ASoC: wm8994: Implement support for self-oscillation mode in the FLL

The FLLs in the WM8994 series devices can be started without any reference
being supplied, mainly for use in analogue bypass cases. Implement support
for this mode.

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

sound/soc/codecs/wm8994.c

@@ -2102,6 +2102,10 @@ static int _wm8994_set_fll(struct snd_soc_codec *codec, int id, int src,
 	case WM8994_FLL_SRC_LRCLK:
 	case WM8994_FLL_SRC_BCLK:
 		break;
+	case WM8994_FLL_SRC_INTERNAL:
+		freq_in = 12000000;
+		freq_out = 12000000;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -2164,9 +2168,11 @@ static int _wm8994_set_fll(struct snd_soc_codec *codec, int id, int src,
 				    fll.n << WM8994_FLL1_N_SHIFT);
 
 	snd_soc_update_bits(codec, WM8994_FLL1_CONTROL_5 + reg_offset,
-			    WM8958_FLL1_BYP |
+			    WM8994_FLL1_FRC_NCO | WM8958_FLL1_BYP |
 			    WM8994_FLL1_REFCLK_DIV_MASK |
 			    WM8994_FLL1_REFCLK_SRC_MASK,
+			    ((src == WM8994_FLL_SRC_INTERNAL)
+			     << WM8994_FLL1_FRC_NCO_SHIFT) |
 			    (fll.clk_ref_div << WM8994_FLL1_REFCLK_DIV_SHIFT) |
 			    (src - 1));
 
@@ -2192,13 +2198,16 @@ static int _wm8994_set_fll(struct snd_soc_codec *codec, int id, int src,
 			}
 		}
 
+		reg = WM8994_FLL1_ENA;
+
 		if (fll.k)
-			reg = WM8994_FLL1_ENA | WM8994_FLL1_FRAC;
-		else
-			reg = WM8994_FLL1_ENA;
+			reg |= WM8994_FLL1_FRAC;
+		if (src == WM8994_FLL_SRC_INTERNAL)
+			reg |= WM8994_FLL1_OSC_ENA;
+
 		snd_soc_update_bits(codec, WM8994_FLL1_CONTROL_1 + reg_offset,
-				    WM8994_FLL1_ENA | WM8994_FLL1_FRAC,
-				    reg);
+				    WM8994_FLL1_ENA | WM8994_FLL1_OSC_ENA |
+				    WM8994_FLL1_FRAC, reg);
 
 		if (wm8994->fll_locked_irq) {
 			timeout = wait_for_completion_timeout(&wm8994->fll_locked[id],

sound/soc/codecs/wm8994.h

@@ -28,10 +28,11 @@
 #define WM8994_FLL1 1
 #define WM8994_FLL2 2
 
-#define WM8994_FLL_SRC_MCLK1  1
-#define WM8994_FLL_SRC_MCLK2  2
-#define WM8994_FLL_SRC_LRCLK  3
-#define WM8994_FLL_SRC_BCLK   4
+#define WM8994_FLL_SRC_MCLK1    1
+#define WM8994_FLL_SRC_MCLK2    2
+#define WM8994_FLL_SRC_LRCLK    3
+#define WM8994_FLL_SRC_BCLK     4
+#define WM8994_FLL_SRC_INTERNAL 5
 
 enum wm8994_vmid_mode {
 	WM8994_VMID_NORMAL,