375 lines
8.9 KiB
C
375 lines
8.9 KiB
C
/*
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* Copyright (c) 2017 Piotr Mienkowski
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* Copyright (c) 2018 Justin Watson
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT atmel_sam_uart
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/** @file
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* @brief UART driver for Atmel SAM MCU family.
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*
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* Note:
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* - Error handling is not implemented.
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* - The driver works only in polling mode, interrupt mode is not implemented.
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*/
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#include <errno.h>
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#include <sys/__assert.h>
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#include <device.h>
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#include <init.h>
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#include <soc.h>
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#include <drivers/uart.h>
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/* Device constant configuration parameters */
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struct uart_sam_dev_cfg {
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Uart *regs;
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uint32_t periph_id;
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struct soc_gpio_pin pin_rx;
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struct soc_gpio_pin pin_tx;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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uart_irq_config_func_t irq_config_func;
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#endif
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};
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/* Device run time data */
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struct uart_sam_dev_data {
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uint32_t baud_rate;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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uart_irq_callback_user_data_t irq_cb; /* Interrupt Callback */
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void *irq_cb_data; /* Interrupt Callback Arg */
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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};
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#define DEV_CFG(dev) \
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((const struct uart_sam_dev_cfg *const)(dev)->config)
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#define DEV_DATA(dev) \
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((struct uart_sam_dev_data *const)(dev)->data)
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static int baudrate_set(Uart *const uart, uint32_t baudrate,
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uint32_t mck_freq_hz);
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static int uart_sam_init(const struct device *dev)
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{
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int retval;
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const struct uart_sam_dev_cfg *const cfg = DEV_CFG(dev);
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struct uart_sam_dev_data *const dev_data = DEV_DATA(dev);
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Uart *const uart = cfg->regs;
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/* Enable UART clock in PMC */
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soc_pmc_peripheral_enable(cfg->periph_id);
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/* Connect pins to the peripheral */
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soc_gpio_configure(&cfg->pin_rx);
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soc_gpio_configure(&cfg->pin_tx);
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/* Reset and disable UART */
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uart->UART_CR = UART_CR_RSTRX | UART_CR_RSTTX
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| UART_CR_RXDIS | UART_CR_TXDIS | UART_CR_RSTSTA;
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/* Disable Interrupts */
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uart->UART_IDR = 0xFFFFFFFF;
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/* 8 bits of data, no parity, 1 stop bit in normal mode, baud rate
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* driven by the peripheral clock, UART does not filter the receive line
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*/
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uart->UART_MR = UART_MR_PAR_NO
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| UART_MR_CHMODE_NORMAL;
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/* Set baud rate */
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retval = baudrate_set(uart, dev_data->baud_rate,
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SOC_ATMEL_SAM_MCK_FREQ_HZ);
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if (retval != 0) {
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return retval;
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}
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/* Enable receiver and transmitter */
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uart->UART_CR = UART_CR_RXEN | UART_CR_TXEN;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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cfg->irq_config_func(dev);
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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return 0;
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}
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static int uart_sam_poll_in(const struct device *dev, unsigned char *c)
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{
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Uart *const uart = DEV_CFG(dev)->regs;
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if (!(uart->UART_SR & UART_SR_RXRDY)) {
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return -EBUSY;
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}
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/* got a character */
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*c = (unsigned char)uart->UART_RHR;
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return 0;
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}
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static void uart_sam_poll_out(const struct device *dev, unsigned char c)
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{
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Uart *const uart = DEV_CFG(dev)->regs;
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/* Wait for transmitter to be ready */
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while (!(uart->UART_SR & UART_SR_TXRDY)) {
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}
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/* send a character */
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uart->UART_THR = (uint32_t)c;
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}
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static int uart_sam_err_check(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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int errors = 0;
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if (uart->UART_SR & UART_SR_OVRE) {
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errors |= UART_ERROR_OVERRUN;
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}
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if (uart->UART_SR & UART_SR_PARE) {
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errors |= UART_ERROR_PARITY;
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}
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if (uart->UART_SR & UART_SR_FRAME) {
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errors |= UART_ERROR_FRAMING;
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}
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return errors;
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}
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static int baudrate_set(Uart *const uart, uint32_t baudrate,
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uint32_t mck_freq_hz)
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{
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uint32_t divisor;
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__ASSERT(baudrate,
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"baud rate has to be bigger than 0");
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__ASSERT(mck_freq_hz/16U >= baudrate,
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"MCK frequency is too small to set required baud rate");
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divisor = mck_freq_hz / 16U / baudrate;
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if (divisor > 0xFFFF) {
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return -EINVAL;
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}
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uart->UART_BRGR = UART_BRGR_CD(divisor);
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return 0;
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}
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static int uart_sam_fifo_fill(const struct device *dev,
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const uint8_t *tx_data,
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int size)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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/* Wait for transmitter to be ready. */
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while ((uart->UART_SR & UART_SR_TXRDY) == 0) {
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}
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uart->UART_THR = *tx_data;
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return 1;
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}
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static int uart_sam_fifo_read(const struct device *dev, uint8_t *rx_data,
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const int size)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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int bytes_read;
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bytes_read = 0;
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while (bytes_read < size) {
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if (uart->UART_SR & UART_SR_RXRDY) {
