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

 /*
  * Copyright (c) 2018 Justin Watson
  * Copyright (c) 2016 Piotr Mienkowski
  * SPDX-License-Identifier: Apache-2.0
  */

 /** @file
  * @brief USART driver for Atmel SAM MCU family.
  *
  * Note:
  * - Only basic USART features sufficient to support printf functionality
  *   are currently implemented.
  */

 #include <errno.h>
 #include <misc/__assert.h>
 #include <device.h>
 #include <init.h>
 #include <soc.h>
 #include <uart.h>

 /*
  * Verify Kconfig configuration
  */

 #if CONFIG_USART_SAM_PORT_0 == 1

 #if DT_USART_SAM_PORT_0_BAUD_RATE == 0
 #error "DT_USART_SAM_PORT_0_BAUD_RATE has to be bigger than 0"
 #endif

 #endif

 #if CONFIG_USART_SAM_PORT_1 == 1

 #if DT_USART_SAM_PORT_1_BAUD_RATE == 0
 #error "DT_USART_SAM_PORT_1_BAUD_RATE has to be bigger than 0"
 #endif

 #endif

 #if CONFIG_USART_SAM_PORT_2 == 1

 #if DT_USART_SAM_PORT_2_BAUD_RATE == 0
 #error "DT_USART_SAM_PORT_2_BAUD_RATE has to be bigger than 0"
 #endif

 #endif

 /* Device constant configuration parameters */
 struct usart_sam_dev_cfg {
 	Usart *regs;
 	u32_t periph_id;
 	struct soc_gpio_pin pin_rx;
 	struct soc_gpio_pin pin_tx;

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	uart_irq_config_func_t	irq_config_func;
 #endif
 };

 /* Device run time data */
 struct usart_sam_dev_data {
 	u32_t baud_rate;

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	uart_irq_callback_user_data_t irq_cb;	/* Interrupt Callback */
 	void *cb_data;	/* Interrupt Callback Arg */
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */
 };

 #define DEV_CFG(dev) \
 	((const struct usart_sam_dev_cfg *const)(dev)->config->config_info)
 #define DEV_DATA(dev) \
 	((struct usart_sam_dev_data *const)(dev)->driver_data)


 static int baudrate_set(Usart *const usart, u32_t baudrate,
 			u32_t mck_freq_hz);


 static int usart_sam_init(struct device *dev)
 {
 	int retval;
 	const struct usart_sam_dev_cfg *const cfg = DEV_CFG(dev);
 	struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);
 	Usart *const usart = cfg->regs;

 	/* Enable USART clock in PMC */
 	soc_pmc_peripheral_enable(cfg->periph_id);

 	/* Connect pins to the peripheral */
 	soc_gpio_configure(&cfg->pin_rx);
 	soc_gpio_configure(&cfg->pin_tx);

 	/* Reset and disable USART */
 	usart->US_CR =   US_CR_RSTRX | US_CR_RSTTX
 		       | US_CR_RXDIS | US_CR_TXDIS | US_CR_RSTSTA;

 	/* Disable Interrupts */
 	usart->US_IDR = 0xFFFFFFFF;

 	/* 8 bits of data, no parity, 1 stop bit in normal mode */
 	usart->US_MR =   US_MR_NBSTOP_1_BIT
 		       | US_MR_PAR_NO
 		       | US_MR_CHRL_8_BIT
 		       | US_MR_USCLKS_MCK
 		       | US_MR_CHMODE_NORMAL;

 	/* Set baud rate */
 	retval = baudrate_set(usart, dev_data->baud_rate,
 			      SOC_ATMEL_SAM_MCK_FREQ_HZ);
 	if (retval != 0) {
 		return retval;
 	}

 	/* Enable receiver and transmitter */
 	usart->US_CR = US_CR_RXEN | US_CR_TXEN;

