Hi, Chen-Yu Tsai > - hsync_pol = !!(bus->flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH); > - vsync_pol = !!(bus->flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH); > + /* > + * This hardware uses [HV]REF instead of [HV]SYNC. Based on the > + * provided timing diagrams in the manual, positive polarity > + * equals active high [HV]REF. > + * > + * When the back porch is 0, [HV]REF is more or less equivalent > + * to [HV]SYNC inverted. > + */ > + href_pol = !!(bus->flags & V4L2_MBUS_HSYNC_ACTIVE_LOW); > + vref_pol = !!(bus->flags & V4L2_MBUS_VSYNC_ACTIVE_LOW); After this change has been made there is a need of explicit explanation of what "Active high" / "Active low" in dts really mean. Currently physical high/low voltage levels are like that: (I'm not sure about vsync-active) * hsync-active = <0>; /* HSYNC active 'low' => wire active is 'high' */ CSI register setting: href_pol: 1, That is confusing: [PATCH v6 5/5] DO NOT MERGE: ARM: dts: bananapi: Add Camera support https://lore.kernel.org/linux-arm-kernel/cf0e40b0bca9219d2bb023a5b7f23bad8baba1e5.1562847292.git-series.maxime.ripard@xxxxxxxxxxx/#r > + port { > + csi_from_ov5640: endpoint { > + remote-endpoint = <&ov5640_to_csi>; > + bus-width = <8>; > + hsync-active = <1>; /* Active high */ original CSI driver > + vsync-active = <0>; /* Active low */ > + data-active = <1>; /* Active high */ > + pclk-sample = <1>; /* Rising */ > + }; > + }; [PATCH 13/14] [DO NOT MERGE] ARM: dts: sun7i: cubieboard2: Enable OV7670 camera on CSI1 https://lore.kernel.org/linux-arm-kernel/20191215165924.28314-14-wens@xxxxxxxxxx/ > + port { > + /* Parallel bus endpoint */ > + csi_from_ov7670: endpoint { > + remote-endpoint = <&ov7670_to_csi>; > + bus-width = <8>; > + /* driver is broken */ > + hsync-active = <0>; /* Active high */ this change patchset > + vsync-active = <1>; /* Active high */ > + data-active = <1>; /* Active high */ > + pclk-sample = <1>; /* Rising */ > + }; > + ov7670_to_csi: endpoint { > + remote-endpoint = <&csi_from_ov7670>; > + bus-width = <8>; > + hsync-active = <1>; /* Active high */ this patcheset > + vsync-active = <1>; /* Active high */ > + data-active = <1>; /* Active high */ > + pclk-sample = <1>; /* Rising */ > + }; > + };