irqchip/qcom-pdc: Add irqchip set/get state calls

Add irqchip calls to set/get interrupt state from the parent interrupt
controller. When GPIOs are renabled as interrupt lines, it is desirable
to clear the interrupt state at the GIC. This avoids any unwanted
interrupt as a result of stale pending state recorded when the line was
used as a GPIO.

Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
[Lina: updated commit text, rearranged code]
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1573855915-9841-8-git-send-email-ilina@codeaurora.org

drivers/irqchip/qcom-pdc.c

@@ -5,6 +5,7 @@
 
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irqchip.h>
 #include <linux/irqdomain.h>
@@ -50,6 +51,26 @@ static u32 pdc_reg_read(int reg, u32 i)
 	return readl_relaxed(pdc_base + reg + i * sizeof(u32));
 }
 
+static int qcom_pdc_gic_get_irqchip_state(struct irq_data *d,
+					  enum irqchip_irq_state which,
+					  bool *state)
+{
+	if (d->hwirq == GPIO_NO_WAKE_IRQ)
+		return 0;
+
+	return irq_chip_get_parent_state(d, which, state);
+}
+
+static int qcom_pdc_gic_set_irqchip_state(struct irq_data *d,
+					  enum irqchip_irq_state which,
+					  bool value)
+{
+	if (d->hwirq == GPIO_NO_WAKE_IRQ)
+		return 0;
+
+	return irq_chip_set_parent_state(d, which, value);
+}
+
 static void pdc_enable_intr(struct irq_data *d, bool on)
 {
 	int pin_out = d->hwirq;
@@ -178,6 +199,8 @@ static struct irq_chip qcom_pdc_gic_chip = {
 	.irq_unmask		= qcom_pdc_gic_unmask,
 	.irq_disable		= qcom_pdc_gic_disable,
 	.irq_enable		= qcom_pdc_gic_enable,
+	.irq_get_irqchip_state	= qcom_pdc_gic_get_irqchip_state,
+	.irq_set_irqchip_state	= qcom_pdc_gic_set_irqchip_state,
 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
 	.irq_set_type		= qcom_pdc_gic_set_type,
 	.flags			= IRQCHIP_MASK_ON_SUSPEND |