On Wed, Jun 13, 2012 at 10:09:54AM -0500, Rob Herring wrote:
> 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@xxxxxxxxxxxxx>
> > Cc: Shawn Guo <shawn.guo@xxxxxxxxxx>
> > Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
> > Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
> > ---
> > .../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
It's misc things, but is hw description.
> and should be solved within the
> kernel or bootloader. Either fix this in u-boot,
Kernel might be better not to depend on uboot.
> the platform code, or
How do I get gpio in platfrom code without dts description?
> make the generic driver support this in a generic way.
It's called just after populate devices. It's hard for generic driver to
decide when it's called.
Thanks
Richard
>
> 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();
> > }
> >
>
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