[PATCH 14/25] ASoC: sun8i-codec: Correct the BCLK divisor calculation

[Samuel Holland]

Previously, the BCLK divisor calculation assumed a power-of-two slot
width and exactly two slots. In order to support the TDM slot binding
and 20/24-bit word sizes, those assumptions must be removed.

Due to hardware limitations, the BCLK/LRCK ratio is not as simple as
"slot_width * slots". However, the correct value is already calculated
elsewhere in this function, since it must also be programmed into the
hardware. Reuse that value to calculate the correct SYSCLK/BCLK divisor.

Signed-off-by: Samuel Holland <sam...@sholland.org>
---
 sound/soc/sunxi/sun8i-codec.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/sound/soc/sunxi/sun8i-codec.c b/sound/soc/sunxi/sun8i-codec.c
index 779853d023fe..78feed37aa42 100644
--- a/sound/soc/sunxi/sun8i-codec.c
+++ b/sound/soc/sunxi/sun8i-codec.c
@@ -279,21 +279,21 @@ static const struct sun8i_codec_clk_div 
sun8i_codec_bclk_div[] = {
        { .div = 48,    .val = 9 },
        { .div = 64,    .val = 10 },
        { .div = 96,    .val = 11 },
        { .div = 128,   .val = 12 },
        { .div = 192,   .val = 13 },
 };
 
 static u8 sun8i_codec_get_bclk_div(struct sun8i_codec *scodec,
-                                  unsigned int rate,
-                                  unsigned int word_size)
+                                  unsigned int lrck_div_order,
+                                  unsigned int sample_rate)
 {
        unsigned long clk_rate = clk_get_rate(scodec->clk_module);
-       unsigned int div = clk_rate / rate / word_size / 2;
+       unsigned int div = clk_rate / sample_rate >> lrck_div_order;
        unsigned int best_val = 0, best_diff = ~0;
        int i;
 
        for (i = 0; i < ARRAY_SIZE(sun8i_codec_bclk_div); i++) {
                const struct sun8i_codec_clk_div *bdiv = 
&sun8i_codec_bclk_div[i];
                unsigned int diff = abs(bdiv->div - div);
 
                if (diff < best_diff) {
@@ -343,30 +343,31 @@ static int sun8i_codec_hw_params(struct snd_pcm_substream 
*substream,
        default:
                return -EINVAL;
        }
 
        regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL,
                           SUN8I_AIF1CLK_CTRL_AIF1_WORD_SIZ_MASK,
                           word_size << SUN8I_AIF1CLK_CTRL_AIF1_WORD_SIZ);
 
-       bclk_div = sun8i_codec_get_bclk_div(scodec, params_rate(params), 16);
-       regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL,
-                          SUN8I_AIF1CLK_CTRL_AIF1_BCLK_DIV_MASK,
-                          bclk_div << SUN8I_AIF1CLK_CTRL_AIF1_BCLK_DIV);
-
        /* LRCK divider (BCLK/LRCK ratio) */
        lrck_div_order = sun8i_codec_get_lrck_div_order(slots, slot_width);
        if (lrck_div_order < 0)
                return lrck_div_order;
 
        regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL,
                           SUN8I_AIF1CLK_CTRL_AIF1_LRCK_DIV_MASK,
                           (lrck_div_order - 4) << 
SUN8I_AIF1CLK_CTRL_AIF1_LRCK_DIV);
 
+       /* BCLK divider (SYSCLK/BCLK ratio) */
+       bclk_div = sun8i_codec_get_bclk_div(scodec, lrck_div_order, 
params_rate(params));
+       regmap_update_bits(scodec->regmap, SUN8I_AIF1CLK_CTRL,
+                          SUN8I_AIF1CLK_CTRL_AIF1_BCLK_DIV_MASK,
+                          bclk_div << SUN8I_AIF1CLK_CTRL_AIF1_BCLK_DIV);
+
        sample_rate = sun8i_codec_get_hw_rate(params);
        if (sample_rate < 0)
                return sample_rate;
 
        regmap_update_bits(scodec->regmap, SUN8I_SYS_SR_CTRL,
                           SUN8I_SYS_SR_CTRL_AIF1_FS_MASK,
                           sample_rate << SUN8I_SYS_SR_CTRL_AIF1_FS);
 
-- 
2.26.2