drivers/serial/uart_mcux_lpuart.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2017,2021 NXP
  * Copyright (c) 2020 Softube
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 #define DT_DRV_COMPAT nxp_kinetis_lpuart

 #include <errno.h>
 #include <soc.h>
 #include <fsl_lpuart.h>
 #include <device.h>
 #include <drivers/uart.h>
 #include <drivers/clock_control.h>
 #include <pm/policy.h>
 #ifdef CONFIG_PINCTRL
 #include <drivers/pinctrl.h>
 #endif

 struct mcux_lpuart_config {
 	LPUART_Type *base;
 	const struct device *clock_dev;
 #ifdef CONFIG_PINCTRL
 	const struct pinctrl_dev_config *pincfg;
 #endif
 	clock_control_subsys_t clock_subsys;
 	uint32_t baud_rate;
 	uint8_t flow_ctrl;
 #if defined(CONFIG_UART_INTERRUPT_DRIVEN) || defined(CONFIG_PM)
 	void (*irq_config_func)(const struct device *dev);
 #endif
 };

 struct mcux_lpuart_data {
 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	uart_irq_callback_user_data_t callback;
 	void *cb_data;
 #endif
 #ifdef CONFIG_PM
 	bool pm_state_lock_on;
 	bool tx_poll_stream_on;
 	bool tx_int_stream_on;
 #endif /* CONFIG_PM */
 	struct uart_config uart_config;
 };

 #ifdef CONFIG_PM
 static void mcux_lpuart_pm_policy_state_lock_get(const struct device *dev)
 {
 	struct mcux_lpuart_data *data = dev->data;

 	if (!data->pm_state_lock_on) {
 		data->pm_state_lock_on = true;
 		pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_IDLE);
 	}
 }

 static void mcux_lpuart_pm_policy_state_lock_put(const struct device *dev)
 {
 	struct mcux_lpuart_data *data = dev->data;

 	if (data->pm_state_lock_on) {
 		data->pm_state_lock_on = false;
 		pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_IDLE);
 	}
 }
 #endif /* CONFIG_PM */

 static int mcux_lpuart_poll_in(const struct device *dev, unsigned char *c)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t flags = LPUART_GetStatusFlags(config->base);
 	int ret = -1;

 	if (flags & kLPUART_RxDataRegFullFlag) {
 		*c = LPUART_ReadByte(config->base);
 		ret = 0;
 	}

 	return ret;
 }

 static void mcux_lpuart_poll_out(const struct device *dev, unsigned char c)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	int key;
 #ifdef CONFIG_PM
 	struct mcux_lpuart_data *data = dev->data;
 #endif

 	while (!(LPUART_GetStatusFlags(config->base)
 		& kLPUART_TxDataRegEmptyFlag)) {
 	}
 	/* Lock interrupts while we send data */
 	key = irq_lock();
 #ifdef CONFIG_PM
 	/*
 	 * We must keep the part from entering lower power mode until the
 	 * transmission completes. Set the power constraint, and enable
 	 * the transmission complete interrupt so we know when transmission is
 	 * completed.
 	 */
 	if (!data->tx_poll_stream_on && !data->tx_int_stream_on) {
 		data->tx_poll_stream_on = true;
 		mcux_lpuart_pm_policy_state_lock_get(dev);
 		/* Enable TC interrupt */
 		LPUART_EnableInterrupts(config->base,
 			kLPUART_TransmissionCompleteInterruptEnable);

 	}
 #endif /* CONFIG_PM */

 	LPUART_WriteByte(config->base, c);
 	irq_unlock(key);
 }

 static int mcux_lpuart_err_check(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t flags = LPUART_GetStatusFlags(config->base);
 	int err = 0;

 	if (flags & kLPUART_RxOverrunFlag) {
 		err |= UART_ERROR_OVERRUN;
 	}

 	if (flags & kLPUART_ParityErrorFlag) {
 		err |= UART_ERROR_PARITY;
 	}

 	if (flags & kLPUART_FramingErrorFlag) {
 		err |= UART_ERROR_FRAMING;
 	}

 	LPUART_ClearStatusFlags(config->base, kLPUART_RxOverrunFlag |
 					      kLPUART_ParityErrorFlag |
 					      kLPUART_FramingErrorFlag);

 	return err;
 }

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 static int mcux_lpuart_fifo_fill(const struct device *dev,
 				 const uint8_t *tx_data,
 				 int len)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint8_t num_tx = 0U;

 	while ((len - num_tx > 0) &&
 	       (LPUART_GetStatusFlags(config->base)
 		& kLPUART_TxDataRegEmptyFlag)) {

