[PATCH v3 3/7] drm/connector: implement generic HDMI codec helpers

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Sat Nov 9 04:48:29 PST 2024


Several DRM drivers implement HDMI codec support (despite its name it
applies to both HDMI and DisplayPort drivers). Implement generic
framework to be used by these drivers. This removes a requirement to
implement get_eld() callback and provides default implementation for
codec's plug handling.

The framework is integrated with the DRM HDMI Connector framework, but
can be used by DisplayPort drivers.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/gpu/drm/Makefile                   |   1 +
 drivers/gpu/drm/drm_connector.c            |  10 ++
 drivers/gpu/drm/drm_connector_hdmi_codec.c | 186 +++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_internal.h             |   5 +
 include/drm/drm_connector.h                |  80 +++++++++++++
 5 files changed, 282 insertions(+)

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 463afad1b5ca6275e61223adc8ca036c3d4d6b03..ab5b052ad5229229ac46e3804be77dd1d1680f58 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -42,6 +42,7 @@ drm-y := \
 	drm_cache.o \
 	drm_color_mgmt.o \
 	drm_connector.o \
+	drm_connector_hdmi_codec.o \
 	drm_crtc.o \
 	drm_displayid.o \
 	drm_drv.o \
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index fc35f47e2849ed6786d6223ac9c69e1c359fc648..1a155a9fb401f687e5a88e72faca1e81d944b6d2 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -279,6 +279,7 @@ static int __drm_connector_init(struct drm_device *dev,
 	mutex_init(&connector->mutex);
 	mutex_init(&connector->edid_override_mutex);
 	mutex_init(&connector->hdmi.infoframes.lock);
+	mutex_init(&connector->hdmi_codec.lock);
 	connector->edid_blob_ptr = NULL;
 	connector->epoch_counter = 0;
 	connector->tile_blob_ptr = NULL;
@@ -533,6 +534,12 @@ int drmm_connector_hdmi_init(struct drm_device *dev,
 
 	connector->hdmi.funcs = hdmi_funcs;
 
+	if (connector->hdmi_codec.i2s || connector->hdmi_codec.spdif) {
+		ret = drm_connector_hdmi_codec_init(connector);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(drmm_connector_hdmi_init);
@@ -631,6 +638,8 @@ void drm_connector_cleanup(struct drm_connector *connector)
 		    DRM_CONNECTOR_REGISTERED))
 		drm_connector_unregister(connector);
 
+	drm_connector_hdmi_codec_cleanup(connector);
+
 	if (connector->privacy_screen) {
 		drm_privacy_screen_put(connector->privacy_screen);
 		connector->privacy_screen = NULL;
@@ -669,6 +678,7 @@ void drm_connector_cleanup(struct drm_connector *connector)
 		connector->funcs->atomic_destroy_state(connector,
 						       connector->state);
 
+	mutex_destroy(&connector->hdmi_codec.lock);
 	mutex_destroy(&connector->hdmi.infoframes.lock);
 	mutex_destroy(&connector->mutex);
 
