ASoC: fsl-sai: Add SND_SOC_DAIFMT_DSP_A/B support.

o Add SND_SOC_DAIFMT_DSP_A support.
o Add SND_SOC_DAIFMT_DSP_B support.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

2 files changed, 43 insertions, 3 deletions

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 26d9f5ed6959..c4a423111673 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -108,15 +108,44 @@ static int fsl_sai_set_dai_fmt_tr(struct snd_soc_dai *cpu_dai,
         /* DAI mode */
         switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
         case SND_SOC_DAIFMT_I2S:
-                /* Data on rising edge of bclk, frame low, 1clk before data */
+                /*
+                 * Frame low, 1clk before data, one word length for frame sync,
+                 * frame sync starts one serial clock cycle earlier,
+                 * that is, together with the last bit of the previous
+                 * data word.
+                 */
                 val_cr2 &= ~FSL_SAI_CR2_BCP;
                 val_cr4 |= FSL_SAI_CR4_FSE | FSL_SAI_CR4_FSP;
                 break;
         case SND_SOC_DAIFMT_LEFT_J:
-                /* Data on rising edge of bclk, frame high, 0clk before data */
+                /*
+                 * Frame high, one word length for frame sync,
+                 * frame sync asserts with the first bit of the frame.
+                 */
                 val_cr2 &= ~FSL_SAI_CR2_BCP;
                 val_cr4 &= ~(FSL_SAI_CR4_FSE | FSL_SAI_CR4_FSP);
                 break;
+        case SND_SOC_DAIFMT_DSP_A:
+                /*
+                 * Frame high, 1clk before data, one bit for frame sync,
+                 * frame sync starts one serial clock cycle earlier,
+                 * that is, together with the last bit of the previous
+                 * data word.
+                 */
+                val_cr2 &= ~FSL_SAI_CR2_BCP;
+                val_cr4 &= ~FSL_SAI_CR4_FSP;
+                val_cr4 |= FSL_SAI_CR4_FSE;
+                sai->is_dsp_mode = true;
+                break;
+        case SND_SOC_DAIFMT_DSP_B:
+                /*
+                 * Frame high, one bit for frame sync,
+                 * frame sync asserts with the first bit of the frame.
+                 */
+                val_cr2 &= ~FSL_SAI_CR2_BCP;
+                val_cr4 &= ~(FSL_SAI_CR4_FSE | FSL_SAI_CR4_FSP);
+                sai->is_dsp_mode = true;
+                break;
         case SND_SOC_DAIFMT_RIGHT_J:
                 /* To be done */
         default:
@@ -219,7 +248,9 @@ static int fsl_sai_hw_params(struct snd_pcm_substream *substream,
         val_cr5 &= ~FSL_SAI_CR5_W0W_MASK;
         val_cr5 &= ~FSL_SAI_CR5_FBT_MASK;
 
-        val_cr4 |= FSL_SAI_CR4_SYWD(word_width);
+        if (!sai->is_dsp_mode)
+                val_cr4 |= FSL_SAI_CR4_SYWD(word_width);
+
         val_cr5 |= FSL_SAI_CR5_WNW(word_width);
         val_cr5 |= FSL_SAI_CR5_W0W(word_width);
 
@@ -245,6 +276,10 @@ static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
         struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
         u32 tcsr, rcsr;
 
+        /*
+         * The transmitter bit clock and frame sync are to be
+         * used by both the transmitter and receiver.
+         */
         regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC,
                            ~FSL_SAI_CR2_SYNC);
         regmap_update_bits(sai->regmap, FSL_SAI_RCR2, FSL_SAI_CR2_SYNC,
@@ -261,6 +296,10 @@ static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
                 tcsr &= ~FSL_SAI_CSR_FRDE;
         }
 
+        /*
+         * It is recommended that the transmitter is the last enabled
+         * and the first disabled.
+         */
         switch (cmd) {
         case SNDRV_PCM_TRIGGER_START:
         case SNDRV_PCM_TRIGGER_RESUME:
diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h
index 1571459d13ec..e432260be598 100644
--- a/sound/soc/fsl/fsl_sai.h
+++ b/sound/soc/fsl/fsl_sai.h
@@ -103,6 +103,7 @@ struct fsl_sai {
 
         bool big_endian_regs;
         bool big_endian_data;
+        bool is_dsp_mode;
 
         struct snd_dmaengine_dai_dma_data dma_params_rx;
         struct snd_dmaengine_dai_dma_data dma_params_tx;