Merge remote-tracking branches 'asoc/topic/wm8960', 'asoc/topic/wm8978' and 'asoc...
[sfrench/cifs-2.6.git] / sound / soc / codecs / wm8960.c
index 3bf081a7e450993324bb435887aedd23d0bc578f..9ed4557009542b8773806875dbcbc63ee3a8cac5 100644 (file)
@@ -604,12 +604,150 @@ 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
+ *
+ *     If we cannot find an exact match for (sysclk, lrclk, bclk)
+ *     triplet, we relax the bclk such that bclk is chosen as the
+ *     closest available frequency greater than expected bclk.
+ *
+ * @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 we could derive bclk and lrclk from sysclk using
+ *      (@sysclk_idx, @dac_idx, @bclk_idx) dividers
+ */
+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, closest = mclk;
+
+       /* marker for no match */
+       *bclk_idx = -1;
+
+       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 (diff > 0 && closest > diff) {
+                                       *sysclk_idx = i;
+                                       *dac_idx = j;
+                                       *bclk_idx = k;
+                                       closest = diff;
+                               }
+                       }
+                       if (k != ARRAY_SIZE(bclk_divs))
+                               break;
+               }
+               if (j != ARRAY_SIZE(dac_divs))
+                       break;
+       }
+       return *bclk_idx;
+}
+
+/**
+ * wm8960_configure_pll - checks if there is a PLL out frequency available
+ *     The PLL out frequency must be chosen such that:
+ *             - sysclk      = lrclk * dac_divs
+ *             - freq_out    = sysclk * sysclk_divs
+ *             - 10 * sysclk = bclk * bclk_divs
+ *
+ *     If we cannot find an exact match for (sysclk, lrclk, bclk)
+ *     triplet, we relax the bclk such that bclk is chosen as the
+ *     closest available frequency greater than expected bclk.
+ *
+ * @codec: codec structure
+ * @freq_in: input frequency used to derive freq out via PLL
+ * @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:
+ * < 0, in case no PLL frequency out available was found
+ * >=0, in case we could derive bclk, lrclk, sysclk from PLL out using
+ *      (@sysclk_idx, @dac_idx, @bclk_idx) dividers
+ */
+static
+int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
+                        int *sysclk_idx, int *dac_idx, int *bclk_idx)
+{
+       struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
+       int sysclk, bclk, lrclk, freq_out;
+       int diff, closest, best_freq_out;
+       int i, j, k;
+
+       bclk = wm8960->bclk;
+       lrclk = wm8960->lrclk;
+       closest = freq_in;
+
+       best_freq_out = -EINVAL;
+       *sysclk_idx = *dac_idx = *bclk_idx = -1;
+
+       for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
+               if (sysclk_divs[i] == -1)
+                       continue;
+               for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
+                       sysclk = lrclk * dac_divs[j];
+                       freq_out = sysclk * sysclk_divs[i];
+
+                       for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
+                               if (!is_pll_freq_available(freq_in, freq_out))
+                                       continue;
+
+                               diff = sysclk - bclk * bclk_divs[k] / 10;
+                               if (diff == 0) {
+                                       *sysclk_idx = i;
+                                       *dac_idx = j;
+                                       *bclk_idx = k;
+                                       return freq_out;
+                               }
+                               if (diff > 0 && closest > diff) {
+                                       *sysclk_idx = i;
+                                       *dac_idx = j;
+                                       *bclk_idx = k;
+                                       closest = diff;
+                                       best_freq_out = freq_out;
+                               }
+                       }
+               }
+       }
+
+       return best_freq_out;
+}
 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;
+       int 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,
@@ -623,8 +761,6 @@ static int wm8960_configure_clocking(struct snd_soc_codec *codec)
        }
 
        freq_in = wm8960->freq_in;
-       bclk = wm8960->bclk;
-       lrclk = wm8960->lrclk;
        /*
         * If it's sysclk auto mode, check if the MCLK can provide sysclk or
         * not. If MCLK can provide sysclk, using MCLK to provide sysclk
@@ -643,60 +779,21 @@ 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");
                        return -EINVAL;
                }
        }
-       /* get a available pll out frequency and set pll */
-       for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
-               if (sysclk_divs[i] == -1)
-                       continue;
-               for (j = 0; j < ARRAY_SIZE(dac_divs); ++j) {
-                       sysclk = lrclk * dac_divs[j];
-                       freq_out = sysclk * sysclk_divs[i];
 
-                       for (k = 0; k < ARRAY_SIZE(bclk_divs); ++k) {
-                               if (sysclk == bclk * bclk_divs[k] / 10 &&
-                                   is_pll_freq_available(freq_in, freq_out)) {
-                                       wm8960_set_pll(codec,
-                                                      freq_in, freq_out);
-                                       break;
-                               } else {
-                                       continue;
-                               }
-                       }
-                       if (k != ARRAY_SIZE(bclk_divs))
-                               break;
-               }
-               if (j != ARRAY_SIZE(dac_divs))
-                       break;
-       }
-
-       if (i == ARRAY_SIZE(sysclk_divs)) {
-               dev_err(codec->dev, "failed to configure clock\n");
-               return -EINVAL;
+       freq_out = wm8960_configure_pll(codec, freq_in, &i, &j, &k);
+       if (freq_out < 0) {
+               dev_err(codec->dev, "failed to configure clock via PLL\n");
+               return freq_out;
        }
+       wm8960_set_pll(codec, freq_in, freq_out);
 
 configure_clock:
        /* configure sysclk clock */