From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 0F2B134251C; Wed, 12 Nov 2025 14:51:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762959118; cv=none; b=NiRLn3q9hQcoKARPq1RS7TVRCWf2QbLhYy9ztxMiE7YcI3pkGBtGp9X8Aj5gRzoaxk2HQv1d4zDPXDJ/UxUJa9B5oJRsww7PLicKgXNV0CAM7u34OBu2DQnGLuxmD7Ew/Qpo6AfcpHGLRMrsa/QzgBVKD92/8vvU/5fN13GgAQA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762959118; c=relaxed/simple; bh=aWeBdEfnTUEJjDdGlDTINxVDm9Ychxa2S0ZJDIUoXqo=; h=Content-Type:MIME-Version:In-Reply-To:References:Subject:From:Cc: To:Date:Message-ID; b=d0PqmxF3Sg8i7nM37H7QpUsvVqyk+/m1uNQQ6SaqAghKNYcOCu0FI1raGTXyzkRyg9KqHkTYAQ6fl6xpNZoitfgCG/KhlwA5QbmSPZwWFKlxYQX3LQTfsHLUKgA1wVlW/GsunWA0dqNui1OYS3DUAG974zeowLR5DKURn+Ng0z4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=WmFyXDQj; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="WmFyXDQj" Received: from pendragon.ideasonboard.com (cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 35F0050A; Wed, 12 Nov 2025 15:49:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1762958994; bh=aWeBdEfnTUEJjDdGlDTINxVDm9Ychxa2S0ZJDIUoXqo=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=WmFyXDQjTTbicemy8kC86RhVJBI7dGrF9hzwPWx5mM6s1++B3MndNphhFfqjIvqus Mmqd1a29AaqhNugKwq/BSYDaJQsY9exTpulRrBwXkfLdhO1XBLT40WdKgEK9+uXurQ FFT+qHcM2SA/9oZ1sKoLmFAgMpvTuynRf2xCK5FM= Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: References: <20251028-b4-rpi-ov5647-v1-0-098413454f5e@ideasonboard.com> <20251028-b4-rpi-ov5647-v1-6-098413454f5e@ideasonboard.com> <176294861029.13219.15475344635093672267@freya> Subject: Re: [PATCH 06/13] media: i2c: ov5647: Support HFLIP and VFLIP From: Kieran Bingham Cc: Jacopo Mondi , Sakari Ailus , Jacopo Mondi , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Mauro Carvalho Chehab , David Plowman , Laurent Pinchart , Peter Robinson , Stefan Wahren , Ivan T. Ivanov To: Dave Stevenson , Jai Luthra Date: Wed, 12 Nov 2025 14:51:50 +0000 Message-ID: <176295911050.2141792.17985652989180570149@ping.linuxembedded.co.uk> User-Agent: alot/0.9.1 Quoting Dave Stevenson (2025-11-12 14:35:49) > Hi Jai & Jacopo. >=20 > On Wed, 12 Nov 2025 at 11:56, Jai Luthra wr= ote: > > > > Hi Jacopo, > > > > Thanks a lot for the review. > > > > Quoting Jacopo Mondi (2025-11-02 16:20:36) > > > Hi Jai > > > > > > On Tue, Oct 28, 2025 at 12:57:17PM +0530, Jai Luthra wrote: > > > > From: David Plowman > > > > > > > > Add missing controls for horizontal and vertical flipping. > > > > > > > > Signed-off-by: David Plowman > > > > Signed-off-by: Jai Luthra > > > > --- > > > > drivers/media/i2c/ov5647.c | 77 ++++++++++++++++++++++++++++++++++= ++++++++---- > > > > 1 file changed, 71 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c > > > > index 977b878b0d4b8cd5f39f510ebd8b33c9163f7da2..a33e2d8edc114d302e8= 30639cb7cb161f16a6208 100644 > > > > --- a/drivers/media/i2c/ov5647.c > > > > +++ b/drivers/media/i2c/ov5647.c > > > > @@ -54,6 +54,8 @@ > > > > #define OV5647_REG_GAIN_LO 0x350b > > > > #define OV5647_REG_VTS_HI 0x380e > > > > #define OV5647_REG_VTS_LO 0x380f > > > > +#define OV5647_REG_VFLIP 0x3820 > > > > +#define OV5647_REG_HFLIP 0x3821 > > > > #define OV5647_REG_FRAME_OFF_NUMBER 0x4202 > > > > #define OV5647_REG_MIPI_CTRL00 0x4800 > > > > #define OV5647_REG_MIPI_CTRL14 0x4814 > > > > @@ -109,6 +111,8 @@ struct ov5647 { > > > > struct