[Patch 0/3] media: ov5640: updates

[Patch 0/3] media: ov5640: updates

[Benoit Parrot]

This patch series is a collection of patches we have been carrying for a
while.

First, it adds support for PIXEL_RATE control which is used by some
CSI2 receiver driver to properly set-up their DPHY.

Then we fix an issue related to having extra sensor enable/disable in
the register array for the 1920x1080 mode.

Finally we restrict the largest resolution which should only be
available at the lowest FPS.

Benoit Parrot (3):
  media: ov5640: add PIXEL_RATE control
  media: ov5640: Fix 1920x1080 mode to remove extra enable/disable
  media: ov5640: Make 2592x1944 mode only available at 15 fps

 drivers/media/i2c/ov5640.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

-- 
2.17.1

[Patch 1/3] media: ov5640: add PIXEL_RATE control

[Benoit Parrot]

Add v4l2 controls to report the pixel rates of each mode. This is
needed by some CSI2 receiver in order to perform proper DPHY
configuration.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
---
 drivers/media/i2c/ov5640.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index 500d9bbff10b..c2a44f30d56e 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -193,6 +193,9 @@ struct ov5640_mode_info {
 
 struct ov5640_ctrls {
 	struct v4l2_ctrl_handler handler;
+	struct {
+		struct v4l2_ctrl *pixel_rate;
+	};
 	struct {
 		struct v4l2_ctrl *auto_exp;
 		struct v4l2_ctrl *exposure;
@@ -241,6 +244,7 @@ struct ov5640_dev {
 	const struct ov5640_mode_info *last_mode;
 	enum ov5640_frame_rate current_fr;
 	struct v4l2_fract frame_interval;
+	u64 pixel_rate;
 
 	struct ov5640_ctrls ctrls;
 
@@ -2202,6 +2206,7 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
 	const struct ov5640_mode_info *new_mode;
 	struct v4l2_mbus_framefmt *mbus_fmt = &format->format;
 	struct v4l2_mbus_framefmt *fmt;
+	u64 rate;
 	int ret;
 
 	if (format->pad != 0)
@@ -2233,6 +2238,12 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
 	if (mbus_fmt->code != sensor->fmt.code)
 		sensor->pending_fmt_change = true;
 
+	rate = sensor->current_mode->vtot * sensor->current_mode->htot;
+	rate *= ov5640_framerates[sensor->current_fr];
+	sensor->pixel_rate = rate;
+
+	__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
+				 sensor->pixel_rate);
 out:
 	mutex_unlock(&sensor->lock);
 	return ret;
@@ -2657,6 +2668,13 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
 	/* we can use our own mutex for the ctrl lock */
 	hdl->lock = &sensor->lock;
 
+	/* Clock related controls */
+	ctrls->pixel_rate =
+		v4l2_ctrl_new_std(hdl, ops,
+				  V4L2_CID_PIXEL_RATE, 0, INT_MAX, 1,
+				  55969920);
+	ctrls->pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
 	/* Auto/manual white balance */
 	ctrls->auto_wb = v4l2_ctrl_new_std(hdl, ops,
 					   V4L2_CID_AUTO_WHITE_BALANCE,
@@ -2782,6 +2800,7 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
 	struct ov5640_dev *sensor = to_ov5640_dev(sd);
 	const struct ov5640_mode_info *mode;
 	int frame_rate, ret = 0;
+	u64 rate;
 
 	if (fi->pad != 0)
 		return -EINVAL;
@@ -2816,6 +2835,12 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
 		sensor->frame_interval = fi->interval;
 		sensor->current_mode = mode;
 		sensor->pending_mode_change = true;
+
+		rate = sensor->current_mode->vtot * sensor->current_mode->htot;
+		rate *= ov5640_framerates[sensor->current_fr];
+		sensor->pixel_rate = rate;
+		__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
+					 sensor->pixel_rate);
 	}
 out:
 	mutex_unlock(&sensor->lock);
-- 
2.17.1

[Patch 2/3] media: ov5640: Fix 1920x1080 mode to remove extra enable/disable

[Benoit Parrot]

