ALSA: hda - Add power on/off counter

Added the power on/off counter and expose via sysfs files.
The sysfs files, power_on_acct and power_off_acct, are created under
each codec hwdep sysfs directory (e.g. /sys/class/sound/hwC0D0).
The files show the msec length of the codec power-on and power-off,
respectively.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 38 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_hwdep.c b/sound/pci/hda/hda_hwdep.c
index cc24e6721d74..d24328661c6a 100644
--- a/sound/pci/hda/hda_hwdep.c
+++ b/sound/pci/hda/hda_hwdep.c
@@ -154,6 +154,44 @@ int /*__devinit*/ snd_hda_create_hwdep(struct hda_codec *codec)
         return 0;
 }
 
+#ifdef CONFIG_SND_HDA_POWER_SAVE
+static ssize_t power_on_acct_show(struct device *dev,
+                                  struct device_attribute *attr,
+                                  char *buf)
+{
+        struct snd_hwdep *hwdep = dev_get_drvdata(dev);
+        struct hda_codec *codec = hwdep->private_data;
+        snd_hda_update_power_acct(codec);
+        return sprintf(buf, "%u\n", jiffies_to_msecs(codec->power_on_acct));
+}
+
+static ssize_t power_off_acct_show(struct device *dev,
+                                   struct device_attribute *attr,
+                                   char *buf)
+{
+        struct snd_hwdep *hwdep = dev_get_drvdata(dev);
+        struct hda_codec *codec = hwdep->private_data;
+        snd_hda_update_power_acct(codec);
+        return sprintf(buf, "%u\n", jiffies_to_msecs(codec->power_off_acct));
+}
+
+static struct device_attribute power_attrs[] = {
+        __ATTR_RO(power_on_acct),
+        __ATTR_RO(power_off_acct),
+};
+
+int snd_hda_hwdep_add_power_sysfs(struct hda_codec *codec)
+{
+        struct snd_hwdep *hwdep = codec->hwdep;
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(power_attrs); i++)
+                snd_add_device_sysfs_file(SNDRV_DEVICE_TYPE_HWDEP, hwdep->card,
+                                          hwdep->device, &power_attrs[i]);
+        return 0;
+}
+#endif /* CONFIG_SND_HDA_POWER_SAVE */
+
 #ifdef CONFIG_SND_HDA_RECONFIG
 
 /*