[PATCH v4 4/4] iio: accel: adxl367: add support for INT2 interrupt pin

[Antoniu Miclaus <antoniu.miclaus@analog.com>]

The ADXL367 provides two independent interrupt output pins, INT1 and
INT2, each with its own event mapping register (INTMAP1_LOWER at 0x2A
and INTMAP2_LOWER at 0x2B) sharing an identical bit layout. Until now
the driver hardcoded INT1 for all interrupt mappings, so a board that
routes only INT2 to the host could never receive activity, inactivity
or FIFO watermark interrupts.

Determine the connected pin from the interrupt-names device tree
property using fwnode_irq_get_byname(), and route the interrupt
mappings to the matching register. Use the interrupt number returned by
the lookup for devm_request_threaded_irq() so the requested line always
matches the routed INTMAP register, regardless of the order in which the
interrupts are listed. When no interrupt-names are present, default to
INT1 and the bus-provided interrupt to preserve the existing behaviour.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
Changes in v4:
- Propagate errors from fwnode_irq_get_byname() instead of silently
  falling back: only -EINVAL (no interrupt-names) and -ENODATA (requested
  name not listed) select the INT1 default, so -EPROBE_DEFER and other
  errors are returned to the caller.

 drivers/iio/accel/adxl367.c | 45 ++++++++++++++++++++++++++++++++++---
 1 file changed, 42 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/accel/adxl367.c b/drivers/iio/accel/adxl367.c
index 54c4d1226790..9a2312da6238 100644
--- a/drivers/iio/accel/adxl367.c
+++ b/drivers/iio/accel/adxl367.c
@@ -13,6 +13,7 @@
 #include <linux/iio/sysfs.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/unaligned.h>
@@ -81,6 +82,7 @@
 #define ADXL367_SAMPLES_L_MASK		GENMASK(7, 0)
 
 #define ADXL367_REG_INT1_MAP		0x2A
+#define ADXL367_REG_INT2_MAP		0x2B
 #define ADXL367_INT_INACT_MASK		BIT(5)
 #define ADXL367_INT_ACT_MASK		BIT(4)
 #define ADXL367_INT_FIFO_WATERMARK_MASK	BIT(2)
@@ -168,6 +170,8 @@ struct adxl367_state {
 	enum adxl367_odr	odr;
 	enum adxl367_range	range;
 
+	u8		int_map_reg;
+
 	unsigned int	act_threshold;
 	unsigned int	act_time_ms;
 	unsigned int	inact_threshold;
@@ -366,7 +370,7 @@ static int adxl367_set_act_interrupt_en(struct adxl367_state *st,
 {
 	unsigned int mask = adxl367_act_int_mask_tbl[act];
 
-	return regmap_assign_bits(st->regmap, ADXL367_REG_INT1_MAP, mask, en);
+	return regmap_assign_bits(st->regmap, st->int_map_reg, mask, en);
 }
 
 static int adxl367_get_act_interrupt_en(struct adxl367_state *st,
@@ -377,7 +381,7 @@ static int adxl367_get_act_interrupt_en(struct adxl367_state *st,
 	unsigned int val;
 	int ret;
 
-	ret = regmap_read(st->regmap, ADXL367_REG_INT1_MAP, &val);
+	ret = regmap_read(st->regmap, st->int_map_reg, &val);
 	if (ret)
 		return ret;
 
@@ -400,7 +404,7 @@ static int adxl367_set_act_en(struct adxl367_state *st,
 static int adxl367_set_fifo_watermark_interrupt_en(struct adxl367_state *st,
 						   bool en)
 {
-	return regmap_assign_bits(st->regmap, ADXL367_REG_INT1_MAP,
+	return regmap_assign_bits(st->regmap, st->int_map_reg,
 				  ADXL367_INT_FIFO_WATERMARK_MASK, en);
 }
 
@@ -1423,6 +1427,36 @@ static int adxl367_setup(struct adxl367_state *st)
 	return adxl367_set_measure_en(st, true);
 }
 
+static int adxl367_set_int_map_reg(struct adxl367_state *st, int irq)
+{
+	int ret;
+
+	/*
+	 * Route the mappings to whichever of INT1/INT2 is named in the
+	 * interrupt-names property. -EINVAL (property absent) and -ENODATA
+	 * (name not listed) are not errors; anything else is.
+	 */
+	ret = fwnode_irq_get_byname(dev_fwnode(st->dev), "INT1");
+	if (ret > 0) {
+		st->int_map_reg = ADXL367_REG_INT1_MAP;
+		return ret;
+	}
+	if (ret != -ENODATA && ret != -EINVAL)
+		return ret;
+
+	ret = fwnode_irq_get_byname(dev_fwnode(st->dev), "INT2");
+	if (ret > 0) {
+		st->int_map_reg = ADXL367_REG_INT2_MAP;
+		return ret;
+	}
+	if (ret != -ENODATA && ret != -EINVAL)
+		return ret;
+
+	/* No INT1/INT2 named: default to INT1 and the bus interrupt. */
+	st->int_map_reg = ADXL367_REG_INT1_MAP;
+	return irq;
+}
+
 int adxl367_probe(struct device *dev, const struct adxl367_ops *ops,
 		  void *context, struct regmap *regmap, int irq)
 {
@@ -1479,6 +1513,11 @@ int adxl367_probe(struct device *dev, const struct adxl367_ops *ops,
 	if (ret)
 		return ret;
 
+	ret = adxl367_set_int_map_reg(st, irq);
+	if (ret < 0)
+		return dev_err_probe(st->dev, ret, "Failed to get interrupt\n");
+	irq = ret;
+
 	ret = devm_request_threaded_irq(st->dev, irq, NULL,
 					adxl367_irq_handler, IRQF_ONESHOT,
 					indio_dev->name, indio_dev);
-- 
2.43.0