ASoC: davinci-mcasp: Get rid of bclk_lrclk_ratio in private data

The slot_width is for essentially same thing. Instead of storing
bclk_lrclk_ratio, just store the slot_width. Comments has been updated
accordingly and some variable names changed to more descriptive.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index fa47a39..452f2a3 100644 (file)
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -87,7 +87,6 @@ struct davinci_mcasp {
        u8      *serial_dir;
        u8      version;
        u8      bclk_div;
-       u16     bclk_lrclk_ratio;
        int     streams;
        u32     irq_request[2];
        int     dma_request[2];
@@ -558,8 +557,21 @@ static int __davinci_mcasp_set_clkdiv(struct snd_soc_dai *dai, int div_id,
                        mcasp->bclk_div = div;
                break;
 
-       case 2:         /* BCLK/LRCLK ratio */
-               mcasp->bclk_lrclk_ratio = div;
+       case 2: /*
+                * BCLK/LRCLK ratio descries how many bit-clock cycles
+                * fit into one frame. The clock ratio is given for a
+                * full period of data (for I2S format both left and
+                * right channels), so it has to be divided by number
+                * of tdm-slots (for I2S - divided by 2).
+                * Instead of storing this ratio, we calculate a new
+                * tdm_slot width by dividing the the ratio by the
+                * number of configured tdm slots.
+                */
+               mcasp->slot_width = div / mcasp->tdm_slots;
+               if (div % mcasp->tdm_slots)
+                       dev_warn(mcasp->dev,
+                                "%s(): BCLK/LRCLK %d is not divisible by %d tdm slots",
+                                __func__, div, mcasp->tdm_slots);
                break;
 
        default:
@@ -677,11 +689,13 @@ static int davinci_mcasp_set_tdm_slot(struct snd_soc_dai *dai,
 }
 
 static int davinci_config_channel_size(struct davinci_mcasp *mcasp,
-                                      int word_length)
+                                      int sample_width)
 {
        u32 fmt;
-       u32 tx_rotate = (word_length / 4) & 0x7;
-       u32 mask = (1ULL << word_length) - 1;
+       u32 tx_rotate = (sample_width / 4) & 0x7;
+       u32 mask = (1ULL << sample_width) - 1;
+       u32 slot_width = sample_width;
+
        /*
         * For captured data we should not rotate, inversion and masking is
         * enoguh to get the data to the right position:
@@ -694,31 +708,23 @@ static int davinci_config_channel_size(struct davinci_mcasp *mcasp,
        u32 rx_rotate = 0;
 
        /*
-        * if s BCLK-to-LRCLK ratio has been configured via the set_clkdiv()
-        * callback, take it into account here. That allows us to for example
-        * send 32 bits per channel to the codec, while only 16 of them carry
-        * audio payload.
-        * The clock ratio is given for a full period of data (for I2S format
-        * both left and right channels), so it has to be divided by number of
-        * tdm-slots (for I2S - divided by 2).
+        * Setting the tdm slot width either with set_clkdiv() or
+        * set_tdm_slot() allows us to for example send 32 bits per
+        * channel to the codec, while only 16 of them carry audio
+        * payload.
         */
-       if (mcasp->bclk_lrclk_ratio) {
-               u32 slot_length = mcasp->bclk_lrclk_ratio / mcasp->tdm_slots;
-
+       if (mcasp->slot_width) {
                /*
-                * When we have more bclk then it is needed for the data, we
-                * need to use the rotation to move the received samples to have
-                * correct alignment.
+                * When we have more bclk then it is needed for the
+                * data, we need to use the rotation to move the
+                * received samples to have correct alignment.
                 */
-               rx_rotate = (slot_length - word_length) / 4;
-               word_length = slot_length;
-       } else if (mcasp->slot_width) {
-               rx_rotate = (mcasp->slot_width - word_length) / 4;
-               word_length = mcasp->slot_width;
+               slot_width = mcasp->slot_width;
+               rx_rotate = (slot_width - sample_width) / 4;
        }
 
        /* mapping of the XSSZ bit-field as described in the datasheet */
-       fmt = (word_length >> 1) - 1;
+       fmt = (slot_width >> 1) - 1;
 
        if (mcasp->op_mode != DAVINCI_MCASP_DIT_MODE) {
                mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, RXSSZ(fmt),