 		LPUART_WriteByte(config->base, tx_data[num_tx++]);
 	}
 	return num_tx;
 }

 static int mcux_lpuart_fifo_read(const struct device *dev, uint8_t *rx_data,
 				 const int len)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint8_t num_rx = 0U;

 	while ((len - num_rx > 0) &&
 	       (LPUART_GetStatusFlags(config->base)
 		& kLPUART_RxDataRegFullFlag)) {

 		rx_data[num_rx++] = LPUART_ReadByte(config->base);
 	}

 	return num_rx;
 }

 static void mcux_lpuart_irq_tx_enable(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_TxDataRegEmptyInterruptEnable;
 #ifdef CONFIG_PM
 	struct mcux_lpuart_data *data = dev->data;
 	int key;
 #endif

 #ifdef CONFIG_PM
 	key = irq_lock();
 	data->tx_poll_stream_on = false;
 	data->tx_int_stream_on = true;
 	/* Do not allow system to sleep while UART tx is ongoing */
 	mcux_lpuart_pm_policy_state_lock_get(dev);
 #endif
 	LPUART_EnableInterrupts(config->base, mask);
 #ifdef CONFIG_PM
 	irq_unlock(key);
 #endif
 }

 static void mcux_lpuart_irq_tx_disable(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_TxDataRegEmptyInterruptEnable;
 #ifdef CONFIG_PM
 	struct mcux_lpuart_data *data = dev->data;
 	int key;

 	key = irq_lock();
 #endif

 	LPUART_DisableInterrupts(config->base, mask);
 #ifdef CONFIG_PM
 	data->tx_int_stream_on = false;
 	/*
 	 * If transmission IRQ is no longer enabled,
 	 * transmission is complete. Release pm constraint.
 	 */
 	mcux_lpuart_pm_policy_state_lock_put(dev);
 	irq_unlock(key);
 #endif
 }

 static int mcux_lpuart_irq_tx_complete(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t flags = LPUART_GetStatusFlags(config->base);

 	return (flags & kLPUART_TransmissionCompleteFlag) != 0U;
 }

 static int mcux_lpuart_irq_tx_ready(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_TxDataRegEmptyInterruptEnable;
 	uint32_t flags = LPUART_GetStatusFlags(config->base);

 	return (LPUART_GetEnabledInterrupts(config->base) & mask)
 		&& (flags & kLPUART_TxDataRegEmptyFlag);
 }

 static void mcux_lpuart_irq_rx_enable(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_RxDataRegFullInterruptEnable;

 	LPUART_EnableInterrupts(config->base, mask);
 }

 static void mcux_lpuart_irq_rx_disable(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_RxDataRegFullInterruptEnable;

 	LPUART_DisableInterrupts(config->base, mask);
 }

 static int mcux_lpuart_irq_rx_full(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t flags = LPUART_GetStatusFlags(config->base);

 	return (flags & kLPUART_RxDataRegFullFlag) != 0U;
 }

 static int mcux_lpuart_irq_rx_pending(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_RxDataRegFullInterruptEnable;

 	return (LPUART_GetEnabledInterrupts(config->base) & mask)
 		&& mcux_lpuart_irq_rx_full(dev);
 }

 static void mcux_lpuart_irq_err_enable(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_NoiseErrorInterruptEnable |
 			kLPUART_FramingErrorInterruptEnable |
 			kLPUART_ParityErrorInterruptEnable;

 	LPUART_EnableInterrupts(config->base, mask);
 }

 static void mcux_lpuart_irq_err_disable(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	uint32_t mask = kLPUART_NoiseErrorInterruptEnable |
 			kLPUART_FramingErrorInterruptEnable |
 			kLPUART_ParityErrorInterruptEnable;

 	LPUART_DisableInterrupts(config->base, mask);
 }

 static int mcux_lpuart_irq_is_pending(const struct device *dev)
 {
 	return (mcux_lpuart_irq_tx_ready(dev)
 		|| mcux_lpuart_irq_rx_pending(dev));
 }

 static int mcux_lpuart_irq_update(const struct device *dev)
 {
 	return 1;
 }

 static void mcux_lpuart_irq_callback_set(const struct device *dev,
 					 uart_irq_callback_user_data_t cb,
 					 void *cb_data)
 {
 	struct mcux_lpuart_data *data = dev->data;

 	data->callback = cb;
 	data->cb_data = cb_data;
 }

 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 #if defined(CONFIG_UART_INTERRUPT_DRIVEN) || defined(CONFIG_PM)
 static void mcux_lpuart_isr(const struct device *dev)
 {
 	struct mcux_lpuart_data *data = dev->data;
 #if CONFIG_PM
 	const struct mcux_lpuart_config *config = dev->config;
 #endif

 #if CONFIG_PM
 	if (LPUART_GetStatusFlags(config->base) &
 		kLPUART_TransmissionCompleteFlag) {

 		if (data->tx_poll_stream_on) {
 			/* Poll transmission complete. Allow system to sleep */
 			LPUART_DisableInterrupts(config->base,
 				kLPUART_TransmissionCompleteInterruptEnable);
 			data->tx_poll_stream_on = false;
 			mcux_lpuart_pm_policy_state_lock_put(dev);
 		}
 	}
 #endif /* CONFIG_PM */