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rx_data[bytes_read] = uart->UART_RHR;
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bytes_read++;
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} else {
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break;
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}
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}
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return bytes_read;
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}
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static void uart_sam_irq_tx_enable(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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uart->UART_IER = UART_IER_TXRDY;
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}
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static void uart_sam_irq_tx_disable(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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uart->UART_IDR = UART_IDR_TXRDY;
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}
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static int uart_sam_irq_tx_ready(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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return (uart->UART_SR & UART_SR_TXRDY);
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}
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static void uart_sam_irq_rx_enable(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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uart->UART_IER = UART_IER_RXRDY;
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}
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static void uart_sam_irq_rx_disable(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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uart->UART_IDR = UART_IDR_RXRDY;
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}
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static int uart_sam_irq_tx_complete(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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return !(uart->UART_SR & UART_SR_TXRDY);
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}
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static int uart_sam_irq_rx_ready(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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return (uart->UART_SR & UART_SR_RXRDY);
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}
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static void uart_sam_irq_err_enable(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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uart->UART_IER = UART_IER_OVRE | UART_IER_FRAME | UART_IER_PARE;
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}
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static void uart_sam_irq_err_disable(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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uart->UART_IDR = UART_IDR_OVRE | UART_IDR_FRAME | UART_IDR_PARE;
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}
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static int uart_sam_irq_is_pending(const struct device *dev)
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{
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volatile Uart * const uart = DEV_CFG(dev)->regs;
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return (uart->UART_IMR & (UART_IMR_TXRDY | UART_IMR_RXRDY)) &
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(uart->UART_SR & (UART_SR_TXRDY | UART_SR_RXRDY));
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}
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static int uart_sam_irq_update(const struct device *dev)
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{
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ARG_UNUSED(dev);
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return 1;
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}
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static void uart_sam_irq_callback_set(const struct device *dev,
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uart_irq_callback_user_data_t cb,
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void *cb_data)
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{
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struct uart_sam_dev_data *const dev_data = DEV_DATA(dev);
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dev_data->irq_cb = cb;
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dev_data->irq_cb_data = cb_data;
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}
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static void uart_sam_isr(const struct device *dev)
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{
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struct uart_sam_dev_data *const dev_data = DEV_DATA(dev);
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if (dev_data->irq_cb) {
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dev_data->irq_cb(dev, dev_data->irq_cb_data);
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}
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}
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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static const struct uart_driver_api uart_sam_driver_api = {
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.poll_in = uart_sam_poll_in,
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.poll_out = uart_sam_poll_out,
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.err_check = uart_sam_err_check,
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.fifo_fill = uart_sam_fifo_fill,
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.fifo_read = uart_sam_fifo_read,
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.irq_tx_enable = uart_sam_irq_tx_enable,
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.irq_tx_disable = uart_sam_irq_tx_disable,
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.irq_tx_ready = uart_sam_irq_tx_ready,
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.irq_rx_enable = uart_sam_irq_rx_enable,
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.irq_rx_disable = uart_sam_irq_rx_disable,
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.irq_tx_complete = uart_sam_irq_tx_complete,
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.irq_rx_ready = uart_sam_irq_rx_ready,
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.irq_err_enable = uart_sam_irq_err_enable,
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.irq_err_disable = uart_sam_irq_err_disable,
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.irq_is_pending = uart_sam_irq_is_pending,
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.irq_update = uart_sam_irq_update,
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.irq_callback_set = uart_sam_irq_callback_set,
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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};
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#define UART_SAM_DECLARE_CFG(n, IRQ_FUNC_INIT) \
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static const struct uart_sam_dev_cfg uart##n##_sam_config = { \
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.regs = (Uart *)DT_INST_REG_ADDR(n), \
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.periph_id = DT_INST_PROP(n, peripheral_id), \
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\
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.pin_rx = ATMEL_SAM_DT_INST_PIN(n, 0), \
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.pin_tx = ATMEL_SAM_DT_INST_PIN(n, 1), \
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\
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IRQ_FUNC_INIT \
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}
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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#define UART_SAM_CONFIG_FUNC(n) \
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static void uart##n##_sam_irq_config_func(const struct device *port) \
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{ \
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IRQ_CONNECT(DT_INST_IRQN(n), \
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DT_INST_IRQ(n, priority), \
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uart_sam_isr, \
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DEVICE_DT_INST_GET(n), 0); \
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irq_enable(DT_INST_IRQN(n)); \
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}
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#define UART_SAM_IRQ_CFG_FUNC_INIT(n) \
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.irq_config_func = uart##n##_sam_irq_config_func
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#define UART_SAM_INIT_CFG(n) \
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UART_SAM_DECLARE_CFG(n, UART_SAM_IRQ_CFG_FUNC_INIT(n))
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#else
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#define UART_SAM_CONFIG_FUNC(n)
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#define UART_SAM_IRQ_CFG_FUNC_INIT
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#define UART_SAM_INIT_CFG(n) \
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UART_SAM_DECLARE_CFG(n, UART_SAM_IRQ_CFG_FUNC_INIT)
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#endif
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#define UART_SAM_INIT(n) \
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static struct uart_sam_dev_data uart##n##_sam_data = { \
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.baud_rate = DT_INST_PROP(n, current_speed), \
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}; \
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\
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static const struct uart_sam_dev_cfg uart##n##_sam_config; \
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\
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DEVICE_DT_INST_DEFINE(n, &uart_sam_init, \
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NULL, &uart##n##_sam_data, \
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&uart##n##_sam_config, PRE_KERNEL_1, \
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CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
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&uart_sam_driver_api); \
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\
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UART_SAM_CONFIG_FUNC(n) \
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\
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UART_SAM_INIT_CFG(n);
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DT_INST_FOREACH_STATUS_OKAY(UART_SAM_INIT)
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