drm/exynos: implement display-mode-check callback in mixer driver

This patch adds the implementation of check_timing callback in the mixer
driver. Based on the mixer version, correct set of restrictions will be
exposed by the mixer driver. A resolution will be acceptable only if passes
the criteria set by mixer and hdmi IPs.
Signed-off-by: NRahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NInki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_mixer.c

@@ -818,6 +818,29 @@ static void mixer_win_disable(void *ctx, int win)
 	mixer_ctx->win_data[win].enabled = false;
 }
 
+int mixer_check_timing(void *ctx, struct fb_videomode *timing)
+{
+	struct mixer_context *mixer_ctx = ctx;
+	u32 w, h;
+
+	w = timing->xres;
+	h = timing->yres;
+
+	DRM_DEBUG_KMS("%s : xres=%d, yres=%d, refresh=%d, intl=%d\n",
+		__func__, timing->xres, timing->yres,
+		timing->refresh, (timing->vmode &
+		FB_VMODE_INTERLACED) ? true : false);
+
+	if (mixer_ctx->mxr_ver == MXR_VER_0_0_0_16)
+		return 0;
+
+	if ((w >= 464 && w <= 720 && h >= 261 && h <= 576) ||
+		(w >= 1024 && w <= 1280 && h >= 576 && h <= 720) ||
+		(w >= 1664 && w <= 1920 && h >= 936 && h <= 1080))
+		return 0;
+
+	return -EINVAL;
+}
 static void mixer_wait_for_vblank(void *ctx)
 {
 	struct mixer_context *mixer_ctx = ctx;
@@ -955,6 +978,9 @@ static struct exynos_mixer_ops mixer_ops = {
 	.win_mode_set		= mixer_win_mode_set,
 	.win_commit		= mixer_win_commit,
 	.win_disable		= mixer_win_disable,
+
+	/* display */
+	.check_timing		= mixer_check_timing,
 };
 
 static irqreturn_t mixer_irq_handler(int irq, void *arg)