In the 1920x1080 register array an extra pair of reset ctrl disable
re-enable was causing unwanted init delays.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
---
 drivers/media/i2c/ov5640.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index c2a44f30d56e..aa56a5a93283 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -493,7 +493,6 @@ static const struct reg_value ov5640_setting_720P_1280_720[] = {
 };
 
 static const struct reg_value ov5640_setting_1080P_1920_1080[] = {
-	{0x3008, 0x42, 0, 0},
 	{0x3c07, 0x08, 0, 0},
 	{0x3c09, 0x1c, 0, 0}, {0x3c0a, 0x9c, 0, 0}, {0x3c0b, 0x40, 0, 0},
 	{0x3814, 0x11, 0, 0},
@@ -521,7 +520,7 @@ static const struct reg_value ov5640_setting_1080P_1920_1080[] = {
 	{0x3a0e, 0x03, 0, 0}, {0x3a0d, 0x04, 0, 0}, {0x3a14, 0x04, 0, 0},
 	{0x3a15, 0x60, 0, 0}, {0x4407, 0x04, 0, 0},
 	{0x460b, 0x37, 0, 0}, {0x460c, 0x20, 0, 0}, {0x3824, 0x04, 0, 0},
-	{0x4005, 0x1a, 0, 0}, {0x3008, 0x02, 0, 0},
+	{0x4005, 0x1a, 0, 0},
 };
 
 static const struct reg_value ov5640_setting_QSXGA_2592_1944[] = {
-- 
2.17.1

[Patch 3/3] media: ov5640: Make 2592x1944 mode only available at 15 fps

[Benoit Parrot]

The sensor data sheet clearly state that 2592x1944 only works at 15 fps
make sure we don't try to miss configure the pll out of acceptable
range.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
---
 drivers/media/i2c/ov5640.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index aa56a5a93283..3c9e61f948a5 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -1614,6 +1614,11 @@ ov5640_find_mode(struct ov5640_dev *sensor, enum ov5640_frame_rate fr,
 	    !(mode->hact == 640 && mode->vact == 480))
 		return NULL;
 
+	/* 2592x1944 only works at 15fps */
+	if (fr != OV5640_15_FPS &&
+	    (mode->hact == 2592 && mode->vact == 1944))
+		return NULL;
+
 	return mode;
 }
 
-- 
2.17.1

Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Sakari Ailus]

Hi Benoit,

On Wed, Sep 25, 2019 at 10:22:59AM -0500, Benoit Parrot wrote:
> Add v4l2 controls to report the pixel rates of each mode. This is
> needed by some CSI2 receiver in order to perform proper DPHY
> configuration.
> 
> Signed-off-by: Benoit Parrot <bparrot@ti.com>
> ---
>  drivers/media/i2c/ov5640.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 500d9bbff10b..c2a44f30d56e 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -193,6 +193,9 @@ struct ov5640_mode_info {
>  
>  struct ov5640_ctrls {
>  	struct v4l2_ctrl_handler handler;
> +	struct {
> +		struct v4l2_ctrl *pixel_rate;
> +	};
>  	struct {
>  		struct v4l2_ctrl *auto_exp;
>  		struct v4l2_ctrl *exposure;
> @@ -241,6 +244,7 @@ struct ov5640_dev {
>  	const struct ov5640_mode_info *last_mode;
>  	enum ov5640_frame_rate current_fr;
>  	struct v4l2_fract frame_interval;
> +	u64 pixel_rate;
>  
>  	struct ov5640_ctrls ctrls;
>  
> @@ -2202,6 +2206,7 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
>  	const struct ov5640_mode_info *new_mode;
>  	struct v4l2_mbus_framefmt *mbus_fmt = &format->format;
>  	struct v4l2_mbus_framefmt *fmt;
> +	u64 rate;
>  	int ret;
>  
>  	if (format->pad != 0)
> @@ -2233,6 +2238,12 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
>  	if (mbus_fmt->code != sensor->fmt.code)
>  		sensor->pending_fmt_change = true;
>  
> +	rate = sensor->current_mode->vtot * sensor->current_mode->htot;
> +	rate *= ov5640_framerates[sensor->current_fr];
> +	sensor->pixel_rate = rate;
> +
> +	__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
> +				 sensor->pixel_rate);
>  out:
>  	mutex_unlock(&sensor->lock);
>  	return ret;
> @@ -2657,6 +2668,13 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
>  	/* we can use our own mutex for the ctrl lock */
>  	hdl->lock = &sensor->lock;
>  
> +	/* Clock related controls */
> +	ctrls->pixel_rate =
> +		v4l2_ctrl_new_std(hdl, ops,
> +				  V4L2_CID_PIXEL_RATE, 0, INT_MAX, 1,
> +				  55969920);

