From: Libin Yang <libin.yang@xxxxxxxxxxxxxxx>
Add snd_hda_get_dev_select() and snd_hda_set_dev_select() functions
for DP MST audio support.
Signed-off-by: Libin Yang <libin.yang@xxxxxxxxxxxxxxx>
---
sound/pci/hda/hda_codec.c | 80 +++++++++++++++++++++++++++++++++++++++++++++--
sound/pci/hda/hda_codec.h | 3 ++
2 files changed, 80 insertions(+), 3 deletions(-)
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index d4c81f7..1a42c51 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -424,8 +424,16 @@ int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux,
EXPORT_SYMBOL_GPL(snd_hda_get_conn_index);
-/* return DEVLIST_LEN parameter of the given widget */
-static unsigned int get_num_devices(struct hda_codec *codec, hda_nid_t nid)
+/**
+ * snd_hda_get_num_devices - get DEVLIST_LEN parameter of the given widget
+ * @codec: the HDA codec
+ * @nid: NID of the pin to parse
+ *
+ * Get the device entry number on the given widget.
+ * This is a feature of DP MST audio. Each pin can
+ * have several device entries in it.
+ */
+unsigned int snd_hda_get_num_devices(struct hda_codec *codec, hda_nid_t nid)
{
unsigned int wcaps = get_wcaps(codec, nid);
unsigned int parm;
@@ -439,6 +447,7 @@ static unsigned int get_num_devices(struct hda_codec *codec, hda_nid_t nid)
parm = 0;
return parm & AC_DEV_LIST_LEN_MASK;
}
+EXPORT_SYMBOL_GPL(snd_hda_get_num_devices);
/**
* snd_hda_get_devices - copy device list without cache
@@ -456,7 +465,7 @@ int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
unsigned int parm;
int i, dev_len, devices;
- parm = get_num_devices(codec, nid);
+ parm = snd_hda_get_num_devices(codec, nid);
if (!parm) /* not multi-stream capable */
return 0;
@@ -480,6 +489,71 @@ int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
return devices;
}
+/**
+ * snd_hda_get_dev_select - get device entry select on the pin
+ * @codec: the HDA codec
+ * @nid: NID of the pin to get device entry select
+ *
+ * Get the devcie entry select on the pin. Return the device entry
+ * id selected on the pin. Return 0 means the first device entry
+ * is selected or MST is not supported.
+ */
+int snd_hda_get_dev_select(struct hda_codec *codec, hda_nid_t nid)
+{
+ /* not support dp_mst will always return 0, using first dev_entry */
+ if (!codec->dp_mst)
+ return 0;
+
+ return snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_DEVICE_SEL, 0);
+}
+EXPORT_SYMBOL_GPL(snd_hda_get_dev_select);
+
+/**
+ * snd_hda_set_dev_select - set device entry select on the pin
+ * @codec: the HDA codec
+ * @nid: NID of the pin to set device entry select
+ * @dev_id: device entry id to be set
+ *
+ * Set the device entry select on the pin nid.
+ */
+int snd_hda_set_dev_select(struct hda_codec *codec, hda_nid_t nid, int dev_id)
+{
+ int ret, dev;
+ unsigned long timeout;
+
+ /* not support dp_mst will always return 0, using first dev_entry */
+ if (!codec->dp_mst)
+ return 0;
+
+ /* If Device List Length is 0, the pin is not multi stream capable.
+ */
+ if ((snd_hda_get_num_devices(codec, nid) + 1) == 0)
+ return 0;
+
+ /* Behavior of setting index being equal to or greater than
+ * Device List Length is not predictable
+ */
+ if ((snd_hda_get_num_devices(codec, nid) + 1) <= dev_id)
+ return 0;
+
+ timeout = jiffies + msecs_to_jiffies(500);
+
+ /* make sure the device entry selection takes effect */
+ do {
+ ret = snd_hda_codec_write(codec, nid, 0,
+ AC_VERB_SET_DEVICE_SEL, dev_id);
+ udelay(20);
+
+ dev = snd_hda_get_dev_select(codec, nid);
+ if (dev == dev_id)
+ break;
+ msleep(20);
+ } while (time_before(jiffies, timeout));
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snd_hda_set_dev_select);
+
/*
* read widget caps for each widget and store in cache
*/
diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index deeed35..8362cb6 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -352,8 +352,11 @@ int snd_hda_override_conn_list_mst(struct hda_codec *codec, hda_nid_t nid,
int dev_id, int len, const hda_nid_t *list);
int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux,
hda_nid_t nid, int recursive);
+unsigned int snd_hda_get_num_devices(struct hda_codec *codec, hda_nid_t nid);
int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
u8 *dev_list, int max_devices);
+int snd_hda_get_dev_select(struct hda_codec *codec, hda_nid_t nid);
+int snd_hda_set_dev_select(struct hda_codec *codec, hda_nid_t nid, int dev_id);
struct hda_verb {
hda_nid_t nid;
--
1.9.1
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