LF-6143-1 iio: accel: fxls8962af: support set interrupt pin as open-drain

This patch add the support to set interrupt pin as open-drain even
this interrupt pin is not used at all. There is a specail case on
imx8ulp-9x9 evk board. Three sensors share their interrupt pin, and
this pin belong to M core side, need M image implement the interrupt
handler. So for linux on A core side, driver can't use this shared
interrupt pin. But need to make sure all the three sensors interrupt
pin is open-drain, otherwise may impact the share interrupt pad behavior.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Jason Liu <jason.hui.liu@nxp.com>

drivers/iio/accel/fxls8962af-core.c

@@ -931,6 +931,13 @@ int fxls8962af_core_probe(struct device *dev, struct regmap *regmap, int irq)
 						  &fxls8962af_buffer_ops);
 		if (ret)
 			return ret;
+	} else 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;
+
 	}
 
 	ret = pm_runtime_set_active(dev);