ASoC: atmel_ssc_dai: if not provided, default to sensible dividers

When this driver masters BCLK and/or LRCLK, and noone has stated
differently, assume that all the bits of a frame are used.

This relieves the cpu dai users from the duty to fill in the dividers for
the common case.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
index 16e459aedffe4c3a4af7733b9ea6cf22087c7fa2..a1e2c5682dcda82b5c04566f6d773659dcc4bb47 100644 (file)
--- a/sound/soc/atmel/atmel_ssc_dai.c
+++ b/sound/soc/atmel/atmel_ssc_dai.c
@@ -380,6 +380,7 @@ static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
                ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
                /* Clear the SSC dividers */
                ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
+               ssc_p->forced_divider = 0;
        }
        spin_unlock_irq(&ssc_p->lock);
 
@@ -426,14 +427,17 @@ static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
                else
                        if (div != ssc_p->cmr_div)
                                return -EBUSY;
+               ssc_p->forced_divider |= BIT(ATMEL_SSC_CMR_DIV);
                break;
 
        case ATMEL_SSC_TCMR_PERIOD:
                ssc_p->tcmr_period = div;
+               ssc_p->forced_divider |= BIT(ATMEL_SSC_TCMR_PERIOD);
                break;
 
        case ATMEL_SSC_RCMR_PERIOD:
                ssc_p->rcmr_period = div;
+               ssc_p->forced_divider |= BIT(ATMEL_SSC_RCMR_PERIOD);
                break;
 
        default:
@@ -443,6 +447,28 @@ static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
        return 0;
 }
 
+/* Is the cpu-dai master of the frame clock? */
+static int atmel_ssc_cfs(struct atmel_ssc_info *ssc_p)
+{
+       switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
+       case SND_SOC_DAIFMT_CBM_CFS:
+       case SND_SOC_DAIFMT_CBS_CFS:
+               return 1;
+       }
+       return 0;
+}
+
+/* Is the cpu-dai master of the bit clock? */
+static int atmel_ssc_cbs(struct atmel_ssc_info *ssc_p)
+{
+       switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
+       case SND_SOC_DAIFMT_CBS_CFM:
+       case SND_SOC_DAIFMT_CBS_CFS:
+               return 1;
+       }
+       return 0;
+}
+
 /*
  * Configure the SSC.
  */
@@ -459,6 +485,9 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
        u32 tfmr, rfmr, tcmr, rcmr;
        int ret;
        int fslen, fslen_ext;
+       u32 cmr_div;
+       u32 tcmr_period;
+       u32 rcmr_period;
 
        /*
         * Currently, there is only one set of dma params for
@@ -470,6 +499,46 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
        else
                dir = 1;
 
+       /*
+        * If the cpu dai should provide BCLK, but noone has provided the
+        * divider needed for that to work, fall back to something sensible.
+        */
+       cmr_div = ssc_p->cmr_div;
+       if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_CMR_DIV)) &&
+           atmel_ssc_cbs(ssc_p)) {
+               int bclk_rate = snd_soc_params_to_bclk(params);
+
+               if (bclk_rate < 0) {
+                       dev_err(dai->dev, "unable to calculate cmr_div: %d\n",
+                               bclk_rate);
+                       return bclk_rate;
+               }
+
+               cmr_div = DIV_ROUND_CLOSEST(ssc_p->mck_rate, 2 * bclk_rate);
+       }
+
+       /*
+        * If the cpu dai should provide LRCLK, but noone has provided the
+        * dividers needed for that to work, fall back to something sensible.
+        */
+       tcmr_period = ssc_p->tcmr_period;
+       rcmr_period = ssc_p->rcmr_period;
+       if (atmel_ssc_cfs(ssc_p)) {
+               int frame_size = snd_soc_params_to_frame_size(params);
+
+               if (frame_size < 0) {
+                       dev_err(dai->dev,
+                               "unable to calculate tx/rx cmr_period: %d\n",
+                               frame_size);
+                       return frame_size;
+               }
+
+               if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_TCMR_PERIOD)))
+                       tcmr_period = frame_size / 2 - 1;
+               if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_RCMR_PERIOD)))
+                       rcmr_period = frame_size / 2 - 1;
+       }
+
        dma_params = ssc_p->dma_params[dir];
 
        channels = params_channels(params);
@@ -524,7 +593,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
                fslen_ext = (bits - 1) / 16;
                fslen = (bits - 1) % 16;
 