Could you calculate this value instead of using a seemingly random number?

> +	ctrls->pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> +
>  	/* Auto/manual white balance */
>  	ctrls->auto_wb = v4l2_ctrl_new_std(hdl, ops,
>  					   V4L2_CID_AUTO_WHITE_BALANCE,
> @@ -2782,6 +2800,7 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
>  	struct ov5640_dev *sensor = to_ov5640_dev(sd);
>  	const struct ov5640_mode_info *mode;
>  	int frame_rate, ret = 0;
> +	u64 rate;
>  
>  	if (fi->pad != 0)
>  		return -EINVAL;
> @@ -2816,6 +2835,12 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
>  		sensor->frame_interval = fi->interval;
>  		sensor->current_mode = mode;
>  		sensor->pending_mode_change = true;
> +
> +		rate = sensor->current_mode->vtot * sensor->current_mode->htot;
> +		rate *= ov5640_framerates[sensor->current_fr];
> +		sensor->pixel_rate = rate;

I think it'd be better to have a function to calculate the value instead of
duplicating the code here.

> +		__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
> +					 sensor->pixel_rate);
>  	}
>  out:
>  	mutex_unlock(&sensor->lock);

-- 
Kind regards,

Sakari Ailus
sakari.ailus@linux.intel.com

Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Benoit Parrot]

Hi Sakari,

Thanks for the review.

Sakari Ailus <sakari.ailus@linux.intel.com> wrote on Tue [2019-Oct-01 10:57:04 +0300]:
> Hi Benoit,
> 
> On Wed, Sep 25, 2019 at 10:22:59AM -0500, Benoit Parrot wrote:
> > Add v4l2 controls to report the pixel rates of each mode. This is
> > needed by some CSI2 receiver in order to perform proper DPHY
> > configuration.
> > 
> > Signed-off-by: Benoit Parrot <bparrot@ti.com>
> > ---
> >  drivers/media/i2c/ov5640.c | 25 +++++++++++++++++++++++++
> >  1 file changed, 25 insertions(+)
> > 
> > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> > index 500d9bbff10b..c2a44f30d56e 100644
> > --- a/drivers/media/i2c/ov5640.c
> > +++ b/drivers/media/i2c/ov5640.c
> > @@ -193,6 +193,9 @@ struct ov5640_mode_info {
> >  
> >  struct ov5640_ctrls {
> >  	struct v4l2_ctrl_handler handler;
> > +	struct {
> > +		struct v4l2_ctrl *pixel_rate;
> > +	};
> >  	struct {
> >  		struct v4l2_ctrl *auto_exp;
> >  		struct v4l2_ctrl *exposure;
> > @@ -241,6 +244,7 @@ struct ov5640_dev {
> >  	const struct ov5640_mode_info *last_mode;
> >  	enum ov5640_frame_rate current_fr;
> >  	struct v4l2_fract frame_interval;
> > +	u64 pixel_rate;
> >  
> >  	struct ov5640_ctrls ctrls;
> >  
> > @@ -2202,6 +2206,7 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
> >  	const struct ov5640_mode_info *new_mode;
> >  	struct v4l2_mbus_framefmt *mbus_fmt = &format->format;
> >  	struct v4l2_mbus_framefmt *fmt;
> > +	u64 rate;
> >  	int ret;
> >  
> >  	if (format->pad != 0)
> > @@ -2233,6 +2238,12 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
> >  	if (mbus_fmt->code != sensor->fmt.code)
> >  		sensor->pending_fmt_change = true;
> >  
> > +	rate = sensor->current_mode->vtot * sensor->current_mode->htot;
> > +	rate *= ov5640_framerates[sensor->current_fr];
> > +	sensor->pixel_rate = rate;
> > +
> > +	__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
> > +				 sensor->pixel_rate);
> >  out:
> >  	mutex_unlock(&sensor->lock);
> >  	return ret;
> > @@ -2657,6 +2668,13 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
> >  	/* we can use our own mutex for the ctrl lock */
> >  	hdl->lock = &sensor->lock;
> >  
> > +	/* Clock related controls */
> > +	ctrls->pixel_rate =
> > +		v4l2_ctrl_new_std(hdl, ops,
> > +				  V4L2_CID_PIXEL_RATE, 0, INT_MAX, 1,
> > +				  55969920);
> 
> Could you calculate this value instead of using a seemingly random number?

