On 01/20/2017 06:48 AM, Hans Verkuil wrote:

On 01/07/2017 03:11 AM, Steve Longerbeam wrote:

quoted

+
+	/* cached control settings */
+	int ctrl_cache[OV5640_MAX_CONTROLS];

This is just duplicating the cached value in the control framework. I think this can be dropped.

done, see below.

quoted

+
+static struct ov5640_control ov5640_ctrls[] = {
+	{
+		.set = ov5640_set_agc,
+		.ctrl = {
+			.id = V4L2_CID_AUTOGAIN,
+			.name = "Auto Gain/Exposure Control",
+			.minimum = 0,
+			.maximum = 1,
+			.step = 1,
+			.default_value = 1,
+			.type = V4L2_CTRL_TYPE_BOOLEAN,
+		},
+	}, {
+		.set = ov5640_set_exposure,
+		.ctrl = {
+			.id = V4L2_CID_EXPOSURE,
+			.name = "Exposure",
+			.minimum = 0,
+			.maximum = 65535,
+			.step = 1,
+			.default_value = 0,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+		},
+	}, {
+		.set = ov5640_set_gain,
+		.ctrl = {
+			.id = V4L2_CID_GAIN,
+			.name = "Gain",
+			.minimum = 0,
+			.maximum = 1023,
+			.step = 1,
+			.default_value = 0,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+		},
+	}, {
+		.set = ov5640_set_hue,
+		.ctrl = {
+			.id = V4L2_CID_HUE,
+			.name = "Hue",
+			.minimum = 0,
+			.maximum = 359,
+			.step = 1,
+			.default_value = 0,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+		},
+	}, {
+		.set = ov5640_set_contrast,
+		.ctrl = {
+			.id = V4L2_CID_CONTRAST,
+			.name = "Contrast",
+			.minimum = 0,
+			.maximum = 255,
+			.step = 1,
+			.default_value = 0,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+		},
+	}, {
+		.set = ov5640_set_saturation,
+		.ctrl = {
+			.id = V4L2_CID_SATURATION,
+			.name = "Saturation",
+			.minimum = 0,
+			.maximum = 255,
+			.step = 1,
+			.default_value = 64,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+		},
+	}, {
+		.set = ov5640_set_awb,
+		.ctrl = {
+			.id = V4L2_CID_AUTO_WHITE_BALANCE,
+			.name = "Auto White Balance",
+			.minimum = 0,
+			.maximum = 1,
+			.step = 1,
+			.default_value = 1,
+			.type = V4L2_CTRL_TYPE_BOOLEAN,
+		},
+	}, {
+		.set = ov5640_set_red_balance,
+		.ctrl = {
+			.id = V4L2_CID_RED_BALANCE,
+			.name = "Red Balance",
+			.minimum = 0,
+			.maximum = 4095,
+			.step = 1,
+			.default_value = 0,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+		},
+	}, {
+		.set = ov5640_set_blue_balance,
+		.ctrl = {
+			.id = V4L2_CID_BLUE_BALANCE,
+			.name = "Blue Balance",
+			.minimum = 0,
+			.maximum = 4095,
+			.step = 1,
+			.default_value = 0,
+			.type = V4L2_CTRL_TYPE_INTEGER,
+		},
+	},
+};
+#define OV5640_NUM_CONTROLS ARRAY_SIZE(ov5640_ctrls)

This should use v4l2_ctrl_new_std() instead of this array.
Just put a switch on ctrl->id in s_ctrl, and each case calls the corresponding
set function.

In this case, because there are lots of controls, my preference is to use
table lookup rather than a large switch statement. However I did remove
.name and .type from the table entries, leaving only .def, .min, .max, .step
as required to pass to v4l2_ctrl_new_std(). Also converted to 'struct 
v4l2_ctrl_config'
in the table.

quoted

+
+static int ov5640_restore_ctrls(struct ov5640_dev *sensor)
+{
+	struct ov5640_control *c;
+	int i;
+
+	for (i = 0; i < OV5640_NUM_CONTROLS; i++) {
+		c = &ov5640_ctrls[i];
+		c->set(sensor, sensor->ctrl_cache[i]);
+	}
+
+	return 0;
+}

This does the same as v4l2_ctrl_handler_setup() if I understand the code correctly.

yes thanks. I remember looking at this and thinking 
v4l2_ctrl_handler_setup()
was setting up the default values rather than the current values, but 
after a
re-read it does look to be restoring the current values, which is 
exactly what
is needed here.

quoted

+
+static int ov5640_init_controls(struct ov5640_dev *sensor)
+{
+	struct ov5640_control *c;
+	int i;
+
+	v4l2_ctrl_handler_init(&sensor->ctrl_hdl, OV5640_NUM_CONTROLS);
+
+	for (i = 0; i < OV5640_NUM_CONTROLS; i++) {
+		c = &ov5640_ctrls[i];
+
+		v4l2_ctrl_new_std(&sensor->ctrl_hdl, &ov5640_ctrl_ops,
+				  c->ctrl.id, c->ctrl.minimum, c->ctrl.maximum,
+				  c->ctrl.step, c->ctrl.default_value);
+	}

As mentioned, just drop the ov5640_ctrls array and call v4l2_ctr_new_std for each
control you're adding.

if really pressed I can be persuaded to use a switch statement and call
v4l2_ctrl_new_std() multiple times, but I don't any problem with using
a table.

quoted

+
+module_i2c_driver(ov5640_i2c_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_AUTHOR("Steve Longerbeam [off-list ref]");
+MODULE_DESCRIPTION("OV5640 MIPI Camera Subdev Driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");

Same comments apply to the next patch, so I won't repeat them.

done, I've made the same mods to the ov5642 subdev.

Steve