ASoC: tlv320dac33: Some cleanup for 32/24 bit support

Change the structure of FIFO handling in order to
pave the way for adding 32/24 bit audio support.

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>

1 files changed, 27 insertions, 20 deletions

diff --git a/sound/soc/codecs/tlv320dac33.c b/sound/soc/codecs/tlv320dac33.c
index c574ae238973..05a4e9fade47 100644
--- a/sound/soc/codecs/tlv320dac33.c
+++ b/sound/soc/codecs/tlv320dac33.c
@@ -42,12 +42,15 @@
 #include <sound/tlv320dac33-plat.h>
 #include "tlv320dac33.h"
 
-#define DAC33_BUFFER_SIZE_BYTES         24576   /* bytes, 12288 16 bit words,
-                                                 * 6144 stereo */
-#define DAC33_BUFFER_SIZE_SAMPLES       6144
-
-#define MODE7_LTHR              10
-#define MODE7_UTHR              (DAC33_BUFFER_SIZE_SAMPLES - 10)
+/*
+ * The internal FIFO is 24576 bytes long
+ * It can be configured to hold 16bit or 24bit samples
+ * In 16bit configuration the FIFO can hold 6144 stereo samples
+ * In 24bit configuration the FIFO can hold 4096 stereo samples
+ */
+#define DAC33_FIFO_SIZE_16BIT   6144
+#define DAC33_FIFO_SIZE_24BIT   4096
+#define DAC33_MODE7_MARGIN      10      /* Safety margin for FIFO in Mode7 */
 
 #define BURST_BASEFREQ_HZ       49152000
 
@@ -98,6 +101,7 @@ struct tlv320dac33_priv {
 
         unsigned int alarm_threshold;   /* set to be half of LATENCY_TIME_MS */
         enum dac33_fifo_modes fifo_mode;/* FIFO mode selection */
+        unsigned int fifo_size;         /* Size of the FIFO in samples */
         unsigned int nsample;           /* burst read amount from host */
         int mode1_latency;              /* latency caused by the i2c writes in
                                          * us */
@@ -650,7 +654,7 @@ static inline void dac33_prefill_handler(struct tlv320dac33_priv *dac33)
                 spin_unlock_irq(&dac33->lock);
 
                 dac33_write16(codec, DAC33_PREFILL_MSB,
-                                DAC33_THRREG(MODE7_LTHR));
+                                DAC33_THRREG(DAC33_MODE7_MARGIN));
 
                 /* Enable Upper Threshold IRQ */
                 dac33_write(codec, DAC33_FIFO_IRQ_MASK, DAC33_MUT);
@@ -773,12 +777,15 @@ static void dac33_shutdown(struct snd_pcm_substream *substream,
         dac33->substream = NULL;
 }
 
+#define CALC_BURST_RATE(bclkdiv, bclk_per_sample) \
+        (BURST_BASEFREQ_HZ / bclkdiv / bclk_per_sample)
 static int dac33_hw_params(struct snd_pcm_substream *substream,
                            struct snd_pcm_hw_params *params,
                            struct snd_soc_dai *dai)
 {
         struct snd_soc_pcm_runtime *rtd = substream->private_data;
         struct snd_soc_codec *codec = rtd->codec;
+        struct tlv320dac33_priv *dac33 = snd_soc_codec_get_drvdata(codec);
 
         /* Check parameters for validity */
         switch (params_rate(params)) {
@@ -793,6 +800,8 @@ static int dac33_hw_params(struct snd_pcm_substream *substream,
 
         switch (params_format(params)) {
         case SNDRV_PCM_FORMAT_S16_LE:
+                dac33->fifo_size = DAC33_FIFO_SIZE_16BIT;
+                dac33->burst_rate = CALC_BURST_RATE(dac33->burst_bclkdiv, 32);
                 break;
         default:
                 dev_err(codec->dev, "unsupported format %d\n",
@@ -994,7 +1003,8 @@ static int dac33_prepare_chip(struct snd_pcm_substream *substream)
                  * at the bottom, and also at the top of the FIFO
                  */
                 dac33_write16(codec, DAC33_UTHR_MSB, DAC33_THRREG(dac33->uthr));
-                dac33_write16(codec, DAC33_LTHR_MSB, DAC33_THRREG(MODE7_LTHR));
+                dac33_write16(codec, DAC33_LTHR_MSB,
+                              DAC33_THRREG(DAC33_MODE7_MARGIN));
                 break;
         default:
                 break;
@@ -1023,8 +1033,7 @@ static void dac33_calculate_times(struct snd_pcm_substream *substream)
                 /* Number of samples under i2c latency */
                 dac33->alarm_threshold = US_TO_SAMPLES(rate,
                                                 dac33->mode1_latency);
-                nsample_limit = DAC33_BUFFER_SIZE_SAMPLES -
-                                dac33->alarm_threshold;
+                nsample_limit = dac33->fifo_size - dac33->alarm_threshold;
 
                 if (period_size <= dac33->alarm_threshold)
                         /*
@@ -1048,14 +1057,14 @@ static void dac33_calculate_times(struct snd_pcm_substream *substream)
         case DAC33_FIFO_MODE7:
                 dac33->uthr = UTHR_FROM_PERIOD_SIZE(period_size, rate,
                                                     dac33->burst_rate) + 9;
-                if (dac33->uthr > MODE7_UTHR)
-                        dac33->uthr = MODE7_UTHR;
-                if (dac33->uthr < (MODE7_LTHR + 10))
-                        dac33->uthr = (MODE7_LTHR + 10);
+                if (dac33->uthr > (dac33->fifo_size - DAC33_MODE7_MARGIN))
+                        dac33->uthr = dac33->fifo_size - DAC33_MODE7_MARGIN;
+                if (dac33->uthr < (DAC33_MODE7_MARGIN + 10))
+                        dac33->uthr = (DAC33_MODE7_MARGIN + 10);
 
                 dac33->mode7_us_to_lthr =
                                 SAMPLES_TO_US(substream->runtime->rate,
-                                        dac33->uthr - MODE7_LTHR + 1);
+                                        dac33->uthr - DAC33_MODE7_MARGIN + 1);
                 dac33->t_stamp1 = 0;
                 break;
         default:
@@ -1173,8 +1182,8 @@ static snd_pcm_sframes_t dac33_dai_delay(
                         samples += (samples_in - samples_out);
 
                         if (likely(samples > 0))
-                                delay = samples > DAC33_BUFFER_SIZE_SAMPLES ?
-                                        DAC33_BUFFER_SIZE_SAMPLES : samples;
+                                delay = samples > dac33->fifo_size ?
+                                        dac33->fifo_size : samples;
                         else
                                 delay = 0;
                 }
@@ -1226,7 +1235,7 @@ static snd_pcm_sframes_t dac33_dai_delay(
                         samples_in = US_TO_SAMPLES(
                                         dac33->burst_rate,
                                         time_delta);
-                        delay = MODE7_LTHR + samples_in - samples_out;
+                        delay = DAC33_MODE7_MARGIN + samples_in - samples_out;
 
                         if (unlikely(delay > uthr))
                                 delay = uthr;
@@ -1477,8 +1486,6 @@ static int __devinit dac33_i2c_probe(struct i2c_client *client,
 
         dac33->power_gpio = pdata->power_gpio;
         dac33->burst_bclkdiv = pdata->burst_bclkdiv;
-        /* 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)