V4L/DVB: gspca - zc3xx: Add back the brightness control

This patch also changes a bit the contrast control.

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 56 insertions, 17 deletions

diff --git a/drivers/media/video/gspca/zc3xx.c b/drivers/media/video/gspca/zc3xx.c
index 73c4ebbcbfb..1420eb2a9d3 100644
--- a/drivers/media/video/gspca/zc3xx.c
+++ b/drivers/media/video/gspca/zc3xx.c
@@ -40,6 +40,7 @@ static int force_sensor = -1;
 struct sd {
         struct gspca_dev gspca_dev;     /* !! must be the first item */
 
+        u8 brightness;
         u8 contrast;
         u8 gamma;
         u8 autogain;
@@ -79,6 +80,8 @@ struct sd {
 };
 
 /* V4L2 controls supported by the driver */
+static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val);
+static int sd_getbrightness(struct gspca_dev *gspca_dev, __s32 *val);
 static int sd_setcontrast(struct gspca_dev *gspca_dev, __s32 val);
 static int sd_getcontrast(struct gspca_dev *gspca_dev, __s32 *val);
 static int sd_setautogain(struct gspca_dev *gspca_dev, __s32 val);
@@ -93,6 +96,20 @@ static int sd_getsharpness(struct gspca_dev *gspca_dev, __s32 *val);
 static const struct ctrl sd_ctrls[] = {
         {
             {
+                .id      = V4L2_CID_BRIGHTNESS,
+                .type    = V4L2_CTRL_TYPE_INTEGER,
+                .name    = "Brightness",
+                .minimum = 0,
+                .maximum = 255,
+                .step    = 1,
+#define BRIGHTNESS_DEF 128
+                .default_value = BRIGHTNESS_DEF,
+            },
+            .set = sd_setbrightness,
+            .get = sd_getbrightness,
+        },
+        {
+            {
                 .id      = V4L2_CID_CONTRAST,
                 .type    = V4L2_CTRL_TYPE_INTEGER,
                 .name    = "Contrast",
@@ -132,7 +149,7 @@ static const struct ctrl sd_ctrls[] = {
             .set = sd_setautogain,
             .get = sd_getautogain,
         },
-#define LIGHTFREQ_IDX 3
+#define LIGHTFREQ_IDX 4
         {
             {
                 .id      = V4L2_CID_POWER_LINE_FREQUENCY,
@@ -6011,9 +6028,12 @@ static void setcontrast(struct gspca_dev *gspca_dev)
         struct sd *sd = (struct sd *) gspca_dev;
         struct usb_device *dev = gspca_dev->dev;
         const u8 *Tgamma;
-        int g, i, k, adj, gp;
+        int g, i, brightness, contrast, adj, gp1, gp2;
         u8 gr[16];
-        static const u8 delta_tb[16] =          /* delta for contrast */
+        static const u8 delta_b[16] =           /* delta for brightness */
+                {0x50, 0x38, 0x2d, 0x28, 0x24, 0x21, 0x1e, 0x1d,
+                 0x1d, 0x1b, 0x1b, 0x1b, 0x19, 0x18, 0x18, 0x18};
+        static const u8 delta_c[16] =           /* delta for contrast */
                 {0x2c, 0x1a, 0x12, 0x0c, 0x0a, 0x06, 0x06, 0x06,
                  0x04, 0x06, 0x04, 0x04, 0x03, 0x03, 0x02, 0x02};
         static const u8 gamma_tb[6][16] = {
@@ -6033,30 +6053,30 @@ static void setcontrast(struct gspca_dev *gspca_dev)
 
         Tgamma = gamma_tb[sd->gamma - 1];
 
-        k = ((int) sd->contrast - 128);         /* -128 / 128 */
+        contrast = ((int) sd->contrast - 128);          /* -128 / 127 */
+        brightness = ((int) sd->brightness - 128);      /* -128 / 92 */
         adj = 0;
-        gp = 0;
+        gp1 = gp2 = 0;
         for (i = 0; i < 16; i++) {
-                g = Tgamma[i] - delta_tb[i] * k / 256 - adj / 2;
+                g = Tgamma[i] + delta_b[i] * brightness / 256
+                                - delta_c[i] * contrast / 256 - adj / 2;
                 if (g > 0xff)
                         g = 0xff;
                 else if (g < 0)
                         g = 0;
                 reg_w(dev, g, 0x0120 + i);      /* gamma */
-                if (k > 0)
+                if (contrast > 0)
                         adj--;
-                else
+                else if (contrast < 0)
                         adj++;
-
-                if (i != 0) {
-                        if (gp == 0)
-                                gr[i - 1] = 0;
-                        else
-                                gr[i - 1] = g - gp;
-                }
-                gp = g;
+                if (i > 1)
+                        gr[i - 1] = (g - gp2) / 2;
+                else if (i != 0)
+                        gr[0] = gp1 == 0 ? 0 : (g - gp1);
+                gp2 = gp1;
+                gp1 = g;
         }
-        gr[15] = gr[14] / 2;
+        gr[15] = (0xff - gp2) / 2;
         for (i = 0; i < 16; i++)
                 reg_w(dev, gr[i], 0x0130 + i);  /* gradient */
 }
@@ -6744,6 +6764,7 @@ static int sd_config(struct gspca_dev *gspca_dev,
                 cam->nmodes = ARRAY_SIZE(broken_vga_mode);
                 break;
         }
+        sd->brightness = BRIGHTNESS_DEF;
         sd->contrast = CONTRAST_DEF;
         sd->gamma = gamma[sd->sensor];
         sd->autogain = AUTOGAIN_DEF;
@@ -6954,6 +6975,24 @@ static void sd_pkt_scan(struct gspca_dev *gspca_dev,
         gspca_frame_add(gspca_dev, INTER_PACKET, data, len);
 }
 
+static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val)
+{
+        struct sd *sd = (struct sd *) gspca_dev;
+
+        sd->brightness = val;
+        if (gspca_dev->streaming)
+                setcontrast(gspca_dev);
+        return 0;
+}
+
+static int sd_getbrightness(struct gspca_dev *gspca_dev, __s32 *val)
+{
+        struct sd *sd = (struct sd *) gspca_dev;
+
+        *val = sd->brightness;
+        return 0;
+}
+
 static int sd_setcontrast(struct gspca_dev *gspca_dev, __s32 val)
 {
         struct sd *sd = (struct sd *) gspca_dev;