@@ -125,6 +125,75 @@ struct hdac_hdmi_priv {
struct hdac_chmap chmap;
};
+/* MST supported verbs */
+/*
+ * Get the no devices that can be connected to a port on the Pin widget.
+ */
+static int hdac_hdmi_get_port_len(struct hdac_ext_device *hdac, hda_nid_t nid)
+{
+ unsigned int caps;
+ unsigned int type, param;
+
+ caps = get_wcaps(&hdac->hdac, nid);
+ type = get_wcaps_type(caps);
+
+ if (!(caps & AC_WCAP_DIGITAL) || (type != AC_WID_PIN))
+ return 0;
+
+ param = snd_hdac_read_parm_uncached(&hdac->hdac, nid,
+ AC_PAR_DEVLIST_LEN);
+ if (param == -1)
+ return param;
+
+ return param & AC_DEV_LIST_LEN_MASK;
+}
+
+/*
+ * Get the port entry select on the pin. Return the port entry
+ * id selected on the pin. Return 0 means the first port entry
+ * is selected or MST is not supported.
+ */
+static int hdac_hdmi_port_select_get(struct hdac_ext_device *hdac,
+ struct hdac_hdmi_port *port)
+{
+ return snd_hdac_codec_read(&hdac->hdac, port->pin->nid,
+ 0, AC_VERB_GET_DEVICE_SEL, 0);
+}
+
+/*
+ * Sets the selected port entry for the configuring Pin widget verb.
+ * returns error if port set is not equal to port get otherwise success
+ */
+static int hdac_hdmi_port_select_set(struct hdac_ext_device *hdac,
+ struct hdac_hdmi_port *port)
+{
+ int num_ports;
+
+ if (!port->pin->is_mst_capable)
+ return 0;
+
+ /* AC_PAR_DEVLIST_LEN is 0 based. */
+ num_ports = hdac_hdmi_get_port_len(hdac, port->pin->nid);
+
+ if (num_ports < 0)
+ return -EIO;
+ /*
+ * Device List Length is a 0 based integer value indicating the
+ * number of sink device that a MST Pin Widget can support.
+ */
+ if (num_ports +1 <port->id)
+ return 0;
+
+ snd_hdac_codec_write(&hdac->hdac, port->pin->nid, 0,
+ AC_VERB_SET_DEVICE_SEL, port->id);
+
+ if (port->id != hdac_hdmi_port_select_get(hdac, port))
+ return -EIO;
+
+ dev_dbg(&hdac->hdac.dev, "Selected the port=%d\n", port->id);
+ return 0;
+}
+
static void hdac_hdmi_enable_cvt(struct hdac_ext_device *edev,
struct hdac_hdmi_dai_port_map *dai_map);