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	cfg->irq_config_func(dev);
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 	return 0;
 }

 static int usart_sam_poll_in(struct device *dev, unsigned char *c)
 {
 	Usart *const usart = DEV_CFG(dev)->regs;

 	if (!(usart->US_CSR & US_CSR_RXRDY)) {
 		return -EBUSY;
 	}

 	/* got a character */
 	*c = (unsigned char)usart->US_RHR;

 	return 0;
 }

 static void usart_sam_poll_out(struct device *dev, unsigned char c)
 {
 	Usart *const usart = DEV_CFG(dev)->regs;

 	/* Wait for transmitter to be ready */
 	while (!(usart->US_CSR & US_CSR_TXRDY)) {
 		;
 	}

 	/* send a character */
 	usart->US_THR = (u32_t)c;
 }

 static int usart_sam_err_check(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;
 	int errors = 0;

 	if (usart->US_CSR & US_CSR_OVRE) {
 		errors |= UART_ERROR_OVERRUN;
 	}

 	if (usart->US_CSR & US_CSR_PARE) {
 		errors |= UART_ERROR_PARITY;
 	}

 	if (usart->US_CSR & US_CSR_FRAME) {
 		errors |= UART_ERROR_FRAMING;
 	}

 	return errors;
 }

 static int baudrate_set(Usart *const usart, u32_t baudrate,
 			u32_t mck_freq_hz)
 {
 	u32_t divisor;

 	__ASSERT(baudrate,
 		 "baud rate has to be bigger than 0");
 	__ASSERT(mck_freq_hz/16 >= baudrate,
 		 "MCK frequency is too small to set required baud rate");

 	divisor = mck_freq_hz / 16 / baudrate;

 	if (divisor > 0xFFFF) {
 		return -EINVAL;
 	}

 	usart->US_BRGR = US_BRGR_CD(divisor);

 	return 0;
 }

 #if CONFIG_UART_INTERRUPT_DRIVEN

 static int usart_sam_fifo_fill(struct device *dev, const uint8_t *tx_data,
 			       int size)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	/* Wait for transmitter to be ready. */
 	while ((usart->US_CSR & US_CSR_TXRDY) == 0) {
 		;
 	}

 	usart->US_THR = *tx_data;

 	return 1;
 }

 static int usart_sam_fifo_read(struct device *dev, uint8_t *rx_data,
 			       const int size)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;
 	int bytes_read;

 	bytes_read = 0;

 	while (bytes_read < size) {
 		if (usart->US_CSR & US_CSR_RXRDY) {
 			rx_data[bytes_read] = usart->US_RHR;
 			bytes_read++;
 		} else {
 			break;
 		}
 	}

 	return bytes_read;
 }

 static void usart_sam_irq_tx_enable(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	usart->US_IER = US_IER_TXRDY;
 }

 static void usart_sam_irq_tx_disable(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	usart->US_IDR = US_IDR_TXRDY;
 }

 static int usart_sam_irq_tx_ready(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	return (usart->US_CSR & US_CSR_TXRDY);
 }

 static void usart_sam_irq_rx_enable(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	usart->US_IER = US_IER_RXRDY;
 }

 static void usart_sam_irq_rx_disable(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	usart->US_IDR = US_IDR_RXRDY;
 }

 static int usart_sam_irq_tx_complete(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	return !(usart->US_CSR & US_CSR_TXRDY);
 }

 static int usart_sam_irq_rx_ready(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	return (usart->US_CSR & US_CSR_RXRDY);
 }

 static void usart_sam_irq_err_enable(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	usart->US_IER = US_IER_OVRE | US_IER_FRAME | US_IER_PARE;
 }

 static void usart_sam_irq_err_disable(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	usart->US_IDR = US_IDR_OVRE | US_IDR_FRAME | US_IDR_PARE;
 }

 static int usart_sam_irq_is_pending(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	return    ((usart->US_CSR & US_CSR_TXRDY)
 		| (usart->US_CSR & US_CSR_RXRDY));
 }

