mfd: wm5110: Add register patch required for low power sleep

Some register settings must be applied before the first time low power
sleep mode is entered on the wm5110 to ensure optimium performance.
These settings require SYSCLK to be enabled whilst they are being
applied. This patch applies the settings using the recently factored out
boot time SYSCLK functionality.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/arizona-core.c

@@ -378,6 +378,35 @@ err:
 	return ret ?: err;
 }
 
+/*
+ * Register patch to some of the CODECs internal write sequences
+ * to ensure a clean exit from the low power sleep state.
+ */
+static const struct reg_default wm5110_sleep_patch[] = {
+	{ 0x337A, 0xC100 },
+	{ 0x337B, 0x0041 },
+	{ 0x3300, 0xA210 },
+	{ 0x3301, 0x050C },
+};
+
+static int wm5110_apply_sleep_patch(struct arizona *arizona)
+{
+	struct arizona_sysclk_state state;
+	int err, ret;
+
+	ret = arizona_enable_freerun_sysclk(arizona, &state);
+	if (ret)
+		return ret;
+
+	ret = regmap_multi_reg_write_bypassed(arizona->regmap,
+					      wm5110_sleep_patch,
+					      ARRAY_SIZE(wm5110_sleep_patch));
+
+	err = arizona_disable_freerun_sysclk(arizona, &state);
+
+	return ret ?: err;
+}
+
 static int wm5102_clear_write_sequencer(struct arizona *arizona)
 {
 	int ret;
@@ -966,6 +995,16 @@ int arizona_dev_init(struct arizona *arizona)
 				goto err_reset;
 			}
 			break;
+		case WM5110:
+		case WM8280:
+			ret = wm5110_apply_sleep_patch(arizona);
+			if (ret) {
+				dev_err(arizona->dev,
+					"Failed to apply sleep patch: %d\n",
+					ret);
+				goto err_reset;
+			}
+			break;
 		default:
 			break;
 		}