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>

sound/pci/hda/hda_codec.c

@@ -515,6 +515,7 @@ static int snd_hda_bus_dev_register(struct snd_device *device)
 	struct hda_codec *codec;
 	list_for_each_entry(codec, &bus->codec_list, list) {
 		snd_hda_hwdep_add_sysfs(codec);
+		snd_hda_hwdep_add_power_sysfs(codec);
 	}
 	return 0;
 }
@@ -2452,9 +2453,11 @@ static void hda_call_codec_suspend(struct hda_codec *codec)
 			    codec->afg ? codec->afg : codec->mfg,
 			    AC_PWRST_D3);
 #ifdef CONFIG_SND_HDA_POWER_SAVE
+	snd_hda_update_power_acct(codec);
 	cancel_delayed_work(&codec->power_work);
 	codec->power_on = 0;
 	codec->power_transition = 0;
+	codec->power_jiffies = jiffies;
 #endif
 }
 
@@ -3191,6 +3194,17 @@ static void hda_keep_power_on(struct hda_codec *codec)
 {
 	codec->power_count++;
 	codec->power_on = 1;
+	codec->power_jiffies = jiffies;
+}
+
+void snd_hda_update_power_acct(struct hda_codec *codec)
+{
+	unsigned long delta = jiffies - codec->power_jiffies;
+	if (codec->power_on)
+		codec->power_on_acct += delta;
+	else
+		codec->power_off_acct += delta;
+	codec->power_jiffies += delta;
 }
 
 void snd_hda_power_up(struct hda_codec *codec)
@@ -3201,7 +3215,9 @@ void snd_hda_power_up(struct hda_codec *codec)
 	if (codec->power_on || codec->power_transition)
 		return;
 
+	snd_hda_update_power_acct(codec);
 	codec->power_on = 1;
+	codec->power_jiffies = jiffies;
 	if (bus->ops.pm_notify)
 		bus->ops.pm_notify(bus);
 	hda_call_codec_resume(codec);

sound/pci/hda/hda_codec.h

@@ -812,6 +812,9 @@ struct hda_codec {
 	unsigned int power_transition :1; /* power-state in transition */
 	int power_count;	/* current (global) power refcount */
 	struct delayed_work power_work; /* delayed task for powerdown */
+	unsigned long power_on_acct;
+	unsigned long power_off_acct;
+	unsigned long power_jiffies;
 #endif
 
 	/* codec-specific additional proc output */
@@ -936,6 +939,7 @@ const char *snd_hda_get_jack_location(u32 cfg);
 void snd_hda_power_up(struct hda_codec *codec);
 void snd_hda_power_down(struct hda_codec *codec);
 #define snd_hda_codec_needs_resume(codec) codec->power_count
+void snd_hda_update_power_acct(struct hda_codec *codec);
 #else
 static inline void snd_hda_power_up(struct hda_codec *codec) {}
 static inline void snd_hda_power_down(struct hda_codec *codec) {}

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
 
 /*

sound/pci/hda/hda_local.h

@@ -437,6 +437,15 @@ int snd_hda_create_hwdep(struct hda_codec *codec);
 static inline int snd_hda_create_hwdep(struct hda_codec *codec) { return 0; }
 #endif
 
+#ifdef CONFIG_SND_HDA_POWER_SAVE
+int snd_hda_hwdep_add_power_sysfs(struct hda_codec *codec);
+#else
+static inline int snd_hda_hwdep_add_power_sysfs(struct hda_codec *codec)
+{
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_SND_HDA_RECONFIG
 int snd_hda_hwdep_add_sysfs(struct hda_codec *codec);
 #else