linux-kernel - Re: [PATCH v2 2/2] media: i2c: add ov2735 image sensor driver

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Message-ID:
 <PN3P287MB35199F4D8EA9F384660A337DFF4EA@PN3P287MB3519.INDP287.PROD.OUTLOOK.COM>
Date: Tue, 8 Jul 2025 11:28:30 +0000
From: Hardevsinh Palaniya <hardevsinh.palaniya@...iconsignals.io>
To: Krzysztof Kozlowski <krzk@...nel.org>, "sakari.ailus@...ux.intel.com"
	<sakari.ailus@...ux.intel.com>, "andriy.shevchenko@...ux.intel.com"
	<andriy.shevchenko@...ux.intel.com>, "krzk+dt@...nel.org"
	<krzk+dt@...nel.org>
CC: Himanshu Bhavani <himanshu.bhavani@...iconsignals.io>, Mauro Carvalho
 Chehab <mchehab@...nel.org>, Rob Herring <robh@...nel.org>, Conor Dooley
	<conor+dt@...nel.org>, Hans Verkuil <hverkuil@...all.nl>,
	André Apitzsch <git@...tzsch.eu>, Hans de Goede
	<hansg@...nel.org>, Ricardo Ribalda <ribalda@...omium.org>, Heimir Thor
 Sverrisson <heimir.sverrisson@...il.com>, Matthias Fend
	<matthias.fend@...end.at>, Benjamin Mugnier <benjamin.mugnier@...s.st.com>,
	Jingjing Xiong <jingjing.xiong@...el.com>, Sylvain Petinot
	<sylvain.petinot@...s.st.com>, Dongcheng Yan <dongcheng.yan@...el.com>, Arnd
 Bergmann <arnd@...db.de>, Bryan O'Donoghue <bryan.odonoghue@...aro.org>,
	"linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] media: i2c: add ov2735 image sensor driver

> On 08/07/2025 12:25, Hardevsinh Palaniya wrote:
> > +
> > +static const struct v4l2_subdev_ops ov2735_subdev_ops = {
> > +     .video = &ov2735_video_ops,
> > +     .pad = &ov2735_pad_ops,
> > +};
> > +
> > +static const struct v4l2_subdev_internal_ops ov2735_internal_ops = {
> > +     .init_state = ov2735_init_state,
> > +};
> > +
> > +static int ov2735_power_on(struct device *dev)
> > +{
> > +     struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > +     struct ov2735 *ov2735 = to_ov2735(sd);
> > +     unsigned long delay_us;
> > +     int ret;
> > +
> > +     gpiod_set_value_cansleep(ov2735->pwdn_gpio, 0);
> 
> So you power up here...
> 
> > +     fsleep(3000);
> > +
> > +     ret = regulator_bulk_enable(ARRAY_SIZE(ov2735_supply_name),
> > +                                 ov2735->supplies);
> > +     if (ret) {
> > +             dev_err(ov2735->dev, "failed to enable regulators\n");
> > +             return ret;
> > +     }
> > +
> > +     gpiod_set_value_cansleep(ov2735->pwdn_gpio, 1);
> 
> And here you power down your device. This makes no sense... unless this
> is not a power down GPIO.
 
In Datasheet 
Power-up sequence:

	  |--------------------------------------
avdd  ----|
	   <-t1->
		|--------------------------------
dovdd  ---------|
		  <-T2->
			|--------------------------
dvdd  ------------------|
			 <-T3->
          |---------------------|
pwdn -----|			|-------------------
				  <-T4->
					|-------------
rst ------------------------------------| 

Best Regards,
Hardev