From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [Patch v5 08/13] ARM: imx6q: add config-on-boot gpios
Date: Wed, 20 Jun 2012 09:41:26 -0600 [thread overview]
Message-ID: <4FE1EF26.9080401@wwwdotorg.org> (raw)
In-Reply-To: <4FE1DE53.4070202@gmail.com>
On 06/20/2012 08:29 AM, Rob Herring wrote:
> On 06/13/2012 08:33 PM, Richard Zhao wrote:
>> On Wed, Jun 13, 2012 at 11:50:35AM -0500, Rob Herring wrote:
>>> 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.
...
>>>>>> diff --git a/Documentation/devicetree/bindings/arm/config-on-boot.txt b/Documentation/devicetree/bindings/arm/config-on-boot.txt
...
>>>>>> +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
...
>>> 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.
>>
>> PCI has dev id and may add quirks. But for embedded, I don't know how
>> to connect a of node to a hub device enumerated by usb core code. And
>> it may also pollute the usb core code.
>
> USB also uses device and manufacturer ids. One of the main reasons for
> putting pci devices into dts is to describe out of band signals just
> like this.
>
> Creating a binding and support code for full usb bus topology would be a
> lot of work which is why I propose a simpler approach below.
>
>>> A simpler approach would be to just add
>>> the gpio to the ehci controller node, but that's not exactly correct.
>> That's exactly why this patch comes out.
>
> I mean just something like "fsl,hub-reset-gpios" in the ehci device
> node. It's at least under a usb node. Whether the ehci driver handles
> this or you just have a separate piece of code to find this property and
> setup the gpio is up to you.
I haven't been following the thread, but just noticed it. Very similar
things (DT nodes for probed devices) are coming up quite a bit recently,
for example:
Re: Where to power on the wifi device before loading the driver.
http://www.spinics.net/lists/arm-kernel/msg180368.html
dt: rfkill-gpio: add bindings documentation
http://www.spinics.net/lists/linux-tegra/msg03977.html
I wonder if there's any kind of infra-structure or standardized bindings
that would be useful here?
next prev parent reply other threads:[~2012-06-20 15:41 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-13 12:34 [Patch v5 00/13] add imx usb driver for mx28/6x Richard Zhao
2012-06-13 12:34 ` [Patch v5 01/13] usb: otg: add notify_connect/notify_disconnect callback Richard Zhao
2012-06-13 12:34 ` [Patch v5 02/13] USB: move transceiver from ehci_hcd and ohci_hcd to hcd and rename it as phy Richard Zhao
2012-06-13 18:17 ` Alan Stern
2012-06-13 12:34 ` [Patch v5 03/13] USB: notify phy when root hub port connect change Richard Zhao
2012-06-13 18:25 ` Alan Stern
2012-06-14 0:36 ` Richard Zhao
2012-06-14 14:11 ` Alan Stern
2012-06-13 12:34 ` [Patch v5 04/13] usb: chipidea: permit driver bindings pass phy pointer Richard Zhao
2012-06-13 12:34 ` [Patch v5 05/13] usb: otg: add basic mxs phy driver support Richard Zhao
2012-06-13 21:33 ` Sascha Hauer
2012-06-13 21:56 ` Marek Vasut
2012-06-13 22:03 ` Sascha Hauer
2012-06-14 1:12 ` Richard Zhao
2012-06-13 12:34 ` [Patch v5 06/13] usb: chipidea: add imx platform driver Richard Zhao
2012-06-13 21:46 ` Sascha Hauer
2012-06-13 21:57 ` Marek Vasut
2012-06-13 22:07 ` Sascha Hauer
2012-06-14 1:21 ` Richard Zhao
2012-06-14 1:56 ` Richard Zhao
2012-06-13 12:34 ` [Patch v5 07/13] ARM: imx6q: correct device name of usbphy and usb controller clock export Richard Zhao
2012-06-13 12:34 ` [Patch v5 08/13] ARM: imx6q: add config-on-boot gpios Richard Zhao
2012-06-13 15:09 ` Rob Herring
2012-06-13 15:19 ` Marek Vasut
2012-06-13 16:45 ` Rob Herring
2012-06-13 17:15 ` Marek Vasut
2012-06-13 15:28 ` Richard Zhao
2012-06-13 16:00 ` Marek Vasut
2012-06-15 15:34 ` Shawn Guo
2012-06-13 16:50 ` Rob Herring
2012-06-14 1:33 ` Richard Zhao
2012-06-20 14:29 ` Rob Herring
2012-06-20 15:05 ` Shawn Guo
2012-06-21 21:32 ` Rob Herring
2012-06-20 15:41 ` Stephen Warren [this message]
2012-06-21 1:32 ` Chen Peter-B29397
2012-06-21 22:22 ` Stephen Warren
2012-06-22 0:03 ` Chen Peter-B29397
2012-06-25 15:43 ` Stephen Warren
2012-06-26 2:05 ` Chen Peter-B29397
2012-06-19 23:36 ` Fabio Estevam
2012-06-19 23:41 ` Richard Zhao
2012-07-17 12:30 ` Dirk Behme
2012-07-19 2:15 ` Richard Zhao
2012-06-13 12:34 ` [Patch v5 09/13] ARM: imx6q: add usbphy clocks Richard Zhao
2012-06-13 21:54 ` Sascha Hauer
2012-06-14 0:15 ` Chen Peter-B29397
2012-06-13 12:34 ` [Patch v5 10/13] ARM: imx6q: disable usb charger detector Richard Zhao
2012-06-13 12:34 ` [Patch v5 11/13] ARM: dts: imx6q-sabrelite: add usb devices Richard Zhao
2012-06-19 23:39 ` Fabio Estevam
2012-06-13 12:34 ` [Patch v5 12/13] ARM: mxs: clk_register_clkdev mx28 usb clocks Richard Zhao
2012-06-13 12:34 ` [Patch v5 13/13] ARM: dts: imx28-evk: add usb devices Richard Zhao
2012-06-18 17:10 ` [Patch v5 00/13] add imx usb driver for mx28/6x Fabio Estevam
2012-06-18 17:13 ` Marek Vasut
2012-06-18 17:25 ` Fabio Estevam
2012-06-19 1:14 ` Chen Peter-B29397
2012-06-19 1:33 ` Fabio Estevam
2012-06-19 2:07 ` Marek Vasut
2012-06-19 2:17 ` Fabio Estevam
2012-06-19 6:14 ` Shawn Guo
2012-06-19 12:24 ` Fabio Estevam
2012-06-19 12:38 ` Shawn Guo
2012-06-19 13:54 ` Fabio Estevam
2012-06-19 18:34 ` Fabio Estevam
2012-06-19 19:03 ` Dirk Behme
2012-06-19 12:59 ` Marek Vasut
2012-06-20 17:53 ` Subodh Nijsure
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