drm/vc4: txp: Add horizontal and vertical size offset toggle bit

The new writeback controllers that can be found on the BCM2712 require
to have their horizontal and vertical size reduced by one.

Let's tie that behaviour to the compatible so we can support both the
new and old controllers.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 6954e88..7a78593 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -549,6 +549,7 @@ struct vc4_crtc_data {
 struct vc4_txp_data {
        struct vc4_crtc_data    base;
        unsigned int has_byte_enable:1;
+       unsigned int size_minus_one:1;
 };
 
 extern const struct vc4_txp_data bcm2835_txp_data;

diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
index eaf30b2..d2ee872 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_txp.c
+++ b/drivers/gpu/drm/vc4/vc4_txp.c
@@ -291,6 +291,8 @@ static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
        struct drm_gem_dma_object *gem;
        struct drm_display_mode *mode;
        struct drm_framebuffer *fb;
+       unsigned int hdisplay;
+       unsigned int vdisplay;
        u32 ctrl;
        int idx;
        int i;
@@ -330,9 +332,17 @@ static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
        gem = drm_fb_dma_get_gem_obj(fb, 0);
        TXP_WRITE(TXP_DST_PTR, gem->dma_addr + fb->offsets[0]);
        TXP_WRITE(TXP_DST_PITCH, fb->pitches[0]);
+
+       hdisplay = mode->hdisplay ?: 1;
+       vdisplay = mode->vdisplay ?: 1;
+       if (txp_data->size_minus_one) {
+               hdisplay -= 1;
+               vdisplay -= 1;
+       }
+
        TXP_WRITE(TXP_DIM,
-                 VC4_SET_FIELD(mode->hdisplay, TXP_WIDTH) |
-                 VC4_SET_FIELD(mode->vdisplay, TXP_HEIGHT));
+                 VC4_SET_FIELD(hdisplay, TXP_WIDTH) |
+                 VC4_SET_FIELD(vdisplay, TXP_HEIGHT));
 
        TXP_WRITE(TXP_DST_CTRL, ctrl);