 static int usart_sam_irq_update(struct device *dev)
 {
 	volatile Usart * const usart = DEV_CFG(dev)->regs;

 	return (usart->US_CSR & US_CSR_TXEMPTY);
 }

 static void usart_sam_irq_callback_set(struct device *dev,
 				       uart_irq_callback_user_data_t cb,
 				       void *cb_data)
 {
 	struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);

 	dev_data->irq_cb = cb;
 	dev_data->cb_data = cb_data;
 }

 static void usart_sam_isr(void *arg)
 {
 	struct device *dev = arg;
 	struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);

 	if (dev_data->irq_cb) {
 		dev_data->irq_cb(dev_data->cb_data);
 	}
 }

 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 static const struct uart_driver_api usart_sam_driver_api = {
 	.poll_in = usart_sam_poll_in,
 	.poll_out = usart_sam_poll_out,
 	.err_check = usart_sam_err_check,
 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	.fifo_fill = usart_sam_fifo_fill,
 	.fifo_read = usart_sam_fifo_read,
 	.irq_tx_enable = usart_sam_irq_tx_enable,
 	.irq_tx_disable = usart_sam_irq_tx_disable,
 	.irq_tx_ready = usart_sam_irq_tx_ready,
 	.irq_rx_enable = usart_sam_irq_rx_enable,
 	.irq_rx_disable = usart_sam_irq_rx_disable,
 	.irq_tx_complete = usart_sam_irq_tx_complete,
 	.irq_rx_ready = usart_sam_irq_rx_ready,
 	.irq_err_enable = usart_sam_irq_err_enable,
 	.irq_err_disable = usart_sam_irq_err_disable,
 	.irq_is_pending = usart_sam_irq_is_pending,
 	.irq_update = usart_sam_irq_update,
 	.irq_callback_set = usart_sam_irq_callback_set,
 #endif	/* CONFIG_UART_INTERRUPT_DRIVEN */
 };

 /* USART0 */

 #ifdef CONFIG_USART_SAM_PORT_0

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 /* Forward declare function */
 static void usart0_sam_irq_config_func(struct device *port);
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 static const struct usart_sam_dev_cfg usart0_sam_config = {
 	.regs = USART0,
 	.periph_id = DT_USART_SAM_PORT_0_PERIPHERAL_ID,
 	.pin_rx = PIN_USART0_RXD,
 	.pin_tx = PIN_USART0_TXD,

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	.irq_config_func = usart0_sam_irq_config_func,
 #endif
 };

 static struct usart_sam_dev_data usart0_sam_data = {
 	.baud_rate = DT_USART_SAM_PORT_0_BAUD_RATE,
 };

 DEVICE_AND_API_INIT(usart0_sam, DT_USART_SAM_PORT_0_NAME, &usart_sam_init,
 		    &usart0_sam_data, &usart0_sam_config, PRE_KERNEL_1,
 		    CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 static void usart0_sam_irq_config_func(struct device *port)
 {
 	IRQ_CONNECT(DT_USART_SAM_PORT_0_IRQ,
 		    DT_USART_SAM_PORT_0_IRQ_PRIO,
 		    usart_sam_isr,
 		    DEVICE_GET(usart0_sam), 0);
 	irq_enable(DT_USART_SAM_PORT_0_IRQ);
 }
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 #endif

 /* USART1 */

 #ifdef CONFIG_USART_SAM_PORT_1

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 /* Forward declare function */
 static void usart1_sam_irq_config_func(struct device *port);
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 static const struct usart_sam_dev_cfg usart1_sam_config = {
 	.regs = USART1,
 	.periph_id = DT_USART_SAM_PORT_1_PERIPHERAL_ID,
 	.pin_rx = PIN_USART1_RXD,
 	.pin_tx = PIN_USART1_TXD,

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	.irq_config_func = usart1_sam_irq_config_func,
 #endif
 };

 static struct usart_sam_dev_data usart1_sam_data = {
 	.baud_rate = DT_USART_SAM_PORT_1_BAUD_RATE,
 };

