[PATCH v4 5/7] pinctrl: qcom: Acknowledge IRQs for PDC interrupt controller

[Maulik Shah <maulik.shah@oss.qualcomm.com>]

From: Stephan Gerhold <stephan.gerhold@linaro.org>

PDC needs to acknowledge incoming GPIO interrupts to clear the latched
interrupt status in secondary mode of PDC. For level-triggered IRQs this
happens automatically in irq_eoi() but for edge-triggered IRQs this needs
to happen as early as possible in the IRQ handler.

Implement this by using handle_fasteoi_ack_irq() as IRQ handler in this
situation and forward the irq_ack() callback to the parent IRQ chip.

Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
---
 drivers/pinctrl/qcom/pinctrl-msm.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
index fe94ce5f9b81..9c720f49465b 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -994,6 +994,16 @@ static void msm_gpio_irq_ack(struct irq_data *d)
 	if (test_bit(d->hwirq, pctrl->skip_wake_irqs)) {
 		if (test_bit(d->hwirq, pctrl->dual_edge_irqs))
 			msm_gpio_update_dual_edge_parent(d);
+
+		/*
+		 * During early initialization of the IRQ hierarchy,
+		 * irq_ack() is called by __irq_set_handler() before
+		 * the parent IRQ chip has been set up. This is why
+		 * we additionally need to check for d->parent_data->chip.
+		 */
+
+		if (d->parent_data->chip && d->parent_data->chip->irq_ack)
+			irq_chip_ack_parent(d);
 		return;
 	}
 
@@ -1064,7 +1074,10 @@ static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 
 	if (test_bit(d->hwirq, pctrl->skip_wake_irqs)) {
 		clear_bit(d->hwirq, pctrl->dual_edge_irqs);
-		irq_set_handler_locked(d, handle_fasteoi_irq);
+		if (type & IRQ_TYPE_LEVEL_MASK)
+			irq_set_handler_locked(d, handle_fasteoi_irq);
+		else
+			irq_set_handler_locked(d, handle_fasteoi_ack_irq);
 		return 0;
 	}
 

-- 
2.43.0