diff options
Diffstat (limited to 'sound/hda/hdac_device.c')
| -rw-r--r-- | sound/hda/hdac_device.c | 35 |
1 files changed, 35 insertions, 0 deletions
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 <linux/init.h> +#include <linux/delay.h> #include <linux/device.h> #include <linux/slab.h> #include <linux/module.h> @@ -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); |