v4l2_ctrl *hblank; > > > > struct v4l2_ctrl *vblank; > > > > struct v4l2_ctrl *exposure; > > > > + struct v4l2_ctrl *hflip; > > > > + struct v4l2_ctrl *vflip; > > > > }; > > > > > > > > static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd) > > > > @@ -150,7 +154,7 @@ static struct regval_list ov5647_2592x1944_10bp= p[] =3D { > > > > {0x3036, 0x69}, > > > > {0x303c, 0x11}, > > > > {0x3106, 0xf5}, > > > > - {0x3821, 0x06}, > > > > + {0x3821, 0x00}, > > > > {0x3820, 0x00}, > > > > > > That's interesting, as the datasheet says that by default > > > > > > 3820 =3D 0x40 > > > 3821 =3D 0x00 > > > > > > And > > > - BIT[2] =3D flip ISP > > > - BIT[1] =3D flip SNR > > > > > > The implementation of ov5647_s_flip() toggles BIT(1) and ignores > > > BIT(2) while the modes definition have both (BIT(2) | BIT(1)) set > > > > > > More interestingly the datasheet says: > > > > > > In flip mode, the OV5647 does not need additional settings because the > > > ISP block will auto-detect whether the pixel is in the red line or > > > blue line and make the necessary adjustments > > > > > > Might this suggest that if we flip using BIT(2) we don't need to > > > change the bayer pattern ordering ? > > > > Indeed! That was a great find, I am now able to set BIT(2) to get flips > > without needing to modify the pixelarray layout. > > > > Will do that in v2. >=20 > Are you going to update the rectangles reported by g_selection then? > The sensor can't magically change the filter colour of the pixels > being read out, therefore it must be reading different pixels. > Figure 3-1 sensor array region color filter layout lists 2592x1944 > active pixels, and we're reading out all of those. "The backend > processor can use the boundary pixels for additional processing", but > how? There are no details. >=20 > Yes it's minor, but in using BIT(1) we know exactly what the sensor is > doing. Handling the change of Bayer order in the driver isn't that > involved, and is common to so many sensors that clients have to > support it anyway. >=20 > None of the ISP features of OV5647 are used by this driver. I suspect > the bits mentioned in the datasheet are probably a hang-over from > OV5640 which is effectively the same sensor array with built-in ISP > processing to produce YUYV images. >=20 > Just my two-cents. I'm also on this side of the fence. Any magic that keeps the bayer order - moves the picture, and unless we can report that accurately it's undesireable. It might be worth trying out the crop-detector in camshark to measure the movements and relative positions of the full raw captures and crops modes! For instance on the IMX283 and IMX335 - in the product we worked on for those sensors, the images are used for measurements - so even a single pixel offset matters! -- Kieran >=20 > > > > > > Now, I admit I'm not sure what are the ISP functions on the ov5647 and > > > this patch is super-duper-tested as it comes from the RPi BSP, so if > > > you don't have answers to the above questions, I'm fine with this > > > patch! > > > > > > > {0x3827, 0xec}, > > > > {0x370c, 0x03}, > > > > @@ -239,7 +243,7 @@ static struct regval_list ov5647_1080p30_10bpp[= ] =3D { > > > > {0x3036, 0x62}, > > > > {0x303c, 0x11}, > > > > {0x3106, 0xf5}, > > > > - {0x3821, 0x06}, > > > > + {0x3821, 0x00}, > > > > {0x3820, 0x00}, > > > > {0x3827, 