ALSA: hdac: add link pm and ref counting
The HDA links can be switched off when not is use, similarly
command DMA can be stopped as well. This calls for a reference
counting mechanism on the link by it's users to manage the link
power. The DMA can be turned off when all links are off
For this we add two APIs
snd_hdac_ext_bus_link_get
snd_hdac_ext_bus_link_put
They help users to turn up/down link and manage the DMA as well
Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/include/sound/hdaudio_ext.h b/include/sound/hdaudio_ext.h
index 07fa592..b9593b2 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 @@
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 @@
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_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)), \