From: Frank Zago <frank@zago.net>
To: Johan Hovold <johan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org,
Jan-Niklas Burfeind <kernel@aiyionpri.me>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Wolfram Sang <wsa@kernel.org>,
linux-usb@vger.kernel.org, gunar@schorcht.net
Subject: Re: [PATCH v2 1/2] Revert "USB: serial: ch341: add new Product ID for CH341A"
Date: Tue, 11 May 2021 20:07:31 -0500 [thread overview]
Message-ID: <8b3c348f-9e05-29f9-9197-8ddf1c8a9e8b@zago.net> (raw)
In-Reply-To: <YJjjfx49nCflzFbR@hovoldconsulting.com>
Hello,
On 5/10/21 2:40 AM, Johan Hovold wrote:
> On Thu, Apr 22, 2021 at 07:28:51PM -0500, Frank Zago wrote:
>> From: frank zago <frank@zago.net>
>>
>> The 0x5512 USB PID is for the I2C/GPIO/SPI interfaces. UART is
>> still present but only the TX and RX pins are available; DTS, DTR,
>> ... are used for other things. Remove the PID, and let a I2C
>> driver bind to it.
>>
>> Existing CH341 boards usually have physical jumpers to switch
>> between the 3 modes.
>>
>> This reverts commit 46ee4abb10a07bd8f8ce910ee6b4ae6a947d7f63.
>
> You can't just revert something which people clearly depend on and
> therefore added to the kernel in the first place.
That device in UART mode was already supported by the serial driver. The
original submitter just had to move a jumper on his board. There was no
need to patch the kernel.
That product ID also supports UART but in a limited way, as only the RX and TX
pins are available. However it is the only one that supports i2c/spi/gpio, and
that's why I have to revert the patch.
If that's desired, the new driver could add support for that as well, but I don't
think it's worth the effort.
>
> Can you reprogram the device with a newly allocated PID to be used
> for i2c-only instead?
It is possible if the device has an SPI flash connected to it, but none of
the cheap boards have that.
Frank.
next prev parent reply other threads:[~2021-05-12 1:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 0:28 [PATCH v2 1/2] Revert "USB: serial: ch341: add new Product ID for CH341A" Frank Zago
2021-04-23 0:28 ` [PATCH v2 2/2] USB: misc: Add driver for the WCH CH341 in I2C/GPIO mode Frank Zago
2021-05-10 7:53 ` Johan Hovold
2021-05-10 7:40 ` [PATCH v2 1/2] Revert "USB: serial: ch341: add new Product ID for CH341A" Johan Hovold
2021-05-12 1:07 ` Frank Zago [this message]
2021-05-12 9:55 ` Johan Hovold
2021-05-13 1:00 ` Frank Zago
2021-05-13 11:31 ` Johan Hovold
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=8b3c348f-9e05-29f9-9197-8ddf1c8a9e8b@zago.net \
--to=frank@zago.net \
--cc=bgolaszewski@baylibre.com \
--cc=gregkh@linuxfoundation.org \
--cc=gunar@schorcht.net \
--cc=johan@kernel.org \
--cc=kernel@aiyionpri.me \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=wsa@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.