On Sunday, January 23, 2011 04:38:21 Kim HeungJun wrote:
> Hello,
>
> I'm reading threads about the new v4l2_ctrl framework and If you don't mind
> I gotta tell you my humble opinion about testing result the new v4l2_ctrl
> framework subdev.
> I have actually similar curcumstance, with I2C subdev M5MOLS Fujitsu device
> which is just send the patch and S5PC210 board for testing this, except not
> using soc_camera framework.
> But, it's maybe helpful to discuss about this changes to everyone.
>
> 2011. 1. 23., 오전 6:21, Guennadi Liakhovetski 작성:
>
> > On Wed, 12 Jan 2011, Hans Verkuil wrote:
> >
> >> Signed-off-by: Hans Verkuil <hverkuil@xxxxxxxxx>
>
> [snip]
>
> >> - case V4L2_CID_EXPOSURE:
> >> - /* mt9m001 has maximum == default */
> >> - if (ctrl->value > qctrl->maximum || ctrl->value < qctrl->minimum)
> >> - return -EINVAL;
> >> - else {
> >> - unsigned long range = qctrl->maximum - qctrl->minimum;
> >> - unsigned long shutter = ((ctrl->value - qctrl->minimum) * 1048 +
> >> + case V4L2_CID_EXPOSURE_AUTO:
> >> + /* Force manual exposure if only the exposure was changed */
> >> + if (!ctrl->has_new)
> >> + ctrl->val = V4L2_EXPOSURE_MANUAL;
> >> + if (ctrl->val == V4L2_EXPOSURE_MANUAL) {
> >> + unsigned long range = exp->maximum - exp->minimum;
> >> + unsigned long shutter = ((exp->val - exp->minimum) * 1048 +
> >> range / 2) / range + 1;
> >>
> >> dev_dbg(&client->dev,
> >> "Setting shutter width from %d to %lu\n",
> >> - reg_read(client, MT9M001_SHUTTER_WIDTH),
> >> - shutter);
> >> + reg_read(client, MT9M001_SHUTTER_WIDTH), shutter);
> >> if (reg_write(client, MT9M001_SHUTTER_WIDTH, shutter) < 0)
> >> return -EIO;
> >> - mt9m001->exposure = ctrl->value;
> >> - mt9m001->autoexposure = 0;
> >> - }
> >> - break;
> >> - case V4L2_CID_EXPOSURE_AUTO:
> >> - if (ctrl->value) {
> >> + } else {
> >> const u16 vblank = 25;
> >> unsigned int total_h = mt9m001->rect.height +
> >> mt9m001->y_skip_top + vblank;
> >> - if (reg_write(client, MT9M001_SHUTTER_WIDTH,
> >> - total_h) < 0)
> >> +
> >> + if (reg_write(client, MT9M001_SHUTTER_WIDTH, total_h) < 0)
> >> return -EIO;
> >> - qctrl = soc_camera_find_qctrl(icd->ops, V4L2_CID_EXPOSURE);
> >> - mt9m001->exposure = (524 + (total_h - 1) *
> >> - (qctrl->maximum - qctrl->minimum)) /
> >> - 1048 + qctrl->minimum;
> >> - mt9m001->autoexposure = 1;
> >> - } else
> >> - mt9m001->autoexposure = 0;
> >> - break;
> >> + exp->val = (524 + (total_h - 1) *
> >> + (exp->maximum - exp->minimum)) / 1048 +
> >> + exp->minimum;
> >> + }
> >> + return 0;
> >> }
> >> - return 0;
> >> + return -EINVAL;
> >
> > It seems to me, that you've dropped V4L2_CID_EXPOSURE here, was it
> > intentional? I won't verify this in detail now, because, if it wasn't
> > intentional and you fix it in v2, I'll have to re-check it anyway. Or is
> > it supposed to be handled by that V4L2_EXPOSURE_MANUAL? So, if the user
> > issues a V4L2_CID_EXPOSURE, are you getting V4L2_CID_EXPOSURE_AUTO with
> > val == V4L2_EXPOSURE_MANUAL instead? Weird...
>
> I also wonder first at this part for a long time like below:
>
> 1. when calling V4L2_CID_EXPOSURE_AUTO with V4L2_EXPOSURE_AUTO, it's ok.
> 2. when calling V4L2_CID_EXPOSURE_AUTO with V4L2_EXPOSURE_MANUAL, it's
> also ok.
> 3. when calling V4L2_CID_EXPOSURE? where the device handle this CID?
>
> but, after testing with application step by step, I finally know below:
> when calling V4L2_CID_EXPOSURE, changing internal(v4l2_ctrl framework) variable,
> exactly struct v4l2_ctrl exposure, which is register for probing time by
> V4L2_CID_EXPOSURE, and clustered with struct v4l2_ctrl autoexposure. So, when
> the device no needs to handle this values, but it automatically calls control clustered with
> itself, in this case the V4L2_CID_EXPOSURE calls(just words)V4L2_CID_EXPOSURE_AUTO.
>
> So, the my POV is that foo clustered with auto_foo calls auto_foo with foo's characteristics.
Correct. This tells me two things: 1) nobody ever reads documentation, and 2) I
must place a comment in the code making people aware that the V4L2_CID_EXPOSURE_AUTO
case will handle all controls in the cluster.
Regards,
Hans
>
> But, Hans probably would do more clear answer.
>
> Regards,
> Heungjun Kim
>
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>
--
Hans Verkuil - video4linux developer - sponsored by Cisco
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