drm/exynos: add ratio calculation

Calculation ratio from exynos_drm plane codes, then each hw drivers can
use it without extra operation. Also this fixes width and height of
source used for actual crtc shown via screen.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_drv.h

@@ -61,6 +61,8 @@ enum exynos_drm_output_type {
  * @crtc_height: window height to be displayed (hardware screen).
  * @mode_width: width of screen mode.
  * @mode_height: height of screen mode.
+ * @h_ratio: horizontal scaling ratio, 16.16 fixed point
+ * @v_ratio: vertical scaling ratio, 16.16 fixed point
  * @refresh: refresh rate.
  * @scan_flag: interlace or progressive way.
  *	(it could be DRM_MODE_FLAG_*)
@@ -97,6 +99,8 @@ struct exynos_drm_plane {
 	unsigned int crtc_height;
 	unsigned int mode_width;
 	unsigned int mode_height;
+	unsigned int h_ratio;
+	unsigned int v_ratio;
 	unsigned int refresh;
 	unsigned int scan_flag;
 	unsigned int bpp;

drivers/gpu/drm/exynos/exynos_drm_plane.c

@@ -110,11 +110,15 @@ void exynos_plane_mode_set(struct drm_plane *plane, struct drm_crtc *crtc,
 		crtc_y = 0;
 	}
 
+	/* set ratio */
+	exynos_plane->h_ratio = (src_w << 16) / crtc_w;
+	exynos_plane->v_ratio = (src_h << 16) / crtc_h;
+
 	/* set drm framebuffer data. */
 	exynos_plane->src_x = src_x;
 	exynos_plane->src_y = src_y;
-	exynos_plane->src_width = src_w;
-	exynos_plane->src_height = src_h;
+	exynos_plane->src_width = (actual_w * exynos_plane->h_ratio) >> 16;
+	exynos_plane->src_height = (actual_h * exynos_plane->v_ratio) >> 16;
 	exynos_plane->fb_width = fb->width;
 	exynos_plane->fb_height = fb->height;
 	exynos_plane->bpp = fb->bits_per_pixel;

drivers/gpu/drm/exynos/exynos_mixer.c

@@ -382,7 +382,6 @@ static void vp_video_buffer(struct mixer_context *ctx, int win)
 	struct mixer_resources *res = &ctx->mixer_res;
 	unsigned long flags;
 	struct exynos_drm_plane *plane;
-	unsigned int x_ratio, y_ratio;
 	unsigned int buf_num = 1;
 	dma_addr_t luma_addr[2], chroma_addr[2];
 	bool tiled_mode = false;
@@ -407,10 +406,6 @@ static void vp_video_buffer(struct mixer_context *ctx, int win)
 		return;
 	}
 
-	/* scaling feature: (src << 16) / dst */
-	x_ratio = (plane->src_width << 16) / plane->crtc_width;
-	y_ratio = (plane->src_height << 16) / plane->crtc_height;
-
 	if (buf_num == 2) {
 		luma_addr[0] = plane->dma_addr[0];
 		chroma_addr[0] = plane->dma_addr[1];
@@ -470,8 +465,8 @@ static void vp_video_buffer(struct mixer_context *ctx, int win)
 		vp_reg_write(res, VP_DST_V_POSITION, plane->crtc_y);
 	}
 
-	vp_reg_write(res, VP_H_RATIO, x_ratio);
-	vp_reg_write(res, VP_V_RATIO, y_ratio);
+	vp_reg_write(res, VP_H_RATIO, plane->h_ratio);
+	vp_reg_write(res, VP_V_RATIO, plane->v_ratio);
 
 	vp_reg_write(res, VP_ENDIAN_MODE, VP_ENDIAN_MODE_LITTLE);