diff mbox series

[v6,4/4] media: i2c: ov5675: add .get_selection support

Message ID 20220607153335.875956-4-foss+kernel@0leil.net
State Superseded
Headers show
Series [v6,1/4] media: dt-bindings: ov5675: document YAML binding | expand

Commit Message

Quentin Schulz June 7, 2022, 3:33 p.m. UTC
From: Quentin Schulz <quentin.schulz@theobroma-systems.com>

The sensor has 2592*1944 active pixels, surrounded by 16 active dummy
pixels and there are an additional 24 black rows "at the bottom".

                     [2624]
        +-----+------------------+-----+
        |     |     16 dummy     |     |
        +-----+------------------+-----+
        |     |                  |     |
        |     |     [2592]       |     |
        |     |                  |     |
        |16   |      valid       | 16  |[2000]
        |dummy|                  |dummy|
        |     |            [1944]|     |
        |     |                  |     |
        +-----+------------------+-----+
        |     |     16 dummy     |     |
        +-----+------------------+-----+
        |     |  24 black lines  |     |
        +-----+------------------+-----+

The top-left coordinate is gotten from the registers specified in the
modes which are identical for both currently supported modes.

There are currently two modes supported by this driver: 2592*1944 and
1296*972. The second mode is obtained thanks to subsampling while
keeping the same field of view (FoV). No cropping involved, hence the
harcoded values.

Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
---

v6:
 - explicit a bit more the commit log around subsampling for lower
 resolution modes,
 - (again) fixed reporting for V4L2_SEL_TGT_CROP_* thanks to Jacopo's help,

v4:
 - explicit a bit more the commit log,
 - added drawing in the commit log,
 - fixed reporting for V4L2_SEL_TGT_CROP_* thanks to Jacopo's help,

added in v3

 drivers/media/i2c/ov5675.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

Comments

Quentin Schulz June 8, 2022, 1:05 p.m. UTC | #1
Jacopo, Tommaso,

On 6/8/22 08:42, Jacopo Mondi wrote:
> Hi
> 
> On Wed, Jun 08, 2022 at 12:04:05AM +0200, Tommaso Merciai wrote:
>> Hi Quentin/Jacopo,
>>
>> On Tue, Jun 07, 2022 at 06:51:36PM +0200, Jacopo Mondi wrote:
>>> Hi Quentin,
>>>
>>> On Tue, Jun 07, 2022 at 05:33:35PM +0200, Quentin Schulz wrote:
>>>> From: Quentin Schulz <quentin.schulz@theobroma-systems.com>
>>>>
>>>> The sensor has 2592*1944 active pixels, surrounded by 16 active dummy
>>>> pixels and there are an additional 24 black rows "at the bottom".
>>>>
>>>>                       [2624]
>>>>          +-----+------------------+-----+
>>>>          |     |     16 dummy     |     |
>>>>          +-----+------------------+-----+
>>>>          |     |                  |     |
>>>>          |     |     [2592]       |     |
>>>>          |     |                  |     |
>>>>          |16   |      valid       | 16  |[2000]
>>>>          |dummy|                  |dummy|
>>>>          |     |            [1944]|     |
>>>>          |     |                  |     |
>>>>          +-----+------------------+-----+
>>>>          |     |     16 dummy     |     |
>>>>          +-----+------------------+-----+
>>>>          |     |  24 black lines  |     |
>>>>          +-----+------------------+-----+
>>>>
>>>> The top-left coordinate is gotten from the registers specified in the
>>>> modes which are identical for both currently supported modes.
>>>>
>>>> There are currently two modes supported by this driver: 2592*1944 and
>>>> 1296*972. The second mode is obtained thanks to subsampling while
>>>> keeping the same field of view (FoV). No cropping involved, hence the
>>>> harcoded values.
>>>>
>>>> Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
>>>> ---
>>>>
>>>> v6:
>>>>   - explicit a bit more the commit log around subsampling for lower
>>>>   resolution modes,
>>>>   - (again) fixed reporting for V4L2_SEL_TGT_CROP_* thanks to Jacopo's help,
>>>>
>>>> v4:
>>>>   - explicit a bit more the commit log,
>>>>   - added drawing in the commit log,
>>>>   - fixed reporting for V4L2_SEL_TGT_CROP_* thanks to Jacopo's help,
>>>>
>>>> added in v3
>>>>
>>>>   drivers/media/i2c/ov5675.c | 21 +++++++++++++++++++++
>>>>   1 file changed, 21 insertions(+)
>>>>
>>>> diff --git a/drivers/media/i2c/ov5675.c b/drivers/media/i2c/ov5675.c
>>>> index 80840ad7bbb0..2230ff47ef49 100644
>>>> --- a/drivers/media/i2c/ov5675.c
>>>> +++ b/drivers/media/i2c/ov5675.c
>>>> @@ -1121,6 +1121,26 @@ static int ov5675_get_format(struct v4l2_subdev *sd,
>>>>   	return 0;
>>>>   }
>>>>
>>>> +static int ov5675_get_selection(struct v4l2_subdev *sd,
>>>> +				struct v4l2_subdev_state *state,
>>>> +				struct v4l2_subdev_selection *sel)
>>>> +{
>>>> +	if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
>>>> +		return -EINVAL;
>>>> +
>>>> +	switch (sel->target) {
>>>> +	case V4L2_SEL_TGT_CROP:
>>>> +	case V4L2_SEL_TGT_CROP_BOUNDS:
>>>
>>> Seem like we have trouble understanding each other, or better, I have
>>> troubles explaining myself most probably :)
>>>
>>> If the dummy/black area is readable, this should just be (0, 0, 2624,
>>> 2000) like it was in your previous version. What has changed that I
>>> have missed ?
>>

I wouldn't say there's some misunderstanding, it's just super hard to 
figure out how to match what the datasheet says to what the kernel 
wants. Yay to obscure/confusing datasheets \o/

I just did things too quickly, nothing changed. Sorry, will send a v7.

>> Taking as reference drivers/media/i2c/ov5693.c and others,
>> seems ok what Quentin have done from my side.
>>
>> Just one thing: maybe is better to avoid magic numbers with more
>> explicit defines like:
>>
>>   + case V4L2_SEL_TGT_CROP_DEFAULT:
>>   +           sel->r.top = OV5675_ACTIVE_START_TOP;
>>   +           sel->r.left = OV5693_ACTIVE_START_LEFT;
>>   +           sel->r.width = OV5693_ACTIVE_WIDTH;
>>   +           sel->r.height = OV5693_ACTIVE_HEIGHT;
>>

They are hardcoded today but actually depend on what;s set in the 
registers too, which might differ if we add more modes in the future? 
It's anyway auto-magic and it's the only place it's used, so not sure it 
brings much especially since the variable names on the left hand side of 
the operator are pretty self-explanatory (not talking about 
V4L2_SEL_TGT_CROP_* :p)? Not that I'm against it.

Cheers,
Quentin
diff mbox series

Patch

diff --git a/drivers/media/i2c/ov5675.c b/drivers/media/i2c/ov5675.c
index 80840ad7bbb0..2230ff47ef49 100644
--- a/drivers/media/i2c/ov5675.c
+++ b/drivers/media/i2c/ov5675.c
@@ -1121,6 +1121,26 @@  static int ov5675_get_format(struct v4l2_subdev *sd,
 	return 0;
 }
 
+static int ov5675_get_selection(struct v4l2_subdev *sd,
+				struct v4l2_subdev_state *state,
+				struct v4l2_subdev_selection *sel)
+{
+	if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
+		return -EINVAL;
+
+	switch (sel->target) {
+	case V4L2_SEL_TGT_CROP:
+	case V4L2_SEL_TGT_CROP_BOUNDS:
+	case V4L2_SEL_TGT_CROP_DEFAULT:
+		sel->r.top = 16;
+		sel->r.left = 16;
+		sel->r.width = 2592;
+		sel->r.height = 1944;
+		return 0;
+	}
+	return -EINVAL;
+}
+
 static int ov5675_enum_mbus_code(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_state *sd_state,
 				 struct v4l2_subdev_mbus_code_enum *code)
@@ -1170,6 +1190,7 @@  static const struct v4l2_subdev_video_ops ov5675_video_ops = {
 static const struct v4l2_subdev_pad_ops ov5675_pad_ops = {
 	.set_fmt = ov5675_set_format,
 	.get_fmt = ov5675_get_format,
+	.get_selection = ov5675_get_selection,
 	.enum_mbus_code = ov5675_enum_mbus_code,
 	.enum_frame_size = ov5675_enum_frame_size,
 };