gpio: dwapb: use a second irq chip

Right new have one irq chip running always in level mode. It would nicer
to have two irq chips where one is handling level type interrupts and
the other one is doing edge interrupts. So we can have at runtime two users
where one is using edge and the other level.
Acked-by: Alan Tull <delicious.quinoa@gmail.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -198,6 +198,8 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
 		break;
 	}
 
+	irq_setup_alt_chip(d, type);
+
 	writel(level, gpio->regs + GPIO_INTTYPE_LEVEL);
 	writel(polarity, gpio->regs + GPIO_INT_POLARITY);
 	spin_unlock_irqrestore(&bgc->lock, flags);
@@ -213,7 +215,7 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
 	struct irq_chip_generic	*irq_gc;
 	unsigned int hwirq, ngpio = gc->ngpio;
 	struct irq_chip_type *ct;
-	int err, irq;
+	int err, irq, i;
 
 	irq = irq_of_parse_and_map(node, 0);
 	if (!irq) {
@@ -227,7 +229,7 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
 	if (!gpio->domain)
 		return;
 
-	err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 1,
+	err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 2,
 					     "gpio-dwapb", handle_level_irq,
 					     IRQ_NOREQUEST, 0,
 					     IRQ_GC_INIT_NESTED_LOCK);
@@ -248,17 +250,24 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
 	irq_gc->reg_base = gpio->regs;
 	irq_gc->private = gpio;
 
-	ct = irq_gc->chip_types;
-	ct->chip.irq_ack = irq_gc_ack_set_bit;
-	ct->chip.irq_mask = irq_gc_mask_set_bit;
-	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
-	ct->chip.irq_set_type = dwapb_irq_set_type;
-	ct->chip.irq_enable = dwapb_irq_enable;
-	ct->chip.irq_disable = dwapb_irq_disable;
-	ct->chip.irq_request_resources = dwapb_irq_reqres;
-	ct->chip.irq_release_resources = dwapb_irq_relres;
-	ct->regs.ack = GPIO_PORTA_EOI;
-	ct->regs.mask = GPIO_INTMASK;
+	for (i = 0; i < 2; i++) {
+		ct = &irq_gc->chip_types[i];
+		ct->chip.irq_ack = irq_gc_ack_set_bit;
+		ct->chip.irq_mask = irq_gc_mask_set_bit;
+		ct->chip.irq_unmask = irq_gc_mask_clr_bit;
+		ct->chip.irq_set_type = dwapb_irq_set_type;
+		ct->chip.irq_enable = dwapb_irq_enable;
+		ct->chip.irq_disable = dwapb_irq_disable;
+		ct->chip.irq_request_resources = dwapb_irq_reqres;
+		ct->chip.irq_release_resources = dwapb_irq_relres;
+		ct->regs.ack = GPIO_PORTA_EOI;
+		ct->regs.mask = GPIO_INTMASK;
+		ct->type = IRQ_TYPE_LEVEL_MASK;
+	}
+
+	irq_gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
+	irq_gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
+	irq_gc->chip_types[1].handler = handle_edge_irq;
 
 	irq_set_chained_handler(irq, dwapb_irq_handler);
 	irq_set_handler_data(irq, gpio);