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authorVinod Koul <vinod.koul@intel.com>2016-05-12 08:58:53 +0530
committerMark Brown <broonie@kernel.org>2016-05-13 11:43:00 +0100
commit4446085d21e75dd6c0c45577f12db0bd7c7bf35f (patch)
tree2a96c35b59641cb3cf898333398388b0155af77e /sound/hda
parentbfb7802a06ac1855096a3f248822e8f943e6574d (diff)
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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>
Diffstat (limited to 'sound/hda')
-rw-r--r--sound/hda/ext/hdac_ext_bus.c3
-rw-r--r--sound/hda/ext/hdac_ext_controller.c66
2 files changed, 69 insertions, 0 deletions
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);