[media] em28xx: introduce #defines for the image quality default settings

The image quality default values will be used in at least two different places
and by using #defines we make sure that they are always consistent.
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/em28xx/em28xx-core.c

@@ -607,12 +607,12 @@ EXPORT_SYMBOL_GPL(em28xx_audio_setup);
 
 int em28xx_colorlevels_set_default(struct em28xx *dev)
 {
-	em28xx_write_reg(dev, EM28XX_R20_YGAIN, 0x10);	/* contrast */
-	em28xx_write_reg(dev, EM28XX_R21_YOFFSET, 0x00);	/* brightness */
-	em28xx_write_reg(dev, EM28XX_R22_UVGAIN, 0x10);	/* saturation */
-	em28xx_write_reg(dev, EM28XX_R23_UOFFSET, 0x00);
-	em28xx_write_reg(dev, EM28XX_R24_VOFFSET, 0x00);
-	em28xx_write_reg(dev, EM28XX_R25_SHARPNESS, 0x00);
+	em28xx_write_reg(dev, EM28XX_R20_YGAIN, CONTRAST_DEFAULT);
+	em28xx_write_reg(dev, EM28XX_R21_YOFFSET, BRIGHTNESS_DEFAULT);
+	em28xx_write_reg(dev, EM28XX_R22_UVGAIN, SATURATION_DEFAULT);
+	em28xx_write_reg(dev, EM28XX_R23_UOFFSET, BLUE_BALANCE_DEFAULT);
+	em28xx_write_reg(dev, EM28XX_R24_VOFFSET, RED_BALANCE_DEFAULT);
+	em28xx_write_reg(dev, EM28XX_R25_SHARPNESS, SHARPNESS_DEFAULT);
 
 	em28xx_write_reg(dev, EM28XX_R14_GAMMA, 0x20);
 	em28xx_write_reg(dev, EM28XX_R15_RGAIN, 0x20);

drivers/media/usb/em28xx/em28xx-reg.h

@@ -120,12 +120,23 @@
 #define EM28XX_R1E_CWIDTH	0x1e
 #define EM28XX_R1F_CHEIGHT	0x1f
 
-#define EM28XX_R20_YGAIN	0x20
-#define EM28XX_R21_YOFFSET	0x21
-#define EM28XX_R22_UVGAIN	0x22
-#define EM28XX_R23_UOFFSET	0x23
-#define EM28XX_R24_VOFFSET	0x24
-#define EM28XX_R25_SHARPNESS	0x25
+#define EM28XX_R20_YGAIN	0x20 /* contrast [0:4]   */
+#define   CONTRAST_DEFAULT	0x10
+
+#define EM28XX_R21_YOFFSET	0x21 /* brightness       */	/* signed */
+#define   BRIGHTNESS_DEFAULT	0x00
+
+#define EM28XX_R22_UVGAIN	0x22 /* saturation [0:4] */
+#define   SATURATION_DEFAULT	0x10
+
+#define EM28XX_R23_UOFFSET	0x23 /* blue balance     */	/* signed */
+#define   BLUE_BALANCE_DEFAULT	0x00
+
+#define EM28XX_R24_VOFFSET	0x24 /* red balance      */	/* signed */
+#define   RED_BALANCE_DEFAULT	0x00
+
+#define EM28XX_R25_SHARPNESS	0x25 /* sharpness [0:4]  */
+#define   SHARPNESS_DEFAULT	0x00
 
 #define EM28XX_R26_COMPR	0x26
 #define EM28XX_R27_OUTFMT	0x27