From 09787492537462e3c7b8f67b30ff9704062f97cc Mon Sep 17 00:00:00 2001 From: Abhijeet Kumar Date: Tue, 23 Jan 2018 23:00:51 +0530 Subject: ALSA: hda: Copying sync power state helper to core The current sync_power_state is local to hda code, moving it core so that other users apart from hda legacy can use it. The helper function ensures the actual state reaches the target state. Signed-off-by: Abhijeet Kumar Signed-off-by: Takashi Iwai --- sound/hda/hdac_device.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'sound/hda') diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c index 06f845e293cb..7ba100bb1c3f 100644 --- a/sound/hda/hdac_device.c +++ b/sound/hda/hdac_device.c @@ -3,6 +3,7 @@ */ #include +#include #include #include #include @@ -1064,3 +1065,37 @@ bool snd_hdac_check_power_state(struct hdac_device *hdac, return (state == target_state); } EXPORT_SYMBOL_GPL(snd_hdac_check_power_state); +/** + * snd_hdac_sync_power_state - wait until actual power state matches + * with the target state + * + * @hdac: the HDAC device + * @nid: NID to send the command + * @target_state: target state to check for + * + * Return power state or PS_ERROR if codec rejects GET verb. + */ +unsigned int snd_hdac_sync_power_state(struct hdac_device *codec, + hda_nid_t nid, unsigned int power_state) +{ + unsigned long end_time = jiffies + msecs_to_jiffies(500); + unsigned int state, actual_state, count; + + for (count = 0; count < 500; count++) { + state = snd_hdac_codec_read(codec, nid, 0, + AC_VERB_GET_POWER_STATE, 0); + if (state & AC_PWRST_ERROR) { + msleep(20); + break; + } + actual_state = (state >> 4) & 0x0f; + if (actual_state == power_state) + break; + if (time_after_eq(jiffies, end_time)) + break; + /* wait until the codec reachs to the target state */ + msleep(1); + } + return state; +} +EXPORT_SYMBOL_GPL(snd_hdac_sync_power_state); -- cgit v1.2.3