iio: accel: fxls8962af: add interrupt support

Preparation commit for the next that adds hw buffered sampling.
Adds the interrupt function and reads the devicetree for which
interrupt pin that is used.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/fxls8962af-core.c

@@ -15,6 +15,7 @@
 #include <linux/bits.h>
 #include <linux/bitfield.h>
 #include <linux/module.h>
+#include <linux/of_irq.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
 #include <linux/regmap.h>
@@ -54,6 +55,10 @@
 #define FXLS8962AF_SC3_WAKE_ODR_PREP(x)		FIELD_PREP(FXLS8962AF_SC3_WAKE_ODR_MASK, (x))
 #define FXLS8962AF_SC3_WAKE_ODR_GET(x)		FIELD_GET(FXLS8962AF_SC3_WAKE_ODR_MASK, (x))
 #define FXLS8962AF_SENS_CONFIG4			0x18
+#define FXLS8962AF_SC4_INT_PP_OD_MASK		BIT(1)
+#define FXLS8962AF_SC4_INT_PP_OD_PREP(x)	FIELD_PREP(FXLS8962AF_SC4_INT_PP_OD_MASK, (x))
+#define FXLS8962AF_SC4_INT_POL_MASK		BIT(0)
+#define FXLS8962AF_SC4_INT_POL_PREP(x)		FIELD_PREP(FXLS8962AF_SC4_INT_POL_MASK, (x))
 #define FXLS8962AF_SENS_CONFIG5			0x19
 
 #define FXLS8962AF_WAKE_IDLE_LSB		0x1b
@@ -62,6 +67,9 @@
 
 #define FXLS8962AF_INT_EN			0x20
 #define FXLS8962AF_INT_PIN_SEL			0x21
+#define FXLS8962AF_INT_PIN_SEL_MASK		GENMASK(7, 0)
+#define FXLS8962AF_INT_PIN_SEL_INT1		0x00
+#define FXLS8962AF_INT_PIN_SEL_INT2		GENMASK(7, 0)
 
 #define FXLS8962AF_OFF_X			0x22
 #define FXLS8962AF_OFF_Y			0x23
@@ -142,6 +150,11 @@ enum {
 	fxls8962af_idx_ts,
 };
 
+enum fxls8962af_int_pin {
+	FXLS8962AF_PIN_INT1,
+	FXLS8962AF_PIN_INT2,
+};
+
 static int fxls8962af_power_on(struct fxls8962af_data *data)
 {
 	struct device *dev = regmap_get_device(data->regmap);
@@ -504,6 +517,20 @@ static int fxls8962af_reset(struct fxls8962af_data *data)
 	return ret;
 }
 
+static irqreturn_t fxls8962af_interrupt(int irq, void *p)
+{
+	struct iio_dev *indio_dev = p;
+	struct fxls8962af_data *data = iio_priv(indio_dev);
+	unsigned int reg;
+	int ret;
+
+	ret = regmap_read(data->regmap, FXLS8962AF_INT_STATUS, &reg);
+	if (ret)
+		return IRQ_NONE;
+
+	return IRQ_NONE;
+}
+
 static void fxls8962af_regulator_disable(void *data_ptr)
 {
 	struct fxls8962af_data *data = data_ptr;
@@ -523,6 +550,87 @@ static void fxls8962af_pm_disable(void *dev_ptr)
 	fxls8962af_standby(iio_priv(indio_dev));
 }
 
+static void fxls8962af_get_irq(struct device_node *of_node,
+			       enum fxls8962af_int_pin *pin)
+{
+	int irq;
+
+	irq = of_irq_get_byname(of_node, "INT2");
+	if (irq > 0) {
+		*pin = FXLS8962AF_PIN_INT2;
+		return;
+	}
+
+	*pin = FXLS8962AF_PIN_INT1;
+}
+
+static int fxls8962af_irq_setup(struct iio_dev *indio_dev, int irq)
+{
+	struct fxls8962af_data *data = iio_priv(indio_dev);
+	struct device *dev = regmap_get_device(data->regmap);
+	unsigned long irq_type;
+	bool irq_active_high;
+	enum fxls8962af_int_pin int_pin;
+	u8 int_pin_sel;
+	int ret;
+
+	fxls8962af_get_irq(dev->of_node, &int_pin);
+	switch (int_pin) {
+	case FXLS8962AF_PIN_INT1:
+		int_pin_sel = FXLS8962AF_INT_PIN_SEL_INT1;
+		break;
+	case FXLS8962AF_PIN_INT2:
+		int_pin_sel = FXLS8962AF_INT_PIN_SEL_INT2;
+		break;
+	default:
+		dev_err(dev, "unsupported int pin selected\n");
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(data->regmap, FXLS8962AF_INT_PIN_SEL,
+				 FXLS8962AF_INT_PIN_SEL_MASK, int_pin_sel);
+	if (ret)
+		return ret;
+
+	irq_type = irqd_get_trigger_type(irq_get_irq_data(irq));
+
+	switch (irq_type) {
+	case IRQF_TRIGGER_HIGH:
+	case IRQF_TRIGGER_RISING:
+		irq_active_high = true;
+		break;
+	case IRQF_TRIGGER_LOW:
+	case IRQF_TRIGGER_FALLING:
+		irq_active_high = false;
+		break;
+	default:
+		dev_info(dev, "mode %lx unsupported\n", irq_type);
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(data->regmap, FXLS8962AF_SENS_CONFIG4,
+				 FXLS8962AF_SC4_INT_POL_MASK,
+				 FXLS8962AF_SC4_INT_POL_PREP(irq_active_high));
+	if (ret)
+		return ret;
+
+	if (device_property_read_bool(dev, "drive-open-drain")) {
+		ret = regmap_update_bits(data->regmap, FXLS8962AF_SENS_CONFIG4,
+					 FXLS8962AF_SC4_INT_PP_OD_MASK,
+					 FXLS8962AF_SC4_INT_PP_OD_PREP(1));
+		if (ret)
+			return ret;
+
+		irq_type |= IRQF_SHARED;
+	}
+
+	return devm_request_threaded_irq(dev,
+					 irq,
+					 NULL, fxls8962af_interrupt,
+					 irq_type | IRQF_ONESHOT,
+					 indio_dev->name, indio_dev);
+}
+
 int fxls8962af_core_probe(struct device *dev, struct regmap *regmap, int irq)
 {
 	struct fxls8962af_data *data;
@@ -582,6 +690,12 @@ int fxls8962af_core_probe(struct device *dev, struct regmap *regmap, int irq)
 	if (ret)
 		return ret;
 
+	if (irq) {
+		ret = fxls8962af_irq_setup(indio_dev, irq);
+		if (ret)
+			return ret;
+	}
+
 	ret = pm_runtime_set_active(dev);
 	if (ret)
 		return ret;