452 lines
10 KiB
C
452 lines
10 KiB
C
/*
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* Copyright (c) 2018 Justin Watson
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* Copyright (c) 2016 Piotr Mienkowski
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* SPDX-License-Identifier: Apache-2.0
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*/
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/** @file
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* @brief USART driver for Atmel SAM MCU family.
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*
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* Note:
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* - Only basic USART features sufficient to support printf functionality
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* are currently implemented.
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*/
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#include <errno.h>
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#include <misc/__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 <uart.h>
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/*
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* Verify Kconfig configuration
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*/
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#if CONFIG_USART_SAM_PORT_0 == 1
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#if CONFIG_USART_SAM_PORT_0_BAUD_RATE == 0
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#error "CONFIG_USART_SAM_PORT_0_BAUD_RATE has to be bigger than 0"
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#endif
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#endif
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#if CONFIG_USART_SAM_PORT_1 == 1
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#if CONFIG_USART_SAM_PORT_1_BAUD_RATE == 0
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#error "CONFIG_USART_SAM_PORT_1_BAUD_RATE has to be bigger than 0"
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#endif
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#endif
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#if CONFIG_USART_SAM_PORT_2 == 1
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#if CONFIG_USART_SAM_PORT_2_BAUD_RATE == 0
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#error "CONFIG_USART_SAM_PORT_2_BAUD_RATE has to be bigger than 0"
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#endif
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#endif
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/* Device constant configuration parameters */
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struct usart_sam_dev_cfg {
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Usart *regs;
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u32_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 usart_sam_dev_data {
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u32_t baud_rate;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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uart_irq_callback_t irq_cb; /* Interrupt Callback */
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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 usart_sam_dev_cfg *const)(dev)->config->config_info)
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#define DEV_DATA(dev) \
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((struct usart_sam_dev_data *const)(dev)->driver_data)
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static int baudrate_set(Usart *const usart, u32_t baudrate,
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u32_t mck_freq_hz);
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static int usart_sam_init(struct device *dev)
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{
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int retval;
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const struct usart_sam_dev_cfg *const cfg = DEV_CFG(dev);
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struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);
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Usart *const usart = cfg->regs;
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/* Enable USART 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 USART */
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usart->US_CR = US_CR_RSTRX | US_CR_RSTTX
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| US_CR_RXDIS | US_CR_TXDIS | US_CR_RSTSTA;
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/* Disable Interrupts */
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usart->US_IDR = 0xFFFFFFFF;
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/* 8 bits of data, no parity, 1 stop bit in normal mode */
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usart->US_MR = US_MR_NBSTOP_1_BIT
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| US_MR_PAR_NO
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| US_MR_CHRL_8_BIT
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| US_MR_USCLKS_MCK
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| US_MR_CHMODE_NORMAL;
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/* Set baud rate */
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retval = baudrate_set(usart, 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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usart->US_CR = US_CR_RXEN | US_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 usart_sam_poll_in(struct device *dev, unsigned char *c)
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{
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Usart *const usart = DEV_CFG(dev)->regs;
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if (!(usart->US_CSR & US_CSR_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)usart->US_RHR;
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return 0;
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}
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static unsigned char usart_sam_poll_out(struct device *dev, unsigned char c)
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{
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Usart *const usart = DEV_CFG(dev)->regs;
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/* Wait for transmitter to be ready */
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while (!(usart->US_CSR & US_CSR_TXRDY)) {
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;
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}
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/* send a character */
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usart->US_THR = (u32_t)c;
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return c;
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}
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static int usart_sam_err_check(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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int errors = 0;
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if (usart->US_CSR & US_CSR_OVRE) {
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errors |= UART_ERROR_OVERRUN;
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}
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if (usart->US_CSR & US_CSR_PARE) {
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errors |= UART_ERROR_PARITY;
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}
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if (usart->US_CSR & US_CSR_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(Usart *const usart, u32_t baudrate,
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u32_t mck_freq_hz)
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{
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u32_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/16 >= baudrate,
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"MCK frequency is too small to set required baud rate");
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divisor = mck_freq_hz / 16 / baudrate;
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if (divisor > 0xFFFF) {
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return -EINVAL;
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};
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usart->US_BRGR = US_BRGR_CD(divisor);
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return 0;
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}
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#if CONFIG_UART_INTERRUPT_DRIVEN
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static int usart_sam_fifo_fill(struct device *dev, const uint8_t *tx_data,
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int size)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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/* Wait for transmitter to be ready. */
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while ((usart->US_CSR & US_CSR_TXRDY) == 0) {
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;
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}
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usart->US_THR = *tx_data;
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return 1;
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}
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static int usart_sam_fifo_read(struct device *dev, uint8_t *rx_data,
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const int size)
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{
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volatile Usart * const usart = 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 (usart->US_CSR & US_CSR_RXRDY) {
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rx_data[bytes_read] = usart->US_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 usart_sam_irq_tx_enable(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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usart->US_IER = US_IER_TXRDY;
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}
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static void usart_sam_irq_tx_disable(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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usart->US_IDR = US_IDR_TXRDY;
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}
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static int usart_sam_irq_tx_ready(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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return (usart->US_CSR & US_CSR_TXRDY);
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}
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static void usart_sam_irq_rx_enable(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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usart->US_IER = US_IER_RXRDY;
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}
