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Diffstat (limited to 'sound/pci/hda/hda_codec.c')
-rw-r--r--sound/pci/hda/hda_codec.c72
1 files changed, 68 insertions, 4 deletions
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 9913be8532ab..9dc847db1cc4 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -311,9 +311,15 @@ 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;
@@ -327,6 +333,7 @@ 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
@@ -344,7 +351,7 @@ 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;
@@ -368,6 +375,63 @@ 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, num_devices;
+
+ /* not support dp_mst will always return 0, using first dev_entry */
+ if (!codec->dp_mst)
+ return 0;
+
+ /* AC_PAR_DEVLIST_LEN is 0 based. */
+ num_devices = snd_hda_get_num_devices(codec, nid) + 1;
+ /* If Device List Length is 0 (num_device = 1),
+ * the pin is not multi stream capable.
+ * Do nothing in this case.
+ */
+ if (num_devices == 1)
+ return 0;
+
+ /* Behavior of setting index being equal to or greater than
+ * Device List Length is not predictable
+ */
+ if (num_devices <= dev_id)
+ return -EINVAL;
+
+ ret = snd_hda_codec_write(codec, nid, 0,
+ AC_VERB_SET_DEVICE_SEL, dev_id);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snd_hda_set_dev_select);
+
/*
* read widget caps for each widget and store in cache
*/