Yes I guess I could, especially if I make a helper function for it :).

> 
> > +	ctrls->pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > +
> >  	/* Auto/manual white balance */
> >  	ctrls->auto_wb = v4l2_ctrl_new_std(hdl, ops,
> >  					   V4L2_CID_AUTO_WHITE_BALANCE,
> > @@ -2782,6 +2800,7 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
> >  	struct ov5640_dev *sensor = to_ov5640_dev(sd);
> >  	const struct ov5640_mode_info *mode;
> >  	int frame_rate, ret = 0;
> > +	u64 rate;
> >  
> >  	if (fi->pad != 0)
> >  		return -EINVAL;
> > @@ -2816,6 +2835,12 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
> >  		sensor->frame_interval = fi->interval;
> >  		sensor->current_mode = mode;
> >  		sensor->pending_mode_change = true;
> > +
> > +		rate = sensor->current_mode->vtot * sensor->current_mode->htot;
> > +		rate *= ov5640_framerates[sensor->current_fr];
> > +		sensor->pixel_rate = rate;
> 
> I think it'd be better to have a function to calculate the value instead of
> duplicating the code here.

Yes I'll create a helper function.

Benoit

> 
> > +		__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
> > +					 sensor->pixel_rate);
> >  	}
> >  out:
> >  	mutex_unlock(&sensor->lock);
> 
> -- 
> Kind regards,
> 
> Sakari Ailus
> sakari.ailus@linux.intel.com

Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Jacopo Mondi]

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Hi Benoit,
  +Hugues

If you're considering an helper, this thread might be useful to you:
https://patchwork.kernel.org/patch/11019673/

