From: Frieder Schrempf <frieder.schrempf@kontron.de>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
Marek Vasut <marex@denx.de>,
Alexander Stein <alexander.stein@ew.tq-group.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Andrzej Hajda <andrzej.hajda@intel.com>,
Neil Armstrong <neil.armstrong@linaro.org>,
Robert Foss <robert.foss@linaro.org>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Jonas Karlman <jonas@kwiboo.se>,
Jernej Skrabec <jernej.skrabec@gmail.com>,
David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
Rob Herring <robh+dt@kernel.org>,
dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: drm/bridge: ti-sn65dsi83: Add enable delay property
Date: Mon, 12 Dec 2022 13:29:37 +0100 [thread overview]
Message-ID: <8dc209df-8b69-d4a5-a056-b5aacdf41a14@kontron.de> (raw)
In-Reply-To: <5f61cc70-9501-ee4e-010f-5188f87e3ef1@linaro.org>
On 12.12.22 10:23, Krzysztof Kozlowski wrote:
> On 12/12/2022 10:09, Frieder Schrempf wrote:
>>>>> This does seem like a hardware bug right there, can you double-check
>>>>> this with the hardware engineer ?
>>>>
>>>> Yep, checked with hardware engineer. An 470nF is attached, together
>>>> with an
>>>> open drain output and only the internal pull-up. So yes ~113ms rising
>>>> time
>>>> until 0.7 x VCC.
>>>
>>> I don't suppose you can have that capacitor reduced or better yet, some
>>> external pull up added, can you ?
>>
>> Actually our HW engineers have implemented a similar RC circuit to
>> provide a hardware delay for the EN signal. I think this is due to a
>> design note in the datasheet (see chapter 7.4.1) and therefore it's
>> probably widely spread.
>
> If I read section 7.4.1 correctly, it would be enough to just add delay
> Ten=1ms instead of the capacitor, right? And that would be
> device-specific. But if one chooses the capacitor solution, it becomes
> now board specific.
Yes, seems like that's the case.
next prev parent reply other threads:[~2022-12-12 12:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-09 8:33 [PATCH 0/2] TI SN65DSI83 GPIO enable delay support Alexander Stein
2022-12-09 8:33 ` [PATCH 1/2] dt-bindings: drm/bridge: ti-sn65dsi83: Add enable delay property Alexander Stein
2022-12-09 8:39 ` Krzysztof Kozlowski
2022-12-09 8:54 ` Alexander Stein
2022-12-09 9:07 ` Krzysztof Kozlowski
2022-12-09 9:36 ` Alexander Stein
2022-12-09 9:50 ` Krzysztof Kozlowski
2022-12-09 9:51 ` Krzysztof Kozlowski
2022-12-09 12:02 ` Marek Vasut
2022-12-09 12:10 ` Krzysztof Kozlowski
2022-12-09 12:23 ` Alexander Stein
2022-12-09 12:21 ` Alexander Stein
2022-12-09 12:43 ` Marek Vasut
2022-12-09 13:38 ` Alexander Stein
2022-12-09 14:49 ` Marek Vasut
2022-12-12 9:09 ` Frieder Schrempf
2022-12-12 9:23 ` Krzysztof Kozlowski
2022-12-12 12:29 ` Frieder Schrempf [this message]
2022-12-12 12:50 ` Marek Vasut
2022-12-12 9:32 ` Laurent Pinchart
2022-12-12 11:49 ` Frieder Schrempf
2022-12-12 12:05 ` Laurent Pinchart
2022-12-11 18:50 ` Laurent Pinchart
2022-12-09 8:33 ` [PATCH 2/2] drm: bridge: ti-sn65dsi83: Add enable delay support Alexander Stein
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=8dc209df-8b69-d4a5-a056-b5aacdf41a14@kontron.de \
--to=frieder.schrempf@kontron.de \
--cc=Laurent.pinchart@ideasonboard.com \
--cc=airlied@gmail.com \
--cc=alexander.stein@ew.tq-group.com \
--cc=andrzej.hajda@intel.com \
--cc=daniel@ffwll.ch \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=jernej.skrabec@gmail.com \
--cc=jonas@kwiboo.se \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=krzysztof.kozlowski@linaro.org \
--cc=marex@denx.de \
--cc=neil.armstrong@linaro.org \
--cc=robert.foss@linaro.org \
--cc=robh+dt@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).