[RFC 2/5] drm: add helper functions to add bridge audio capabilities
Arnaud Pouliquen
arnaud.pouliquen at st.com
Mon Sep 21 06:19:53 PDT 2015
Extend bridge capabilities for audio to enable to connect an audio driver to a
DRM driver with audio capabilities
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
---
drivers/gpu/drm/drm_bridge.c | 114 +++++++++++++++++++++++++++++++++++++++++++
include/drm/drm_crtc.h | 31 ++++++++++++
include/linux/hdmi.h | 16 ++++++
3 files changed, 161 insertions(+)
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 6b8f721..2284ac9 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -328,6 +328,120 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np)
EXPORT_SYMBOL(of_drm_find_bridge);
#endif
+/**
+ * DOC: audio bridge callbacks
+ *
+ * The drm_audio_bridge_funcs ops are populated by the bridge driver that have
+ * audio capabilities (a.e HDMI)
+ * The drm internals(atomic and crtc helpers) use the helpers defined in
+ * drm_bridge.c
+ * These helpers call a specific drm_audio_bridge_funcs ops for all the bridges
+ * during encoder configuration.
+ *
+ * When creating a bridge driver, one can implement drm_audio_bridge_funcs op
+ * with the help of these rough rules:
+ *
+ * pre_enable: this contains things needed to be done for the bridge before
+ * audio is enabled by its source.
+ *
+ * enable: this contains things needed to be done for the audio bridge once its
+ * source is enabled. In other words, enable is called once the source is
+ * ready to start stream rendering.
+ *
+ * disable: this contains things needed to be done for audio bridge when to
+ * disable the audio part for the bridge, assuming that its source is still
+ * enabled.
+ *
+ * post_disable: this contains things needed to be done for the bridge once
+ * its source is disabled.
+ *
+ * mode_set: this sets up the mode for the audio bridge. It assumes that its
+ * source (an encoder or a bridge) has set the mode too.
+ */
+
+/**
+ * drm_audio_bridge_pre_enable - calls 'pre_enable' drm_audio_bridge_funcs ops
+ * for audio bridges in the encoder chain.
+ * @bridge: bridge control structure
+ *
+ * Calls 'pre_enable' drm_audio_bridge_funcs op for audio bridge in the
+ * encoder chain.
+ *
+ */
+
+void drm_audio_bridge_pre_enable(struct drm_bridge *bridge)
+{
+ if (!bridge)
+ return;
+
+ if (bridge->audio_funcs->pre_enable)
+ bridge->audio_funcs->pre_enable(bridge);
+}
+EXPORT_SYMBOL(drm_audio_bridge_pre_enable);
+
+/**
+ * drm_audio_bridge_disable - calls 'disable' drm_audio_bridge_funcs op for
+ * audio bridge in the encoder chain.
+ * @bridge: bridge control structure
+ *
+ * Calls 'disable' drm_audio_bridge_funcs op for bridges with audio in the
+ * encoder chain.
+ *
+ */
+void drm_audio_bridge_disable(struct drm_bridge *bridge)
+{
+ if (!bridge)
+ return;
+
+ if (bridge->audio_funcs->disable)
+ bridge->audio_funcs->disable(bridge);
+}
+EXPORT_SYMBOL(drm_audio_bridge_disable);
+
+/**
+ * drm_audio_bridge_mode_set - set audio mode for audio bridge in the
+ * encoder chain
+ * @bridge: bridge control structure
+ * @mode: desired audio mode to be set for the audio bridge
+ *
+ * Calls 'mode_set' drm_audio_bridge_funcs op for audio bridge in the
+ * encoder chain.
+ *
+ */
+void drm_audio_bridge_mode_set(struct drm_bridge *bridge,
+ struct hdmi_audio_mode *mode)
+{
+ if (!bridge)
+ return;
+
+ if (bridge->audio_funcs->mode_set)
+ bridge->audio_funcs->mode_set(bridge, mode);
+}
+EXPORT_SYMBOL(drm_audio_bridge_mode_set);
+
+/**
+ * drm_audio_bridge_enable - calls 'enable' drm_audio_bridge_funcs op for all bridges
+ * in the encoder chain.
+ * @bridge: bridge control structure
+ *
+ * Calls 'enable' drm_audio_bridge_funcs op for all the bridges in the encoder
+ * chain, starting from the first bridge to the last. These are called
+ * after completing the encoder's commit op.
