linux-kernel - Re: [PATCH v2 1/3] media: i2c: ov5647: Convert to CCI register access helpers

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Message-ID:
 <PN3P287MB18298EF36CFD5CECF6D266528BBFA@PN3P287MB1829.INDP287.PROD.OUTLOOK.COM>
Date: Mon, 29 Dec 2025 14:52:45 +0000
From: Tarang Raval <tarang.raval@...iconsignals.io>
To: Xiaolei Wang <xiaolei.wang@...driver.com>,
	"laurent.pinchart@...asonboard.com" <laurent.pinchart@...asonboard.com>,
	"sakari.ailus@...ux.intel.com" <sakari.ailus@...ux.intel.com>,
	"dave.stevenson@...pberrypi.com" <dave.stevenson@...pberrypi.com>,
	"jacopo@...ndi.org" <jacopo@...ndi.org>, "mchehab@...nel.org"
	<mchehab@...nel.org>, "prabhakar.mahadev-lad.rj@...renesas.com"
	<prabhakar.mahadev-lad.rj@...renesas.com>, "hverkuil+cisco@...nel.org"
	<hverkuil+cisco@...nel.org>, "johannes.goede@....qualcomm.com"
	<johannes.goede@....qualcomm.com>, "hverkuil-cisco@...all.nl"
	<hverkuil-cisco@...all.nl>, "jai.luthra@...asonboard.com"
	<jai.luthra@...asonboard.com>
CC: "linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 1/3] media: i2c: ov5647: Convert to CCI register access
 helpers

>  static int ov5647_set_mode(struct v4l2_subdev *sd)
>  {
>         struct i2c_client *client = v4l2_get_subdevdata(sd);
>         struct ov5647 *sensor = to_sensor(sd);
> -       u8 resetval, rdval;
> +       u64 resetval, rdval;
>         int ret;
> 
> -       ret = ov5647_read(sd, OV5647_SW_STANDBY, &rdval);
> +       ret = cci_read(sensor->regmap, OV5647_SW_STANDBY, &rdval, NULL);
>         if (ret < 0)
>                 return ret;
> 
> -       ret = ov5647_write_array(sd, sensor->mode->reg_list,
> -                                sensor->mode->num_regs);
> +       ret = cci_multi_reg_write(sensor->regmap, sensor->mode->reg_list,
> +                                 sensor->mode->num_regs, NULL);
>         if (ret < 0) {
>                 dev_err(&client->dev, "write sensor default regs error\n");
>                 return ret;
> @@ -706,13 +624,13 @@ static int ov5647_set_mode(struct v4l2_subdev *sd)
>         if (ret < 0)
>                 return ret;
> 
> -       ret = ov5647_read(sd, OV5647_SW_STANDBY, &resetval);
> +       ret = cci_read(sensor->regmap, OV5647_SW_STANDBY, &resetval, NULL);
>         if (ret < 0)
>                 return ret;

Are both read operations in ov5647_set_mode() really needed?

Every mode table already ends with writing 0x0100 => 0x01.

Does anyone know the purpose of these reads, or are they unused?

Best Regards,
Tarang

>         if (!(resetval & 0x01)) {
>                 dev_err(&client->dev, "Device was in SW standby");
> -               ret = ov5647_write(sd, OV5647_SW_STANDBY, 0x01);
> +               ret = cci_write(sensor->regmap, OV5647_SW_STANDBY, 0x01, NULL);
>                 if (ret < 0)
>                         return ret;
>         }