 DEVICE_AND_API_INIT(usart1_sam, DT_USART_SAM_PORT_1_NAME, &usart_sam_init,
 		    &usart1_sam_data, &usart1_sam_config, PRE_KERNEL_1,
 		    CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 static void usart1_sam_irq_config_func(struct device *port)
 {
 	IRQ_CONNECT(DT_USART_SAM_PORT_1_IRQ,
 		    DT_USART_SAM_PORT_1_IRQ_PRIO,
 		    usart_sam_isr,
 		    DEVICE_GET(usart1_sam), 0);
 	irq_enable(DT_USART_SAM_PORT_1_IRQ);
 }
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 #endif

 /* USART2 */

 #ifdef CONFIG_USART_SAM_PORT_2

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 /* Forward declare function */
 static void usart2_sam_irq_config_func(struct device *port);
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 static const struct usart_sam_dev_cfg usart2_sam_config = {
 	.regs = USART2,
 	.periph_id = DT_USART_SAM_PORT_2_PERIPHERAL_ID,
 	.pin_rx = PIN_USART2_RXD,
 	.pin_tx = PIN_USART2_TXD,

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 	.irq_config_func = usart2_sam_irq_config_func,
 #endif
 };

 static struct usart_sam_dev_data usart2_sam_data = {
 	.baud_rate = DT_USART_SAM_PORT_2_BAUD_RATE,
 };

 DEVICE_AND_API_INIT(usart2_sam, DT_USART_SAM_PORT_2_NAME, &usart_sam_init,
 		    &usart2_sam_data, &usart2_sam_config, PRE_KERNEL_1,
 		    CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);

 #ifdef CONFIG_UART_INTERRUPT_DRIVEN
 static void usart2_sam_irq_config_func(struct device *port)
 {
 	IRQ_CONNECT(DT_USART_SAM_PORT_2_IRQ,
 		    DT_USART_SAM_PORT_2_IRQ_PRIO,
 		    usart_sam_isr,
 		    DEVICE_GET(usart2_sam), 0);
 	irq_enable(DT_USART_SAM_PORT_2_IRQ);
 }
 #endif /* CONFIG_UART_INTERRUPT_DRIVEN */

 #endif
	/*
	* Copyright (c) 2018 Justin Watson
	* Copyright (c) 2016 Piotr Mienkowski
	* SPDX-License-Identifier: Apache-2.0
	*/

	/** @file
	* @brief USART driver for Atmel SAM MCU family.
	*
	* Note:
	* - Only basic USART features sufficient to support printf functionality
	* are currently implemented.
	*/

	#include <errno.h>
	#include <misc/__assert.h>
	#include <device.h>
	#include <init.h>
	#include <soc.h>
	#include <uart.h>

	/*
	* Verify Kconfig configuration
	*/

	#if CONFIG_USART_SAM_PORT_0 == 1

	#if DT_USART_SAM_PORT_0_BAUD_RATE == 0
	#error "DT_USART_SAM_PORT_0_BAUD_RATE has to be bigger than 0"
	#endif

	#endif

	#if CONFIG_USART_SAM_PORT_1 == 1

	#if DT_USART_SAM_PORT_1_BAUD_RATE == 0
	#error "DT_USART_SAM_PORT_1_BAUD_RATE has to be bigger than 0"
	#endif

	#endif

	#if CONFIG_USART_SAM_PORT_2 == 1

	#if DT_USART_SAM_PORT_2_BAUD_RATE == 0
	#error "DT_USART_SAM_PORT_2_BAUD_RATE has to be bigger than 0"
	#endif

	#endif

	/* Device constant configuration parameters */
	struct usart_sam_dev_cfg {
	Usart *regs;
	u32_t periph_id;
	struct soc_gpio_pin pin_rx;
	struct soc_gpio_pin pin_tx;

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	uart_irq_config_func_t irq_config_func;
	#endif
	};