Thanks
   j

On Tue, Oct 01, 2019 at 11:23:41AM -0500, Benoit Parrot wrote:
> Hi Sakari,
>
> Thanks for the review.
>
> Sakari Ailus <sakari.ailus@linux.intel.com> wrote on Tue [2019-Oct-01 10:57:04 +0300]:
> > Hi Benoit,
> >
> > On Wed, Sep 25, 2019 at 10:22:59AM -0500, Benoit Parrot wrote:
> > > Add v4l2 controls to report the pixel rates of each mode. This is
> > > needed by some CSI2 receiver in order to perform proper DPHY
> > > configuration.
> > >
> > > Signed-off-by: Benoit Parrot <bparrot@ti.com>
> > > ---
> > >  drivers/media/i2c/ov5640.c | 25 +++++++++++++++++++++++++
> > >  1 file changed, 25 insertions(+)
> > >
> > > diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> > > index 500d9bbff10b..c2a44f30d56e 100644
> > > --- a/drivers/media/i2c/ov5640.c
> > > +++ b/drivers/media/i2c/ov5640.c
> > > @@ -193,6 +193,9 @@ struct ov5640_mode_info {
> > >
> > >  struct ov5640_ctrls {
> > >  	struct v4l2_ctrl_handler handler;
> > > +	struct {
> > > +		struct v4l2_ctrl *pixel_rate;
> > > +	};
> > >  	struct {
> > >  		struct v4l2_ctrl *auto_exp;
> > >  		struct v4l2_ctrl *exposure;
> > > @@ -241,6 +244,7 @@ struct ov5640_dev {
> > >  	const struct ov5640_mode_info *last_mode;
> > >  	enum ov5640_frame_rate current_fr;
> > >  	struct v4l2_fract frame_interval;
> > > +	u64 pixel_rate;
> > >
> > >  	struct ov5640_ctrls ctrls;
> > >
> > > @@ -2202,6 +2206,7 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
> > >  	const struct ov5640_mode_info *new_mode;
> > >  	struct v4l2_mbus_framefmt *mbus_fmt = &format->format;
> > >  	struct v4l2_mbus_framefmt *fmt;
> > > +	u64 rate;
> > >  	int ret;
> > >
> > >  	if (format->pad != 0)
> > > @@ -2233,6 +2238,12 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
> > >  	if (mbus_fmt->code != sensor->fmt.code)
> > >  		sensor->pending_fmt_change = true;
> > >
> > > +	rate = sensor->current_mode->vtot * sensor->current_mode->htot;
> > > +	rate *= ov5640_framerates[sensor->current_fr];
> > > +	sensor->pixel_rate = rate;
> > > +
> > > +	__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
> > > +				 sensor->pixel_rate);
> > >  out:
> > >  	mutex_unlock(&sensor->lock);
> > >  	return ret;
> > > @@ -2657,6 +2668,13 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
> > >  	/* we can use our own mutex for the ctrl lock */
> > >  	hdl->lock = &sensor->lock;
> > >
> > > +	/* Clock related controls */
> > > +	ctrls->pixel_rate =
> > > +		v4l2_ctrl_new_std(hdl, ops,
> > > +				  V4L2_CID_PIXEL_RATE, 0, INT_MAX, 1,
> > > +				  55969920);
> >
> > Could you calculate this value instead of using a seemingly random number?
>
> Yes I guess I could, especially if I make a helper function for it :).
>
> >
> > > +	ctrls->pixel_rate->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > > +
> > >  	/* Auto/manual white balance */
> > >  	ctrls->auto_wb = v4l2_ctrl_new_std(hdl, ops,
> > >  					   V4L2_CID_AUTO_WHITE_BALANCE,
> > > @@ -2782,6 +2800,7 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
> > >  	struct ov5640_dev *sensor = to_ov5640_dev(sd);
> > >  	const struct ov5640_mode_info *mode;
> > >  	int frame_rate, ret = 0;
> > > +	u64 rate;
> > >
> > >  	if (fi->pad != 0)
> > >  		return -EINVAL;
> > > @@ -2816,6 +2835,12 @@ static int ov5640_s_frame_interval(struct v4l2_subdev *sd,
> > >  		sensor->frame_interval = fi->interval;
> > >  		sensor->current_mode = mode;
> > >  		sensor->pending_mode_change = true;
> > > +
> > > +		rate = sensor->current_mode->vtot * sensor->current_mode->htot;
> > > +		rate *= ov5640_framerates[sensor->current_fr];
> > > +		sensor->pixel_rate = rate;
> >
> > I think it'd be better to have a function to calculate the value instead of
> > duplicating the code here.
>
> Yes I'll create a helper function.
>
> Benoit
>
> >
> > > +		__v4l2_ctrl_s_ctrl_int64(sensor->ctrls.pixel_rate,
> > > +					 sensor->pixel_rate);
> > >  	}
> > >  out:
> > >  	mutex_unlock(&sensor->lock);
> >
> > --
> > Kind regards,
> >
> > Sakari Ailus
> > sakari.ailus@linux.intel.com

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Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Benoit Parrot]

Hi Jacopo,

Maybe, I miss spoke when I mentioned a helper I did not intent a framework
level generic function. Just a function to help in this case :)

That being said, I re-read the thread you mentioned. And as Hughes pointed
out dynamically generating a "working" link frequency value which can be
used by a CSI2 receiver to properly configure its PHY is not trivial.

When I created this patch, I also had another to add V4L2_CID_LINK_FREQ
support. I am testing this against the TI CAL CSI2 receiver, which already
uses the V4L2_CID_PIXEL_RATE value for that purpose, so I also had a patch
to add support for V4L2_CID_LINK_FREQ to that driver as well.

