/*
 * 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)