| /* |
| * Copyright (c) 2018 Justin Watson |
| * Copyright (c) 2016 Piotr Mienkowski |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #define DT_DRV_COMPAT atmel_sam_usart |
| |
| /** @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 <zephyr/sys/__assert.h> |
| #include <zephyr/device.h> |
| #include <zephyr/init.h> |
| #include <soc.h> |
| #include <zephyr/drivers/uart.h> |
| #include <zephyr/drivers/pinctrl.h> |
| |
| /* Device constant configuration parameters */ |
| struct usart_sam_dev_cfg { |
| Usart *regs; |
| uint32_t periph_id; |
| bool hw_flow_control; |
| const struct pinctrl_dev_config *pcfg; |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| uart_irq_config_func_t irq_config_func; |
| #endif |
| }; |
| |
| /* Device run time data */ |
| struct usart_sam_dev_data { |
| uint32_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 */ |
| }; |
| |
| static int baudrate_set(Usart *const usart, uint32_t baudrate, |
| uint32_t mck_freq_hz); |
| |
| |
| static int usart_sam_init(const struct device *dev) |
| { |
| int retval; |
| const struct usart_sam_dev_cfg *const cfg = dev->config; |
| struct usart_sam_dev_data *const dev_data = dev->data; |
| Usart *const usart = cfg->regs; |
| uint32_t us_mr; |
| |
| /* Enable USART clock in PMC */ |
| soc_pmc_peripheral_enable(cfg->periph_id); |
| |
| /* Connect pins to the peripheral */ |
| retval = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT); |
| if (retval < 0) { |
| return retval; |
| } |
| |
| /* 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 */ |
| us_mr = US_MR_NBSTOP_1_BIT |
| | US_MR_PAR_NO |
| | US_MR_CHRL_8_BIT |
| | US_MR_USCLKS_MCK |
| | US_MR_CHMODE_NORMAL; |
| |
| if (cfg->hw_flow_control) { |
| us_mr |= US_MR_USART_MODE_HW_HANDSHAKING; |
| } |
| |
| usart->US_MR = us_mr; |
| |
| /* 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(const struct device *dev, unsigned char *c) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| Usart * const usart = config->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(const struct device *dev, unsigned char c) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| Usart * const usart = config->regs; |
| |
| /* Wait for transmitter to be ready */ |
| while (!(usart->US_CSR & US_CSR_TXRDY)) { |
| } |
| |
| /* send a character */ |
| usart->US_THR = (uint32_t)c; |
| } |
| |
| static int usart_sam_err_check(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->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, uint32_t baudrate, |
| uint32_t mck_freq_hz) |
| { |
| uint32_t divisor; |
| |
| __ASSERT(baudrate, |
| "baud rate has to be bigger than 0"); |
| __ASSERT(mck_freq_hz/16U >= baudrate, |
| "MCK frequency is too small to set required baud rate"); |
| |
| divisor = mck_freq_hz / 16U / 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(const struct device *dev, |
| const uint8_t *tx_data, |
| int size) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->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(const struct device *dev, uint8_t *rx_data, |
| const int size) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->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(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| usart->US_IER = US_IER_TXRDY; |
| } |
| |
| static void usart_sam_irq_tx_disable(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| usart->US_IDR = US_IDR_TXRDY; |
| } |
| |
| static int usart_sam_irq_tx_ready(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| /* Check that the transmitter is ready but only |
| * return true if the interrupt is also enabled |
| */ |
