ASoC: codec: wm8960: Refactor sysclk freq search

Add a separate function for finding (sysclk, lrclk, bclk)
when the clock is auto or mclk. This makes code easier to
read and reduces the indentation level in wm8960_configure_clocking.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 61 insertions, 19 deletions

diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 3bf081a7e450..25a4a11929fe 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -604,12 +604,71 @@ static const int bclk_divs[] = {
         120, 160, 220, 240, 320, 320, 320
 };
 
+/**
+ * wm8960_configure_sysclk - checks if there is a sysclk frequency available
+ *      The sysclk must be chosen such that:
+ *              - sysclk     = MCLK / sysclk_divs
+ *              - lrclk      = sysclk / dac_divs
+ *              - 10 * bclk  = sysclk / bclk_divs
+ *
+ * @wm8960_priv: wm8960 codec private data
+ * @mclk: MCLK used to derive sysclk
+ * @sysclk_idx: sysclk_divs index for found sysclk
+ * @dac_idx: dac_divs index for found lrclk
+ * @bclk_idx: bclk_divs index for found bclk
+ *
+ * Returns:
+ * -1, in case no sysclk frequency available found
+ *  0, in case an exact (@sysclk_idx, @dac_idx, @bclk_idx) match is found
+ */
+static
+int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk,
+                            int *sysclk_idx, int *dac_idx, int *bclk_idx)
+{
+        int sysclk, bclk, lrclk;
+        int i, j, k;
+        int diff;
+
+        bclk = wm8960->bclk;
+        lrclk = wm8960->lrclk;
+
+        /* check if the sysclk frequency is available. */
+        for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+                if (sysclk_divs[i] == -1)
+                        continue;
+                sysclk = mclk / sysclk_divs[i];
+                for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
+                        if (sysclk != dac_divs[j] * lrclk)
+                                continue;
+                        for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
+                                diff = sysclk - bclk * bclk_divs[k] / 10;
+                                if (diff == 0) {
+                                        *sysclk_idx = i;
+                                        *dac_idx = j;
+                                        *bclk_idx = k;
+                                        break;
+                                }
+                        }
+                        if (k != ARRAY_SIZE(bclk_divs))
+                                break;
+                }
+                if (j != ARRAY_SIZE(dac_divs))
+                        break;
+        }
+
+        if (i != ARRAY_SIZE(sysclk_divs))
+                return 0;
+
+        return -1;
+}
+
 static int wm8960_configure_clocking(struct snd_soc_codec *codec)
 {
         struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
         int sysclk, bclk, lrclk, freq_out, freq_in;
         u16 iface1 = snd_soc_read(codec, WM8960_IFACE1);
         int i, j, k;
+        int ret;
 
         if (!(iface1 & (1<<6))) {
                 dev_dbg(codec->dev,
@@ -643,25 +702,8 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec)
         }
 
         if (wm8960->clk_id != WM8960_SYSCLK_PLL) {
-                /* check if the sysclk frequency is available. */
-                for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
-                        if (sysclk_divs[i] == -1)
-                                continue;
-                        sysclk = freq_out / sysclk_divs[i];
-                        for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
-                                if (sysclk != dac_divs[j] * lrclk)
-                                        continue;
-                                for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k)
-                                        if (sysclk == bclk * bclk_divs[k] / 10)
-                                                break;
-                                if (k != ARRAY_SIZE(bclk_divs))
-                                        break;
-                        }
-                        if (j != ARRAY_SIZE(dac_divs))
-                                break;
-                }
-
-                if (i != ARRAY_SIZE(sysclk_divs)) {
+                ret = wm8960_configure_sysclk(wm8960, freq_out, &i, &j, &k);
+                if (ret == 0) {
                         goto configure_clock;
                 } else if (wm8960->clk_id != WM8960_SYSCLK_AUTO) {
                         dev_err(codec->dev, "failed to configure clock\n");