 #if CONFIG_UART_INTERRUPT_DRIVEN
 	if (data->callback) {
 		data->callback(dev, data->cb_data);
 	}
 #endif
 }
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN || CONFIG_PM */

 static int mcux_lpuart_configure_init(const struct device *dev,
 				      const struct uart_config *cfg)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	struct mcux_lpuart_data *data = dev->data;
 	uint32_t clock_freq;

 	if (clock_control_get_rate(config->clock_dev, config->clock_subsys,
 				   &clock_freq)) {
 		return -EINVAL;
 	}

 	lpuart_config_t uart_config;
 	LPUART_GetDefaultConfig(&uart_config);

 	/* Translate UART API enum to LPUART enum from HAL */
 	switch (cfg->parity) {
 	case UART_CFG_PARITY_NONE:
 		uart_config.parityMode = kLPUART_ParityDisabled;
 		break;
 	case UART_CFG_PARITY_ODD:
 		uart_config.parityMode = kLPUART_ParityOdd;
 		break;
 	case UART_CFG_PARITY_EVEN:
 		uart_config.parityMode = kLPUART_ParityEven;
 		break;
 	default:
 		return -ENOTSUP;
 	}

 	switch (cfg->data_bits) {
 #if defined(FSL_FEATURE_LPUART_HAS_7BIT_DATA_SUPPORT) && \
 	FSL_FEATURE_LPUART_HAS_7BIT_DATA_SUPPORT
 	case UART_CFG_DATA_BITS_7:
 		uart_config.dataBitsCount  = kLPUART_SevenDataBits;
 		break;
 #endif
 	case UART_CFG_DATA_BITS_8:
 		uart_config.dataBitsCount  = kLPUART_EightDataBits;
 		break;
 	default:
 		return -ENOTSUP;
 	}

 #if defined(FSL_FEATURE_LPUART_HAS_STOP_BIT_CONFIG_SUPPORT) && \
 	FSL_FEATURE_LPUART_HAS_STOP_BIT_CONFIG_SUPPORT
 	switch (cfg->stop_bits) {
 	case UART_CFG_STOP_BITS_1:
 		uart_config.stopBitCount = kLPUART_OneStopBit;
 		break;
 	case UART_CFG_STOP_BITS_2:
 		uart_config.stopBitCount = kLPUART_TwoStopBit;
 		break;
 	default:
 		return -ENOTSUP;
 	}
 #endif

 #if defined(FSL_FEATURE_LPUART_HAS_MODEM_SUPPORT) && \
 	FSL_FEATURE_LPUART_HAS_MODEM_SUPPORT
 	switch (cfg->flow_ctrl) {
 	case UART_CFG_FLOW_CTRL_NONE:
 		uart_config.enableTxCTS = false;
 		uart_config.enableRxRTS = false;
 		break;
 	case UART_CFG_FLOW_CTRL_RTS_CTS:
 		uart_config.enableTxCTS = true;
 		uart_config.enableRxRTS = true;
 		break;
 	default:
 		return -ENOTSUP;
 	}
 #endif
 	uart_config.baudRate_Bps = cfg->baudrate;
 	uart_config.enableTx = true;
 	uart_config.enableRx = true;

 	LPUART_Init(config->base, &uart_config, clock_freq);

 	/* update internal uart_config */
 	data->uart_config = *cfg;

 	return 0;
 }

 #ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
 static int mcux_lpuart_config_get(const struct device *dev, struct uart_config *cfg)
 {
 	struct mcux_lpuart_data *data = dev->data;
 	*cfg = data->uart_config;
 	return 0;
 }

 static int mcux_lpuart_configure(const struct device *dev,
 				 const struct uart_config *cfg)
 {
 	const struct mcux_lpuart_config *config = dev->config;

 	/* disable LPUART */
 	LPUART_Deinit(config->base);

 	int ret = mcux_lpuart_configure_init(dev, cfg);
 	if (ret) {
 		return ret;
 	}

 	/* wait for hardware init */
 	k_sleep(K_MSEC(1));

 	return 0;
 }
 #endif /* CONFIG_UART_USE_RUNTIME_CONFIGURE */

 static int mcux_lpuart_init(const struct device *dev)
 {
 	const struct mcux_lpuart_config *config = dev->config;
 	struct mcux_lpuart_data *data = dev->data;
 	struct uart_config *uart_api_config = &data->uart_config;
 #ifdef CONFIG_PINCTRL
 	int err;
 #endif

 	uart_api_config->baudrate = config->baud_rate;
 	uart_api_config->parity = UART_CFG_PARITY_NONE;
 	uart_api_config->stop_bits = UART_CFG_STOP_BITS_1;
 	uart_api_config->data_bits = UART_CFG_DATA_BITS_8;
 	uart_api_config->flow_ctrl = config->flow_ctrl;

 	/* set initial configuration */
 	mcux_lpuart_configure_init(dev, uart_api_config);
 #ifdef CONFIG_PINCTRL
 	err = pinctrl_apply_state(config->pincfg, PINCTRL_STATE_DEFAULT);
 	if (err < 0) {
 		return err;
 	}
 #endif