diff --git a/drivers/gpu/drm/drm_connector_hdmi_codec.c b/drivers/gpu/drm/drm_connector_hdmi_codec.c
new file mode 100644
index 0000000000000000000000000000000000000000..e362852c186109644e9033eb8eaf63b864166d5a
--- /dev/null
+++ b/drivers/gpu/drm/drm_connector_hdmi_codec.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (c) 2024 Linaro Ltd
+ */
+
+#include <linux/mutex.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_device.h>
+
+#include <sound/hdmi-codec.h>
+
+#include "drm_internal.h"
+
+static int drm_connector_hdmi_codec_audio_startup(struct device *dev, void *data)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_codec_funcs *funcs =
+		connector->hdmi.funcs->codec_funcs;
+
+	if (funcs->audio_startup)
+		return funcs->audio_startup(connector);
+
+	return 0;
+}
+
+static int drm_connector_hdmi_codec_prepare(struct device *dev, void *data,
+					    struct hdmi_codec_daifmt *fmt,
+					    struct hdmi_codec_params *hparms)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_codec_funcs *funcs =
+		connector->hdmi.funcs->codec_funcs;
+
+	return funcs->prepare(connector, fmt, hparms);
+}
+
+static void drm_connector_hdmi_codec_audio_shutdown(struct device *dev, void *data)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_codec_funcs *funcs =
+		connector->hdmi.funcs->codec_funcs;
+
+	return funcs->audio_shutdown(connector);
+}
+
+static int drm_connector_hdmi_codec_mute_stream(struct device *dev, void *data,
+						bool enable, int direction)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_codec_funcs *funcs =
+		connector->hdmi.funcs->codec_funcs;
+
+	if (funcs->mute_stream)
+		return funcs->mute_stream(connector, enable, direction);
+
+	return -ENOTSUPP;
+}
+
+static int drm_connector_hdmi_codec_get_dai_id(struct snd_soc_component *comment,
+		  struct device_node *endpoint,
+		  void *data)
+{
+	struct drm_connector *connector = data;
+	struct of_endpoint of_ep;
+	int ret;
+
+	if (connector->hdmi_codec.sound_dai_port < 0)
+		return -ENOTSUPP;
+
+	ret = of_graph_parse_endpoint(endpoint, &of_ep);
+	if (ret < 0)
+		return ret;
+
+	if (of_ep.port == connector->hdmi_codec.sound_dai_port)
+		return 0;
+
+	return -EINVAL;
+}
+
+static int drm_connector_hdmi_codec_get_eld(struct device *dev, void *data,
+					    uint8_t *buf, size_t len)
+{
+	struct drm_connector *connector = data;
+
+	//  FIXME: locking against drm_edid_to_eld ?
+	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
+
+	return 0;
+}
+
+static int drm_connector_hdmi_codec_hook_plugged_cb(struct device *dev,
+						    void *data,
+						    hdmi_codec_plugged_cb fn,
+						    struct device *codec_dev)
+{
+	struct drm_connector *connector = data;
+
+	mutex_lock(&connector->hdmi_codec.lock);
+
+	connector->hdmi_codec.plugged_cb = fn;
+	connector->hdmi_codec.plugged_cb_dev = codec_dev;
+
+	fn(codec_dev, connector->hdmi_codec.last_state);
+
+	mutex_unlock(&connector->hdmi_codec.lock);
+
+	return 0;
+}
+
+void drm_connector_hdmi_codec_plugged_notify(struct drm_connector *connector,
+					     bool plugged)
+{
+	mutex_lock(&connector->hdmi_codec.lock);
+
+	connector->hdmi_codec.last_state = plugged;
+
+	if (connector->hdmi_codec.plugged_cb &&
+	    connector->hdmi_codec.plugged_cb_dev)
+		connector->hdmi_codec.plugged_cb(connector->hdmi_codec.plugged_cb_dev,
+						 connector->hdmi_codec.last_state);
+
+	mutex_unlock(&connector->hdmi_codec.lock);
+}
+EXPORT_SYMBOL(drm_connector_hdmi_codec_plugged_notify);
+
+static const struct hdmi_codec_ops drm_connector_hdmi_codec_ops = {
+	.audio_startup = drm_connector_hdmi_codec_audio_startup,
+	.prepare = drm_connector_hdmi_codec_prepare,
+	.audio_shutdown = drm_connector_hdmi_codec_audio_shutdown,
+	.mute_stream = drm_connector_hdmi_codec_mute_stream,
+	.get_eld = drm_connector_hdmi_codec_get_eld,
+	.get_dai_id = drm_connector_hdmi_codec_get_dai_id,
+	.hook_plugged_cb = drm_connector_hdmi_codec_hook_plugged_cb,
+};
+
+/**
+ * drm_connector_hdmi_codec_cleanup - Cleanup the HDMI Codec for the connector
+ * @connector: A pointer to the connector to cleanup
+ *
+ * Cleanup the HDMI codec device created for the specified connector.
+ * Can be called even if the codec wasn't allocated.
+ */
+void drm_connector_hdmi_codec_cleanup(struct drm_connector *connector)
+{
+	platform_device_unregister(connector->hdmi_codec.codec_pdev);
+}
+
+/**
+ * drm_connector_hdmi_codec_init - Initialize HDMI Codec device for the DRM connector
+ * @connector: A pointer to the connector to allocate codec for
+ *
+ * Create a HDMI codec device to be used with the specified connector.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int drm_connector_hdmi_codec_init(struct drm_connector *connector)
+{
+	struct hdmi_codec_pdata codec_pdata = {};
+	struct platform_device *pdev;
+
+	if (!connector->hdmi.funcs->codec_funcs->prepare ||
+	    !connector->hdmi.funcs->codec_funcs->audio_shutdown ||
+	    !connector->hdmi_codec.dev)
+		return -EINVAL;
+
+	codec_pdata.ops = &drm_connector_hdmi_codec_ops;
+	codec_pdata.i2s = connector->hdmi_codec.i2s,
+	codec_pdata.spdif = connector->hdmi_codec.spdif,
+	codec_pdata.max_i2s_channels = connector->hdmi_codec.max_i2s_channels,
+	codec_pdata.data = connector;
+
+	pdev = platform_device_register_data(connector->hdmi_codec.dev,
+					     HDMI_CODEC_DRV_NAME,
+					     PLATFORM_DEVID_AUTO,
+					     &codec_pdata, sizeof(codec_pdata));
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
+
+	connector->hdmi_codec.codec_pdev = pdev;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index b2b6a8e49dda46f1cb3b048ef7b28356dd3aaa4e..8ed58e482fac4662b659276e8bc17690e1fdb9b7 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -280,4 +280,9 @@ void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
 				const struct drm_framebuffer *fb);
 void drm_framebuffer_debugfs_init(struct drm_device *dev);
 
