drm/stm: Remove usage of drm_display_mode_to_videomode()

There is not much value in the extra conversion step, the calculations
required for the LTDC IP are different than what is used in the
drm_display_mode_to_videomode(), so just do the right ones in the LTDC
driver right away.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Antonio Borneo <antonio.borneo@foss.st.com>
Cc: Benjamin Gaignard <benjamin.gaignard@foss.st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Philippe Cornu <philippe.cornu@foss.st.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Vincent Abriou <vincent.abriou@foss.st.com>
Cc: Yannick Fertre <yannick.fertre@foss.st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: dri-devel@lists.freedesktop.org
Tested-by: Yannick Fertré <yannick.fertre@st.com>
Signed-off-by: Philippe Cornu <philippe.cornu@foss.st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210607172457.14471-1-marex@denx.de

drivers/gpu/drm/stm/ltdc.c

@@ -531,7 +531,6 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	struct drm_encoder *encoder = NULL;
 	struct drm_bridge *bridge = NULL;
 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
-	struct videomode vm;
 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
 	u32 total_width, total_height;
 	u32 bus_flags = 0;
@@ -570,31 +569,33 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 		}
 	}
 
-	drm_display_mode_to_videomode(mode, &vm);
-
 	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
-	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
+	DRM_DEBUG_DRIVER("Video mode: %dx%d", mode->hdisplay, mode->vdisplay);
 	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
-			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
-			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
+			 mode->hsync_start - mode->hdisplay,
+			 mode->htotal - mode->hsync_end,
+			 mode->hsync_end - mode->hsync_start,
+			 mode->vsync_start - mode->vdisplay,
+			 mode->vtotal - mode->vsync_end,
+			 mode->vsync_end - mode->vsync_start);
 
 	/* Convert video timings to ltdc timings */
-	hsync = vm.hsync_len - 1;
-	vsync = vm.vsync_len - 1;
-	accum_hbp = hsync + vm.hback_porch;
-	accum_vbp = vsync + vm.vback_porch;
-	accum_act_w = accum_hbp + vm.hactive;
-	accum_act_h = accum_vbp + vm.vactive;
-	total_width = accum_act_w + vm.hfront_porch;
-	total_height = accum_act_h + vm.vfront_porch;
+	hsync = mode->hsync_end - mode->hsync_start - 1;
+	vsync = mode->vsync_end - mode->vsync_start - 1;
+	accum_hbp = mode->htotal - mode->hsync_start - 1;
+	accum_vbp = mode->vtotal - mode->vsync_start - 1;
+	accum_act_w = accum_hbp + mode->hdisplay;
+	accum_act_h = accum_vbp + mode->vdisplay;
+	total_width = mode->htotal - 1;
+	total_height = mode->vtotal - 1;
 
 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
 	val = 0;
 
-	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
+	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
 		val |= GCR_HSPOL;
 
-	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
+	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
 		val |= GCR_VSPOL;
 
 	if (bus_flags & DRM_BUS_FLAG_DE_LOW)