ASoC: arizona: Support new fratio encoding on the wm5110 rev D

The reference clock path on newer IP FLLs requires a different
configuration, and should avoid integer mode operation. This patch adds
support for both the new encoding and updates the calculation.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index 219d1d5..c388486 100644 (file)
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -53,8 +53,10 @@
 #define ARIZONA_AIF_RX_ENABLES                  0x1A
 #define ARIZONA_AIF_FORCE_WRITE                 0x1B
 
+#define ARIZONA_FLL_VCO_CORNER 141900000
 #define ARIZONA_FLL_MAX_FREF   13500000
 #define ARIZONA_FLL_MIN_FVCO   90000000
+#define ARIZONA_FLL_MAX_FRATIO 16
 #define ARIZONA_FLL_MAX_REFDIV 8
 #define ARIZONA_FLL_MIN_OUTDIV 2
 #define ARIZONA_FLL_MAX_OUTDIV 7
@@ -1406,9 +1408,99 @@ static int arizona_validate_fll(struct arizona_fll *fll,
        return 0;
 }
 
+static int arizona_find_fratio(unsigned int Fref, int *fratio)
+{
+       int i;
+
+       /* Find an appropriate FLL_FRATIO */
+       for (i = 0; i < ARRAY_SIZE(fll_fratios); i++) {
+               if (fll_fratios[i].min <= Fref && Fref <= fll_fratios[i].max) {
+                       if (fratio)
+                               *fratio = fll_fratios[i].fratio;
+                       return fll_fratios[i].ratio;
+               }
+       }
+
+       return -EINVAL;
+}
+
+static int arizona_calc_fratio(struct arizona_fll *fll,
+                              struct arizona_fll_cfg *cfg,
+                              unsigned int target,
+                              unsigned int Fref, bool sync)
+{
+       int init_ratio, ratio;
+       int refdiv, div;
+
+       /* Fref must be <=13.5MHz, find initial refdiv */
+       div = 1;
+       cfg->refdiv = 0;
+       while (Fref > ARIZONA_FLL_MAX_FREF) {
+               div *= 2;
+               Fref /= 2;
+               cfg->refdiv++;
+
+               if (div > ARIZONA_FLL_MAX_REFDIV)
+                       return -EINVAL;
+       }
+
+       /* Find an appropriate FLL_FRATIO */
+       init_ratio = arizona_find_fratio(Fref, &cfg->fratio);
+       if (init_ratio < 0) {
+               arizona_fll_err(fll, "Unable to find FRATIO for Fref=%uHz\n",
+                               Fref);
+               return init_ratio;
+       }
+
+       switch (fll->arizona->type) {
+       case WM5110:
+               if (fll->arizona->rev < 3 || sync)
+                       return init_ratio;
+               break;
+       default:
+               return init_ratio;
+       }
+
+       cfg->fratio = init_ratio - 1;
+
+       /* Adjust FRATIO/refdiv to avoid integer mode if possible */
+       refdiv = cfg->refdiv;
+
+       while (div <= ARIZONA_FLL_MAX_REFDIV) {
+               for (ratio = init_ratio; ratio <= ARIZONA_FLL_MAX_FRATIO;
+                    ratio++) {
+                       if (target % (ratio * Fref)) {
+                               cfg->refdiv = refdiv;
+                               cfg->fratio = ratio - 1;
+                               return ratio;
+                       }
+               }
+
+               for (ratio = init_ratio - 1; ratio >= 0; ratio--) {
+                       if (ARIZONA_FLL_VCO_CORNER / (fll->vco_mult * ratio) <
+                           Fref)
+                               break;
+
+                       if (target % (ratio * Fref)) {
+                               cfg->refdiv = refdiv;
+                               cfg->fratio = ratio - 1;
+                               return ratio;
+                       }
+               }
+
+               div *= 2;
+               Fref /= 2;
+               refdiv++;
+               init_ratio = arizona_find_fratio(Fref, NULL);
+       }
+
+       arizona_fll_warn(fll, "Falling back to integer mode operation\n");
+       return cfg->fratio + 1;
+}
+
 static int arizona_calc_fll(struct arizona_fll *fll,
                            struct arizona_fll_cfg *cfg,
-                           unsigned int Fref)
+                           unsigned int Fref, bool sync)
 {
        unsigned int target, div, gcd_fll;
        int i, ratio;
@@ -1427,33 +1519,13 @@ static int arizona_calc_fll(struct arizona_fll *fll,
 
        arizona_fll_dbg(fll, "Fvco=%dHz\n", target);
 
-       /* Fref must be <=13.5MHz */
-       div = 1;
-       cfg->refdiv = 0;
-       while ((Fref / div) > ARIZONA_FLL_MAX_FREF) {
-               div *= 2;
-               cfg->refdiv++;
-
-               if (div > ARIZONA_FLL_MAX_REFDIV)
-                       return -EINVAL;
-       }
+       /* Find an appropriate FLL_FRATIO and refdiv */
+       ratio = arizona_calc_fratio(fll, cfg, target, Fref, sync);
+       if (ratio < 0)
+               return ratio;
 
        /* Apply the division for our remaining calculations */
-       Fref /= div;
-
-       /* Find an appropraite FLL_FRATIO and factor it out of the target */
-       for (i = 0; i < ARRAY_SIZE(fll_fratios); i++) {
-               if (fll_fratios[i].min <= Fref && Fref <= fll_fratios[i].max) {
-                       cfg->fratio = fll_fratios[i].fratio;
-                       ratio = fll_fratios[i].ratio;
-                       break;
-               }
-       }
-       if (i == ARRAY_SIZE(fll_fratios)) {
-               arizona_fll_err(fll, "Unable to find FRATIO for Fref=%uHz\n",
-                               Fref);
-               return -EINVAL;
-       }
+       Fref = Fref / (1 << cfg->refdiv);
 
        cfg->n = target / (ratio * Fref);
 
@@ -1564,19 +1636,19 @@ static void arizona_enable_fll(struct arizona_fll *fll)
         */
        if (fll->ref_src >= 0 && fll->ref_freq &&
            fll->ref_src != fll->sync_src) {
-               arizona_calc_fll(fll, &cfg, fll->ref_freq);
+               arizona_calc_fll(fll, &cfg, fll->ref_freq, false);
 
                arizona_apply_fll(arizona, fll->base, &cfg, fll->ref_src,
                                  false);
                if (fll->sync_src >= 0) {
-                       arizona_calc_fll(fll, &cfg, fll->sync_freq);
+                       arizona_calc_fll(fll, &cfg, fll->sync_freq, true);
 
                        arizona_apply_fll(arizona, fll->base + 0x10, &cfg,
                                          fll->sync_src, true);
                        use_sync = true;
                }
        } else if (fll->sync_src >= 0) {
-               arizona_calc_fll(fll, &cfg, fll->sync_freq);
+               arizona_calc_fll(fll, &cfg, fll->sync_freq, false);
 
                arizona_apply_fll(arizona, fll->base, &cfg,
                                  fll->sync_src, false);