Unfortunately, similar to Hughes' findings I was not able to make it "work"
with all supported resolution/framerate.

Unlike my V4L2_CID_PIXEL_RATE solution which now works in all mode with the
same receiver.

So long story short I dropped the V4L2_CID_LINK_FREQ patch and focused on
V4L2_CID_PIXEL_RATE instead.

Regard,
Benoit

Jacopo Mondi <jacopo@jmondi.org> wrote on Wed [2019-Oct-02 09:59:51 +0200]:
> Hi Benoit,
>   +Hugues
> 
> If you're considering an helper, this thread might be useful to you:
> https://patchwork.kernel.org/patch/11019673/
> 
> Thanks
>    j
> 

Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Sakari Ailus]

Hi Benoit,

On Wed, Oct 02, 2019 at 07:14:38AM -0500, Benoit Parrot wrote:
> Hi Jacopo,
> 
> Maybe, I miss spoke when I mentioned a helper I did not intent a framework
> level generic function. Just a function to help in this case :)
> 
> That being said, I re-read the thread you mentioned. And as Hughes pointed
> out dynamically generating a "working" link frequency value which can be
> used by a CSI2 receiver to properly configure its PHY is not trivial.
> 
> When I created this patch, I also had another to add V4L2_CID_LINK_FREQ
> support. I am testing this against the TI CAL CSI2 receiver, which already
> uses the V4L2_CID_PIXEL_RATE value for that purpose, so I also had a patch
> to add support for V4L2_CID_LINK_FREQ to that driver as well.
> 
> Unfortunately, similar to Hughes' findings I was not able to make it "work"
> with all supported resolution/framerate.
> 
> Unlike my V4L2_CID_PIXEL_RATE solution which now works in all mode with the
> same receiver.
> 
> So long story short I dropped the V4L2_CID_LINK_FREQ patch and focused on
> V4L2_CID_PIXEL_RATE instead.

It shouldn't make a difference which one you use; if you know the bus type
(and if it's CSI-2 with D-PHY, number of lanes and how many bits per pixel
the media bus format has), you can convert fairly trivially between the
two.

-- 
Sakari Ailus
sakari.ailus@linux.intel.com

Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Benoit Parrot]

Sakari Ailus <sakari.ailus@linux.intel.com> wrote on Wed [2019-Oct-02 15:35:13 +0300]:
> Hi Benoit,
> 
> On Wed, Oct 02, 2019 at 07:14:38AM -0500, Benoit Parrot wrote:
> > Hi Jacopo,
> > 
> > Maybe, I miss spoke when I mentioned a helper I did not intent a framework
> > level generic function. Just a function to help in this case :)
> > 
> > That being said, I re-read the thread you mentioned. And as Hughes pointed
> > out dynamically generating a "working" link frequency value which can be
> > used by a CSI2 receiver to properly configure its PHY is not trivial.
> > 
> > When I created this patch, I also had another to add V4L2_CID_LINK_FREQ
> > support. I am testing this against the TI CAL CSI2 receiver, which already
> > uses the V4L2_CID_PIXEL_RATE value for that purpose, so I also had a patch
> > to add support for V4L2_CID_LINK_FREQ to that driver as well.
> > 
> > Unfortunately, similar to Hughes' findings I was not able to make it "work"
> > with all supported resolution/framerate.
> > 
> > Unlike my V4L2_CID_PIXEL_RATE solution which now works in all mode with the
> > same receiver.
> > 
> > So long story short I dropped the V4L2_CID_LINK_FREQ patch and focused on
> > V4L2_CID_PIXEL_RATE instead.
> 
> It shouldn't make a difference which one you use; if you know the bus type
> (and if it's CSI-2 with D-PHY, number of lanes and how many bits per pixel
> the media bus format has), you can convert fairly trivially between the
> two.

Sakari,

Yes I get that, but at this point as they say I will leave that as an
exercise to the reader...