+/* drm_connector_hdmi_codec.c */
+
+int drm_connector_hdmi_codec_init(struct drm_connector *connector);
+void drm_connector_hdmi_codec_cleanup(struct drm_connector *connector);
+
 #endif /* __DRM_INTERNAL_H__ */
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index e3fa43291f449d70f3b92a00985336c4f2237bc6..b89f791cfa2be86ce1c5aa124c0f071d7c8a6489 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -46,6 +46,8 @@ struct drm_property_blob;
 struct drm_printer;
 struct drm_privacy_screen;
 struct edid;
+struct hdmi_codec_daifmt;
+struct hdmi_codec_params;
 struct i2c_adapter;
 
 enum drm_connector_force {
@@ -1141,6 +1143,52 @@ struct drm_connector_state {
 	struct drm_connector_hdmi_state hdmi;
 };
 
+struct drm_connector_hdmi_codec_funcs {
+	/**
+	 * @audio_startup:
+	 *
+	 * Called when ASoC starts an audio stream setup. The
+	 * @hdmi_audio_startup is optional.
+	 *
+	 * Returns:
+	 * 0 on success, a negative error code otherwise
+	 */
+	int (*audio_startup)(struct drm_connector *connector);
+
+	/**
+	 * @prepare:
+	 * Configures HDMI-encoder for audio stream. Can be called
+	 * multiple times for each setup. Mandatory.
+	 *
+	 * Returns:
+	 * 0 on success, a negative error code otherwise
+	 */
+	int (*prepare)(struct drm_connector *connector,
+		       struct hdmi_codec_daifmt *fmt,
+		       struct hdmi_codec_params *hparms);
+	/**
+	 * @audio_shutdown:
+	 *
+	 * Shut down the audio stream. Mandatory.
+	 *
+	 * Returns:
+	 * 0 on success, a negative error code otherwise
+	 */
+	void (*audio_shutdown)(struct drm_connector *connector);
+
+	/**
+	 * @mute_stream:
+	 *
+	 * Mute/unmute HDMI audio stream. The @mute_stream callback is
+	 * optional.
+	 *
+	 * Returns:
+	 * 0 on success, a negative error code otherwise
+	 */
+	int (*mute_stream)(struct drm_connector *connector,
+			   bool enable, int direction);
+};
+
 /**
  * struct drm_connector_hdmi_funcs - drm_hdmi_connector control functions
  */
@@ -1198,6 +1246,14 @@ struct drm_connector_hdmi_funcs {
 	int (*write_infoframe)(struct drm_connector *connector,
 			       enum hdmi_infoframe_type type,
 			       const u8 *buffer, size_t len);
+
+	/**
+	 * @codec_funcs:
+	 *
+	 * Implementation of the HDMI codec functionality to be used by the DRM
+	 * HDMI Codec framework.
+	 */
+	const struct drm_connector_hdmi_codec_funcs *codec_funcs;
 };
 
 /**
@@ -1660,6 +1716,22 @@ struct drm_cmdline_mode {
 	bool tv_mode_specified;
 };
 
+struct drm_connector_hdmi_codec {
+	struct platform_device *codec_pdev;
+	struct device *dev;
+
+	struct mutex lock; /* protects last_state and plugged_cb */
+	void (*plugged_cb)(struct device *dev, bool plugged);
+	struct device *plugged_cb_dev;
+	bool last_state;
+
+	int max_i2s_channels;
+	uint i2s: 1;
+	uint spdif: 1;
+
+	int sound_dai_port;
+};
+
 /*
  * struct drm_connector_hdmi - DRM Connector HDMI-related structure
  */
@@ -2118,6 +2190,11 @@ struct drm_connector {
 	 * @hdmi: HDMI-related variable and properties.
 	 */
 	struct drm_connector_hdmi hdmi;
+
+	/**
+	 * @hdmi_codec: HDMI codec properties and non-DRM state.
+	 */
+	struct drm_connector_hdmi_codec hdmi_codec;
 };
 
 #define obj_to_connector(x) container_of(x, struct drm_connector, base)
@@ -2151,6 +2228,9 @@ void drm_connector_unregister(struct drm_connector *connector);
 int drm_connector_attach_encoder(struct drm_connector *connector,
 				      struct drm_encoder *encoder);
 
+void drm_connector_hdmi_codec_plugged_notify(struct drm_connector *connector,
+					     bool plugged);
+
 void drm_connector_cleanup(struct drm_connector *connector);
 
 static inline unsigned int drm_connector_index(const struct drm_connector *connector)

-- 
2.39.5




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