[PATCH] pinctrl: armada-37xx: Add edge both type gpio irq support

From: Gregory CLEMENT
Date: Thu Oct 19 2017 - 09:10:54 EST


From: Ken Ma <make@xxxxxxxxxxx>

Current edge both type gpio irqs which need to swap polarity in each
interrupt are not supported, this patch adds edge both type gpio irq
support.

Signed-off-by: Ken Ma <make@xxxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
---
drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 64 +++++++++++++++++++++++++++++
1 file changed, 64 insertions(+)

diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
index 71b944748304..4e8d836a8c6f 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
@@ -576,6 +576,19 @@ static int armada_37xx_irq_set_type(struct irq_data *d, unsigned int type)
case IRQ_TYPE_EDGE_FALLING:
val |= (BIT(d->hwirq % GPIO_PER_REG));
break;
+ case IRQ_TYPE_EDGE_BOTH: {
+ u32 in_val, in_reg = INPUT_VAL;
+
+ armada_37xx_irq_update_reg(&in_reg, d);
+ regmap_read(info->regmap, in_reg, &in_val);
+
+ /* Set initial polarity based on current input level. */
+ if (in_val & d->mask)
+ val |= d->mask; /* falling */
+ else
+ val &= ~d->mask; /* rising */
+ break;
+ }
default:
spin_unlock_irqrestore(&info->irq_lock, flags);
return -EINVAL;
@@ -586,6 +599,40 @@ static int armada_37xx_irq_set_type(struct irq_data *d, unsigned int type)
return 0;
}

+static int armada_37xx_edge_both_irq_swap_pol(struct armada_37xx_pinctrl *info,
+ u32 pin_idx)
+{
+ u32 reg_idx = pin_idx / GPIO_PER_REG;
+ u32 bit_num = pin_idx % GPIO_PER_REG;
+ u32 p, l, ret;
+ unsigned long flags;
+
+ regmap_read(info->regmap, INPUT_VAL + 4*reg_idx, &l);
+
+ spin_lock_irqsave(&info->irq_lock, flags);
+ p = readl(info->base + IRQ_POL + 4 * reg_idx);
+ if ((p ^ l) & (1 << bit_num)) {
+ /*
+ * For the gpios which are used for both-edge irqs, when their
+ * interrupts happen, their input levels are changed,
+ * yet their interrupt polarities are kept in old values, we
+ * should synchronize their interrupt polarities; for example,
+ * at first a gpio's input level is low and its interrupt
+ * polarity control is "Detect rising edge", then the gpio has
+ * a interrupt , its level turns to high, we should change its
+ * polarity control to "Detect falling edge" correspondingly.
+ */
+ p ^= 1 << bit_num;
+ writel(p, info->base + IRQ_POL + 4 * reg_idx);
+ ret = 0;
+ } else {
+ /* Spurious irq */
+ ret = -1;
+ }
+
+ spin_unlock_irqrestore(&info->irq_lock, flags);
+ return ret;
+}

static void armada_37xx_irq_handler(struct irq_desc *desc)
{
@@ -609,6 +656,23 @@ static void armada_37xx_irq_handler(struct irq_desc *desc)
u32 hwirq = ffs(status) - 1;
u32 virq = irq_find_mapping(d, hwirq +
i * GPIO_PER_REG);
+ u32 t = irq_get_trigger_type(virq);
+
+ if ((t & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
+ /* Swap polarity (race with GPIO line) */
+ if (armada_37xx_edge_both_irq_swap_pol(info,
+ hwirq + i * GPIO_PER_REG)) {
+ /*
+ * For spurious irq, which gpio level
+ * is not as expected after incoming
+ * edge, just ack the gpio irq.
+ */
+ writel(1 << hwirq,
+ info->base +
+ IRQ_STATUS + 4 * i);
+ continue;
+ }
+ }

generic_handle_irq(virq);

--
2.14.2