 #if defined(CONFIG_UART_INTERRUPT_DRIVEN) || defined(CONFIG_PM)
 	config->irq_config_func(dev);
 #endif

 #ifdef CONFIG_PM
 	data->pm_state_lock_on = false;
 	data->tx_poll_stream_on = false;
 	data->tx_int_stream_on = false;
 #endif

 	return 0;
 }

 static const struct uart_driver_api mcux_lpuart_driver_api = {
 	.poll_in = mcux_lpuart_poll_in,
 	.poll_out = mcux_lpuart_poll_out,
 	.err_check = mcux_lpuart_err_check,
 #ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
 	.configure = mcux_lpuart_configure,
 	.config_get = mcux_lpuart_config_get,
 #endif
 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	.fifo_fill = mcux_lpuart_fifo_fill,
 	.fifo_read = mcux_lpuart_fifo_read,
 	.irq_tx_enable = mcux_lpuart_irq_tx_enable,
 	.irq_tx_disable = mcux_lpuart_irq_tx_disable,
 	.irq_tx_complete = mcux_lpuart_irq_tx_complete,
 	.irq_tx_ready = mcux_lpuart_irq_tx_ready,
 	.irq_rx_enable = mcux_lpuart_irq_rx_enable,
 	.irq_rx_disable = mcux_lpuart_irq_rx_disable,
 	.irq_rx_ready = mcux_lpuart_irq_rx_full,
 	.irq_err_enable = mcux_lpuart_irq_err_enable,
 	.irq_err_disable = mcux_lpuart_irq_err_disable,
 	.irq_is_pending = mcux_lpuart_irq_is_pending,
 	.irq_update = mcux_lpuart_irq_update,
 	.irq_callback_set = mcux_lpuart_irq_callback_set,
 #endif
 };


 #if defined(CONFIG_UART_INTERRUPT_DRIVEN) || defined(CONFIG_PM)
 #define MCUX_LPUART_IRQ_INSTALL(n, i)					\
 	do {								\
 		IRQ_CONNECT(DT_INST_IRQ_BY_IDX(n, i, irq),		\
 			    DT_INST_IRQ_BY_IDX(n, i, priority),		\
 			    mcux_lpuart_isr, DEVICE_DT_INST_GET(n), 0);	\
 									\
 		irq_enable(DT_INST_IRQ_BY_IDX(n, i, irq));		\
 	} while (0)
 #define MCUX_LPUART_IRQ_INIT(n) .irq_config_func = mcux_lpuart_config_func_##n,
 #define MCUX_LPUART_IRQ_DEFINE(n)						\
 	static void mcux_lpuart_config_func_##n(const struct device *dev)	\
 	{									\
 		MCUX_LPUART_IRQ_INSTALL(n, 0);				\
 									\
 		IF_ENABLED(DT_INST_IRQ_HAS_IDX(n, 1),			\
 			   (MCUX_LPUART_IRQ_INSTALL(n, 1);))		\
 	}
 #else
 #define MCUX_LPUART_IRQ_INIT(n)
 #define MCUX_LPUART_IRQ_DEFINE(n)
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */


 #if CONFIG_PINCTRL
 #define PINCTRL_DEFINE(n) PINCTRL_DT_INST_DEFINE(n);
 #define PINCTRL_INIT(n) .pincfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n),
 #else
 #define PINCTRL_DEFINE(n)
 #define PINCTRL_INIT(n)
 #endif /* CONFIG_PINCTRL */

 #define LPUART_MCUX_DECLARE_CFG(n)						\
 static const struct mcux_lpuart_config mcux_lpuart_##n##_config = {		\
 	.base = (LPUART_Type *) DT_INST_REG_ADDR(n),				\
 	.clock_dev = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(n)),			\
 	.clock_subsys = (clock_control_subsys_t)DT_INST_CLOCKS_CELL(n, name),	\
 	.baud_rate = DT_INST_PROP(n, current_speed),				\
 	.flow_ctrl = DT_INST_PROP(n, hw_flow_control) ?				\
 		UART_CFG_FLOW_CTRL_RTS_CTS : UART_CFG_FLOW_CTRL_NONE,		\
 	PINCTRL_INIT(n)								\
 	MCUX_LPUART_IRQ_INIT(n)							\
 };

 #define LPUART_MCUX_INIT(n)						\
 									\
 	static struct mcux_lpuart_data mcux_lpuart_##n##_data;		\
 									\
 	PINCTRL_DEFINE(n)						\
 	MCUX_LPUART_IRQ_DEFINE(n)					\
 									\
 	LPUART_MCUX_DECLARE_CFG(n)					\
 									\
 	DEVICE_DT_INST_DEFINE(n,					\
 			    &mcux_lpuart_init,				\
 			    NULL,					\
 			    &mcux_lpuart_##n##_data,			\
 			    &mcux_lpuart_##n##_config,			\
 			    PRE_KERNEL_1,				\
 			    CONFIG_SERIAL_INIT_PRIORITY,		\
 			    &mcux_lpuart_driver_api);			\

