Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [RFC] usb: chipidea: Add minimal support for HSIC interface on
 i.MX6QDL
To:     Peter Chen <peter.chen@nxp.com>
Cc:     "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <1539005352-10909-1-git-send-email-frieder.schrempf@exceet.de>
 <VI1PR04MB5327D0F4AA27C5AED5C535388BE70@VI1PR04MB5327.eurprd04.prod.outlook.com>
From:   Frieder Schrempf <frieder.schrempf@exceet.de>
Message-ID: <e13ac59e-6698-8ef2-685e-75cd5ed35d98@exceet.de>
Date:   Wed, 10 Oct 2018 14:52:07 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <VI1PR04MB5327D0F4AA27C5AED5C535388BE70@VI1PR04MB5327.eurprd04.prod.outlook.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Peter,

On 09.10.2018 03:24, Peter Chen wrote:
>   
>>
>> The topic has been discussed before: [1] And there is some implementation in the
>> vendor kernel: [2]
>>
>> It seems like two things need to be done:
>>
>> 1. Switch the pinmux of the strobe signal to use a pullup after
>>     the core has been initialized.
>> 2. Enable HSIC mode and HSIC clock
>>
>> This patch only implements these basics in a minimal approach.
>> You need to have an additional pinmux setting "active" in the dt, that sets the pullup.
>>
>> It was tested with the SMSC LAN9730 USB Ethernet adapter on the iMXceet Solo S
>> board.
>>
> 
> Thanks, I should do it earlier, I could not find a suitable board with HSIC support at mainline kernel.
> It is very kind that you could help on it and test function at real board. My suggestion is
> follow all flows in Link [2] since we need to cover suspend/resume and remote wakeup.

It seems like power management and other things in the linux-imx kernel 
are not fully implemented in mainline so there are quite a few differences.

My knowledge of USB, etc. is very limited, so I guess this is currently 
beyond my skills. Can you or someone else provide a patch to get 
started? I could help with testing, reviewing, etc.

Or maybe you can point out what needs to be done in more detail?

Thanks,
Frieder