[PATCH v2 2/4] ALSA: hda: Introduce HOST stream setup mechanism

[Cezary Rojewski <cezary.rojewski@xxxxxxxxx>]

HDAudio stream setup procedure differs between revisions of the
controller device. Currently the differences are handled directly within
AudioDSP platform drivers with if-statements. Implement a more generic
approach and expose a function that a platform driver may use to ensure
the correct procedure is followed each time.

Signed-off-by: Cezary Rojewski <cezary.rojewski@xxxxxxxxx>
---
 include/sound/hdaudio_ext.h     |  3 +++
 sound/hda/ext/hdac_ext_stream.c | 41 +++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/include/sound/hdaudio_ext.h b/include/sound/hdaudio_ext.h
index 511211f4a2b6..d32959cb71d2 100644
--- a/include/sound/hdaudio_ext.h
+++ b/include/sound/hdaudio_ext.h
@@ -60,6 +60,8 @@ struct hdac_ext_stream {
 	bool link_locked:1;
 	bool link_prepared;
 
+	int (*host_setup)(struct hdac_stream *);
+
 	struct snd_pcm_substream *link_substream;
 };
 
@@ -86,6 +88,7 @@ void snd_hdac_ext_stream_start(struct hdac_ext_stream *hext_stream);
 void snd_hdac_ext_stream_clear(struct hdac_ext_stream *hext_stream);
 void snd_hdac_ext_stream_reset(struct hdac_ext_stream *hext_stream);
 int snd_hdac_ext_stream_setup(struct hdac_ext_stream *hext_stream, int fmt);
+int snd_hdac_ext_host_stream_setup(struct hdac_ext_stream *hext_stream);
 
 struct hdac_ext_link {
 	struct hdac_bus *bus;
diff --git a/sound/hda/ext/hdac_ext_stream.c b/sound/hda/ext/hdac_ext_stream.c
index 11b7119cc47e..f12fe348b9fc 100644
--- a/sound/hda/ext/hdac_ext_stream.c
+++ b/sound/hda/ext/hdac_ext_stream.c
@@ -10,12 +10,45 @@
  */
 
 #include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
 #include <linux/slab.h>
 #include <sound/pcm.h>
 #include <sound/hda_register.h>
 #include <sound/hdaudio_ext.h>
 #include <sound/compress_driver.h>
 
+/**
+ * snd_hdac_ext_host_stream_setup - Setup a HOST stream.
+ * @hext_stream - HDAudio stream to set up.
+ *
+ * Return: Zero on success or negative error code.
+ */
+int snd_hdac_ext_host_stream_setup(struct hdac_ext_stream *hext_stream)
+{
+	return hext_stream->host_setup(hdac_stream(hext_stream));
+}
+EXPORT_SYMBOL_GPL(snd_hdac_ext_host_stream_setup);
+
+/**
+ * snd_hdac_apl_host_stream_setup - Setup a HOST stream following procedure
+ *                                  recommended for ApolloLake devices.
+ * @hstream - HDAudio stream to set up.
+ *
+ * Return: Zero on success or negative error code.
+ */
+static int snd_hdac_apl_host_stream_setup(struct hdac_stream *hstream)
+{
+	struct hdac_ext_stream *hext_stream = stream_to_hdac_ext_stream(hstream);
+	int ret;
+
+	snd_hdac_ext_stream_decouple(hstream->bus, hext_stream, false);
+	ret = snd_hdac_stream_setup(hstream);
+	snd_hdac_ext_stream_decouple(hstream->bus, hext_stream, true);
+
+	return ret;
+}
+
 /**
  * snd_hdac_ext_stream_init - initialize each stream (aka device)
  * @bus: HD-audio core bus
@@ -55,9 +88,16 @@ static void snd_hdac_ext_stream_init(struct hdac_bus *bus,
 int snd_hdac_ext_stream_init_all(struct hdac_bus *bus, int start_idx,
 				 int num_stream, int dir)
 {
+	struct pci_dev *pci = to_pci_dev(bus->dev);
+	int (*setup_op)(struct hdac_stream *);
 	int stream_tag = 0;
 	int i, tag, idx = start_idx;
 
+	if (pci->device == PCI_DEVICE_ID_INTEL_HDA_APL)
+		setup_op = snd_hdac_apl_host_stream_setup;
+	else
+		setup_op = snd_hdac_stream_setup;
+
 	for (i = 0; i < num_stream; i++) {
 		struct hdac_ext_stream *hext_stream =
 				kzalloc(sizeof(*hext_stream), GFP_KERNEL);
@@ -66,6 +106,7 @@ int snd_hdac_ext_stream_init_all(struct hdac_bus *bus, int start_idx,
 		tag = ++stream_tag;
 		snd_hdac_ext_stream_init(bus, hext_stream, idx, dir, tag);
 		idx++;
+		hext_stream->host_setup = setup_op;
 	}
 
 	return 0;
-- 
2.25.1