Benoit

> 
> -- 
> Sakari Ailus
> sakari.ailus@linux.intel.com

Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Jacopo Mondi]

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Hi Benoit,

On Wed, Oct 02, 2019 at 07:14:38AM -0500, Benoit Parrot wrote:
> Hi Jacopo,
>
> Maybe, I miss spoke when I mentioned a helper I did not intent a framework
> level generic function. Just a function to help in this case :)

Yes indeed, the discussion thread I linked here was mostly interesting
because Hugues tried to do the same for LINK_FREQ iirc, and there
where some usefult pointers.

>
> That being said, I re-read the thread you mentioned. And as Hughes pointed
> out dynamically generating a "working" link frequency value which can be
> used by a CSI2 receiver to properly configure its PHY is not trivial.
>
> When I created this patch, I also had another to add V4L2_CID_LINK_FREQ
> support. I am testing this against the TI CAL CSI2 receiver, which already
> uses the V4L2_CID_PIXEL_RATE value for that purpose, so I also had a patch
> to add support for V4L2_CID_LINK_FREQ to that driver as well.
>
> Unfortunately, similar to Hughes' findings I was not able to make it "work"
> with all supported resolution/framerate.

As reported by Hugues findings, the PLL calculation procedure might be
faulty, and the actuall frequencies on the bus are different from the
calculated ones.

I wish I had more time to re-look at that, as they worked for my and
Sam's use case, but deserve some rework.

>
> Unlike my V4L2_CID_PIXEL_RATE solution which now works in all mode with the
> same receiver.
>

It seems to me you're reporting a fixed rate. It might make your
receiver happy, but does not report what is acutally put on the bus.
Am I missing something ?

> So long story short I dropped the V4L2_CID_LINK_FREQ patch and focused on
> V4L2_CID_PIXEL_RATE instead.
>

As Sakari pointed out, going from one to the other is trivial and
could be done on top.

Thanks
   j

> Regard,
> Benoit
>
> Jacopo Mondi <jacopo@jmondi.org> wrote on Wed [2019-Oct-02 09:59:51 +0200]:
> > Hi Benoit,
> >   +Hugues
> >
> > If you're considering an helper, this thread might be useful to you:
> > https://patchwork.kernel.org/patch/11019673/
> >
> > Thanks
> >    j
> >
>
>

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Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Benoit Parrot]

Jacopo Mondi <jacopo@jmondi.org> wrote on Wed [2019-Oct-02 16:32:26 +0200]:
> Hi Benoit,
> 
> On Wed, Oct 02, 2019 at 07:14:38AM -0500, Benoit Parrot wrote:
> > Hi Jacopo,
> >
> > Maybe, I miss spoke when I mentioned a helper I did not intent a framework
> > level generic function. Just a function to help in this case :)
> 
> Yes indeed, the discussion thread I linked here was mostly interesting
> because Hugues tried to do the same for LINK_FREQ iirc, and there
> where some usefult pointers.
> 
> >
> > That being said, I re-read the thread you mentioned. And as Hughes pointed
> > out dynamically generating a "working" link frequency value which can be
> > used by a CSI2 receiver to properly configure its PHY is not trivial.
> >
> > When I created this patch, I also had another to add V4L2_CID_LINK_FREQ
> > support. I am testing this against the TI CAL CSI2 receiver, which already
> > uses the V4L2_CID_PIXEL_RATE value for that purpose, so I also had a patch
> > to add support for V4L2_CID_LINK_FREQ to that driver as well.
> >
> > Unfortunately, similar to Hughes' findings I was not able to make it "work"
> > with all supported resolution/framerate.
> 
> As reported by Hugues findings, the PLL calculation procedure might be
> faulty, and the actuall frequencies on the bus are different from the
> calculated ones.
> 
> I wish I had more time to re-look at that, as they worked for my and
> Sam's use case, but deserve some rework.
> 
> >
> > Unlike my V4L2_CID_PIXEL_RATE solution which now works in all mode with the
> > same receiver.
> >
> 
> It seems to me you're reporting a fixed rate. It might make your
> receiver happy, but does not report what is acutally put on the bus.
> Am I missing something ?

No it is not fixed, the only fixed value was the initial value (which
representative of the initial/default resolution and framerate), I
fixed this in v2. The reported PIXEL_RATE is re-calculated every time there
is a s_fmt and/or framerate change and the V4L2_CID_PIXEL_RATE control
value is updated accordingly.

