drivers: video: emul_imager: use a "PRIV" video CID

Use a video control ID in the private range rather than using an existing
CID, as the emulated imager does not effectively applies these properties
to the image feed and are just for API test purpose.

Signed-off-by: Josuah Demangeon <me@josuah.net>

drivers/video/video_emul_imager.c

@@ -27,14 +27,15 @@ LOG_MODULE_REGISTER(video_emul_imager, CONFIG_VIDEO_LOG_LEVEL);
 #define EMUL_IMAGER_REG_TIMING1   0x0004
 #define EMUL_IMAGER_REG_TIMING2   0x0005
 #define EMUL_IMAGER_REG_TIMING3   0x0006
-#define EMUL_IMAGER_REG_EXPOSURE  0x0007
-#define EMUL_IMAGER_REG_GAIN      0x0008
-#define EMUL_IMAGER_REG_PATTERN   0x0009
+#define EMUL_IMAGER_REG_CUSTOM    0x0007
 #define EMUL_IMAGER_REG_FORMAT    0x000a
 #define EMUL_IMAGER_PATTERN_OFF   0x00
 #define EMUL_IMAGER_PATTERN_BARS1 0x01
 #define EMUL_IMAGER_PATTERN_BARS2 0x02
 
+/* Custom control that is just an I2C write for example and test purpose */
+#define EMUL_IMAGER_CID_CUSTOM (VIDEO_CID_PRIVATE_BASE + 0x01)
+
 /* Emulated register bank */
 uint8_t emul_imager_fake_regs[10];
 
@@ -198,31 +199,18 @@ static int emul_imager_write_multi(const struct device *const dev,
 static int emul_imager_set_ctrl(const struct device *dev, unsigned int cid, void *value)
 {
 	switch (cid) {
-	case VIDEO_CID_EXPOSURE:
-		return emul_imager_write_reg(dev, EMUL_IMAGER_REG_EXPOSURE, (int)value);
-	case VIDEO_CID_GAIN:
-		return emul_imager_write_reg(dev, EMUL_IMAGER_REG_GAIN, (int)value);
-	case VIDEO_CID_TEST_PATTERN:
-		return emul_imager_write_reg(dev, EMUL_IMAGER_REG_PATTERN, (int)value);
+	case EMUL_IMAGER_CID_CUSTOM:
+		return emul_imager_write_reg(dev, EMUL_IMAGER_REG_CUSTOM, (int)value);
 	default:
 		return -ENOTSUP;
 	}
 }
 
 static int emul_imager_get_ctrl(const struct device *dev, unsigned int cid, void *value)
 {
-	struct emul_imager_data *data = dev->data;
-
 	switch (cid) {
-	case VIDEO_CID_EXPOSURE:
-		return emul_imager_read_int(dev, EMUL_IMAGER_REG_EXPOSURE, value);
-	case VIDEO_CID_GAIN:
-		return emul_imager_read_int(dev, EMUL_IMAGER_REG_GAIN, value);
-	case VIDEO_CID_TEST_PATTERN:
-		return emul_imager_read_int(dev, EMUL_IMAGER_REG_PATTERN, value);
-	case VIDEO_CID_PIXEL_RATE:
-		*(int64_t *)value = (int64_t)data->fmt.width * data->fmt.pitch * data->mode->fps;
-		return 0;
+	case EMUL_IMAGER_CID_CUSTOM:
+		return emul_imager_read_int(dev, EMUL_IMAGER_REG_CUSTOM, value);
 	default:
 		return -ENOTSUP;
 	}

tests/drivers/video/api/src/video_emul.c

@@ -130,13 +130,8 @@ ZTEST(video_common, test_video_ctrl)
 	int value;
 
 	/* Exposure control, expected to be supported by all imagers */
-	zexpect_ok(video_set_ctrl(imager_dev, VIDEO_CID_EXPOSURE, (void *)30));
-	zexpect_ok(video_get_ctrl(imager_dev, VIDEO_CID_EXPOSURE, &value));
-	zexpect_equal(value, 30);
-
-	/* Gain control, expected to be supported by all imagers */
-	zexpect_ok(video_set_ctrl(imager_dev, VIDEO_CID_GAIN, (void *)30));
-	zexpect_ok(video_get_ctrl(imager_dev, VIDEO_CID_GAIN, &value));
+	zexpect_ok(video_set_ctrl(imager_dev, VIDEO_CID_PRIVATE_BASE + 0x01, (void *)30));
+	zexpect_ok(video_get_ctrl(imager_dev, VIDEO_CID_PRIVATE_BASE + 0x01, &value));
 	zexpect_equal(value, 30);
 }