 DT_INST_FOREACH_STATUS_OKAY(LPUART_MCUX_INIT)
	/*
	* Copyright (c) 2017,2021 NXP
	* Copyright (c) 2020 Softube
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	#define DT_DRV_COMPAT nxp_kinetis_lpuart

	#include <errno.h>
	#include <soc.h>
	#include <fsl_lpuart.h>
	#include <device.h>
	#include <drivers/uart.h>
	#include <drivers/clock_control.h>
	#include <pm/policy.h>
	#ifdef CONFIG_PINCTRL
	#include <drivers/pinctrl.h>
	#endif

	struct mcux_lpuart_config {
	LPUART_Type *base;
	const struct device *clock_dev;
	#ifdef CONFIG_PINCTRL
	const struct pinctrl_dev_config *pincfg;
	#endif
	clock_control_subsys_t clock_subsys;
	uint32_t baud_rate;
	uint8_t flow_ctrl;
	#if defined(CONFIG_UART_INTERRUPT_DRIVEN) \|\| defined(CONFIG_PM)
	void (irq_config_func)(const struct device dev);
	#endif
	};

	struct mcux_lpuart_data {
	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	uart_irq_callback_user_data_t callback;
	void *cb_data;
	#endif
	#ifdef CONFIG_PM
	bool pm_state_lock_on;
	bool tx_poll_stream_on;
	bool tx_int_stream_on;
	#endif /* CONFIG_PM */
	struct uart_config uart_config;
	};

	#ifdef CONFIG_PM
	static void mcux_lpuart_pm_policy_state_lock_get(const struct device *dev)
	{
	struct mcux_lpuart_data *data = dev->data;

	if (!data->pm_state_lock_on) {
	data->pm_state_lock_on = true;
	pm_policy_state_lock_get(PM_STATE_SUSPEND_TO_IDLE);
	}
	}

	static void mcux_lpuart_pm_policy_state_lock_put(const struct device *dev)
	{
	struct mcux_lpuart_data *data = dev->data;

	if (data->pm_state_lock_on) {
	data->pm_state_lock_on = false;
	pm_policy_state_lock_put(PM_STATE_SUSPEND_TO_IDLE);
	}
	}
	#endif /* CONFIG_PM */

	static int mcux_lpuart_poll_in(const struct device dev, unsigned char c)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t flags = LPUART_GetStatusFlags(config->base);
	int ret = -1;

	if (flags & kLPUART_RxDataRegFullFlag) {
	*c = LPUART_ReadByte(config->base);
	ret = 0;
	}

	return ret;
	}

	static void mcux_lpuart_poll_out(const struct device *dev, unsigned char c)
	{
	const struct mcux_lpuart_config *config = dev->config;
	int key;
	#ifdef CONFIG_PM
	struct mcux_lpuart_data *data = dev->data;
	#endif

	while (!(LPUART_GetStatusFlags(config->base)
	& kLPUART_TxDataRegEmptyFlag)) {
	}
	/* Lock interrupts while we send data */
	key = irq_lock();
	#ifdef CONFIG_PM
	/*
	* We must keep the part from entering lower power mode until the
	* transmission completes. Set the power constraint, and enable
	* the transmission complete interrupt so we know when transmission is
	* completed.
	*/
	if (!data->tx_poll_stream_on && !data->tx_int_stream_on) {
	data->tx_poll_stream_on = true;
	mcux_lpuart_pm_policy_state_lock_get(dev);
	/* Enable TC interrupt */
	LPUART_EnableInterrupts(config->base,
	kLPUART_TransmissionCompleteInterruptEnable);

	}
	#endif /* CONFIG_PM */

	LPUART_WriteByte(config->base, c);
	irq_unlock(key);
	}

	static int mcux_lpuart_err_check(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t flags = LPUART_GetStatusFlags(config->base);
	int err = 0;

	if (flags & kLPUART_RxOverrunFlag) {
	err \|= UART_ERROR_OVERRUN;
	}

	if (flags & kLPUART_ParityErrorFlag) {
	err \|= UART_ERROR_PARITY;
	}

	if (flags & kLPUART_FramingErrorFlag) {
	err \|= UART_ERROR_FRAMING;
	}

	LPUART_ClearStatusFlags(config->base, kLPUART_RxOverrunFlag \|
	kLPUART_ParityErrorFlag \|
	kLPUART_FramingErrorFlag);

	return err;
	}

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	static int mcux_lpuart_fifo_fill(const struct device *dev,
	const uint8_t *tx_data,
	int len)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint8_t num_tx = 0U;

	while ((len - num_tx > 0) &&
	(LPUART_GetStatusFlags(config->base)
	& kLPUART_TxDataRegEmptyFlag)) {

