From: Sylvain Munaut <tnt@246tNt•com>
To: Bartlomiej Sieka <tur@semihalf•com>
Cc: linuxppc-embedded@ozlabs•org
Subject: Re: RFC: MPC52xx serial port configuration from DT blob
Date: Tue, 17 Apr 2007 08:07:28 +0200 [thread overview]
Message-ID: <46246420.8050800@246tNt.com> (raw)
In-Reply-To: <461FF442.8090807@semihalf.com>
Bartlomiej Sieka wrote:
> Hi All,
>
> We have a MPC5200B-based board running an arch/powerpc kernel and we
> need the ability to configure a non-console serial port for a particular
> baud rate during system start-up. It seems that the UART driver in
> drivers/serial/mpc52xx_uart.c does not support this. It only allows to
> set parameters for a port that is used as a console, and for which those
> parameters are passed in the kernel command line. We would like to
> extend the mpc52xx_uart.c driver to be able to retrieve port options
> from the DT blob and configure a given port accordingly. A new
> port-specific property called "options" would be used for this. It would
> have syntax following its namesake in "console" kernel parameter, as
> described in Documentation/kernel-parameters.txt.
>
> For example, the following settings in the .dts file would make UART5 to
> be configured at 115200 baud, no parity, 8 bits.
>
> serial@2800 { // PSC5
> device_type = "serial";
> compatible = "mpc5200b-psc-uart\0mpc5200-psc-uart";
> port-number = <4>; // Logical port assignment
> options = "115200n8"
> cell-index = <4>;
> reg = <2800 100>;
> interrupts = <2 c 0>;
> interrupt-parent = <500>;
> };
>
>
> In case a console port has conflicting options given in the kernel
> command line and in the DT blob, the command line values would be used.
>
> Any comments on the above will be appreciated.
>
The kernel only "use" the serial for console. If it's not a console,
then it's used
by userspace and it's userspace job to configure it as it sees fit imho ...
Sylvain
prev parent reply other threads:[~2007-04-17 6:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-13 21:21 RFC: MPC52xx serial port configuration from DT blob Bartlomiej Sieka
2007-04-13 23:24 ` Dale Farnsworth
2007-04-17 5:34 ` Grant Likely
2007-04-17 6:07 ` Sylvain Munaut [this message]
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=46246420.8050800@246tNt.com \
--to=tnt@246tnt$(echo .)com \
--cc=linuxppc-embedded@ozlabs$(echo .)org \
--cc=tur@semihalf$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox