| /* |
| * Copyright (c) 2018 - 2019 Antmicro <www.antmicro.com> |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #define DT_DRV_COMPAT litex_uart0 |
| |
| #include <zephyr/kernel.h> |
| #include <zephyr/arch/cpu.h> |
| #include <zephyr/init.h> |
| #include <zephyr/irq.h> |
| #include <zephyr/device.h> |
| #include <zephyr/drivers/uart.h> |
| #include <zephyr/types.h> |
| |
| #define UART_RXTX_ADDR DT_INST_REG_ADDR_BY_NAME(0, rxtx) |
| #define UART_TXFULL_ADDR DT_INST_REG_ADDR_BY_NAME(0, txfull) |
| #define UART_RXEMPTY_ADDR DT_INST_REG_ADDR_BY_NAME(0, rxempty) |
| #define UART_EV_STATUS_ADDR DT_INST_REG_ADDR_BY_NAME(0, ev_status) |
| #define UART_EV_PENDING_ADDR DT_INST_REG_ADDR_BY_NAME(0, ev_pending) |
| #define UART_EV_ENABLE_ADDR DT_INST_REG_ADDR_BY_NAME(0, ev_enable) |
| #define UART_TXEMPTY_ADDR DT_INST_REG_ADDR_BY_NAME(0, txempty) |
| #define UART_RXFULL_ADDR DT_INST_REG_ADDR_BY_NAME(0, rxfull) |
| |
| #define UART_EV_TX (1 << 0) |
| #define UART_EV_RX (1 << 1) |
| #define UART_IRQ DT_INST_IRQN(0) |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| typedef void (*irq_cfg_func_t)(void); |
| #endif |
| |
| struct uart_liteuart_device_config { |
| uint32_t port; |
| uint32_t sys_clk_freq; |
| uint32_t baud_rate; |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| irq_cfg_func_t cfg_func; |
| #endif |
| }; |
| |
| struct uart_liteuart_data { |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| uart_irq_callback_user_data_t callback; |
| void *cb_data; |
| #endif |
| }; |
| |
| /** |
| * @brief Output a character in polled mode. |
| * |
| * Writes data to tx register. Waits for space if transmitter is full. |
| * |
| * @param dev UART device struct |
| * @param c Character to send |
| */ |
| static void uart_liteuart_poll_out(const struct device *dev, unsigned char c) |
| { |
| /* wait for space */ |
| while (litex_read8(UART_TXFULL_ADDR)) { |
| } |
| |
| litex_write8(c, UART_RXTX_ADDR); |
| } |
| |
| /** |
| * @brief Poll the device for input. |
| * |
| * @param dev UART device struct |
| * @param c Pointer to character |
| * |
| * @return 0 if a character arrived, -1 if the input buffer if empty. |
| */ |
| static int uart_liteuart_poll_in(const struct device *dev, unsigned char *c) |
| { |
| if (!litex_read8(UART_RXEMPTY_ADDR)) { |
| *c = litex_read8(UART_RXTX_ADDR); |
| |
| /* refresh UART_RXEMPTY by writing UART_EV_RX |
| * to UART_EV_PENDING |
| */ |
| litex_write8(UART_EV_RX, UART_EV_PENDING_ADDR); |
| return 0; |
| } else { |
| return -1; |
| } |
| } |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| /** |
| * @brief Enable TX interrupt in event register |
| * |
| * @param dev UART device struct |
| */ |
| static void uart_liteuart_irq_tx_enable(const struct device *dev) |
| { |
| uint8_t enable = litex_read8(UART_EV_ENABLE_ADDR); |
| |
| litex_write8(enable | UART_EV_TX, UART_EV_ENABLE_ADDR); |
| } |
| |
| /** |
| * @brief Disable TX interrupt in event register |
| * |
| * @param dev UART device struct |
| */ |
| static void uart_liteuart_irq_tx_disable(const struct device *dev) |
| { |
| uint8_t enable = litex_read8(UART_EV_ENABLE_ADDR); |
| |
| litex_write8(enable & ~(UART_EV_TX), UART_EV_ENABLE_ADDR); |
| } |
| |
| /** |
| * @brief Enable RX interrupt in event register |
| * |
| * @param dev UART device struct |
| */ |
| static void uart_liteuart_irq_rx_enable(const struct device *dev) |
| { |
| uint8_t enable = litex_read8(UART_EV_ENABLE_ADDR); |
| |
| litex_write8(enable | UART_EV_RX, UART_EV_ENABLE_ADDR); |
| } |
| |
| /** |
| * @brief Disable RX interrupt in event register |
| * |
| * @param dev UART device struct |
| */ |
| static void uart_liteuart_irq_rx_disable(const struct device *dev) |
| { |
| uint8_t enable = litex_read8(UART_EV_ENABLE_ADDR); |
| |
| litex_write8(enable & ~(UART_EV_RX), UART_EV_ENABLE_ADDR); |
| } |
| |
| /** |
| * @brief Check if Tx IRQ has been raised and UART is ready to accept new data |
| * |
| * @param dev UART device struct |
| * |
| * @return 1 if an IRQ has been raised, 0 otherwise |
| */ |
| static int uart_liteuart_irq_tx_ready(const struct device *dev) |
| { |
| uint8_t val = litex_read8(UART_TXFULL_ADDR); |
| |
| return !val; |
| } |
| |
| /** |
| * @brief Check if Rx IRQ has been raised and there's data to be read from UART |
| * |
| * @param dev UART device struct |
| * |
| * @return 1 if an IRQ has been raised, 0 otherwise |
| */ |
| static int uart_liteuart_irq_rx_ready(const struct device *dev) |
| { |
| uint8_t pending; |
| |
| pending = litex_read8(UART_EV_PENDING_ADDR); |
| |
| if (pending & UART_EV_RX) { |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| |
| /** |
| * @brief Fill FIFO with data |
| * |
| * @param dev UART device struct |
| * @param tx_data Data to transmit |
| * @param size Number of bytes to send |
| * |
| * @return Number of bytes sent |
| */ |
| static int uart_liteuart_fifo_fill(const struct device *dev, |
| const uint8_t *tx_data, int size) |
| { |
| int i; |
| |
| for (i = 0; i < size && !litex_read8(UART_TXFULL_ADDR); i++) { |
| litex_write8(tx_data[i], UART_RXTX_ADDR); |
| } |
| |
| return i; |
| } |
| |
| /** |
| * @brief Read data from FIFO |
| * |
| * @param dev UART device struct |
| * @param rxData Data container |
| * @param size Container size |
| * |
| * @return Number of bytes read |
| */ |
| static int uart_liteuart_fifo_read(const struct device *dev, |
| uint8_t *rx_data, const int size) |
| { |
| int i; |
| |
| for (i = 0; i < size && !litex_read8(UART_RXEMPTY_ADDR); i++) { |
| rx_data[i] = litex_read8(UART_RXTX_ADDR); |
| |
| /* refresh UART_RXEMPTY by writing UART_EV_RX |
| * to UART_EV_PENDING |
| */ |
| litex_write8(UART_EV_RX, UART_EV_PENDING_ADDR); |
| } |
| |
| return i; |
| } |
| |
| static void uart_liteuart_irq_err(const struct device *dev) |
| { |
| ARG_UNUSED(dev); |
| } |
| |
| /** |
| * @brief Check if any IRQ is pending |
| * |
| * @param dev UART device struct |
| * |
| * @return 1 if an IRQ is pending, 0 otherwise |
| */ |
| static int uart_liteuart_irq_is_pending(const struct device *dev) |
| { |
| uint8_t pending; |
| |
| pending = litex_read8(UART_EV_PENDING_ADDR); |
| |
| if (pending & (UART_EV_TX | UART_EV_RX)) { |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| |
| static int uart_liteuart_irq_update(const struct device *dev) |
| { |
| return 1; |
| } |
| |
| /** |
| * @brief Set the callback function pointer for IRQ. |
| * |
| * @param dev UART device struct |
| * @param cb Callback function pointer. |
| */ |
| static void uart_liteuart_irq_callback_set(const struct device *dev, |
| uart_irq_callback_user_data_t cb, |
| void *cb_data) |
| { |
| struct uart_liteuart_data *data; |
| |
| data = dev->data; |
| data->callback = cb; |
| data->cb_data = cb_data; |
| } |
| |
| static void liteuart_uart_irq_handler(const struct device *dev) |
| { |
| struct uart_liteuart_data *data = dev->data; |
| int key = irq_lock(); |
| |
| if (data->callback) { |
| data->callback(dev, data->cb_data); |
| } |
| |
| /* clear events */ |
| litex_write8(UART_EV_TX | UART_EV_RX, UART_EV_PENDING_ADDR); |
| |
| irq_unlock(key); |
| } |
| #endif /* CONFIG_UART_INTERRUPT_DRIVEN */ |
| |
| static const struct uart_driver_api uart_liteuart_driver_api = { |
| .poll_in = uart_liteuart_poll_in, |
| .poll_out = uart_liteuart_poll_out, |
| .err_check = NULL, |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| .fifo_fill = uart_liteuart_fifo_fill, |
| .fifo_read = uart_liteuart_fifo_read, |
| .irq_tx_enable = uart_liteuart_irq_tx_enable, |
| .irq_tx_disable = uart_liteuart_irq_tx_disable, |
| .irq_tx_ready = uart_liteuart_irq_tx_ready, |
| .irq_rx_enable = uart_liteuart_irq_rx_enable, |
| .irq_rx_disable = uart_liteuart_irq_rx_disable, |
| .irq_rx_ready = uart_liteuart_irq_rx_ready, |
| .irq_err_enable = uart_liteuart_irq_err, |
| .irq_err_disable = uart_liteuart_irq_err, |
| .irq_is_pending = uart_liteuart_irq_is_pending, |
| .irq_update = uart_liteuart_irq_update, |
| .irq_callback_set = uart_liteuart_irq_callback_set |
| #endif |
| }; |
| |
| static struct uart_liteuart_data uart_liteuart_data_0; |
| static int uart_liteuart_init(const struct device *dev); |
| |
| static const struct uart_liteuart_device_config uart_liteuart_dev_cfg_0 = { |
| .port = UART_RXTX_ADDR, |
| .baud_rate = DT_INST_PROP(0, current_speed) |
| }; |
| |
| DEVICE_DT_INST_DEFINE(0, |
| uart_liteuart_init, |
| NULL, |
| &uart_liteuart_data_0, &uart_liteuart_dev_cfg_0, |
| PRE_KERNEL_1, CONFIG_SERIAL_INIT_PRIORITY, |
| (void *)&uart_liteuart_driver_api); |
| |
| static int uart_liteuart_init(const struct device *dev) |
| { |
| litex_write8(UART_EV_TX | UART_EV_RX, UART_EV_PENDING_ADDR); |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| IRQ_CONNECT(UART_IRQ, DT_INST_IRQ(0, priority), |
| liteuart_uart_irq_handler, DEVICE_DT_INST_GET(0), |
| 0); |
| irq_enable(UART_IRQ); |
| #endif |
| |
| return 0; |
| } |