Commit a8a729fa authored by Adrian Knoth's avatar Adrian Knoth Committed by Takashi Iwai

ALSA: hdspm - Refactor SS/DS/QS clock multiplier into function

When the DoubleSpeed or QuadSpeed bit is set, the SingleSpeed frequency
has to be multiplied accordingly. Since this functionality will be
required at least twice, refactor it into a separate function.

The second reference to the newly introduced hdspm_rate_multiplier()
will be in a separate commit.
Signed-off-by: default avatarAdrian Knoth <adi@drcomp.erfurt.thur.de>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent a8cd7148
...@@ -1091,6 +1091,26 @@ static int hdspm_round_frequency(int rate) ...@@ -1091,6 +1091,26 @@ static int hdspm_round_frequency(int rate)
return 48000; return 48000;
} }
/* QS and DS rates normally can not be detected
* automatically by the card. Only exception is MADI
* in 96k frame mode.
*
* So if we read SS values (32 .. 48k), check for
* user-provided DS/QS bits in the control register
* and multiply the base frequency accordingly.
*/
static int hdspm_rate_multiplier(struct hdspm *hdspm, int rate)
{
if (rate <= 48000) {
if (hdspm->control_register & HDSPM_QuadSpeed)
return rate * 4;
else if (hdspm->control_register &
HDSPM_DoubleSpeed)
return rate * 2;
};
return rate;
}
static int hdspm_tco_sync_check(struct hdspm *hdspm); static int hdspm_tco_sync_check(struct hdspm *hdspm);
static int hdspm_sync_in_sync_check(struct hdspm *hdspm); static int hdspm_sync_in_sync_check(struct hdspm *hdspm);
...@@ -1268,21 +1288,8 @@ static int hdspm_external_sample_rate(struct hdspm *hdspm) ...@@ -1268,21 +1288,8 @@ static int hdspm_external_sample_rate(struct hdspm *hdspm)
} }
} }
/* QS and DS rates normally can not be detected rate = hdspm_rate_multiplier(hdspm, rate);
* automatically by the card. Only exception is MADI
* in 96k frame mode.
*
* So if we read SS values (32 .. 48k), check for
* user-provided DS/QS bits in the control register
* and multiply the base frequency accordingly.
*/
if (rate <= 48000) {
if (hdspm->control_register & HDSPM_QuadSpeed)
rate *= 4;
else if (hdspm->control_register &
HDSPM_DoubleSpeed)
rate *= 2;
}
break; break;
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment