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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 <abhijeet.kumar@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Abhijeet Kumar 2018-01-23 23:00:51 +05:30 committed by Takashi Iwai
parent 7928b2cbe5
commit 0978749253
2 changed files with 37 additions and 0 deletions
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2
include/sound/hdaudio.h
View File

@ -146,6 +146,8 @@ int snd_hdac_codec_write(struct hdac_device *hdac, hda_nid_t nid,
int flags, unsigned int verb, unsigned int parm);
bool snd_hdac_check_power_state(struct hdac_device *hdac,
hda_nid_t nid, unsigned int target_state);
unsigned int snd_hdac_sync_power_state(struct hdac_device *hdac,
hda_nid_t nid, unsigned int target_state);
/**
* snd_hdac_read_parm - read a codec parameter
* @codec: the codec object

35
sound/hda/hdac_device.c
View File

@ -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);