ALSA: hda - add flags and routines to get devices selection info for DP1.2 MST

This patch adds flags and routines to get device list & selection info on
a pin.

To support Display Port 1.2 multi-stream transport (MST) over single DP port,
a pin can support multiple devices. Please refer to HD-A spec Document Change
Notificaton HDA040-A.

A display audio codec can set flag "dp_mst" in its patch, indicating its pins
can support MST. But at runtime, a pin may not be multi-streaming capable and
report the device list is empty, depending on Gfx driver configuration.

Signed-off-by: Mengdong Lin <mengdong.lin@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 74 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index fdbb09a9b9e5..5b6c4e3c92ca 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -666,6 +666,64 @@ int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux,
 }
 EXPORT_SYMBOL_HDA(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)
+{
+        unsigned int wcaps = get_wcaps(codec, nid);
+        unsigned int parm;
+
+        if (!codec->dp_mst || !(wcaps & AC_WCAP_DIGITAL) ||
+            get_wcaps_type(wcaps) != AC_WID_PIN)
+                return 0;
+
+        parm = snd_hda_param_read(codec, nid, AC_PAR_DEVLIST_LEN);
+        if (parm == -1 && codec->bus->rirb_error)
+                parm = 0;
+        return parm & AC_DEV_LIST_LEN_MASK;
+}
+
+/**
+ * snd_hda_get_devices - copy device list without cache
+ * @codec: the HDA codec
+ * @nid: NID of the pin to parse
+ * @dev_list: device list array
+ * @max_devices: max. number of devices to store
+ *
+ * Copy the device list. This info is dynamic and so not cached.
+ * Currently called only from hda_proc.c, so not exported.
+ */
+int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
+                        u8 *dev_list, int max_devices)
+{
+        unsigned int parm;
+        int i, dev_len, devices;
+
+        parm = get_num_devices(codec, nid);
+        if (!parm)      /* not multi-stream capable */
+                return 0;
+
+        dev_len = parm + 1;
+        dev_len = dev_len < max_devices ? dev_len : max_devices;
+
+        devices = 0;
+        while (devices < dev_len) {
+                parm = snd_hda_codec_read(codec, nid, 0,
+                                          AC_VERB_GET_DEVICE_LIST, devices);
+                if (parm == -1 && codec->bus->rirb_error)
+                        break;
+
+                for (i = 0; i < 8; i++) {
+                        dev_list[devices] = (u8)parm;
+                        parm >>= 4;
+                        devices++;
+                        if (devices >= dev_len)
+                                break;
+                }
+        }
+        return devices;
+}
+
 /**
  * snd_hda_queue_unsol_event - add an unsolicited event to queue
  * @bus: the BUS
diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index 701c2e069b10..b838c70420d1 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -94,6 +94,8 @@ enum {
 #define AC_VERB_GET_HDMI_DIP_XMIT               0x0f32
 #define AC_VERB_GET_HDMI_CP_CTRL                0x0f33
 #define AC_VERB_GET_HDMI_CHAN_SLOT              0x0f34
+#define AC_VERB_GET_DEVICE_SEL                  0xf35
+#define AC_VERB_GET_DEVICE_LIST                 0xf36
 
 /*
  * SET verbs
@@ -133,6 +135,7 @@ enum {
 #define AC_VERB_SET_HDMI_DIP_XMIT               0x732
 #define AC_VERB_SET_HDMI_CP_CTRL                0x733
 #define AC_VERB_SET_HDMI_CHAN_SLOT              0x734
+#define AC_VERB_SET_DEVICE_SEL                  0x735
 
 /*
  * Parameter IDs
@@ -154,6 +157,7 @@ enum {
 #define AC_PAR_GPIO_CAP                 0x11
 #define AC_PAR_AMP_OUT_CAP              0x12
 #define AC_PAR_VOL_KNB_CAP              0x13
+#define AC_PAR_DEVLIST_LEN              0x15
 #define AC_PAR_HDMI_LPCM_CAP            0x20
 
 /*
@@ -352,6 +356,10 @@ enum {
 #define AC_LPCMCAP_44K                  (1<<30) /* 44.1kHz support */
 #define AC_LPCMCAP_44K_MS               (1<<31) /* 44.1kHz-multiplies support */
 
+/* Display pin's device list length */
+#define AC_DEV_LIST_LEN_MASK            0x3f
+#define AC_MAX_DEV_LIST_LEN             64
+
 /*
  * Control Parameters
  */
@@ -460,6 +468,11 @@ enum {
 #define AC_DEFCFG_PORT_CONN             (0x3<<30)
 #define AC_DEFCFG_PORT_CONN_SHIFT       30
 
+/* Display pin's device list entry */
+#define AC_DE_PD                        (1<<0)
+#define AC_DE_ELDV                      (1<<1)
+#define AC_DE_IA                        (1<<2)
+
 /* device device types (0x0-0xf) */
 enum {
         AC_JACK_LINE_OUT,
@@ -885,6 +898,7 @@ struct hda_codec {
         unsigned int pcm_format_first:1; /* PCM format must be set first */
         unsigned int epss:1;            /* supporting EPSS? */
         unsigned int cached_write:1;    /* write only to caches */
+        unsigned int dp_mst:1; /* support DP1.2 Multi-stream transport */
 #ifdef CONFIG_PM
         unsigned int power_on :1;       /* current (global) power-state */
         unsigned int d3_stop_clk:1;     /* support D3 operation without BCLK */
@@ -972,6 +986,8 @@ int snd_hda_override_conn_list(struct hda_codec *codec, hda_nid_t nid, int nums,
                           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);
+int snd_hda_get_devices(struct hda_codec *codec, hda_nid_t nid,
+                        u8 *dev_list, int max_devices);
 int snd_hda_query_supported_pcm(struct hda_codec *codec, hda_nid_t nid,
                                 u32 *ratesp, u64 *formatsp, unsigned int *bpsp);