From: Roger Quadros <rogerq@ti.com>
To: Igor Grinberg <grinberg@compulab.co.il>,
Tony Lindgren <tony@atomide.com>
Cc: Robert Nelson <robertcnelson@gmail.com>,
<devicetree-discuss@lists.ozlabs.org>,
<linux-omap@vger.kernel.org>, <b-cousson@ti.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ARM: dts: omap3-beagle-xm: Add USB Host support for Rev Ax/Bx
Date: Wed, 17 Apr 2013 11:38:54 +0300 [thread overview]
Message-ID: <516E5F9E.3050204@ti.com> (raw)
In-Reply-To: <516E5597.7050801@compulab.co.il>
On 04/17/2013 10:56 AM, Igor Grinberg wrote:
> On 04/17/13 04:30, Robert Nelson wrote:
>> On Tue, Apr 16, 2013 at 7:52 PM, Tony Lindgren <tony@atomide.com> wrote:
>>> * Roger Quadros <rogerq@ti.com> [130415 05:44]:
>>>> On 04/15/2013 03:35 PM, Roger Quadros wrote:
>>>>> Provide RESET and Power regulators for the USB PHY,
>>>>> the USB Host port mode and the PHY device.
>>>>>
>>>>> Also provide pin multiplexer information for USB host
>>>>> pins.
>>>>>
>>>>> This will not work for Rev Cx boards because of reversed logic
>>>>> for USB_POWER_Enable.
>>>>>
>>>>> CC: Benoît Cousson <b-cousson@ti.com>
>>>>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>>>>> ---
>>>>> arch/arm/boot/dts/omap3-beagle-xm.dts | 62 +++++++++++++++++++++++++++++++++
>>>>> 1 files changed, 62 insertions(+), 0 deletions(-)
>>>>>
>>>>> diff --git a/arch/arm/boot/dts/omap3-beagle-xm.dts b/arch/arm/boot/dts/omap3-beagle-xm.dts
>>>>> index 5a31964..d394c51 100644
>>>>> --- a/arch/arm/boot/dts/omap3-beagle-xm.dts
>>>>> +++ b/arch/arm/boot/dts/omap3-beagle-xm.dts
>>>>> @@ -57,6 +57,60 @@
>>>>> ti,mcbsp = <&mcbsp2>;
>>>>> ti,codec = <&twl_audio>;
>>>>> };
>>>>> +
>>>>> + /* HS USB Port 2 RESET */
>>>>> + hsusb2_reset: hsusb2_reset_reg {
>>>>> + compatible = "regulator-fixed";
>>>>> + regulator-name = "hsusb2_reset";
>>>>> + regulator-min-microvolt = <3300000>;
>>>>> + regulator-max-microvolt = <3300000>;
>>>>> + gpio = <&gpio5 19 0>; /* gpio_147 */
>>>>> + startup-delay-us = <70000>;
>>>>> + enable-active-high;
>>>>> + };
>>>>> +
>>>>> + /* HS USB Port 2 Power */
>>>>> + hsusb2_power: hsusb2_power_reg {
>>>>> + compatible = "regulator-fixed";
>>>>> + regulator-name = "hsusb2_vbus";
>>>>> + regulator-min-microvolt = <3300000>;
>>>>> + regulator-max-microvolt = <3300000>;
>>>>> + gpio = <&twl_gpio 18 0>; /* GPIO LEDA */
>>>>> + startup-delay-us = <70000>;
>>>>> + enable-active-high; /* FIXME: active-low for Rev. C */
>>>>
>>>> Benoit & Tony,
>>>>
>>>> Any ideas how to tackle the reversed logic for Rev. C boards?
>>>
>>> Sounds like we need a shared omap3-beage.dtsi, then omap3-beagle-xm.dts
>>> and omap3-beagle-rev-c.dts. Then xm and rev-c can both include the
>>
>> Bike-sheding, but we might want to make that "omap3-beagle-xmc.dts" as
>> there is the "rev c" variant of the original beagle...
>>
>> It's too bad we can't read the 3 gpio pin states in the device tree
>> and make a decision.
>
> I would recommend to move the detection to the boot loader and
> adjust the DT blob at run time (in the boot loader).
> This way, we will not need to deal with all the (sub)revision stuff.
>
>
Moving the detection to bootloader is fine, but modifying the DT at
runtime would create a debug/maintenance issue. Instead it could just
pick one of the .DTBs and pass it to kernel.
Since most users will be using rev-c, I think we should keep the original
file 'omap3-beagle-xm.dts" as it is for rev-c boards.
I can just create a new dts file for Revisions A and B that will be
like so.
+++ b/arch/arm/boot/dts/omap3-beagle-xm-ab.dts
@@ -0,0 +1,6 @@
+/include/ "omap3-beagle-xm.dts"
+
+/* On Rev A/B USBHOST_PWR_EN is active high */
+&hsusb2_power {
+ enable-active-high;
+};
Since omap3-beagle and omap3-beagle-xm use different SoC versions and have
quite many differences, I don't think it is a good idea to create a common
file between the two.
cheers,
-roger
next prev parent reply other threads:[~2013-04-17 8:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-15 12:35 [PATCH] ARM: dts: omap3-beagle-xm: Add USB Host support for Rev Ax/Bx Roger Quadros
2013-04-15 12:39 ` Roger Quadros
2013-04-17 0:52 ` Tony Lindgren
2013-04-17 1:30 ` Robert Nelson
2013-04-17 7:56 ` Igor Grinberg
2013-04-17 8:38 ` Roger Quadros [this message]
2013-04-17 12:26 ` Igor Grinberg
2013-04-17 17:11 ` Tony Lindgren
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