ALSA: hda: Make audio component support more generic

This is the final step for more generic support of DRM audio
component.  The generic audio component code is now moved to its own
file, and the symbols are renamed from snd_hac_i915_* to
snd_hdac_acomp_*, respectively.  The generic code is enabled via the
new kconfig, CONFIG_SND_HDA_COMPONENT, while CONFIG_SND_HDA_I915 is
kept as the super-class.

Along with the split, three new callbacks are added to audio_ops:
pin2port is for providing the conversion between the pin number and
the widget id, and master_bind/master_unbin are called at binding /
unbinding the master component, respectively.  All these are optional,
but used in i915 implementation and also other later implementations.

A note about the new snd_hdac_acomp_init() function: there is a slight
difference between this and the old snd_hdac_i915_init().  The latter
(still) synchronizes with the master component binding, i.e. it
assures that the relevant DRM component gets bound when it returns, or
gives a negative error.  Meanwhile the new function doesn't
synchronize but just leaves as is.  It's the responsibility by the
caller's side to synchronize, or the caller may accept the
asynchronous binding on the fly.

v1->v2: Fix missing NULL check in master_bind/unbind

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 335 insertions, 0 deletions

diff --git a/sound/hda/hdac_component.c b/sound/hda/hdac_component.c
new file mode 100644
index 000000000000..6e46a9c73aed
--- /dev/null
+++ b/sound/hda/hdac_component.c
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0
+// hdac_component.c - routines for sync between HD-A core and DRM driver
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/component.h>
+#include <sound/core.h>
+#include <sound/hdaudio.h>
+#include <sound/hda_component.h>
+#include <sound/hda_register.h>
+
+static void hdac_acomp_release(struct device *dev, void *res)
+{
+}
+
+static struct drm_audio_component *hdac_get_acomp(struct device *dev)
+{
+	return devres_find(dev, hdac_acomp_release, NULL, NULL);
+}
+
+/**
+ * snd_hdac_set_codec_wakeup - Enable / disable HDMI/DP codec wakeup
+ * @bus: HDA core bus
+ * @enable: enable or disable the wakeup
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with graphics driver.
+ *
+ * This function should be called during the chip reset, also called at
+ * resume for updating STATESTS register read.
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable)
+{
+	struct drm_audio_component *acomp = bus->audio_component;
+
+	if (!acomp || !acomp->ops)
+		return -ENODEV;
+
+	if (!acomp->ops->codec_wake_override)
+		return 0;
+
+	dev_dbg(bus->dev, "%s codec wakeup\n",
+		enable ? "enable" : "disable");
+
+	acomp->ops->codec_wake_override(acomp->dev, enable);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_set_codec_wakeup);
+
+/**
+ * snd_hdac_display_power - Power up / down the power refcount
+ * @bus: HDA core bus
+ * @enable: power up or down
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with graphics driver.
+ *
+ * This function manages a refcount and calls the get_power() and
+ * put_power() ops accordingly, toggling the codec wakeup, too.
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_display_power(struct hdac_bus *bus, bool enable)
+{
+	struct drm_audio_component *acomp = bus->audio_component;
+
+	if (!acomp || !acomp->ops)
+		return -ENODEV;
+
+	dev_dbg(bus->dev, "display power %s\n",
+		enable ? "enable" : "disable");
+
+	if (enable) {
+		if (!bus->drm_power_refcount++) {
+			if (acomp->ops->get_power)
+				acomp->ops->get_power(acomp->dev);
+			snd_hdac_set_codec_wakeup(bus, true);
+			snd_hdac_set_codec_wakeup(bus, false);
+		}
+	} else {
+		WARN_ON(!bus->drm_power_refcount);
+		if (!--bus->drm_power_refcount)
+			if (acomp->ops->put_power)
+				acomp->ops->put_power(acomp->dev);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_display_power);
+
+/**
+ * snd_hdac_sync_audio_rate - Set N/CTS based on the sample rate
+ * @codec: HDA codec
+ * @nid: the pin widget NID
+ * @dev_id: device identifier
+ * @rate: the sample rate to set
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with graphics driver.
+ *
+ * This function sets N/CTS value based on the given sample rate.
+ * Returns zero for success, or a negative error code.
+ */
+int snd_hdac_sync_audio_rate(struct hdac_device *codec, hda_nid_t nid,
+			     int dev_id, int rate)
+{
+	struct hdac_bus *bus = codec->bus;
+	struct drm_audio_component *acomp = bus->audio_component;
+	int port, pipe;
+
+	if (!acomp || !acomp->ops || !acomp->ops->sync_audio_rate)
+		return -ENODEV;
+	port = nid;
+	if (acomp->audio_ops && acomp->audio_ops->pin2port) {
+		port = acomp->audio_ops->pin2port(codec, nid);
+		if (port < 0)
+			return -EINVAL;
+	}
+	pipe = dev_id;
+	return acomp->ops->sync_audio_rate(acomp->dev, port, pipe, rate);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_sync_audio_rate);
+
+/**
+ * snd_hdac_acomp_get_eld - Get the audio state and ELD via component
+ * @codec: HDA codec
+ * @nid: the pin widget NID
+ * @dev_id: device identifier
+ * @audio_enabled: the pointer to store the current audio state
+ * @buffer: the buffer pointer to store ELD bytes
+ * @max_bytes: the max bytes to be stored on @buffer
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with graphics driver.
+ *
+ * This function queries the current state of the audio on the given
