From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Richard Acayan <mailingradian@gmail.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konradybcio@kernel.org>,
Tianshu Qiu <tian.shu.qiu@intel.com>,
linux-media@vger.kernel.org, devicetree@vger.kernel.org,
linux-arm-msm@vger.kernel.org,
Robert Mader <robert.mader@collabora.com>,
Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>,
David Heidelberg <david@ixit.cz>,
phone-devel@vger.kernel.org
Subject: Re: [PATCH v7 2/5] media: i2c: imx355: Support devicetree and power management
Date: Tue, 20 Jan 2026 16:49:21 +0200 [thread overview]
Message-ID: <aW-V8VTcOICLWqaU@kekkonen.localdomain> (raw)
In-Reply-To: <578668b0-cba2-4550-b676-26ed0b447bf2@linaro.org>
Hi Bryan, others,
On Tue, Jan 20, 2026 at 12:44:24PM +0000, Bryan O'Donoghue wrote:
> I think reset should be asserted before regulators and power are switched
> on. i.e. before you try to switch the chip on, you should establish that the
> reset pin is in the state that the timing diagram calls for.
Indeed.
The xshutdown pin, as it is typically called labelled as "reset" in this
case, functions as both hardware reset and hardware standby mode control.
It should be asserted (i.e. be set to low level) whenever the sensor is
expected to be powered off. Typically deasserting it is the last step in
the sensor's power-up sequence. This applies to nearly all CSI-2 and DVP
(parallel) camera sensors. (There are some exceptions that use explicitly
two GPIOs for similar functions but there are very few of them.)
--
Regards,
Sakari Ailus
next prev parent reply other threads:[~2026-01-20 14:49 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-17 4:06 [PATCH v7 0/5] media: i2c: IMX355 for the Pixel 3a Richard Acayan
2026-01-17 4:06 ` [PATCH v7 1/5] dt-bindings: media: i2c: Add Sony IMX355 Richard Acayan
2026-01-17 10:52 ` Krzysztof Kozlowski
2026-01-19 8:40 ` Sakari Ailus
2026-01-17 4:06 ` [PATCH v7 2/5] media: i2c: imx355: Support devicetree and power management Richard Acayan
2026-01-17 12:03 ` Vladimir Zapolskiy
2026-01-20 3:50 ` Richard Acayan
2026-01-20 7:36 ` Sakari Ailus
2026-01-20 9:10 ` Krzysztof Kozlowski
2026-01-20 12:44 ` Bryan O'Donoghue
2026-01-20 14:49 ` Sakari Ailus [this message]
2026-01-28 2:53 ` Richard Acayan
2026-01-28 7:59 ` Sakari Ailus
2026-01-28 23:23 ` Richard Acayan
2026-01-17 4:06 ` [PATCH v7 3/5] arm64: dts: qcom: sdm670: label the camss ports instead of endpoints Richard Acayan
2026-01-17 4:06 ` [PATCH v7 4/5] arm64: dts: qcom: sdm670: add camera mclk pins Richard Acayan
2026-01-17 4:06 ` [PATCH v7 5/5] arm64: dts: qcom: sdm670-google-sargo: add imx355 front camera Richard Acayan
2026-01-17 12:07 ` Vladimir Zapolskiy
2026-01-20 11:00 ` Konrad Dybcio
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