3 files changed, 82 insertions, 0 deletions

diff --git a/include/sound/hdaudio_ext.h b/include/sound/hdaudio_ext.h
index 07fa59237feb..b9593b201599 100644
--- a/include/sound/hdaudio_ext.h
+++ b/include/sound/hdaudio_ext.h
@@ -14,6 +14,8 @@
  * @gtscap: gts capabilities pointer
  * @drsmcap: dma resume capabilities pointer
  * @hlink_list: link list of HDA links
+ * @lock: lock for link mgmt
+ * @cmd_dma_state: state of cmd DMAs: CORB and RIRB
  */
 struct hdac_ext_bus {
         struct hdac_bus bus;
@@ -27,6 +29,9 @@ struct hdac_ext_bus {
         void __iomem *drsmcap;
 
         struct list_head hlink_list;
+
+        struct mutex lock;
+        bool cmd_dma_state;
 };
 
 int snd_hdac_ext_bus_init(struct hdac_ext_bus *sbus, struct device *dev,
@@ -142,6 +147,9 @@ struct hdac_ext_link {
         void __iomem *ml_addr; /* link output stream reg pointer */
         u32 lcaps;   /* link capablities */
         u16 lsdiid;  /* link sdi identifier */
+
+        int ref_count;
+
         struct list_head list;
 };
 
@@ -154,6 +162,11 @@ void snd_hdac_ext_link_set_stream_id(struct hdac_ext_link *link,
 void snd_hdac_ext_link_clear_stream_id(struct hdac_ext_link *link,
                                  int stream);
 
+int snd_hdac_ext_bus_link_get(struct hdac_ext_bus *ebus,
+                                struct hdac_ext_link *link);
+int snd_hdac_ext_bus_link_put(struct hdac_ext_bus *ebus,
+                                struct hdac_ext_link *link);
+
 /* update register macro */
 #define snd_hdac_updatel(addr, reg, mask, val)          \
         writel(((readl(addr + reg) & ~(mask)) | (val)), \
diff --git a/sound/hda/ext/hdac_ext_bus.c b/sound/hda/ext/hdac_ext_bus.c
index 2433f7c81472..3b7ae24900fd 100644
--- a/sound/hda/ext/hdac_ext_bus.c
+++ b/sound/hda/ext/hdac_ext_bus.c
@@ -105,6 +105,9 @@ int snd_hdac_ext_bus_init(struct hdac_ext_bus *ebus, struct device *dev,
         INIT_LIST_HEAD(&ebus->hlink_list);
         ebus->idx = idx++;
 
+        mutex_init(&ebus->lock);
+        ebus->cmd_dma_state = true;
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_init);
diff --git a/sound/hda/ext/hdac_ext_controller.c b/sound/hda/ext/hdac_ext_controller.c
index 548cc1e4114b..860f8cad6602 100644
--- a/sound/hda/ext/hdac_ext_controller.c
+++ b/sound/hda/ext/hdac_ext_controller.c
@@ -186,6 +186,9 @@ int snd_hdac_ext_bus_get_ml_capabilities(struct hdac_ext_bus *ebus)
                 hlink->lcaps  = readl(hlink->ml_addr + AZX_REG_ML_LCAP);
                 hlink->lsdiid = readw(hlink->ml_addr + AZX_REG_ML_LSDIID);
 
+                /* since link in On, update the ref */
+                hlink->ref_count = 1;
+
                 list_add_tail(&hlink->list, &ebus->hlink_list);
         }
 
@@ -327,3 +330,66 @@ int snd_hdac_ext_bus_link_power_down_all(struct hdac_ext_bus *ebus)
         return 0;
 }
 EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_link_power_down_all);
+
+int snd_hdac_ext_bus_link_get(struct hdac_ext_bus *ebus,
+                                struct hdac_ext_link *link)
+{
+        int ret = 0;
+
+        mutex_lock(&ebus->lock);
+
+        /*
+         * if we move from 0 to 1, count will be 1 so power up this link
+         * as well, also check the dma status and trigger that
+         */
+        if (++link->ref_count == 1) {
+                if (!ebus->cmd_dma_state) {
+                        snd_hdac_bus_init_cmd_io(&ebus->bus);
+                        ebus->cmd_dma_state = true;
+                }
+
+                ret = snd_hdac_ext_bus_link_power_up(link);
+        }
+
+        mutex_unlock(&ebus->lock);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_link_get);
+
+int snd_hdac_ext_bus_link_put(struct hdac_ext_bus *ebus,
+                                struct hdac_ext_link *link)
+{
+        int ret = 0;
+        struct hdac_ext_link *hlink;
+        bool link_up = false;
+
+        mutex_lock(&ebus->lock);
+
+        /*
+         * if we move from 1 to 0, count will be 0
+         * so power down this link as well
+         */
+        if (--link->ref_count == 0) {
+                ret = snd_hdac_ext_bus_link_power_down(link);
+
+                /*
+                 * now check if all links are off, if so turn off
+                 * cmd dma as well
+                 */
+                list_for_each_entry(hlink, &ebus->hlink_list, list) {
+                        if (hlink->ref_count) {
+                                link_up = true;
+                                break;
+                        }
+                }
+
+                if (!link_up) {
+                        snd_hdac_bus_stop_cmd_io(&ebus->bus);
+                        ebus->cmd_dma_state = false;
+                }
+        }
+
+        mutex_unlock(&ebus->lock);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_link_put);