+ *
+ * Note that the bridge passed should be the one closest to the encoder
+ */
+void drm_audio_bridge_enable(struct drm_bridge *bridge)
+{
+ if (!bridge)
+ return;
+
+ if (bridge->audio_funcs->mode_set)
+ bridge->audio_funcs->enable(bridge);
+
+}
+EXPORT_SYMBOL(drm_audio_bridge_enable);
+
+
MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs at samsung.com>");
MODULE_DESCRIPTION("DRM bridge infrastructure");
MODULE_LICENSE("GPL and additional rights");
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 3b4d8a4..5074019 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -583,6 +583,7 @@ struct drm_encoder_funcs {
* @possible_clones: bitmask of potential sibling encoders for cloning
* @crtc: currently bound CRTC
* @bridge: bridge associated to the encoder
+ * @abridge: optional audio bridge associated to the encoder (HDMI)
* @funcs: control functions
* @helper_private: mid-layer private data
*
@@ -601,6 +602,7 @@ struct drm_encoder {
struct drm_crtc *crtc;
struct drm_bridge *bridge;
+ struct drm_bridge *abridge;
const struct drm_encoder_funcs *funcs;
const void *helper_private;
};
@@ -905,6 +907,24 @@ struct drm_bridge_funcs {
};
/**
+ * struct drm_audio_bridge_funcs - audio drm_bridge control functions
+ * @attach: Called during drm_audio_bridge_attach
+ * @mode_fixup: Try to fixup (or reject entirely) proposed mode for this bridge
+ * @disable: Called right before encoder prepare, disables the bridge
+ * @post_disable: Called right after encoder prepare, for lockstepped disable
+ * @mode_set: Set this mode to the bridge
+ * @pre_enable: Called right before encoder commit, for lockstepped commit
+ * @enable: Called right after encoder commit, enables the bridge
+ */
+struct drm_audio_bridge_funcs {
+ void (*disable)(struct drm_bridge *bridge);
+ void (*pre_enable)(struct drm_bridge *bridge);
+ void (*enable)(struct drm_bridge *bridge);
+ int (*mode_set)(struct drm_bridge *bridge,
+ struct hdmi_audio_mode *mode);
+};
+
+/**
* struct drm_bridge - central DRM bridge control structure
* @dev: DRM device this bridge belongs to
* @encoder: encoder to which this bridge is connected
@@ -925,7 +945,9 @@ struct drm_bridge {
struct list_head list;
const struct drm_bridge_funcs *funcs;
+ const struct drm_audio_bridge_funcs *audio_funcs;
void *driver_private;
+ void *snd_private;
};
/**
@@ -1271,6 +1293,15 @@ extern int drm_encoder_init(struct drm_device *dev,
const struct drm_encoder_funcs *funcs,
int encoder_type);
+int drm_audio_bridge_attach(struct drm_device *dev,
+ struct drm_bridge *bridge);
+void drm_audio_bridge_disable(struct drm_bridge *bridge);
+void drm_audio_bridge_mode_set(struct drm_bridge *bridge,
+ struct hdmi_audio_mode *mode);
+void drm_audio_bridge_pre_enable(struct drm_bridge *bridge);
+void drm_audio_bridge_enable(struct drm_bridge *bridge);
+
+
/**
* drm_encoder_crtc_ok - can a given crtc drive a given encoder?
* @encoder: encoder to test
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index 32107a0..d3d1a80 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -333,11 +333,27 @@ int hdmi_infoframe_unpack(union hdmi_infoframe *frame, void *buffer);
void hdmi_infoframe_log(const char *level, struct device *dev,
union hdmi_infoframe *frame);
+/**
+ * struct hdmi_audio_n_cts - n and cts parameter for ACR packets
+ */
struct hdmi_audio_n_cts {
unsigned int n;
unsigned int cts;
};
+/**
+ * struct hdmi_audio_mode - hdmi audio structure for audio configuration
+ * @enabled audio state
+ * @infoframe: audio infoframe info frame
+ * @data: private data use by alsa driver to retrieve context
+ *
+ * This is used by audio driver to configure the HDMI audio part
+ */
+struct hdmi_audio_mode {
+ bool enabled;
+ struct hdmi_audio_infoframe infoframe;
+};
+
int hdmi_audio_compute_n_cts(unsigned int audio_fs, unsigned long pixel_clk,
struct hdmi_audio_n_cts *n_cts);
--
1.9.1
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