mfd: wm8994: Emulate level triggered interrupts if required

The interrupt controller on the wm8994 series of devices requires a level
triggered parent. If one is not available but a GPIO is available for the
interrupt then emulate.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/linux/mfd/wm8994/core.h

@@ -29,6 +29,7 @@ enum wm8994_type {
 
 struct regulator_dev;
 struct regulator_bulk_data;
+struct irq_domain;
 
 #define WM8994_NUM_GPIO_REGS 11
 #define WM8994_NUM_LDO_REGS   2
@@ -73,6 +74,7 @@ struct wm8994 {
 
 	int irq;
 	struct regmap_irq_chip_data *irq_data;
+	struct irq_domain *edge_irq;
 
 	/* Used over suspend/resume */
 	bool suspended;

include/linux/mfd/wm8994/pdata.h

@@ -223,6 +223,11 @@ struct wm8994_pdata {
 	 * lines is mastered.
 	 */
 	int max_channels_clocked[WM8994_NUM_AIF];
+
+	/**
+	 * GPIO for the IRQ pin if host only supports edge triggering
+	 */
+	int irq_gpio;
 };
 
 #endif