0xec}, > > > > {0x370c, 0x03}, > > > > @@ -403,7 +407,7 @@ static struct regval_list ov5647_2x2binned_10bp= p[] =3D { > > > > {0x4800, 0x24}, > > > > {0x3503, 0x03}, > > > > {0x3820, 0x41}, > > > > - {0x3821, 0x07}, > > > > + {0x3821, 0x01}, > > > > {0x350a, 0x00}, > > > > {0x350b, 0x10}, > > > > {0x3500, 0x00}, > > > > @@ -419,7 +423,7 @@ static struct regval_list ov5647_640x480_10bpp[= ] =3D { > > > > {0x3035, 0x11}, > > > > {0x3036, 0x46}, > > > > {0x303c, 0x11}, > > > > - {0x3821, 0x07}, > > > > + {0x3821, 0x01}, > > > > {0x3820, 0x41}, > > > > {0x370c, 0x03}, > > > > {0x3612, 0x59}, > > > > @@ -935,6 +939,26 @@ static const struct v4l2_subdev_video_ops ov56= 47_subdev_video_ops =3D { > > > > .s_stream =3D ov5647_s_stream, > > > > }; > > > > > > > > +/* > > > > + * This function returns the mbus code for the current settings of= the HFLIP > > > > + * and VFLIP controls. > > > > + */ > > > > +static u32 ov5647_get_mbus_code(struct v4l2_subdev *sd) > > > > +{ > > > > + struct ov5647 *sensor =3D to_sensor(sd); > > > > + /* The control values are only 0 or 1. */ > > > > + int index =3D sensor->hflip->val | (sensor->vflip->val << 1); > > > > + > > > > + static const u32 codes[4] =3D { > > > > + MEDIA_BUS_FMT_SGBRG10_1X10, > > > > + MEDIA_BUS_FMT_SBGGR10_1X10, > > > > + MEDIA_BUS_FMT_SRGGB10_1X10, > > > > + MEDIA_BUS_FMT_SGRBG10_1X10 > > > > + }; > > > > + > > > > + return codes[index]; > > > > +} > > > > + > > > > static int ov5647_enum_mbus_code(struct v4l2_subdev *sd, > > > > struct v4l2_subdev_state *sd_state, > > > > struct v4l2_subdev_mbus_code_enum *c= ode) > > > > @@ -942,7 +966,7 @@ static int ov5647_enum_mbus_code(struct v4l2_su= bdev *sd, > > > > if (code->index > 0) > > > > return -EINVAL; > > > > > > > > - code->code =3D MEDIA_BUS_FMT_SBGGR10_1X10; > > > > + code->code =3D ov5647_get_mbus_code(sd); > > > > > > > > return 0; > > > > } > > > > @@ -953,7 +977,7 @@ static int ov5647_enum_frame_size(struct v4l2_s= ubdev *sd, > > > > { > > > > const struct v4l2_mbus_framefmt *fmt; > > > > > > > > - if (fse->code !=3D MEDIA_BUS_FMT_SBGGR10_1X10 || > > > > + if (fse->code !=3D ov5647_get_mbus_code(sd) || > > > > fse->index >=3D ARRAY_SIZE(ov5647_modes)) > > > > return -EINVAL; > > > > > > > > @@ -986,6 +1010,8 @@ static int ov5647_get_pad_fmt(struct v4l2_subd= ev *sd, > > > > } > > > > > > > > *fmt =3D *sensor_format; > > > > + /* The code we pass back must reflect the current h/vflips. */ > > > > + fmt->code =3D ov5647_get_mbus_code(sd); > > > > mutex_unlock(&sensor->lock); > > > > > > > > return 0; > > > > @@ -1033,6 +1059,8 @@ static int ov5647_set_pad_fmt(struct v4l2_sub= dev *sd, > > > > exposure_def); > > > > } > > > > *fmt =3D mode->format; > > > > + /* The code we pass back must reflect the current h/vflips. */ > > > > + fmt->code =3D ov5647_get_mbus_code(sd); > > > > mutex_unlock(&sensor->lock); > > > > > > > > return 0; > > > > @@ -1208,6 +1236,25 @@ static int ov5647_s_exposure(struct v4l2_sub= dev *sd, u32 val) > > > > return ov5647_write(sd, OV5647_REG_EXP_LO, (val & 0xf) << 4); > > > > } > > > > > > > > +static int ov5647_s_flip(struct v4l2_subdev *sd, u16 reg, u32 ctrl= _val) > > > > +{ > > > > + int ret; > > > > + u8 reg_val; > > > > + > > > > + /* Set or clear bit 1 and leave everything else alone. */ > > > > + ret =3D ov5647_read(sd, reg, ®_val); > > > > + if (ret =3D=3D 0) { > > > > + if (ctrl_val) > > > > + reg_val |=3D 2; > > > > + else > > > > + reg_val &=3D ~2; > > > > + > > > > + ret =3D ov5647_write(sd, reg, reg_val); > > > > + } > > > > + > > > > + return ret; > > > > +} > > > > + > > > > static int ov5647_s_ctrl(struct v4l2_ctrl *ctrl) > > > > { > > > > struct ov5647 *sensor =3D container_of(ctrl->handler, > > > > @@ -1270,6 +1317,14 @@ static int ov5647_s_ctrl(struct v4l2_ctrl *c= trl) > > > > /* Read-only, but we adjust it based on mode. */ > > > > break; > > > > > > > > + case V4L2_CID_HFLIP: > > > > + /* There's an in-built hflip in the sensor, so accoun= t for that here. */ > > > > + ov5647_s_flip(sd, OV5647_REG_HFLIP, !ctrl->val); > > > > + break; > > > > + case V4L2_CID_VFLIP: > > > > + ov5647_s_flip(sd, OV5647_REG_VFLIP, ctrl->val); > > > > + break; > > > > > > The modes definition used to set > > > > > > 0x3820 =3D 0x00 > > > 0x3821 =3D 0x06 > > > > > > Is this the built-in hflip ? > > > > > > Or does it mean that setting the registers value to 1 'disabled' flip= s ? > > > > > > > Yes, this particular sensor flips the image horizontally if 0x3820 =3D = 0x00, > > resulting in a mirrored image. > > > > But now that userspace can control flips, I am a bit confused on how to > > report this in the controls. > > > > > > + > > > > default: > > > > dev_info(&client->dev, > > > > "Control (id:0x%x, val:0x%x) not supported\n= ", > > > > @@ -1341,6 +1396,16 @@ static int ov5647_init_controls(struct ov564= 7 *sensor, struct device *dev) > > > > ARRAY_SIZE(ov5647_test_pattern_m= enu) - 1, > > > > 0, 0, ov5647_test_pattern_menu); > > > > > > > > + sensor->hflip =3D v4l2_ctrl_new_std(&sensor->ctrls, &ov5647_c= trl_ops, > > > > + V4L2_CID_HFLIP, 0, 1, 1, 0); > > > > + if (sensor->hflip) > > > > + sensor->hflip->flags |=3D V4L2_CTRL_FLAG_MODIFY_LAYOU= T; > > > > > > I wonder if hflip is enabled by default we shouldn't register the > > > control with default value of 1 ? > > > > > > > My preference is to let the driver toggle the value for HFLIP before > > writing to the sensor, as it is done currently in this patch. > > > > This makes this sensor behave like others, where you get a normal > > non-mirrored image when you set HFLIP =3D 0, and mirrored if HFLIP =3D = 1. > > > > The alternative is to keep the driver transparent by reporting the regi= ster > > values as-is in the control. In that case, we should make horizontal_fl= ip =3D > > 1 the default value for the control. But I'm not aware if any userspace > > applications will override the default value resulting in bad experience > > for the users. > > > > WDYT? >=20 > My vote would be for the driver to invert the value before writing, as > this patch does. >=20 > Making userspace have to call QUERYCTRL / QUERY_EXT_CTRL to get the > default before it can then work out that it needs to invert any flip > settings is additional overhead for zero gain. >=20 > Dave >=20 > > Thanks, > > Jai > > > > > > + > > > > + sensor->vflip =3D v4l2_ctrl_new_std(&sensor->ctrls, &ov5647_c= trl_ops, > > > > + V4L2_CID_VFLIP, 0, 1, 1, 0); > > > > + if (sensor->vflip) > > > > + sensor->vflip->flags |=3D V4L2_CTRL_FLAG_MODIFY_LAYOU= T; > > > > + > > > > v4l2_fwnode_device_parse(dev, &props); > > > > > > > > v4l2_ctrl_new_fwnode_properties(&sensor->ctrls, &ov5647_ctrl_= ops, > > > > > > > > -- > > > > 2.51.0 > > > >