	/* Device run time data */
	struct usart_sam_dev_data {
	u32_t baud_rate;

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	uart_irq_callback_user_data_t irq_cb; /* Interrupt Callback */
	void cb_data; / Interrupt Callback Arg */
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
	};

	#define DEV_CFG(dev) \
	((const struct usart_sam_dev_cfg *const)(dev)->config->config_info)
	#define DEV_DATA(dev) \
	((struct usart_sam_dev_data *const)(dev)->driver_data)


	static int baudrate_set(Usart *const usart, u32_t baudrate,
	u32_t mck_freq_hz);


	static int usart_sam_init(struct device *dev)
	{
	int retval;
	const struct usart_sam_dev_cfg *const cfg = DEV_CFG(dev);
	struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);
	Usart *const usart = cfg->regs;

	/* Enable USART clock in PMC */
	soc_pmc_peripheral_enable(cfg->periph_id);

	/* Connect pins to the peripheral */
	soc_gpio_configure(&cfg->pin_rx);
	soc_gpio_configure(&cfg->pin_tx);

	/* Reset and disable USART */
	usart->US_CR = US_CR_RSTRX \| US_CR_RSTTX
	\| US_CR_RXDIS \| US_CR_TXDIS \| US_CR_RSTSTA;

	/* Disable Interrupts */
	usart->US_IDR = 0xFFFFFFFF;

	/* 8 bits of data, no parity, 1 stop bit in normal mode */
	usart->US_MR = US_MR_NBSTOP_1_BIT
	\| US_MR_PAR_NO
	\| US_MR_CHRL_8_BIT
	\| US_MR_USCLKS_MCK
	\| US_MR_CHMODE_NORMAL;

	/* Set baud rate */
	retval = baudrate_set(usart, dev_data->baud_rate,
	SOC_ATMEL_SAM_MCK_FREQ_HZ);
	if (retval != 0) {
	return retval;
	}

	/* Enable receiver and transmitter */
	usart->US_CR = US_CR_RXEN \| US_CR_TXEN;

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	cfg->irq_config_func(dev);
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	return 0;
	}

	static int usart_sam_poll_in(struct device dev, unsigned char c)
	{
	Usart *const usart = DEV_CFG(dev)->regs;

	if (!(usart->US_CSR & US_CSR_RXRDY)) {
	return -EBUSY;
	}

	/* got a character */
	*c = (unsigned char)usart->US_RHR;

	return 0;
	}

	static void usart_sam_poll_out(struct device *dev, unsigned char c)
	{
	Usart *const usart = DEV_CFG(dev)->regs;

	/* Wait for transmitter to be ready */
	while (!(usart->US_CSR & US_CSR_TXRDY)) {
	;
	}

	/* send a character */
	usart->US_THR = (u32_t)c;
	}

	static int usart_sam_err_check(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;
	int errors = 0;

	if (usart->US_CSR & US_CSR_OVRE) {
	errors \|= UART_ERROR_OVERRUN;
	}

	if (usart->US_CSR & US_CSR_PARE) {
	errors \|= UART_ERROR_PARITY;
	}

	if (usart->US_CSR & US_CSR_FRAME) {
	errors \|= UART_ERROR_FRAMING;
	}

	return errors;
	}

	static int baudrate_set(Usart *const usart, u32_t baudrate,
	u32_t mck_freq_hz)
	{
	u32_t divisor;