+ * digital port and fetches the ELD bytes onto the given buffer.
+ * It returns the number of bytes for the total ELD data, zero for
+ * invalid ELD, or a negative error code.
+ *
+ * The return size is the total bytes required for the whole ELD bytes,
+ * thus it may be over @max_bytes.  If it's over @max_bytes, it implies
+ * that only a part of ELD bytes have been fetched.
+ */
+int snd_hdac_acomp_get_eld(struct hdac_device *codec, hda_nid_t nid, int dev_id,
+			   bool *audio_enabled, char *buffer, int max_bytes)
+{
+	struct hdac_bus *bus = codec->bus;
+	struct drm_audio_component *acomp = bus->audio_component;
+	int port, pipe;
+
+	if (!acomp || !acomp->ops || !acomp->ops->get_eld)
+		return -ENODEV;
+
+	port = nid;
+	if (acomp->audio_ops && acomp->audio_ops->pin2port) {
+		port = acomp->audio_ops->pin2port(codec, nid);
+		if (port < 0)
+			return -EINVAL;
+	}
+	pipe = dev_id;
+	return acomp->ops->get_eld(acomp->dev, port, pipe, audio_enabled,
+				   buffer, max_bytes);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_acomp_get_eld);
+
+static int hdac_component_master_bind(struct device *dev)
+{
+	struct drm_audio_component *acomp = hdac_get_acomp(dev);
+	int ret;
+
+	if (WARN_ON(!acomp))
+		return -EINVAL;
+
+	ret = component_bind_all(dev, acomp);
+	if (ret < 0)
+		return ret;
+
+	if (WARN_ON(!(acomp->dev && acomp->ops))) {
+		ret = -EINVAL;
+		goto out_unbind;
+	}
+
+	/* pin the module to avoid dynamic unbinding, but only if given */
+	if (!try_module_get(acomp->ops->owner)) {
+		ret = -ENODEV;
+		goto out_unbind;
+	}
+
+	if (acomp->audio_ops && acomp->audio_ops->master_bind) {
+		ret = acomp->audio_ops->master_bind(dev, acomp);
+		if (ret < 0)
+			goto module_put;
+	}
+
+	return 0;
+
+ module_put:
+	module_put(acomp->ops->owner);
+out_unbind:
+	component_unbind_all(dev, acomp);
+
+	return ret;
+}
+
+static void hdac_component_master_unbind(struct device *dev)
+{
+	struct drm_audio_component *acomp = hdac_get_acomp(dev);
+
+	if (acomp->audio_ops && acomp->audio_ops->master_unbind)
+		acomp->audio_ops->master_unbind(dev, acomp);
+	module_put(acomp->ops->owner);
+	component_unbind_all(dev, acomp);
+	WARN_ON(acomp->ops || acomp->dev);
+}
+
+static const struct component_master_ops hdac_component_master_ops = {
+	.bind = hdac_component_master_bind,
+	.unbind = hdac_component_master_unbind,
+};
+
+/**
+ * snd_hdac_acomp_register_notifier - Register audio component ops
+ * @bus: HDA core bus
+ * @aops: audio component ops
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with graphics driver.
+ *
+ * This function sets the given ops to be called by the graphics driver.
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_acomp_register_notifier(struct hdac_bus *bus,
+				    const struct drm_audio_component_audio_ops *aops)
+{
+	if (!bus->audio_component)
+		return -ENODEV;
+
+	bus->audio_component->audio_ops = aops;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_acomp_register_notifier);
+
+/**
+ * snd_hdac_acomp_init - Initialize audio component
+ * @bus: HDA core bus
+ * @match_master: match function for finding components
+ * @extra_size: Extra bytes to allocate
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with graphics driver.
+ *
+ * This function initializes and sets up the audio component to communicate
+ * with graphics driver.
+ *
+ * Unlike snd_hdac_i915_init(), this function doesn't synchronize with the
+ * binding with the DRM component.  Each caller needs to sync via master_bind
+ * audio_ops.
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_acomp_init(struct hdac_bus *bus,
+			const struct drm_audio_component_audio_ops *aops,
+			int (*match_master)(struct device *, void *),
+			size_t extra_size)
+{
+	struct component_match *match = NULL;
+	struct device *dev = bus->dev;
+	struct drm_audio_component *acomp;
+	int ret;
+
+	if (WARN_ON(hdac_get_acomp(dev)))
+		return -EBUSY;
+
+	acomp = devres_alloc(hdac_acomp_release, sizeof(*acomp) + extra_size,
+			     GFP_KERNEL);
+	if (!acomp)
+		return -ENOMEM;
+	acomp->audio_ops = aops;
+	bus->audio_component = acomp;
+	devres_add(dev, acomp);
+
+	component_match_add(dev, &match, match_master, bus);
+	ret = component_master_add_with_match(dev, &hdac_component_master_ops,
+					      match);
+	if (ret < 0)
+		goto out_err;
+
+	return 0;
+
+out_err:
+	bus->audio_component = NULL;
+	devres_destroy(dev, hdac_acomp_release, NULL, NULL);
+	dev_info(dev, "failed to add audio component master (%d)\n", ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_acomp_init);
+
+/**
+ * snd_hdac_acomp_exit - Finalize audio component
+ * @bus: HDA core bus
+ *
+ * This function is supposed to be used only by a HD-audio controller
+ * driver that needs the interaction with graphics driver.
+ *
+ * This function releases the audio component that has been used.
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_acomp_exit(struct hdac_bus *bus)
+{
+	struct device *dev = bus->dev;
+	struct drm_audio_component *acomp = bus->audio_component;
+
+	if (!acomp)
+		return 0;
+
+	WARN_ON(bus->drm_power_refcount);
+	if (bus->drm_power_refcount > 0 && acomp->ops)
+		acomp->ops->put_power(acomp->dev);
+
+	component_master_del(dev, &hdac_component_master_ops);
+
+	bus->audio_component = NULL;
+	devres_destroy(dev, hdac_acomp_release, NULL, NULL);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_acomp_exit);