drm/sun4i: hdmi: Consolidate atomic_check and mode_valid

atomic_check and mode_valid do not check for the same things which can
lead to surprising result if the userspace commits a mode that didn't go
through mode_valid. Let's merge the two implementations into a function
called by both.
Acked-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-35-8f4af575fce2@kernel.org

drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c

@@ -62,18 +62,6 @@ static int sun4i_hdmi_setup_avi_infoframes(struct sun4i_hdmi *hdmi,
 	return 0;
 }
 
-static int sun4i_hdmi_atomic_check(struct drm_encoder *encoder,
-				   struct drm_crtc_state *crtc_state,
-				   struct drm_connector_state *conn_state)
-{
-	struct drm_display_mode *mode = &crtc_state->mode;
-
-	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
-		return -EINVAL;
-
-	return 0;
-}
-
 static void sun4i_hdmi_disable(struct drm_encoder *encoder,
 			       struct drm_atomic_state *state)
 {
@@ -166,31 +154,61 @@ static void sun4i_hdmi_enable(struct drm_encoder *encoder,
 	writel(val, hdmi->base + SUN4I_HDMI_VID_CTRL_REG);
 }
 
-static enum drm_mode_status sun4i_hdmi_mode_valid(struct drm_encoder *encoder,
-					const struct drm_display_mode *mode)
+static const struct drm_encoder_helper_funcs sun4i_hdmi_helper_funcs = {
+	.atomic_disable	= sun4i_hdmi_disable,
+	.atomic_enable	= sun4i_hdmi_enable,
+};
+
+static enum drm_mode_status
+sun4i_hdmi_connector_clock_valid(const struct drm_connector *connector,
+				 const struct drm_display_mode *mode,
+				 unsigned long long clock)
 {
-	struct sun4i_hdmi *hdmi = drm_encoder_to_sun4i_hdmi(encoder);
-	unsigned long rate = mode->clock * 1000;
-	unsigned long diff = rate / 200; /* +-0.5% allowed by HDMI spec */
+	const struct sun4i_hdmi *hdmi = drm_connector_to_sun4i_hdmi(connector);
+	unsigned long diff = clock / 200; /* +-0.5% allowed by HDMI spec */
 	long rounded_rate;
 
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		return MODE_BAD;
+
 	/* 165 MHz is the typical max pixelclock frequency for HDMI <= 1.2 */
-	if (rate > 165000000)
+	if (clock > 165000000)
 		return MODE_CLOCK_HIGH;
-	rounded_rate = clk_round_rate(hdmi->tmds_clk, rate);
+
+	rounded_rate = clk_round_rate(hdmi->tmds_clk, clock);
 	if (rounded_rate > 0 &&
-	    max_t(unsigned long, rounded_rate, rate) -
-	    min_t(unsigned long, rounded_rate, rate) < diff)
+	    max_t(unsigned long, rounded_rate, clock) -
+	    min_t(unsigned long, rounded_rate, clock) < diff)
 		return MODE_OK;
+
 	return MODE_NOCLOCK;
 }
 
-static const struct drm_encoder_helper_funcs sun4i_hdmi_helper_funcs = {
-	.atomic_check	= sun4i_hdmi_atomic_check,
-	.atomic_disable	= sun4i_hdmi_disable,
-	.atomic_enable	= sun4i_hdmi_enable,
-	.mode_valid	= sun4i_hdmi_mode_valid,
-};
+static int sun4i_hdmi_connector_atomic_check(struct drm_connector *connector,
+					     struct drm_atomic_state *state)
+{
+	struct drm_connector_state *conn_state =
+		drm_atomic_get_new_connector_state(state, connector);
+	struct drm_crtc *crtc = conn_state->crtc;
+	struct drm_crtc_state *crtc_state = crtc->state;
+	struct drm_display_mode *mode = &crtc_state->adjusted_mode;
+	enum drm_mode_status status;
+
+	status = sun4i_hdmi_connector_clock_valid(connector, mode,
+						  mode->clock * 1000);
+	if (status != MODE_OK)
+		return -EINVAL;
+
+	return 0;
+}
+
+static enum drm_mode_status
+sun4i_hdmi_connector_mode_valid(struct drm_connector *connector,
+				struct drm_display_mode *mode)
+{
+	return sun4i_hdmi_connector_clock_valid(connector, mode,
+						mode->clock * 1000);
+}
 
 static int sun4i_hdmi_get_modes(struct drm_connector *connector)
 {
@@ -236,6 +254,8 @@ static struct i2c_adapter *sun4i_hdmi_get_ddc(struct device *dev)
 }
 
 static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = {
+	.atomic_check	= sun4i_hdmi_connector_atomic_check,
+	.mode_valid	= sun4i_hdmi_connector_mode_valid,
 	.get_modes	= sun4i_hdmi_get_modes,
 };