mfd: madera: Add shared data for accessory detection

Add variables to struct madera that will be shared by the
extcon and audio codec drivers to synchronize output state
during accessory detection. Also add a mutex to protect
the DAPM pointer.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/madera-core.c

@@ -15,6 +15,7 @@
 #include <linux/gpio.h>
 #include <linux/mfd/core.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/notifier.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
@@ -357,6 +358,8 @@ int madera_dev_init(struct madera *madera)
 
 	dev_set_drvdata(madera->dev, madera);
 	BLOCKING_INIT_NOTIFIER_HEAD(&madera->notifier);
+	mutex_init(&madera->dapm_ptr_lock);
+
 	madera_set_micbias_info(madera);
 
 	/*