-               rcmr =    SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period)
+               rcmr =    SSC_BF(RCMR_PERIOD, rcmr_period)
                        | SSC_BF(RCMR_STTDLY, START_DELAY)
                        | SSC_BF(RCMR_START, SSC_START_FALLING_RF)
                        | SSC_BF(RCMR_CKI, SSC_CKI_RISING)
@@ -540,7 +609,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
                        | SSC_BF(RFMR_LOOP, 0)
                        | SSC_BF(RFMR_DATLEN, (bits - 1));
 
-               tcmr =    SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period)
+               tcmr =    SSC_BF(TCMR_PERIOD, tcmr_period)
                        | SSC_BF(TCMR_STTDLY, START_DELAY)
                        | SSC_BF(TCMR_START, SSC_START_FALLING_RF)
                        | SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
@@ -606,7 +675,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
                fslen_ext = (bits - 1) / 16;
                fslen = (bits - 1) % 16;
 
-               rcmr =    SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period)
+               rcmr =    SSC_BF(RCMR_PERIOD, rcmr_period)
                        | SSC_BF(RCMR_STTDLY, START_DELAY)
                        | SSC_BF(RCMR_START, SSC_START_FALLING_RF)
                        | SSC_BF(RCMR_CKI, SSC_CKI_RISING)
@@ -623,7 +692,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
                        | SSC_BF(RFMR_LOOP, 0)
                        | SSC_BF(RFMR_DATLEN, (bits - 1));
 
-               tcmr =    SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period)
+               tcmr =    SSC_BF(TCMR_PERIOD, tcmr_period)
                        | SSC_BF(TCMR_STTDLY, START_DELAY)
                        | SSC_BF(TCMR_START, SSC_START_FALLING_RF)
                        | SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
@@ -650,7 +719,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
                 * MCK divider, and the BCLK signal is output
                 * on the SSC TK line.
                 */
-               rcmr =    SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period)
+               rcmr =    SSC_BF(RCMR_PERIOD, rcmr_period)
                        | SSC_BF(RCMR_STTDLY, 1)
                        | SSC_BF(RCMR_START, SSC_START_RISING_RF)
                        | SSC_BF(RCMR_CKI, SSC_CKI_RISING)
@@ -665,7 +734,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
                        | SSC_BF(RFMR_LOOP, 0)
                        | SSC_BF(RFMR_DATLEN, (bits - 1));
 
-               tcmr =    SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period)
+               tcmr =    SSC_BF(TCMR_PERIOD, tcmr_period)
                        | SSC_BF(TCMR_STTDLY, 1)
                        | SSC_BF(TCMR_START, SSC_START_RISING_RF)
                        | SSC_BF(TCMR_CKI, SSC_CKI_FALLING)
@@ -760,7 +829,7 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
        }
 
        /* set SSC clock mode register */
-       ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->cmr_div);
+       ssc_writel(ssc_p->ssc->regs, CMR, cmr_div);
 
        /* set receive clock mode and format */
        ssc_writel(ssc_p->ssc->regs, RCMR, rcmr);

diff --git a/sound/soc/atmel/atmel_ssc_dai.h b/sound/soc/atmel/atmel_ssc_dai.h
index 80b153857a88ac25e86d3c4df1fc6ad45f108dc7..75194f5821317411d323c918b1db5cfab9d38f47 100644 (file)
--- a/sound/soc/atmel/atmel_ssc_dai.h
+++ b/sound/soc/atmel/atmel_ssc_dai.h
@@ -113,6 +113,7 @@ struct atmel_ssc_info {
        unsigned short cmr_div;
        unsigned short tcmr_period;
        unsigned short rcmr_period;
+       unsigned int forced_divider;
        struct atmel_pcm_dma_params *dma_params[2];
        struct atmel_ssc_state ssc_state;
        unsigned long mck_rate;