drm/vc4: dpi: Add support for composite syncs to vc4_dpi

The hardware can combine H&V syncs onto the output enable line
as composite syncs, so add the relevant configuration to do that.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-9-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

diff --git a/drivers/gpu/drm/vc4/vc4_dpi.c b/drivers/gpu/drm/vc4/vc4_dpi.c
index c180eb6..ffa5595 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_dpi.c
+++ b/drivers/gpu/drm/vc4/vc4_dpi.c
@@ -131,7 +131,7 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
        struct vc4_dpi *dpi = vc4_encoder->dpi;
        struct drm_connector_list_iter conn_iter;
        struct drm_connector *connector = NULL, *connector_scan;
-       u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
+       u32 dpi_c = DPI_ENABLE;
        int ret;
 
        /* Look up the connector attached to DPI so we can get the
@@ -182,15 +182,22 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
                dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
        }
 
-       if (mode->flags & DRM_MODE_FLAG_NHSYNC)
-               dpi_c |= DPI_HSYNC_INVERT;
-       else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
-               dpi_c |= DPI_HSYNC_DISABLE;
+       if (mode->flags & DRM_MODE_FLAG_CSYNC) {
+               if (mode->flags & DRM_MODE_FLAG_NCSYNC)
+                       dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
+       } else {
+               dpi_c |= DPI_OUTPUT_ENABLE_MODE;
+
+               if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+                       dpi_c |= DPI_HSYNC_INVERT;
+               else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
+                       dpi_c |= DPI_HSYNC_DISABLE;
 
-       if (mode->flags & DRM_MODE_FLAG_NVSYNC)
-               dpi_c |= DPI_VSYNC_INVERT;
-       else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
-               dpi_c |= DPI_VSYNC_DISABLE;
+               if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+                       dpi_c |= DPI_VSYNC_INVERT;
+               else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
+                       dpi_c |= DPI_VSYNC_DISABLE;
+       }
 
        DPI_WRITE(DPI_C, dpi_c);