[media] davinci/dm644x_ccdc: fix compiler warning

drivers/media/platform/davinci/dm644x_ccdc.c: In function ‘validate_ccdc_param’:
drivers/media/platform/davinci/dm644x_ccdc.c:233:32: warning: comparison between ‘enum ccdc_gama_width’ and ‘enum ccdc_data_size’ [-Wenum-compare]
It took a bit of work, see this thread of an earlier attempt to fix this:
https://patchwork.kernel.org/patch/1923091/
I've chosen not to follow the suggestions in that thread since gamma_width is
really a different property from data_size. What you really want is to know if
gamma_width fits inside data_size and for that you need to translate each
enum into a maximum bit number so you can safely compare the two.
So I put in two static inline translation functions instead, keeping the rest
of the code the same (except for fixing the 'gama' typo).

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/include/media/davinci/dm644x_ccdc.h b/include/media/davinci/dm644x_ccdc.h
index 3e178eb52fb3..852e96c4bb46 100644
--- a/include/media/davinci/dm644x_ccdc.h
+++ b/include/media/davinci/dm644x_ccdc.h
@@ -38,17 +38,23 @@ enum ccdc_sample_line {
         CCDC_SAMPLE_16LINES
 };
 
-/* enum for Alaw gama width */
-enum ccdc_gama_width {
-        CCDC_GAMMA_BITS_15_6,
+/* enum for Alaw gamma width */
+enum ccdc_gamma_width {
+        CCDC_GAMMA_BITS_15_6,   /* use bits 15-6 for gamma */
         CCDC_GAMMA_BITS_14_5,
         CCDC_GAMMA_BITS_13_4,
         CCDC_GAMMA_BITS_12_3,
         CCDC_GAMMA_BITS_11_2,
         CCDC_GAMMA_BITS_10_1,
-        CCDC_GAMMA_BITS_09_0
+        CCDC_GAMMA_BITS_09_0    /* use bits 9-0 for gamma */
 };
 
+/* returns the highest bit used for the gamma */
+static inline u8 ccdc_gamma_width_max_bit(enum ccdc_gamma_width width)
+{
+        return 15 - width;
+}
+
 enum ccdc_data_size {
         CCDC_DATA_16BITS,
         CCDC_DATA_15BITS,
@@ -60,12 +66,18 @@ enum ccdc_data_size {
         CCDC_DATA_8BITS
 };
 
+/* returns the highest bit used for this data size */
+static inline u8 ccdc_data_size_max_bit(enum ccdc_data_size sz)
+{
+        return sz == CCDC_DATA_8BITS ? 7 : 15 - sz;
+}
+
 /* structure for ALaw */
 struct ccdc_a_law {
         /* Enable/disable A-Law */
         unsigned char enable;
-        /* Gama Width Input */
-        enum ccdc_gama_width gama_wd;
+        /* Gamma Width Input */
+        enum ccdc_gamma_width gamma_wd;
 };
 
 /* structure for Black Clamping */