	LPUART_WriteByte(config->base, tx_data[num_tx++]);
	}
	return num_tx;
	}

	static int mcux_lpuart_fifo_read(const struct device dev, uint8_t rx_data,
	const int len)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint8_t num_rx = 0U;

	while ((len - num_rx > 0) &&
	(LPUART_GetStatusFlags(config->base)
	& kLPUART_RxDataRegFullFlag)) {

	rx_data[num_rx++] = LPUART_ReadByte(config->base);
	}

	return num_rx;
	}

	static void mcux_lpuart_irq_tx_enable(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_TxDataRegEmptyInterruptEnable;
	#ifdef CONFIG_PM
	struct mcux_lpuart_data *data = dev->data;
	int key;
	#endif

	#ifdef CONFIG_PM
	key = irq_lock();
	data->tx_poll_stream_on = false;
	data->tx_int_stream_on = true;
	/* Do not allow system to sleep while UART tx is ongoing */
	mcux_lpuart_pm_policy_state_lock_get(dev);
	#endif
	LPUART_EnableInterrupts(config->base, mask);
	#ifdef CONFIG_PM
	irq_unlock(key);
	#endif
	}

	static void mcux_lpuart_irq_tx_disable(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_TxDataRegEmptyInterruptEnable;
	#ifdef CONFIG_PM
	struct mcux_lpuart_data *data = dev->data;
	int key;

	key = irq_lock();
	#endif

	LPUART_DisableInterrupts(config->base, mask);
	#ifdef CONFIG_PM
	data->tx_int_stream_on = false;
	/*
	* If transmission IRQ is no longer enabled,
	* transmission is complete. Release pm constraint.
	*/
	mcux_lpuart_pm_policy_state_lock_put(dev);
	irq_unlock(key);
	#endif
	}

	static int mcux_lpuart_irq_tx_complete(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t flags = LPUART_GetStatusFlags(config->base);

	return (flags & kLPUART_TransmissionCompleteFlag) != 0U;
	}

	static int mcux_lpuart_irq_tx_ready(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_TxDataRegEmptyInterruptEnable;
	uint32_t flags = LPUART_GetStatusFlags(config->base);

	return (LPUART_GetEnabledInterrupts(config->base) & mask)
	&& (flags & kLPUART_TxDataRegEmptyFlag);
	}

	static void mcux_lpuart_irq_rx_enable(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_RxDataRegFullInterruptEnable;

	LPUART_EnableInterrupts(config->base, mask);
	}

	static void mcux_lpuart_irq_rx_disable(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_RxDataRegFullInterruptEnable;

	LPUART_DisableInterrupts(config->base, mask);
	}

	static int mcux_lpuart_irq_rx_full(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t flags = LPUART_GetStatusFlags(config->base);

	return (flags & kLPUART_RxDataRegFullFlag) != 0U;
	}

	static int mcux_lpuart_irq_rx_pending(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_RxDataRegFullInterruptEnable;

	return (LPUART_GetEnabledInterrupts(config->base) & mask)
	&& mcux_lpuart_irq_rx_full(dev);
	}

	static void mcux_lpuart_irq_err_enable(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_NoiseErrorInterruptEnable \|
	kLPUART_FramingErrorInterruptEnable \|
	kLPUART_ParityErrorInterruptEnable;

	LPUART_EnableInterrupts(config->base, mask);
	}

	static void mcux_lpuart_irq_err_disable(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	uint32_t mask = kLPUART_NoiseErrorInterruptEnable \|
	kLPUART_FramingErrorInterruptEnable \|
	kLPUART_ParityErrorInterruptEnable;

	LPUART_DisableInterrupts(config->base, mask);
	}

	static int mcux_lpuart_irq_is_pending(const struct device *dev)
	{
	return (mcux_lpuart_irq_tx_ready(dev)
	\|\| mcux_lpuart_irq_rx_pending(dev));
	}

	static int mcux_lpuart_irq_update(const struct device *dev)
	{
	return 1;
	}

	static void mcux_lpuart_irq_callback_set(const struct device *dev,
	uart_irq_callback_user_data_t cb,
	void *cb_data)
	{
	struct mcux_lpuart_data *data = dev->data;

	data->callback = cb;
	data->cb_data = cb_data;
	}

	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	#if defined(CONFIG_UART_INTERRUPT_DRIVEN) \|\| defined(CONFIG_PM)
	static void mcux_lpuart_isr(const struct device *dev)
	{
	struct mcux_lpuart_data *data = dev->data;
	#if CONFIG_PM
	const struct mcux_lpuart_config *config = dev->config;
	#endif

	#if CONFIG_PM
	if (LPUART_GetStatusFlags(config->base) &
	kLPUART_TransmissionCompleteFlag) {

	if (data->tx_poll_stream_on) {
	/* Poll transmission complete. Allow system to sleep */
	LPUART_DisableInterrupts(config->base,
	kLPUART_TransmissionCompleteInterruptEnable);
	data->tx_poll_stream_on = false;
	mcux_lpuart_pm_policy_state_lock_put(dev);
	}
	}
	#endif /* CONFIG_PM */

