Re: [PATCH 2/3] ARM: dts: omap3-igep0020: Add HS USB Host support

[Javier Martinez Canillas <javier.martinez@collabora.co.uk>]

On 10/07/2013 11:06 AM, Roger Quadros wrote:
> +devicetree
> 
> Javier,
> 
> On 10/07/2013 11:50 AM, Javier Martinez Canillas wrote:
>> On Mon, Oct 7, 2013 at 10:33 AM, Roger Quadros <rogerq@ti.com> wrote:
>>> Hi Javier,
>>>
>>> On 10/05/2013 03:04 AM, Javier Martinez Canillas wrote:
>>>> Add device nodes for the HS USB Host port 1, USB PHY and its
>>>> required regulator and also pin mux setup for HS USB1 pins.
>>>>
>>>> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
>>>> ---
>>>>  arch/arm/boot/dts/omap3-igep.dtsi    | 22 ++++++++++++++++++++++
>>>>  arch/arm/boot/dts/omap3-igep0020.dts | 25 +++++++++++++++++++++++++
>>>>  2 files changed, 47 insertions(+)
>>>>
>>>> diff --git a/arch/arm/boot/dts/omap3-igep.dtsi
>> b/arch/arm/boot/dts/omap3-igep.dtsi
>>>> index 0f92224..ec2ecd2 100644
>>>> --- a/arch/arm/boot/dts/omap3-igep.dtsi
>>>> +++ b/arch/arm/boot/dts/omap3-igep.dtsi
>>>> @@ -27,6 +27,11 @@
>>>>  };
>>>>
>>>>  &omap3_pmx_core {
>>>> +     pinctrl-names = "default";
>>>> +     pinctrl-0 = <
>>>> +             &hsusbb1_pins
>>>> +     >;
>>>> +
>>>>       uart1_pins: pinmux_uart1_pins {
>>>>               pinctrl-single,pins = <
>>>>                       0x152 (PIN_INPUT | MUX_MODE0)           /*
>> uart1_rx.uart1_rx */
>>>> @@ -78,6 +83,23 @@
>>>>               >;
>>>>       };
>>>>
>>>> +     hsusbb1_pins: pinmux_hsusbb1_pins {
>>>> +             pinctrl-single,pins = <
>>>> +                     0x5aa (PIN_OUTPUT | MUX_MODE3)          /*
>> etk_ctl.hsusb1_clk */
>>>> +                     0x5a8 (PIN_OUTPUT | MUX_MODE3)          /*
>> etk_clk.hsusb1_stp */
>>>> +                     0x5bc (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d8.hsusb1_dir */
>>>> +                     0x5be (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d9.hsusb1_nxt */
>>>> +                     0x5ac (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d0.hsusb1_data0 */
>>>> +                     0x5ae (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d1.hsusb1_data1 */
>>>> +                     0x5b0 (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d2.hsusb1_data2 */
>>>> +                     0x5b2 (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d3.hsusb1_data7 */
>>>> +                     0x5b4 (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d4.hsusb1_data4 */
>>>> +                     0x5b6 (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d5.hsusb1_data5 */
>>>> +                     0x5b8 (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d6.hsusb1_data6 */
>>>> +                     0x5ba (PIN_INPUT_PULLDOWN | MUX_MODE3)  /*
>> etk_d7.hsusb1_data3 */
>>>> +             >;
>>>> +     };
>>>> +
>>>
>>> Is this pin config required for igep0030 as well? If not then you should move
>> these pinmux
>>> definitions to omap3-igep0020.dts.
>>>
>>> All else looks good to me.
>>>
>> 
>> Hi Roger,
>> 
>> Well that's a very good question indeed.
>> 
>> The thing is that the IGEP0030 is a Computer-on-Module [1] that is used in
>> conjunction with expansion boards and some of them have USB HOST support such as
>> IGEP Paris [2] and IGEP Berlin [3].
>> 
>> Support for this expansion boards is still not in mainline but there are plans
>> to add them using Device Tree overlays [4] once/if this land on mainline.
>> 
> 
> Why would your boards need Device Tree overlays? From the looks of it, the configuration
> of SOM + base board don't seem to change at runtime.
> 

Indeed, a static configuration (DTS) would be enough now that I think about it.

>> So, answering your question right now this is not required but I thought it
>> would be good to have it configured by default in case someone using an IGEP0030
>> and a expansion board wants to extend omap3-igep0030.dts to add support for its
>> expansion board.
> 
> I think all you need is a .dts file for each expansion board that extends
> omap3-iegp0030.dts.
> 
> That way, the pinmux for USB host pins will come only in those boards that have the USB host port.
> 
>> 
>> I've no strong opinion on this though and I can send a new patch with those pins
>> moved to omap3-igep0020.dts though if you think that would be better.
> 
> If you don't put it in omap3-igep0020.dts, how will you handle the case when a omap3-igep0030
> SOM is used with an expansion board that doesn't have USB host port and uses it for something
> else?
> 

You are right, will change and post a v2 of the patch-set, thanks a lot for your
feedback!

>> 
>>>>       leds_pins: pinmux_leds_pins { };
>>>>  };
>>>>
>>>> diff --git a/arch/arm/boot/dts/omap3-igep0020.dts
>> b/arch/arm/boot/dts/omap3-igep0020.dts
>>>> index 903e944..180b186 100644
>>>> --- a/arch/arm/boot/dts/omap3-igep0020.dts
>>>> +++ b/arch/arm/boot/dts/omap3-igep0020.dts
>>>> @@ -55,6 +55,23 @@
>>>>               regulator-name = "vdd33a";
>>>>               regulator-always-on;
>>>>       };
>>>> +
>>>> +       /* HS USB Port 1 Power */
>>>> +       hsusb1_power: hsusb1_power_reg {
>>>> +               compatible = "regulator-fixed";
>>>> +               regulator-name = "hsusb1_vbus";
>>>> +               regulator-min-microvolt = <3300000>;
>>>> +               regulator-max-microvolt = <3300000>;
>>>> +               gpio = <&twl_gpio 18 GPIO_ACTIVE_LOW>;        /* GPIO LEDA */
>>>> +               startup-delay-us = <70000>;
>>>> +       };
>>>> +
>>>> +     /* HS USB Host PHY on PORT 1 */
>>>> +     hsusb1_phy: hsusb1_phy {
>>>> +             compatible = "usb-nop-xceiv";
>>>> +             reset-gpios = <&gpio1 24 GPIO_ACTIVE_LOW>; /* gpio_24 */
>>>> +             vcc-supply = <&hsusb1_power>;
>>>> +     };
>>>>  };
>>>>
>>>>  &leds_pins {
>>>> @@ -173,3 +190,11 @@
>>>>       mode = <3>;
>>>>       power = <50>;
>>>>  };
>>>> +
>>>> +&usbhshost {
>>>> +     port1-mode = "ehci-phy";
>>>> +};
>>>> +
>>>> +&usbhsehci {
>>>> +     phys = <&hsusb1_phy>;
>>>> +};
>>>>
>>>
> 
> cheers,
> -roger
> 
>>> --
>> 
>> Thanks a lot and best regards,
>> Javier
>> 
>> [1]: http://www.isee.biz/products/processor-boards/igep-com-module
>> [2]: http://www.isee.biz/products/expansion-boards/product-igep-paris
>> [3]: http://www.isee.biz/products/expansion-boards/product-igep-berlin
>> [4]:
>> http://learn.adafruit.com/introduction-to-the-beaglebone-black-device-tree/device-tree-overlays
>> 
> 

Best regards,
Javier