| return (usart->US_CSR & US_CSR_TXRDY && |
| usart->US_IMR & US_IMR_TXRDY); |
| } |
| |
| static void usart_sam_irq_rx_enable(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| usart->US_IER = US_IER_RXRDY; |
| } |
| |
| static void usart_sam_irq_rx_disable(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| usart->US_IDR = US_IDR_RXRDY; |
| } |
| |
| static int usart_sam_irq_tx_complete(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| return (usart->US_CSR & US_CSR_TXRDY && |
| usart->US_CSR & US_CSR_TXEMPTY); |
| } |
| |
| static int usart_sam_irq_rx_ready(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| return (usart->US_CSR & US_CSR_RXRDY); |
| } |
| |
| static void usart_sam_irq_err_enable(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| usart->US_IER = US_IER_OVRE | US_IER_FRAME | US_IER_PARE; |
| } |
| |
| static void usart_sam_irq_err_disable(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| usart->US_IDR = US_IDR_OVRE | US_IDR_FRAME | US_IDR_PARE; |
| } |
| |
| static int usart_sam_irq_is_pending(const struct device *dev) |
| { |
| const struct usart_sam_dev_cfg *config = dev->config; |
| |
| volatile Usart * const usart = config->regs; |
| |
| return (usart->US_IMR & (US_IMR_TXRDY | US_IMR_RXRDY)) & |
| (usart->US_CSR & (US_CSR_TXRDY | US_CSR_RXRDY)); |
| } |
| |
| static int usart_sam_irq_update(const struct device *dev) |
| { |
| ARG_UNUSED(dev); |
| |
| return 1; |
| } |
| |
| static void usart_sam_irq_callback_set(const struct device *dev, |
| uart_irq_callback_user_data_t cb, |
| void *cb_data) |
| { |
| struct usart_sam_dev_data *const dev_data = dev->data; |
| |
| dev_data->irq_cb = cb; |
| dev_data->cb_data = cb_data; |
| } |
| |
| static void usart_sam_isr(const struct device *dev) |
| { |
| struct usart_sam_dev_data *const dev_data = dev->data; |
| |
| if (dev_data->irq_cb) { |
| dev_data->irq_cb(dev, 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 */ |
| }; |
| |
| #define USART_SAM_DECLARE_CFG(n, IRQ_FUNC_INIT) \ |
| static const struct usart_sam_dev_cfg usart##n##_sam_config = { \ |
| .regs = (Usart *)DT_INST_REG_ADDR(n), \ |
| .periph_id = DT_INST_PROP(n, peripheral_id), \ |
| .hw_flow_control = DT_INST_PROP(n, hw_flow_control), \ |
| \ |
| .pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(n), \ |
| \ |
| IRQ_FUNC_INIT \ |
| } |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| #define USART_SAM_CONFIG_FUNC(n) \ |
| static void usart##n##_sam_irq_config_func(const struct device *port) \ |
| { \ |
| IRQ_CONNECT(DT_INST_IRQN(n), \ |
| DT_INST_IRQ(n, priority), \ |
| usart_sam_isr, \ |
| DEVICE_DT_INST_GET(n), 0); \ |
| irq_enable(DT_INST_IRQN(n)); \ |
| } |
| #define USART_SAM_IRQ_CFG_FUNC_INIT(n) \ |
| .irq_config_func = usart##n##_sam_irq_config_func |
| #define USART_SAM_INIT_CFG(n) \ |
| USART_SAM_DECLARE_CFG(n, USART_SAM_IRQ_CFG_FUNC_INIT(n)) |
| #else |
| #define USART_SAM_CONFIG_FUNC(n) |
| #define USART_SAM_IRQ_CFG_FUNC_INIT |
| #define USART_SAM_INIT_CFG(n) \ |
| USART_SAM_DECLARE_CFG(n, USART_SAM_IRQ_CFG_FUNC_INIT) |
| #endif |
| |
| #define USART_SAM_INIT(n) \ |
| PINCTRL_DT_INST_DEFINE(n); \ |
| static struct usart_sam_dev_data usart##n##_sam_data = { \ |
| .baud_rate = DT_INST_PROP(n, current_speed), \ |
| }; \ |
| \ |
| static const struct usart_sam_dev_cfg usart##n##_sam_config; \ |
| \ |
| DEVICE_DT_INST_DEFINE(n, \ |
| &usart_sam_init, NULL, \ |
| &usart##n##_sam_data, \ |
| &usart##n##_sam_config, PRE_KERNEL_1, \ |
| CONFIG_SERIAL_INIT_PRIORITY, \ |
| &usart_sam_driver_api); \ |
| \ |
| USART_SAM_CONFIG_FUNC(n) \ |
| \ |
| USART_SAM_INIT_CFG(n); |
| |
| DT_INST_FOREACH_STATUS_OKAY(USART_SAM_INIT) |