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>

1 files changed, 101 insertions, 29 deletions

diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index 219d1d54f536..c3884861e8cb 100644
--- 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);