	#if CONFIG_UART_INTERRUPT_DRIVEN
	if (data->callback) {
	data->callback(dev, data->cb_data);
	}
	#endif
	}
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN \|\| CONFIG_PM */

	static int mcux_lpuart_configure_init(const struct device *dev,
	const struct uart_config *cfg)
	{
	const struct mcux_lpuart_config *config = dev->config;
	struct mcux_lpuart_data *data = dev->data;
	uint32_t clock_freq;

	if (clock_control_get_rate(config->clock_dev, config->clock_subsys,
	&clock_freq)) {
	return -EINVAL;
	}

	lpuart_config_t uart_config;
	LPUART_GetDefaultConfig(&uart_config);

	/* Translate UART API enum to LPUART enum from HAL */
	switch (cfg->parity) {
	case UART_CFG_PARITY_NONE:
	uart_config.parityMode = kLPUART_ParityDisabled;
	break;
	case UART_CFG_PARITY_ODD:
	uart_config.parityMode = kLPUART_ParityOdd;
	break;
	case UART_CFG_PARITY_EVEN:
	uart_config.parityMode = kLPUART_ParityEven;
	break;
	default:
	return -ENOTSUP;
	}

	switch (cfg->data_bits) {
	#if defined(FSL_FEATURE_LPUART_HAS_7BIT_DATA_SUPPORT) && \
	FSL_FEATURE_LPUART_HAS_7BIT_DATA_SUPPORT
	case UART_CFG_DATA_BITS_7:
	uart_config.dataBitsCount = kLPUART_SevenDataBits;
	break;
	#endif
	case UART_CFG_DATA_BITS_8:
	uart_config.dataBitsCount = kLPUART_EightDataBits;
	break;
	default:
	return -ENOTSUP;
	}

	#if defined(FSL_FEATURE_LPUART_HAS_STOP_BIT_CONFIG_SUPPORT) && \
	FSL_FEATURE_LPUART_HAS_STOP_BIT_CONFIG_SUPPORT
	switch (cfg->stop_bits) {
	case UART_CFG_STOP_BITS_1:
	uart_config.stopBitCount = kLPUART_OneStopBit;
	break;
	case UART_CFG_STOP_BITS_2:
	uart_config.stopBitCount = kLPUART_TwoStopBit;
	break;
	default:
	return -ENOTSUP;
	}
	#endif

	#if defined(FSL_FEATURE_LPUART_HAS_MODEM_SUPPORT) && \
	FSL_FEATURE_LPUART_HAS_MODEM_SUPPORT
	switch (cfg->flow_ctrl) {
	case UART_CFG_FLOW_CTRL_NONE:
	uart_config.enableTxCTS = false;
	uart_config.enableRxRTS = false;
	break;
	case UART_CFG_FLOW_CTRL_RTS_CTS:
	uart_config.enableTxCTS = true;
	uart_config.enableRxRTS = true;
	break;
	default:
	return -ENOTSUP;
	}
	#endif
	uart_config.baudRate_Bps = cfg->baudrate;
	uart_config.enableTx = true;
	uart_config.enableRx = true;

	LPUART_Init(config->base, &uart_config, clock_freq);

	/* update internal uart_config */
	data->uart_config = *cfg;

	return 0;
	}

	#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
	static int mcux_lpuart_config_get(const struct device dev, struct uart_config cfg)
	{
	struct mcux_lpuart_data *data = dev->data;
	*cfg = data->uart_config;
	return 0;
	}

	static int mcux_lpuart_configure(const struct device *dev,
	const struct uart_config *cfg)
	{
	const struct mcux_lpuart_config *config = dev->config;

	/* disable LPUART */
	LPUART_Deinit(config->base);

	int ret = mcux_lpuart_configure_init(dev, cfg);
	if (ret) {
	return ret;
	}

	/* wait for hardware init */
	k_sleep(K_MSEC(1));

	return 0;
	}
	#endif /* CONFIG_UART_USE_RUNTIME_CONFIGURE */

	static int mcux_lpuart_init(const struct device *dev)
	{
	const struct mcux_lpuart_config *config = dev->config;
	struct mcux_lpuart_data *data = dev->data;
	struct uart_config *uart_api_config = &data->uart_config;
	#ifdef CONFIG_PINCTRL
	int err;
	#endif

	uart_api_config->baudrate = config->baud_rate;
	uart_api_config->parity = UART_CFG_PARITY_NONE;
	uart_api_config->stop_bits = UART_CFG_STOP_BITS_1;
	uart_api_config->data_bits = UART_CFG_DATA_BITS_8;
	uart_api_config->flow_ctrl = config->flow_ctrl;

	/* set initial configuration */
	mcux_lpuart_configure_init(dev, uart_api_config);
	#ifdef CONFIG_PINCTRL
	err = pinctrl_apply_state(config->pincfg, PINCTRL_STATE_DEFAULT);
	if (err < 0) {
	return err;
	}
	#endif

