> 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();
> >  
> >  }

Best regards,
Marek Vasut
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