[PATCH v2 2/3] drm/sun4i: use drm_mode_validate_mode() helper function

[Sean Nyekjaer]

Use new helper function for HDMI mode validation

Signed-off-by: Sean Nyekjaer <sean at geanix.com>
---
 drivers/gpu/drm/sun4i/sun4i_rgb.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index dfb6acc42f02efc40f36914e2925510cd8056d0b..4f8100e32769cf31c25f5dd849a18f5b77376090 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -51,14 +51,6 @@ static int sun4i_rgb_get_modes(struct drm_connector *connector)
 	return drm_panel_get_modes(rgb->panel, connector);
 }
 
-/*
- * VESA DMT defines a tolerance of 0.5% on the pixel clock, while the
- * CVT spec reuses that tolerance in its examples, so it looks to be a
- * good default tolerance for the EDID-based modes. Define it to 5 per
- * mille to avoid floating point operations.
- */
-#define SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE	5
-
 static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
 						 const struct drm_display_mode *mode)
 {
@@ -67,8 +59,8 @@ static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
 	u32 hsync = mode->hsync_end - mode->hsync_start;
 	u32 vsync = mode->vsync_end - mode->vsync_start;
 	unsigned long long rate = mode->clock * 1000;
-	unsigned long long lowest, highest;
 	unsigned long long rounded_rate;
+	int ret;
 
 	DRM_DEBUG_DRIVER("Validating modes...\n");
 
@@ -122,15 +114,9 @@ static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
 	tcon->dclk_max_div = 127;
 	rounded_rate = clk_round_rate(tcon->dclk, rate);
 
-	lowest = rate * (1000 - SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
-	do_div(lowest, 1000);
-	if (rounded_rate < lowest)
-		return MODE_CLOCK_LOW;
-
-	highest = rate * (1000 + SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
-	do_div(highest, 1000);
-	if (rounded_rate > highest)
-		return MODE_CLOCK_HIGH;
+	ret = drm_mode_validate_mode(mode, rounded_rate);
+	if (ret)
+		return ret;
 
 out:
 	DRM_DEBUG_DRIVER("Clock rate OK\n");

-- 
2.46.2