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ASoC: tlv320dac33: Revisit the FIFO Mode1 handling

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Replace the hardwired latency definition with platform data
parameter, and simplify the nSample parameter calculation.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
This commit is contained in:
Peter Ujfalusi 2010-07-28 15:26:54 +03:00 committed by Liam Girdwood
parent b93cc9f19b
commit f430a27f05
2 changed files with 35 additions and 37 deletions
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1
include/sound/tlv320dac33-plat.h
View file

@ -15,6 +15,7 @@
struct tlv320dac33_platform_data {
int power_gpio;
int mode1_latency; /* latency caused by the i2c writes in us */
int keep_bclk; /* Keep the BCLK running in FIFO modes */
u8 burst_bclkdiv;
};

71
sound/soc/codecs/tlv320dac33.c
View file

@ -49,8 +49,6 @@
#define NSAMPLE_MAX 5700
#define LATENCY_TIME_MS 20
#define MODE7_LTHR 10
#define MODE7_UTHR (DAC33_BUFFER_SIZE_SAMPLES - 10)
@ -107,6 +105,8 @@ struct tlv320dac33_priv {
* this */
enum dac33_fifo_modes fifo_mode;/* FIFO mode selection */
unsigned int nsample; /* burst read amount from host */
int mode1_latency; /* latency caused by the i2c writes in
* us */
u8 burst_bclkdiv; /* BCLK divider value in burst mode */
unsigned int burst_rate; /* Interface speed in Burst modes */
@ -649,7 +649,7 @@ static inline void dac33_prefill_handler(struct tlv320dac33_priv *dac33)
switch (dac33->fifo_mode) {
case DAC33_FIFO_MODE1:
dac33_write16(codec, DAC33_NSAMPLE_MSB,
DAC33_THRREG(dac33->nsample + dac33->alarm_threshold));
DAC33_THRREG(dac33->nsample));
/* Take the timestamps */
spin_lock_irq(&dac33->lock);
@ -798,6 +798,10 @@ static void dac33_shutdown(struct snd_pcm_substream *substream,
struct tlv320dac33_priv *dac33 = snd_soc_codec_get_drvdata(codec);
dac33->substream = NULL;
/* Reset the nSample restrictions */
dac33->nsample_min = 0;
dac33->nsample_max = NSAMPLE_MAX;
}
static int dac33_hw_params(struct snd_pcm_substream *substream,
@ -1040,48 +1044,38 @@ static void dac33_calculate_times(struct snd_pcm_substream *substream)
struct snd_soc_device *socdev = rtd->socdev;
struct snd_soc_codec *codec = socdev->card->codec;
struct tlv320dac33_priv *dac33 = snd_soc_codec_get_drvdata(codec);
unsigned int period_size = substream->runtime->period_size;
unsigned int rate = substream->runtime->rate;
unsigned int nsample_limit;
/* In bypass mode we don't need to calculate */
if (!dac33->fifo_mode)
return;
/* Number of samples (16bit, stereo) in one period */
dac33->nsample_min = snd_pcm_lib_period_bytes(substream) / 4;
/* Number of samples (16bit, stereo) in ALSA buffer */
dac33->nsample_max = snd_pcm_lib_buffer_bytes(substream) / 4;
/* Subtract one period from the total */
dac33->nsample_max -= dac33->nsample_min;
/* Number of samples for LATENCY_TIME_MS / 2 */
dac33->alarm_threshold = substream->runtime->rate /
(1000 / (LATENCY_TIME_MS / 2));
/* Find and fix up the lowest nsmaple limit */
nsample_limit = substream->runtime->rate / (1000 / LATENCY_TIME_MS);
if (dac33->nsample_min < nsample_limit)
dac33->nsample_min = nsample_limit;
if (dac33->nsample < dac33->nsample_min)
dac33->nsample = dac33->nsample_min;
/*
* Find and fix up the highest nsmaple limit
* In order to not overflow the DAC33 buffer substract the
* alarm_threshold value from the size of the DAC33 buffer
*/
nsample_limit = DAC33_BUFFER_SIZE_SAMPLES - dac33->alarm_threshold;
if (dac33->nsample_max > nsample_limit)
dac33->nsample_max = nsample_limit;
if (dac33->nsample > dac33->nsample_max)
dac33->nsample = dac33->nsample_max;
switch (dac33->fifo_mode) {
case DAC33_FIFO_MODE1:
/* Number of samples under i2c latency */
dac33->alarm_threshold = US_TO_SAMPLES(rate,
dac33->mode1_latency);
/* nSample time shall not be shorter than i2c latency */
dac33->nsample_min = dac33->alarm_threshold;
/*
* nSample should not be bigger than alsa buffer minus
* size of one period to avoid overruns
*/
dac33->nsample_max = substream->runtime->buffer_size -
period_size;
nsample_limit = DAC33_BUFFER_SIZE_SAMPLES -
dac33->alarm_threshold;
if (dac33->nsample_max > nsample_limit)
dac33->nsample_max = nsample_limit;
/* Correct the nSample if it is outside of the ranges */
if (dac33->nsample < dac33->nsample_min)
dac33->nsample = dac33->nsample_min;
if (dac33->nsample > dac33->nsample_max)
dac33->nsample = dac33->nsample_max;
dac33->mode1_us_burst = SAMPLES_TO_US(dac33->burst_rate,
dac33->nsample);
dac33->t_stamp1 = 0;
@ -1519,6 +1513,9 @@ static int __devinit dac33_i2c_probe(struct i2c_client *client,
/* Pre calculate the burst rate */
dac33->burst_rate = BURST_BASEFREQ_HZ / dac33->burst_bclkdiv / 32;
dac33->keep_bclk = pdata->keep_bclk;
dac33->mode1_latency = pdata->mode1_latency;
if (!dac33->mode1_latency)
dac33->mode1_latency = 10000; /* 10ms */
dac33->irq = client->irq;
dac33->nsample = NSAMPLE_MAX;
dac33->nsample_max = NSAMPLE_MAX;