drivers: i2c_rtio: Use the NXP Flexcomm driver for interrupt handling

The Low Power Flexcomm driver manages the interrupt handling
and provides an API to register interrupt callbacks.
Register the NXP LPI2C interrupt handler.

Applying dca6e64c93 on RTIO-version.

Authored-by: Mahesh Mahadevan <mahesh.mahadevan@nxp.com>
Signed-off-by: Luis Ubieda <luisf@croxel.com>
(cherry picked from commit c7a00248a6)

drivers/i2c/i2c_mcux_lpi2c_rtio.c

@@ -16,6 +16,9 @@
 #include <zephyr/kernel.h>
 #include <zephyr/irq.h>
 #include <fsl_lpi2c.h>
+#if CONFIG_NXP_LP_FLEXCOMM
+#include <zephyr/drivers/mfd/nxp_lp_flexcomm.h>
+#endif
 
 #include <zephyr/drivers/pinctrl.h>
 
@@ -40,6 +43,9 @@ LOG_MODULE_REGISTER(mcux_lpi2c);
 
 struct mcux_lpi2c_config {
 	DEVICE_MMIO_NAMED_ROM(reg_base);
+#ifdef CONFIG_NXP_LP_FLEXCOMM
+	const struct device *parent_dev;
+#endif
 	const struct device *clock_dev;
 	clock_control_subsys_t clock_subsys;
 	void (*irq_config_func)(const struct device *dev);
@@ -329,7 +335,15 @@ static int mcux_lpi2c_init(const struct device *dev)
 		return error;
 	}
 
+#if CONFIG_NXP_LP_FLEXCOMM
+	/* When using LP Flexcomm driver, register the interrupt handler
+	 * so we receive notification from the LP Flexcomm interrupt handler.
+	 */
+	nxp_lp_flexcomm_setirqhandler(config->parent_dev, dev,
+				      LP_FLEXCOMM_PERIPH_LPI2C, mcux_lpi2c_isr);
+#else
 	config->irq_config_func(dev);
+#endif
 
 	i2c_rtio_init(data->ctx, dev);
 
@@ -363,6 +377,13 @@ static DEVICE_API(i2c, mcux_lpi2c_driver_api) = {
 	IF_ENABLED(DT_INST_IRQ_HAS_IDX(n, 0),				\
 		(I2C_MCUX_LPI2C_MODULE_IRQ_CONNECT(n)))
 
+#ifdef CONFIG_NXP_LP_FLEXCOMM
+#define PARENT_DEV(n)							\
+	.parent_dev = DEVICE_DT_GET(DT_INST_PARENT(n)),
+#else
+#define PARENT_DEV(n)
+#endif /* CONFIG_NXP_LP_FLEXCOMM */
+
 #define I2C_MCUX_LPI2C_INIT(n)						\
 	PINCTRL_DT_INST_DEFINE(n);					\
 									\
@@ -370,6 +391,7 @@ static DEVICE_API(i2c, mcux_lpi2c_driver_api) = {
 									\
 	static const struct mcux_lpi2c_config mcux_lpi2c_config_##n = {	\
 		DEVICE_MMIO_NAMED_ROM_INIT(reg_base, DT_DRV_INST(n)),	\
+		PARENT_DEV(n)						\
 		.clock_dev = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(n)),	\
 		.clock_subsys =						\
 			(clock_control_subsys_t)DT_INST_CLOCKS_CELL(n, name),\