V4L/DVB: gspca - ov534: Fix and document setting manual exposure
Document that even if the state is a u8 value, both MSB and LSB are set
as sd->exposure represents half of the value we are going to set into
registers.
Skip setting exposure when AEC is enabled.
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/gspca/ov534.c b/drivers/media/video/gspca/ov534.c
index 2d89650..4fda098 100644
--- a/drivers/media/video/gspca/ov534.c
+++ b/drivers/media/video/gspca/ov534.c
@@ -686,6 +686,15 @@
struct sd *sd = (struct sd *) gspca_dev;
u8 val;
+ if (sd->aec)
+ return;
+
+ /* 'val' is one byte and represents half of the exposure value we are
+ * going to set into registers, a two bytes value:
+ *
+ * MSB: ((u16) val << 1) >> 8 == val >> 7
+ * LSB: ((u16) val << 1) & 0xff == val << 1
+ */
val = sd->exposure;
sccb_reg_write(gspca_dev, 0x08, val >> 7);
sccb_reg_write(gspca_dev, 0x10, val << 1);