> 
> > So long story short I dropped the V4L2_CID_LINK_FREQ patch and focused on
> > V4L2_CID_PIXEL_RATE instead.
> >
> 
> As Sakari pointed out, going from one to the other is trivial and
> could be done on top.

As you said it could be done on top. :)

Benoit

> 
> Thanks
>    j
> 
> > Regard,
> > Benoit
> >
> > Jacopo Mondi <jacopo@jmondi.org> wrote on Wed [2019-Oct-02 09:59:51 +0200]:
> > > Hi Benoit,
> > >   +Hugues
> > >
> > > If you're considering an helper, this thread might be useful to you:
> > > https://patchwork.kernel.org/patch/11019673/
> > >
> > > Thanks
> > >    j
> > >
> >
> >

Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control

[Jacopo Mondi]

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Hi Benoit,

On Wed, Oct 02, 2019 at 10:06:15AM -0500, Benoit Parrot wrote:
> Jacopo Mondi <jacopo@jmondi.org> wrote on Wed [2019-Oct-02 16:32:26 +0200]:
> > Hi Benoit,
> >
> > On Wed, Oct 02, 2019 at 07:14:38AM -0500, Benoit Parrot wrote:
> > > Hi Jacopo,
> > >
> > > Maybe, I miss spoke when I mentioned a helper I did not intent a framework
> > > level generic function. Just a function to help in this case :)
> >
> > Yes indeed, the discussion thread I linked here was mostly interesting
> > because Hugues tried to do the same for LINK_FREQ iirc, and there
> > where some usefult pointers.
> >
> > >
> > > That being said, I re-read the thread you mentioned. And as Hughes pointed
> > > out dynamically generating a "working" link frequency value which can be
> > > used by a CSI2 receiver to properly configure its PHY is not trivial.
> > >
> > > When I created this patch, I also had another to add V4L2_CID_LINK_FREQ
> > > support. I am testing this against the TI CAL CSI2 receiver, which already
> > > uses the V4L2_CID_PIXEL_RATE value for that purpose, so I also had a patch
> > > to add support for V4L2_CID_LINK_FREQ to that driver as well.
> > >
> > > Unfortunately, similar to Hughes' findings I was not able to make it "work"
> > > with all supported resolution/framerate.
> >
> > As reported by Hugues findings, the PLL calculation procedure might be
> > faulty, and the actuall frequencies on the bus are different from the
> > calculated ones.
> >
> > I wish I had more time to re-look at that, as they worked for my and
> > Sam's use case, but deserve some rework.
> >
> > >
> > > Unlike my V4L2_CID_PIXEL_RATE solution which now works in all mode with the
> > > same receiver.
> > >
> >
> > It seems to me you're reporting a fixed rate. It might make your
> > receiver happy, but does not report what is acutally put on the bus.
> > Am I missing something ?
>
> No it is not fixed, the only fixed value was the initial value (which
> representative of the initial/default resolution and framerate), I
> fixed this in v2. The reported PIXEL_RATE is re-calculated every time there
> is a s_fmt and/or framerate change and the V4L2_CID_PIXEL_RATE control
> value is updated accordingly.

Oh I missed v2! I only seen this one.
I'll reply there.

Thanks
  j

>
> >
> > > So long story short I dropped the V4L2_CID_LINK_FREQ patch and focused on
> > > V4L2_CID_PIXEL_RATE instead.
> > >
> >
> > As Sakari pointed out, going from one to the other is trivial and
> > could be done on top.
>
> As you said it could be done on top. :)
>
> Benoit
>
> >
> > Thanks
> >    j
> >
> > > Regard,
> > > Benoit
> > >
> > > Jacopo Mondi <jacopo@jmondi.org> wrote on Wed [2019-Oct-02 09:59:51 +0200]:
> > > > Hi Benoit,
> > > >   +Hugues
> > > >
> > > > If you're considering an helper, this thread might be useful to you:
> > > > https://patchwork.kernel.org/patch/11019673/
> > > >
> > > > Thanks
> > > >    j
> > > >
> > >
> > >
>
>

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