From: Rob Herring <robherring2@gmail.com>
To: Tomasz Figa <tomasz.figa@gmail.com>,
Alim Akhtar <alim.akhtar@samsung.com>,
gregkh@linuxfoundation.org
Cc: linux-samsung-soc@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Rob Herring <robh@kernel.org>,
thomas.ab@samsung.com,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH] tty/serial: samsung: Add earlycon support
Date: Sat, 20 Sep 2014 13:00:15 -0500 [thread overview]
Message-ID: <541DC0AF.2060704@gmail.com> (raw)
In-Reply-To: <541D83AE.1050006@gmail.com>
On 09/20/2014 08:39 AM, Tomasz Figa wrote:
> Hi Alim,
>
> Please see my comments inline.
>
> On 16.09.2014 13:32, Alim Akhtar wrote:
>> Add earlycon support for the samsung serial port. This allows enabling
>> the samsung serial port for console when early_params are parse and processed.
>>
>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>> ---
>> Documentation/kernel-parameters.txt | 6 ++++++
>> drivers/tty/serial/Kconfig | 1 +
>> drivers/tty/serial/samsung.c | 17 +++++++++++++++++
>> 3 files changed, 24 insertions(+)
>>
>> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
>> index 5ae8608..e01c0e5 100644
>> --- a/Documentation/kernel-parameters.txt
>> +++ b/Documentation/kernel-parameters.txt
>> @@ -936,6 +936,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>> must already be setup and configured. Options are not
>> yet supported.
>>
>> + samsung,<addr>
There will only ever be 1 samsung uart? This is an ABI to some extent,
so you will be stuck with it.
>> + Start an early, polled-mode console on a samsung serial
>> + port at the specified address. The samsung serial port
>> + must already be setup and configured. Options are not
>> + yet supported.
>> +
>
> Couldn't you simply parse this from DT? I believe there is already code
> parsing stdout property in chosen node for earlycon purposes present in
> the kernel.
You should support both and it is just a OF_EARLYCON_DECLARE line to add.
> Anyway, we already had a patch for this in our internal tree, but it
> wasn't submitted because there was no support for early ioremap on ARM
> at that time. I haven't been following it since then (and I'm no longer
> at Samsung; Marek might be able to take this topic), is it already
> available?
No, but should be soonish. fixmap parts are being worked on by Kees.
Rob
WARNING: multiple messages have this Message-ID (diff)
From: robherring2@gmail.com (Rob Herring)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] tty/serial: samsung: Add earlycon support
Date: Sat, 20 Sep 2014 13:00:15 -0500 [thread overview]
Message-ID: <541DC0AF.2060704@gmail.com> (raw)
In-Reply-To: <541D83AE.1050006@gmail.com>
On 09/20/2014 08:39 AM, Tomasz Figa wrote:
> Hi Alim,
>
> Please see my comments inline.
>
> On 16.09.2014 13:32, Alim Akhtar wrote:
>> Add earlycon support for the samsung serial port. This allows enabling
>> the samsung serial port for console when early_params are parse and processed.
>>
>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>> ---
>> Documentation/kernel-parameters.txt | 6 ++++++
>> drivers/tty/serial/Kconfig | 1 +
>> drivers/tty/serial/samsung.c | 17 +++++++++++++++++
>> 3 files changed, 24 insertions(+)
>>
>> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
>> index 5ae8608..e01c0e5 100644
>> --- a/Documentation/kernel-parameters.txt
>> +++ b/Documentation/kernel-parameters.txt
>> @@ -936,6 +936,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>> must already be setup and configured. Options are not
>> yet supported.
>>
>> + samsung,<addr>
There will only ever be 1 samsung uart? This is an ABI to some extent,
so you will be stuck with it.
>> + Start an early, polled-mode console on a samsung serial
>> + port at the specified address. The samsung serial port
>> + must already be setup and configured. Options are not
>> + yet supported.
>> +
>
> Couldn't you simply parse this from DT? I believe there is already code
> parsing stdout property in chosen node for earlycon purposes present in
> the kernel.
You should support both and it is just a OF_EARLYCON_DECLARE line to add.
> Anyway, we already had a patch for this in our internal tree, but it
> wasn't submitted because there was no support for early ioremap on ARM
> at that time. I haven't been following it since then (and I'm no longer
> at Samsung; Marek might be able to take this topic), is it already
> available?
No, but should be soonish. fixmap parts are being worked on by Kees.
Rob
next prev parent reply other threads:[~2014-09-20 18:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-16 11:32 [PATCH] tty/serial: samsung: Add earlycon support Alim Akhtar
2014-09-20 12:41 ` Alim Akhtar
2014-09-20 12:41 ` Alim Akhtar
2014-09-20 13:39 ` Tomasz Figa
2014-09-20 13:39 ` Tomasz Figa
2014-09-20 18:00 ` Rob Herring [this message]
2014-09-20 18:00 ` Rob Herring
2014-09-21 14:36 ` Alim Akhtar
2014-09-21 14:36 ` Alim Akhtar
2014-09-21 17:24 ` Tomasz Figa
2014-09-21 17:24 ` Tomasz Figa
2014-09-21 23:10 ` Alim Akhtar
2014-09-21 23:10 ` Alim Akhtar
2014-09-21 23:19 ` Tomasz Figa
2014-09-21 23:19 ` Tomasz Figa
2014-09-22 13:41 ` Alim Akhtar
2014-09-22 13:41 ` Alim Akhtar
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