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static void usart_sam_irq_rx_disable(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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usart->US_IDR = US_IDR_RXRDY;
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}
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static int usart_sam_irq_tx_complete(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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return !(usart->US_CSR & US_CSR_TXRDY);
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}
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static int usart_sam_irq_rx_ready(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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return (usart->US_CSR & US_CSR_RXRDY);
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}
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static void usart_sam_irq_err_enable(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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usart->US_IER = US_IER_OVRE | US_IER_FRAME | US_IER_PARE;
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}
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static void usart_sam_irq_err_disable(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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usart->US_IDR = US_IDR_OVRE | US_IDR_FRAME | US_IDR_PARE;
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}
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static int usart_sam_irq_is_pending(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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return ((usart->US_CSR & US_CSR_TXRDY)
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| (usart->US_CSR & US_CSR_RXRDY));
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}
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static int usart_sam_irq_update(struct device *dev)
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{
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volatile Usart * const usart = DEV_CFG(dev)->regs;
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return (usart->US_CSR & US_CSR_TXEMPTY);
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}
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static void usart_sam_irq_callback_set(struct device *dev,
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uart_irq_callback_t cb)
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{
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struct usart_sam_dev_data *const dev_data = DEV_DATA(dev);
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dev_data->irq_cb = cb;
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}
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static void usart_sam_isr(void *arg)
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{
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struct device *dev = arg;
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struct usart_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);
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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 usart_sam_driver_api = {
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.poll_in = usart_sam_poll_in,
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.poll_out = usart_sam_poll_out,
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.err_check = usart_sam_err_check,
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.fifo_fill = usart_sam_fifo_fill,
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.fifo_read = usart_sam_fifo_read,
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.irq_tx_enable = usart_sam_irq_tx_enable,
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.irq_tx_disable = usart_sam_irq_tx_disable,
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.irq_tx_ready = usart_sam_irq_tx_ready,
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.irq_rx_enable = usart_sam_irq_rx_enable,
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.irq_rx_disable = usart_sam_irq_rx_disable,
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.irq_tx_complete = usart_sam_irq_tx_complete,
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.irq_rx_ready = usart_sam_irq_rx_ready,
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.irq_err_enable = usart_sam_irq_err_enable,
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.irq_err_disable = usart_sam_irq_err_disable,
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.irq_is_pending = usart_sam_irq_is_pending,
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.irq_update = usart_sam_irq_update,
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.irq_callback_set = usart_sam_irq_callback_set,
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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};
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/* USART0 */
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#ifdef CONFIG_USART_SAM_PORT_0
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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/* Forward declare function */
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static void usart0_sam_irq_config_func(struct device *port);
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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static const struct usart_sam_dev_cfg usart0_sam_config = {
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.regs = USART0,
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.periph_id = CONFIG_USART_SAM_PORT_0_PERIPHERAL_ID,
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.pin_rx = PIN_USART0_RXD,
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.pin_tx = PIN_USART0_TXD,
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.irq_config_func = usart0_sam_irq_config_func,
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#endif
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};
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static struct usart_sam_dev_data usart0_sam_data = {
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.baud_rate = CONFIG_USART_SAM_PORT_0_BAUD_RATE,
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};
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DEVICE_AND_API_INIT(usart0_sam, CONFIG_USART_SAM_PORT_0_NAME, &usart_sam_init,
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&usart0_sam_data, &usart0_sam_config, PRE_KERNEL_1,
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CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void usart0_sam_irq_config_func(struct device *port)
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{
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IRQ_CONNECT(CONFIG_USART_SAM_PORT_0_IRQ,
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CONFIG_USART_SAM_PORT_0_IRQ_PRIO,
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usart_sam_isr,
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DEVICE_GET(usart0_sam), 0);
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irq_enable(CONFIG_USART_SAM_PORT_0_IRQ);
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}
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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#endif
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/* USART1 */
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#ifdef CONFIG_USART_SAM_PORT_1
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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/* Forward declare function */
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static void usart1_sam_irq_config_func(struct device *port);
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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static const struct usart_sam_dev_cfg usart1_sam_config = {
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.regs = USART1,
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.periph_id = CONFIG_USART_SAM_PORT_1_PERIPHERAL_ID,
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.pin_rx = PIN_USART1_RXD,
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.pin_tx = PIN_USART1_TXD,
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.irq_config_func = usart1_sam_irq_config_func,
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#endif
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};
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static struct usart_sam_dev_data usart1_sam_data = {
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.baud_rate = CONFIG_USART_SAM_PORT_1_BAUD_RATE,
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};
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DEVICE_AND_API_INIT(usart1_sam, CONFIG_USART_SAM_PORT_1_NAME, &usart_sam_init,
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&usart1_sam_data, &usart1_sam_config, PRE_KERNEL_1,
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CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void usart1_sam_irq_config_func(struct device *port)
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{
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IRQ_CONNECT(CONFIG_USART_SAM_PORT_1_IRQ,
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CONFIG_USART_SAM_PORT_1_IRQ_PRIO,
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usart_sam_isr,
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DEVICE_GET(usart1_sam), 0);
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irq_enable(CONFIG_USART_SAM_PORT_1_IRQ);
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}
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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#endif
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/* USART2 */
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#ifdef CONFIG_USART_SAM_PORT_2
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static const struct usart_sam_dev_cfg usart2_sam_config = {
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.regs = USART2,
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.periph_id = CONFIG_USART_SAM_PORT_3_PERIPHERAL_ID,
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.pin_rx = PIN_USART2_RXD,
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.pin_tx = PIN_USART2_TXD,
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};
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static struct usart_sam_dev_data usart2_sam_data = {
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.baud_rate = CONFIG_USART_SAM_PORT_2_BAUD_RATE,
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};
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DEVICE_AND_API_INIT(usart2_sam, CONFIG_USART_SAM_PORT_2_NAME, &usart_sam_init,
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&usart2_sam_data, &usart2_sam_config, PRE_KERNEL_1,
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CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &usart_sam_driver_api);
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#endif
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