drm/meson: meson_dw_hdmi: add bridge and switch to drm_bridge_funcs

Switch the dw-hdmi driver to drm_bridge_funcs by implementing a new local
bridge, connecting it to the dw-hdmi bridge, then implement the
atomic_get_input_bus_fmts/atomic_get_output_bus_fmts.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Jernej Škrabec <jernej.skrabec@siol.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200304104052.17196-8-narmstrong@baylibre.com

drivers/gpu/drm/meson/meson_dw_hdmi.c

@@ -16,6 +16,7 @@
 
 #include <drm/bridge/dw_hdmi.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
 #include <drm/drm_device.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_probe_helper.h>
@@ -135,6 +136,7 @@ struct meson_dw_hdmi_data {
 
 struct meson_dw_hdmi {
 	struct drm_encoder encoder;
+	struct drm_bridge bridge;
 	struct dw_hdmi_plat_data dw_plat_data;
 	struct meson_drm *priv;
 	struct device *dev;
@@ -151,6 +153,8 @@ struct meson_dw_hdmi {
 };
 #define encoder_to_meson_dw_hdmi(x) \
 	container_of(x, struct meson_dw_hdmi, encoder)
+#define bridge_to_meson_dw_hdmi(x) \
+	container_of(x, struct meson_dw_hdmi, bridge)
 
 static inline int dw_hdmi_is_compatible(struct meson_dw_hdmi *dw_hdmi,
 					const char *compat)
@@ -368,7 +372,7 @@ static inline void meson_dw_hdmi_phy_reset(struct meson_dw_hdmi *dw_hdmi)
 }
 
 static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
-			     struct drm_display_mode *mode)
+			     const struct drm_display_mode *mode)
 {
 	struct meson_drm *priv = dw_hdmi->priv;
 	int vic = drm_match_cea_mode(mode);
@@ -663,6 +667,10 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 
 /* Encoder */
 
+static const u32 meson_dw_hdmi_out_bus_fmts[] = {
+	MEDIA_BUS_FMT_YUV8_1X24,
+};
+
 static void meson_venc_hdmi_encoder_destroy(struct drm_encoder *encoder)
 {
 	drm_encoder_cleanup(encoder);
@@ -672,16 +680,43 @@ static const struct drm_encoder_funcs meson_venc_hdmi_encoder_funcs = {
 	.destroy        = meson_venc_hdmi_encoder_destroy,
 };
 
-static int meson_venc_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
+static u32 *
+meson_venc_hdmi_encoder_get_inp_bus_fmts(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state,
+					u32 output_fmt,
+					unsigned int *num_input_fmts)
+{
+	u32 *input_fmts = NULL;
+
+	if (output_fmt == meson_dw_hdmi_out_bus_fmts[0]) {
+		*num_input_fmts = 1;
+		input_fmts = kcalloc(*num_input_fmts,
+				     sizeof(*input_fmts),
+				     GFP_KERNEL);
+		if (!input_fmts)
+			return NULL;
+
+		input_fmts[0] = output_fmt;
+	} else {
+		*num_input_fmts = 0;
+	}
+
+	return input_fmts;
+}
+
+static int meson_venc_hdmi_encoder_atomic_check(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
 					struct drm_crtc_state *crtc_state,
 					struct drm_connector_state *conn_state)
 {
 	return 0;
 }
 
-static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
+static void meson_venc_hdmi_encoder_disable(struct drm_bridge *bridge)
 {
-	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
+	struct meson_dw_hdmi *dw_hdmi = bridge_to_meson_dw_hdmi(bridge);
 	struct meson_drm *priv = dw_hdmi->priv;
 
 	DRM_DEBUG_DRIVER("\n");
@@ -693,9 +728,9 @@ static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
 	writel_relaxed(0, priv->io_base + _REG(ENCP_VIDEO_EN));
 }
 
-static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
+static void meson_venc_hdmi_encoder_enable(struct drm_bridge *bridge)
 {
-	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
+	struct meson_dw_hdmi *dw_hdmi = bridge_to_meson_dw_hdmi(bridge);
 	struct meson_drm *priv = dw_hdmi->priv;
 
 	DRM_DEBUG_DRIVER("%s\n", priv->venc.hdmi_use_enci ? "VENCI" : "VENCP");
@@ -706,11 +741,11 @@ static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
 		writel_relaxed(1, priv->io_base + _REG(ENCP_VIDEO_EN));
 }
 
-static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
-				   struct drm_display_mode *mode,
-				   struct drm_display_mode *adjusted_mode)
+static void meson_venc_hdmi_encoder_mode_set(struct drm_bridge *bridge,
+				   const struct drm_display_mode *mode,
+				   const struct drm_display_mode *adjusted_mode)
 {
-	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
+	struct meson_dw_hdmi *dw_hdmi = bridge_to_meson_dw_hdmi(bridge);
 	struct meson_drm *priv = dw_hdmi->priv;
 	int vic = drm_match_cea_mode(mode);
 
@@ -726,11 +761,14 @@ static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
 	writel_relaxed(0, priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
 }
 
-static const struct drm_encoder_helper_funcs
-				meson_venc_hdmi_encoder_helper_funcs = {
+static const struct drm_bridge_funcs meson_venc_hdmi_encoder_bridge_funcs = {
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_get_input_bus_fmts = meson_venc_hdmi_encoder_get_inp_bus_fmts,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
 	.atomic_check = meson_venc_hdmi_encoder_atomic_check,
-	.disable	= meson_venc_hdmi_encoder_disable,
 	.enable	= meson_venc_hdmi_encoder_enable,
+	.disable = meson_venc_hdmi_encoder_disable,
 	.mode_set = meson_venc_hdmi_encoder_mode_set,
 };
 
@@ -852,6 +890,7 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 	struct drm_device *drm = data;
 	struct meson_drm *priv = drm->dev_private;
 	struct dw_hdmi_plat_data *dw_plat_data;
+	struct drm_bridge *next_bridge;
 	struct drm_encoder *encoder;
 	struct resource *res;
 	int irq;
@@ -953,8 +992,6 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 
 	/* Encoder */
 
-	drm_encoder_helper_add(encoder, &meson_venc_hdmi_encoder_helper_funcs);
-
 	ret = drm_encoder_init(drm, encoder, &meson_venc_hdmi_encoder_funcs,
 			       DRM_MODE_ENCODER_TMDS, "meson_hdmi");
 	if (ret) {
@@ -962,6 +999,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 		return ret;
 	}
 
+	meson_dw_hdmi->bridge.funcs = &meson_venc_hdmi_encoder_bridge_funcs;
+	drm_bridge_attach(encoder, &meson_dw_hdmi->bridge, NULL, 0);
+
 	encoder->possible_crtcs = BIT(0);
 
 	DRM_DEBUG_DRIVER("encoder initialized\n");
@@ -984,11 +1024,16 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 
 	platform_set_drvdata(pdev, meson_dw_hdmi);
 
-	meson_dw_hdmi->hdmi = dw_hdmi_bind(pdev, encoder,
+	meson_dw_hdmi->hdmi = dw_hdmi_probe(pdev,
 					    &meson_dw_hdmi->dw_plat_data);
 	if (IS_ERR(meson_dw_hdmi->hdmi))
 		return PTR_ERR(meson_dw_hdmi->hdmi);
 
+	next_bridge = of_drm_find_bridge(pdev->dev.of_node);
+	if (next_bridge)
+		drm_bridge_attach(encoder, next_bridge,
+				  &meson_dw_hdmi->bridge, 0);
+
 	DRM_DEBUG_DRIVER("HDMI controller initialized\n");
 
 	return 0;