From c1180b13d216c9c7157b2c97aa8be986feba709c Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 27 Apr 2023 09:47:54 +0200
Subject: [PATCH 0616/1085] 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>
---
 drivers/gpu/drm/vc4/vc4_drv.h |  1 +
 drivers/gpu/drm/vc4/vc4_txp.c | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

--- 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;
--- 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_com
 	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_com
 	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);
 
