On 06/13/2012 10:28 AM, Richard Zhao wrote:
> 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.
You are defining something based on whether linux has a driver or not.
That should not matter to DT. That's backwards.
>> 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.
You need to describe that you have a hub on the usb bus and add the gpio
line to that node. Just like PCI is probe-able, you still need DT nodes
sometimes for cases like this. A simpler approach would be to just add
the gpio to the ehci controller node, but that's not exactly correct.
Rob
>
> 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();
>>> }
>>>
>>
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
