ASoC: tlv320dac33: Burst mode BCLK divider configuration

Add possibility to configure the burst mode BCLK divider through platform
data structure.
The BCLK divider changes the actual speed of the serial bus in burst mode,
which is faster than the sampling frequency of the running stream.
In this way platforms can experiment with the optimal burst speed without
the need to modify the codec driver itself.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Peter Ujfalusi 2010-01-20 09:39:36 +02:00 committed by Mark Brown
parent 6cd6cede8c
commit 6aceabb459
2 changed files with 14 additions and 2 deletions

View File

@ -15,6 +15,7 @@
struct tlv320dac33_platform_data {
int power_gpio;
u8 burst_bclkdiv;
};
#endif /* __TLV320DAC33_PLAT_H */

View File

@ -91,6 +91,7 @@ struct tlv320dac33_priv {
* this */
enum dac33_fifo_modes fifo_mode;/* FIFO mode selection */
unsigned int nsample; /* burst read amount from host */
u8 burst_bclkdiv; /* BCLK divider value in burst mode */
enum dac33_state state;
};
@ -845,9 +846,18 @@ static int dac33_prepare_chip(struct snd_pcm_substream *substream)
dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_A, aictrl_a);
dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_B, aictrl_b);
/* BCLK divide ratio */
/*
* BCLK divide ratio
* 0: 1.5
* 1: 1
* 2: 2
* ...
* 254: 254
* 255: 255
*/
if (dac33->fifo_mode)
dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_C, 3);
dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_C,
dac33->burst_bclkdiv);
else
dac33_write(codec, DAC33_SER_AUDIOIF_CTRL_C, 32);
@ -1239,6 +1249,7 @@ static int __devinit dac33_i2c_probe(struct i2c_client *client,
i2c_set_clientdata(client, dac33);
dac33->power_gpio = pdata->power_gpio;
dac33->burst_bclkdiv = pdata->burst_bclkdiv;
dac33->irq = client->irq;
dac33->nsample = NSAMPLE_MAX;
/* Disable FIFO use by default */