Hi Pavel,

On Wed, May 31, 2017 at 09:58:21PM +0200, Pavel Machek wrote:

Hi!

quoted

+/* min/typical/max system clock (xclk) frequencies */
+#define OV5640_XCLK_MIN  6000000
+#define OV5640_XCLK_MAX 24000000
+
+/*
+ * FIXME: there is no subdev API to set the MIPI CSI-2
+ * virtual channel yet, so this is hardcoded for now.
+ */
+#define OV5640_MIPI_VC	1

Can the FIXME be fixed?

Yes, but it's quite a bit of work. It makes sense to use a static virtual
channel for now. A patchset which is however incomplete can be found here:

<URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=vc>

For what it's worth, all other devices use virtual channel zero for image
data and so should this one.

quoted

+/*
+ * image size under 1280 * 960 are SUBSAMPLING

-> Image

quoted

+ * image size upper 1280 * 960 are SCALING

above?

quoted

+/*
+ * FIXME: all of these register tables are likely filled with
+ * entries that set the register to their power-on default values,
+ * and which are otherwise not touched by this driver. Those entries
+ * should be identified and removed to speed register load time
+ * over i2c.
+ */

load->loading? Can the FIXME be fixed?

quoted

+	/* Auto/manual exposure */
+	ctrls->auto_exp = v4l2_ctrl_new_std_menu(hdl, ops,
+						 V4L2_CID_EXPOSURE_AUTO,
+						 V4L2_EXPOSURE_MANUAL, 0,
+						 V4L2_EXPOSURE_AUTO);
+	ctrls->exposure = v4l2_ctrl_new_std(hdl, ops,
+					    V4L2_CID_EXPOSURE_ABSOLUTE,
+					    0, 65535, 1, 0);

Is exposure_absolute supposed to be in microseconds...?

Yes. OTOH V4L2_CID_EXPOSURE has no defined unit, so it's a better fit IMO.
Way more drivers appear to be using EXPOSURE than EXPOSURE_ABSOLUTE, too.

Ideally we should have only one control for exposure.

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus at iki.fi	XMPP: sailus at retiisi.org.uk