	#if defined(CONFIG_UART_INTERRUPT_DRIVEN) \|\| defined(CONFIG_PM)
	config->irq_config_func(dev);
	#endif

	#ifdef CONFIG_PM
	data->pm_state_lock_on = false;
	data->tx_poll_stream_on = false;
	data->tx_int_stream_on = false;
	#endif

	return 0;
	}

	static const struct uart_driver_api mcux_lpuart_driver_api = {
	.poll_in = mcux_lpuart_poll_in,
	.poll_out = mcux_lpuart_poll_out,
	.err_check = mcux_lpuart_err_check,
	#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
	.configure = mcux_lpuart_configure,
	.config_get = mcux_lpuart_config_get,
	#endif
	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	.fifo_fill = mcux_lpuart_fifo_fill,
	.fifo_read = mcux_lpuart_fifo_read,
	.irq_tx_enable = mcux_lpuart_irq_tx_enable,
	.irq_tx_disable = mcux_lpuart_irq_tx_disable,
	.irq_tx_complete = mcux_lpuart_irq_tx_complete,
	.irq_tx_ready = mcux_lpuart_irq_tx_ready,
	.irq_rx_enable = mcux_lpuart_irq_rx_enable,
	.irq_rx_disable = mcux_lpuart_irq_rx_disable,
	.irq_rx_ready = mcux_lpuart_irq_rx_full,
	.irq_err_enable = mcux_lpuart_irq_err_enable,
	.irq_err_disable = mcux_lpuart_irq_err_disable,
	.irq_is_pending = mcux_lpuart_irq_is_pending,
	.irq_update = mcux_lpuart_irq_update,
	.irq_callback_set = mcux_lpuart_irq_callback_set,
	#endif
	};


	#if defined(CONFIG_UART_INTERRUPT_DRIVEN) \|\| defined(CONFIG_PM)
	#define MCUX_LPUART_IRQ_INSTALL(n, i) \
	do { \
	IRQ_CONNECT(DT_INST_IRQ_BY_IDX(n, i, irq), \
	DT_INST_IRQ_BY_IDX(n, i, priority), \
	mcux_lpuart_isr, DEVICE_DT_INST_GET(n), 0); \
	\
	irq_enable(DT_INST_IRQ_BY_IDX(n, i, irq)); \
	} while (0)
	#define MCUX_LPUART_IRQ_INIT(n) .irq_config_func = mcux_lpuart_config_func_##n,
	#define MCUX_LPUART_IRQ_DEFINE(n) \
	static void mcux_lpuart_config_func_##n(const struct device *dev) \
	{ \
	MCUX_LPUART_IRQ_INSTALL(n, 0); \
	\
	IF_ENABLED(DT_INST_IRQ_HAS_IDX(n, 1), \
	(MCUX_LPUART_IRQ_INSTALL(n, 1);)) \
	}
	#else
	#define MCUX_LPUART_IRQ_INIT(n)
	#define MCUX_LPUART_IRQ_DEFINE(n)
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */


	#if CONFIG_PINCTRL
	#define PINCTRL_DEFINE(n) PINCTRL_DT_INST_DEFINE(n);
	#define PINCTRL_INIT(n) .pincfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n),
	#else
	#define PINCTRL_DEFINE(n)
	#define PINCTRL_INIT(n)
	#endif /* CONFIG_PINCTRL */

	#define LPUART_MCUX_DECLARE_CFG(n) \
	static const struct mcux_lpuart_config mcux_lpuart_##n##_config = { \
	.base = (LPUART_Type *) DT_INST_REG_ADDR(n), \
	.clock_dev = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(n)), \
	.clock_subsys = (clock_control_subsys_t)DT_INST_CLOCKS_CELL(n, name), \
	.baud_rate = DT_INST_PROP(n, current_speed), \
	.flow_ctrl = DT_INST_PROP(n, hw_flow_control) ? \
	UART_CFG_FLOW_CTRL_RTS_CTS : UART_CFG_FLOW_CTRL_NONE, \
	PINCTRL_INIT(n) \
	MCUX_LPUART_IRQ_INIT(n) \
	};

	#define LPUART_MCUX_INIT(n) \
	\
	static struct mcux_lpuart_data mcux_lpuart_##n##_data; \
	\
	PINCTRL_DEFINE(n) \
	MCUX_LPUART_IRQ_DEFINE(n) \
	\
	LPUART_MCUX_DECLARE_CFG(n) \
	\
	DEVICE_DT_INST_DEFINE(n, \
	&mcux_lpuart_init, \
	NULL, \
	&mcux_lpuart_##n##_data, \
	&mcux_lpuart_##n##_config, \
	PRE_KERNEL_1, \
	CONFIG_SERIAL_INIT_PRIORITY, \
	&mcux_lpuart_driver_api); \

	DT_INST_FOREACH_STATUS_OKAY(LPUART_MCUX_INIT)