	__ASSERT(baudrate,
	"baud rate has to be bigger than 0");
	__ASSERT(mck_freq_hz/16 >= baudrate,
	"MCK frequency is too small to set required baud rate");

	divisor = mck_freq_hz / 16 / baudrate;

	if (divisor > 0xFFFF) {
	return -EINVAL;
	}

	usart->US_BRGR = US_BRGR_CD(divisor);

	return 0;
	}

	#if CONFIG_UART_INTERRUPT_DRIVEN

	static int usart_sam_fifo_fill(struct device dev, const uint8_t tx_data,
	int size)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	/* Wait for transmitter to be ready. */
	while ((usart->US_CSR & US_CSR_TXRDY) == 0) {
	;
	}

	usart->US_THR = *tx_data;

	return 1;
	}

	static int usart_sam_fifo_read(struct device dev, uint8_t rx_data,
	const int size)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;
	int bytes_read;

	bytes_read = 0;

	while (bytes_read < size) {
	if (usart->US_CSR & US_CSR_RXRDY) {
	rx_data[bytes_read] = usart->US_RHR;
	bytes_read++;
	} else {
	break;
	}
	}

	return bytes_read;
	}

	static void usart_sam_irq_tx_enable(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	usart->US_IER = US_IER_TXRDY;
	}

	static void usart_sam_irq_tx_disable(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	usart->US_IDR = US_IDR_TXRDY;
	}

	static int usart_sam_irq_tx_ready(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	return (usart->US_CSR & US_CSR_TXRDY);
	}

	static void usart_sam_irq_rx_enable(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	usart->US_IER = US_IER_RXRDY;
	}

	static void usart_sam_irq_rx_disable(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	usart->US_IDR = US_IDR_RXRDY;
	}

	static int usart_sam_irq_tx_complete(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	return !(usart->US_CSR & US_CSR_TXRDY);
	}

	static int usart_sam_irq_rx_ready(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	return (usart->US_CSR & US_CSR_RXRDY);
	}

	static void usart_sam_irq_err_enable(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	usart->US_IER = US_IER_OVRE \| US_IER_FRAME \| US_IER_PARE;
	}

	static void usart_sam_irq_err_disable(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	usart->US_IDR = US_IDR_OVRE \| US_IDR_FRAME \| US_IDR_PARE;
	}

	static int usart_sam_irq_is_pending(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	return ((usart->US_CSR & US_CSR_TXRDY)
	\| (usart->US_CSR & US_CSR_RXRDY));
	}

	static int usart_sam_irq_update(struct device *dev)
	{
	volatile Usart * const usart = DEV_CFG(dev)->regs;

	return (usart->US_CSR & US_CSR_TXEMPTY);
	}

	static void usart_sam_irq_callback_set(struct device *dev,
	uart_irq_callback_user_data_t cb,
	void *cb_data)
	{
	struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);

	dev_data->irq_cb = cb;
	dev_data->cb_data = cb_data;
	}

	static void usart_sam_isr(void *arg)
	{
	struct device *dev = arg;
	struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);

	if (dev_data->irq_cb) {
	dev_data->irq_cb(dev_data->cb_data);
	}
	}

	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	static const struct uart_driver_api usart_sam_driver_api = {
	.poll_in = usart_sam_poll_in,
	.poll_out = usart_sam_poll_out,
	.err_check = usart_sam_err_check,
	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	.fifo_fill = usart_sam_fifo_fill,
	.fifo_read = usart_sam_fifo_read,
	.irq_tx_enable = usart_sam_irq_tx_enable,
	.irq_tx_disable = usart_sam_irq_tx_disable,
	.irq_tx_ready = usart_sam_irq_tx_ready,
	.irq_rx_enable = usart_sam_irq_rx_enable,
	.irq_rx_disable = usart_sam_irq_rx_disable,
	.irq_tx_complete = usart_sam_irq_tx_complete,
	.irq_rx_ready = usart_sam_irq_rx_ready,
	.irq_err_enable = usart_sam_irq_err_enable,
	.irq_err_disable = usart_sam_irq_err_disable,
	.irq_is_pending = usart_sam_irq_is_pending,
	.irq_update = usart_sam_irq_update,
	.irq_callback_set = usart_sam_irq_callback_set,
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
	};

