ASoC: Refresh WM8974 PLL configuration

Move away from a fixed table to runtime calculation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/codecs/wm8974.c b/sound/soc/codecs/wm8974.c
index 207fe3f..d07bd0d 100644 (file)
--- a/sound/soc/codecs/wm8974.c
+++ b/sound/soc/codecs/wm8974.c
@@ -325,51 +325,84 @@ static int wm8974_add_widgets(struct snd_soc_codec *codec)
 }
 
 struct pll_ {
-       unsigned int in_hz, out_hz;
-       unsigned int pre:4; /* prescale - 1 */
+       unsigned int pre_div:4; /* prescale - 1 */
        unsigned int n:4;
        unsigned int k;
 };
 
-static struct pll_ pll[] = {
-       { 12000000, 11289600, 0, 7, 0x86c220 },
-       { 12000000, 12288000, 0, 8, 0x3126e8 },
-       { 13000000, 11289600, 0, 6, 0xf28bd4 },
-       { 13000000, 12288000, 0, 7, 0x8fd525 },
-       { 12288000, 11289600, 0, 7, 0x59999a },
-       { 11289600, 12288000, 0, 8, 0x80dee9 },
-       { 25000000, 11289600, 1, 7, 0x39B024 },
-       { 25000000, 24576000, 1, 7, 0xdd4413 }
-};
+static struct pll_ pll_div;
+
+/* The size in bits of the pll divide multiplied by 10
+ * to allow rounding later */
+#define FIXED_PLL_SIZE ((1 << 24) * 10)
+
+static void pll_factors(unsigned int target, unsigned int source)
+{
+       unsigned long long Kpart;
+       unsigned int K, Ndiv, Nmod;
+
+       Ndiv = target / source;
+       if (Ndiv < 6) {
+               source >>= 1;
+               pll_div.pre_div = 1;
+               Ndiv = target / source;
+       } else
+               pll_div.pre_div = 0;
+
+       if ((Ndiv < 6) || (Ndiv > 12))
+               printk(KERN_WARNING
+                       "WM8974 N value %u outwith recommended range!d\n",
+                       Ndiv);
+
+       pll_div.n = Ndiv;
+       Nmod = target % source;
+       Kpart = FIXED_PLL_SIZE * (long long)Nmod;
+
+       do_div(Kpart, source);
+
+       K = Kpart & 0xFFFFFFFF;
+
+       /* Check if we need to round */
+       if ((K % 10) >= 5)
+               K += 5;
+
+       /* Move down to proper range now rounding is done */
+       K /= 10;
+
+       pll_div.k = K;
+}
 
 static int wm8974_set_dai_pll(struct snd_soc_dai *codec_dai,
                int pll_id, unsigned int freq_in, unsigned int freq_out)
 {
        struct snd_soc_codec *codec = codec_dai->codec;
-       int i;
        u16 reg;
 
        if (freq_in == 0 || freq_out == 0) {
+               /* Clock CODEC directly from MCLK */
+               reg = wm8974_read_reg_cache(codec, WM8974_CLOCK);
+               wm8974_write(codec, WM8974_CLOCK, reg & 0x0ff);
+
+               /* Turn off PLL */
                reg = wm8974_read_reg_cache(codec, WM8974_POWER1);
                wm8974_write(codec, WM8974_POWER1, reg & 0x1df);
                return 0;
        }
 
-       for (i = 0; i < ARRAY_SIZE(pll); i++) {
-               if (freq_in == pll[i].in_hz && freq_out == pll[i].out_hz) {
-                       wm8974_write(codec, WM8974_PLLN,
-                                    (pll[i].pre << 4) | pll[i].n);
-                       wm8974_write(codec, WM8974_PLLK1, pll[i].k >> 18);
-                       wm8974_write(codec, WM8974_PLLK2,
-                                    (pll[i].k >> 9) & 0x1ff);
-                       wm8974_write(codec, WM8974_PLLK3, pll[i].k & 0x1ff);
-                       reg = wm8974_read_reg_cache(codec, WM8974_POWER1);
-                       wm8974_write(codec, WM8974_POWER1, reg | 0x020);
-                       return 0;
-               }
-       }
+       pll_factors(freq_out*4, freq_in);
+
+       wm8974_write(codec, WM8974_PLLN, (pll_div.pre_div << 4) | pll_div.n);
+       wm8974_write(codec, WM8974_PLLK1, pll_div.k >> 18);
+       wm8974_write(codec, WM8974_PLLK2, (pll_div.k >> 9) & 0x1ff);
+       wm8974_write(codec, WM8974_PLLK3, pll_div.k & 0x1ff);
+       reg = wm8974_read_reg_cache(codec, WM8974_POWER1);
+       wm8974_write(codec, WM8974_POWER1, reg | 0x020);
 
-       return -EINVAL;
+       /* Run CODEC from PLL instead of MCLK */
+       reg = wm8974_read_reg_cache(codec, WM8974_CLOCK);
+       wm8974_write(codec, WM8974_CLOCK, reg | 0x100);
+
+       return 0;
 }
 
 /*