drivers/video: fsl-diu-fb: add support for set_gamma ioctls

The MPC5121 BSP comes with a gamma_set utility that initializes the gamma
table via an ioctl.  Unfortunately, the ioctl number that utility uses
is defined improperly, but we can still support it.

Signed-off-by: Timur Tabi <timur@freescale.com>
diff --git a/drivers/video/fsl-diu-fb.c b/drivers/video/fsl-diu-fb.c
index 5b12e17..9c40547 100644
--- a/drivers/video/fsl-diu-fb.c
+++ b/drivers/video/fsl-diu-fb.c
@@ -1181,6 +1181,23 @@
 			ad->ckmin_b = ck.blue_min;
 		}
 		break;
+#ifdef CONFIG_PPC_MPC512x
+	case MFB_SET_GAMMA: {
+		struct fsl_diu_data *data = mfbi->parent;
+
+		if (copy_from_user(data->gamma, buf, sizeof(data->gamma)))
+			return -EFAULT;
+		setbits32(&data->diu_reg->gamma, 0); /* Force table reload */
+		break;
+	}
+	case MFB_GET_GAMMA: {
+		struct fsl_diu_data *data = mfbi->parent;
+
+		if (copy_to_user(buf, data->gamma, sizeof(data->gamma)))
+			return -EFAULT;
+		break;
+	}
+#endif
 	default:
 		dev_err(info->dev, "unknown ioctl command (0x%08X)\n", cmd);
 		return -ENOIOCTLCMD;