From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.white.stw.pengutronix.de (mx1.white.stw.pengutronix.de [185.203.200.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 89A1A368968; Mon, 22 Jun 2026 09:05:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.200.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782119148; cv=none; b=oNHJWpZL1CEUdxil5CJ9qGWWWuESy+3uI3zWM/gFCULtdMq/eerFJj+iLROQubAUwHKOp1H2Ky+pixYNphu7//h4P/RFZkM9fqjfqqqgA5j3r4NrP1uqmwa7MtL4X0pAT7X6SihVSmYoAZ4anHuvMwvCzPKlpmZZWshKzlrqwks= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782119148; c=relaxed/simple; bh=CRvHUMaPERdvIZaqTgWAAfdNC4myYpz/V1coR8bSrtg=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=a+hqIEbN+6AVSwP1zhDqTU4wXsSnPlLipd2sMVBszlwgxlfnx8/RFW1B0zpWz8tmKJfF8tIyObn5NpUi40871ZiTMRhPlsc/SZOMUJZJ/PKJt0aamVPGw6ZC4pxPL32xbrGop99OYkrIW9XEZkMMecThMXd4La4qEWrKYilCIRc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.200.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de (drehscheibe.grey.stw.pengutronix.de [IPv6:2a0a:edc0:0:c01:1d::a2]) (Authenticated sender: relay-from-drehscheibe.grey.stw.pengutronix.de) by mx1.white.stw.pengutronix.de (Postfix) with ESMTPSA id 64BAA200669; Mon, 22 Jun 2026 11:05:34 +0200 (CEST) Received: from lupine.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::4e] helo=lupine) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wbab0-0043kt-13; Mon, 22 Jun 2026 11:05:34 +0200 Received: from pza by lupine with local (Exim 4.98.2) (envelope-from ) id 1wbab0-000000008iF-0wHT; Mon, 22 Jun 2026 11:05:34 +0200 Message-ID: <7ee62b699c5cabb00cd7706ea42573da81c5bc84.camel@pengutronix.de> Subject: Re: [PATCH v4 2/2] media: i2c: ov5640: Add reset controller support with GPIO fallback From: Philipp Zabel To: Frank Li , robby.cai@oss.nxp.com Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, Frank.Li@nxp.com, s.hauer@pengutronix.de, festevam@gmail.com, sebastian.krzyszkowiak@puri.sm, slongerbeam@gmail.com, sakari.ailus@linux.intel.com, mchehab@kernel.org, kieran.bingham@ideasonboard.com, kernel@pengutronix.de, devicetree@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Mon, 22 Jun 2026 11:05:34 +0200 In-Reply-To: References: <20260619100532.3779934-1-robby.cai@oss.nxp.com> <20260619100532.3779934-3-robby.cai@oss.nxp.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2-0+deb13u1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fr, 2026-06-19 at 09:18 -0500, Frank Li wrote: > On Fri, Jun 19, 2026 at 06:05:32PM +0800, robby.cai@oss.nxp.com wrote: > > [You don't often get email from robby.cai@oss.nxp.com. Learn why this i= s important at https://aka.ms/LearnAboutSenderIdentification ] > >=20 > > From: Robby Cai > >=20 > > Add support for the reset controller framework by acquiring the reset > > line using devm_reset_control_get_optional_shared_deasserted(). This > > allows the driver to handle reset lines provided by a reset controller, > > including shared ones, while avoiding unbalanced deassert counts. > >=20 > > Retain support for legacy reset-gpios as a fallback when no reset > > controller is defined. In that case, request the GPIO and keep it in th= e > > deasserted state as the initial configuration. > >=20 > > This enables the driver to support both reset-controller-backed reset > > lines and older GPIO-based descriptions while preserving the existing > > power-up sequencing behavior. > >=20 > > Signed-off-by: Robby Cai > > --- > > drivers/media/i2c/ov5640.c | 80 +++++++++++++++++++++++++++++++++----- > > 1 file changed, 70 insertions(+), 10 deletions(-) > >=20 > > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c > > index 85ecc23b3587..5e6db8aacb11 100644 > > --- a/drivers/media/i2c/ov5640.c > > +++ b/drivers/media/i2c/ov5640.c > > @@ -17,6 +17,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -442,6 +443,7 @@ struct ov5640_dev { > > u32 xclk_freq; > >=20 > > struct regulator_bulk_data supplies[OV5640_NUM_SUPPLIES]; > > + struct reset_control *reset; > > struct gpio_desc *reset_gpio; > > struct gpio_desc *pwdn_gpio; > > bool upside_down; > > @@ -2431,6 +2433,48 @@ static int ov5640_restore_mode(struct ov5640_dev= *sensor) > > return ov5640_set_framefmt(sensor, &sensor->fmt); > > } > >=20 > > +static int ov5640_get_reset(struct device *dev, struct ov5640_dev *sen= sor) > > +{ > > + /* use deasserted version to avoid unbalanced deassert counts *= / > > + sensor->reset =3D > > + devm_reset_control_get_optional_shared_deasserted(dev, NULL= ); > > + if (IS_ERR(sensor->reset)) > > + return dev_err_probe(dev, PTR_ERR(sensor->reset), > > + "Failed to get reset\n"); > > + else if (sensor->reset) > > + return 0; > > + > > + /* > > + * fallback to legacy reset-gpios > > + * GPIOD_OUT_HIGH ensures deasserted state for ACTIVE_LOW reset > > + */ > > + sensor->reset_gpio =3D devm_gpiod_get_optional(dev, "reset", > > + GPIOD_OUT_HIGH); > > + if (IS_ERR(sensor->reset_gpio)) > > + return dev_err_probe(dev, PTR_ERR(sensor->reset_gpio), > > + "Failed to get reset gpio"); >=20 > I think needn't fallback here, NO ABI change, just change to use reset-gp= io > driver. Please keep the gpiod fallback, the reset-gpio driver may not be available on all platforms using ov5640. > > + > > + return 0; > > +} > > + > > +static int ov5640_reset_assert(struct ov5640_dev *sensor) > > +{ > > + if (sensor->reset) > > + return reset_control_assert(sensor->reset); >=20 > needn't check sensor->reset, reset_control_assert() is no ops if NULL. >=20 > > + > > + gpiod_set_value_cansleep(sensor->reset_gpio, 1); >=20 > Needn't fallback, directly replace. See above. regards Philipp