[PATCH v4 06/21] mfd: axp20x: Allow AXP chips without interrupt lines

[Andre Przywara]

Currently the AXP chip requires to have its IRQ line connected to some
interrupt controller, and will fail probing when this is not the case.

On a new Allwinner SoC (H616) there is no NMI pin anymore, and at
least one board does not connect the AXP's IRQ pin to anything else,
so the interrupt functionality of the AXP chip is simply not available.

Check whether the interrupt line number returned by the platform code is
valid, before trying to register the irqchip. If not, we skip this
registration, to avoid the driver to bail out completely.

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
 drivers/mfd/axp20x.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
index 3eae04e24ac8..00c163a1e20d 100644
--- a/drivers/mfd/axp20x.c
+++ b/drivers/mfd/axp20x.c
@@ -959,12 +959,17 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
 				     AXP806_REG_ADDR_EXT_ADDR_SLAVE_MODE);
 	}
 
-	ret = regmap_add_irq_chip(axp20x->regmap, axp20x->irq,
-			  IRQF_ONESHOT | IRQF_SHARED | axp20x->irq_flags,
-			   -1, axp20x->regmap_irq_chip, &axp20x->regmap_irqc);
-	if (ret) {
-		dev_err(axp20x->dev, "failed to add irq chip: %d\n", ret);
-		return ret;
+	/* Only if there is an interrupt line connected towards the CPU. */
+	if (axp20x->irq > 0) {
+		ret = regmap_add_irq_chip(axp20x->regmap, axp20x->irq,
+				IRQF_ONESHOT | IRQF_SHARED | axp20x->irq_flags,
+				-1, axp20x->regmap_irq_chip,
+				&axp20x->regmap_irqc);
+		if (ret) {
+			dev_err(axp20x->dev, "failed to add irq chip: %d\n",
+				ret);
+			return ret;
+		}
 	}
 
 	ret = mfd_add_devices(axp20x->dev, -1, axp20x->cells,
-- 
2.17.5