[alsa-devel] [PATCH 1/2] ALSA: hda - check supported power states

[Wang Xingchao]

Add function to check whether power states supported by specific
codec node.

Signed-off-by: Wang Xingchao <xingchao.wang at intel.com>
---
 sound/pci/hda/hda_codec.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 41ca803..b89c8ec 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -3505,6 +3505,22 @@ void snd_hda_codec_set_power_to_all(struct hda_codec *codec, hda_nid_t fg,
 EXPORT_SYMBOL_HDA(snd_hda_codec_set_power_to_all);
 
 /*
+ *  supported power states check
+ */
+static bool snd_hda_codec_get_supported_ps(struct hda_codec *codec, hda_nid_t fg,
+				unsigned int power_state)
+{
+	int sup = snd_hda_param_read(codec, fg, AC_PAR_POWER_STATE);
+
+	if (sup < 0)
+		return false;
+	if (sup & power_state)
+		return true;
+	else
+		return false;
+}
+
+/*
  * set power state of the codec
  */
 static void hda_set_power_state(struct hda_codec *codec, hda_nid_t fg,
-- 
1.7.9.5