	/* USART0 */

	#ifdef CONFIG_USART_SAM_PORT_0

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	/* Forward declare function */
	static void usart0_sam_irq_config_func(struct device *port);
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	static const struct usart_sam_dev_cfg usart0_sam_config = {
	.regs = USART0,
	.periph_id = DT_USART_SAM_PORT_0_PERIPHERAL_ID,
	.pin_rx = PIN_USART0_RXD,
	.pin_tx = PIN_USART0_TXD,

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	.irq_config_func = usart0_sam_irq_config_func,
	#endif
	};

	static struct usart_sam_dev_data usart0_sam_data = {
	.baud_rate = DT_USART_SAM_PORT_0_BAUD_RATE,
	};

	DEVICE_AND_API_INIT(usart0_sam, DT_USART_SAM_PORT_0_NAME, &usart_sam_init,
	&usart0_sam_data, &usart0_sam_config, PRE_KERNEL_1,
	CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	static void usart0_sam_irq_config_func(struct device *port)
	{
	IRQ_CONNECT(DT_USART_SAM_PORT_0_IRQ,
	DT_USART_SAM_PORT_0_IRQ_PRIO,
	usart_sam_isr,
	DEVICE_GET(usart0_sam), 0);
	irq_enable(DT_USART_SAM_PORT_0_IRQ);
	}
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	#endif

	/* USART1 */

	#ifdef CONFIG_USART_SAM_PORT_1

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	/* Forward declare function */
	static void usart1_sam_irq_config_func(struct device *port);
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	static const struct usart_sam_dev_cfg usart1_sam_config = {
	.regs = USART1,
	.periph_id = DT_USART_SAM_PORT_1_PERIPHERAL_ID,
	.pin_rx = PIN_USART1_RXD,
	.pin_tx = PIN_USART1_TXD,

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	.irq_config_func = usart1_sam_irq_config_func,
	#endif
	};

	static struct usart_sam_dev_data usart1_sam_data = {
	.baud_rate = DT_USART_SAM_PORT_1_BAUD_RATE,
	};

	DEVICE_AND_API_INIT(usart1_sam, DT_USART_SAM_PORT_1_NAME, &usart_sam_init,
	&usart1_sam_data, &usart1_sam_config, PRE_KERNEL_1,
	CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	static void usart1_sam_irq_config_func(struct device *port)
	{
	IRQ_CONNECT(DT_USART_SAM_PORT_1_IRQ,
	DT_USART_SAM_PORT_1_IRQ_PRIO,
	usart_sam_isr,
	DEVICE_GET(usart1_sam), 0);
	irq_enable(DT_USART_SAM_PORT_1_IRQ);
	}
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	#endif

	/* USART2 */

	#ifdef CONFIG_USART_SAM_PORT_2

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	/* Forward declare function */
	static void usart2_sam_irq_config_func(struct device *port);
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	static const struct usart_sam_dev_cfg usart2_sam_config = {
	.regs = USART2,
	.periph_id = DT_USART_SAM_PORT_2_PERIPHERAL_ID,
	.pin_rx = PIN_USART2_RXD,
	.pin_tx = PIN_USART2_TXD,

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	.irq_config_func = usart2_sam_irq_config_func,
	#endif
	};

	static struct usart_sam_dev_data usart2_sam_data = {
	.baud_rate = DT_USART_SAM_PORT_2_BAUD_RATE,
	};

	DEVICE_AND_API_INIT(usart2_sam, DT_USART_SAM_PORT_2_NAME, &usart_sam_init,
	&usart2_sam_data, &usart2_sam_config, PRE_KERNEL_1,
	CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);

	#ifdef CONFIG_UART_INTERRUPT_DRIVEN
	static void usart2_sam_irq_config_func(struct device *port)
	{
	IRQ_CONNECT(DT_USART_SAM_PORT_2_IRQ,
	DT_USART_SAM_PORT_2_IRQ_PRIO,
	usart_sam_isr,
	DEVICE_GET(usart2_sam), 0);
	irq_enable(DT_USART_SAM_PORT_2_IRQ);
	}
	#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

	#endif