| /* |
| * Copyright (c) 2017 Jean-Paul Etienne <fractalclone@gmail.com> |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| /** |
| * @brief UART driver for the SiFive Freedom Processor |
| */ |
| |
| #define DT_DRV_COMPAT sifive_uart0 |
| |
| #include <kernel.h> |
| #include <arch/cpu.h> |
| #include <drivers/uart.h> |
| |
| #define RXDATA_EMPTY (1 << 31) /* Receive FIFO Empty */ |
| #define RXDATA_MASK 0xFF /* Receive Data Mask */ |
| |
| #define TXDATA_FULL (1 << 31) /* Transmit FIFO Full */ |
| |
| #define TXCTRL_TXEN (1 << 0) /* Activate Tx Channel */ |
| |
| #define RXCTRL_RXEN (1 << 0) /* Activate Rx Channel */ |
| |
| #define IE_TXWM (1 << 0) /* TX Interrupt Enable/Pending */ |
| #define IE_RXWM (1 << 1) /* RX Interrupt Enable/Pending */ |
| |
| /* |
| * RX/TX Threshold count to generate TX/RX Interrupts. |
| * Used by txctrl and rxctrl registers |
| */ |
| #define CTRL_CNT(x) (((x) & 0x07) << 16) |
| |
| struct uart_sifive_regs_t { |
| uint32_t tx; |
| uint32_t rx; |
| uint32_t txctrl; |
| uint32_t rxctrl; |
| uint32_t ie; |
| uint32_t ip; |
| uint32_t div; |
| }; |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| typedef void (*irq_cfg_func_t)(void); |
| #endif |
| |
| struct uart_sifive_device_config { |
| uintptr_t port; |
| uint32_t sys_clk_freq; |
| uint32_t baud_rate; |
| uint32_t rxcnt_irq; |
| uint32_t txcnt_irq; |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| irq_cfg_func_t cfg_func; |
| #endif |
| }; |
| |
| struct uart_sifive_data { |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| uart_irq_callback_user_data_t callback; |
| void *cb_data; |
| #endif |
| }; |
| |
| #define DEV_CFG(dev) \ |
| ((const struct uart_sifive_device_config * const) \ |
| (dev)->config) |
| #define DEV_UART(dev) \ |
| ((struct uart_sifive_regs_t *)(DEV_CFG(dev))->port) |
| #define DEV_DATA(dev) \ |
| ((struct uart_sifive_data * const)(dev)->data) |
| |
| /** |
| * @brief Output a character in polled mode. |
| * |
| * Writes data to tx register if transmitter is not full. |
| * |
| * @param dev UART device struct |
| * @param c Character to send |
| */ |
| static void uart_sifive_poll_out(const struct device *dev, |
| unsigned char c) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| /* Wait while TX FIFO is full */ |
| while (uart->tx & TXDATA_FULL) { |
| } |
| |
| uart->tx = (int)c; |
| } |
| |
| /** |
| * @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_sifive_poll_in(const struct device *dev, unsigned char *c) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| uint32_t val = uart->rx; |
| |
| if (val & RXDATA_EMPTY) { |
| return -1; |
| } |
| |
| *c = (unsigned char)(val & RXDATA_MASK); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| |
| /** |
| * @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_sifive_fifo_fill(const struct device *dev, |
| const uint8_t *tx_data, |
| int size) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| int i; |
| |
| for (i = 0; i < size && !(uart->tx & TXDATA_FULL); i++) |
| uart->tx = (int)tx_data[i]; |
| |
| 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_sifive_fifo_read(const struct device *dev, |
| uint8_t *rx_data, |
| const int size) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| int i; |
| uint32_t val; |
| |
| for (i = 0; i < size; i++) { |
| val = uart->rx; |
| |
| if (val & RXDATA_EMPTY) |
| break; |
| |
| rx_data[i] = (uint8_t)(val & RXDATA_MASK); |
| } |
| |
| return i; |
| } |
| |
| /** |
| * @brief Enable TX interrupt in ie register |
| * |
| * @param dev UART device struct |
| * |
| * @return N/A |
| */ |
| static void uart_sifive_irq_tx_enable(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| uart->ie |= IE_TXWM; |
| } |
| |
| /** |
| * @brief Disable TX interrupt in ie register |
| * |
| * @param dev UART device struct |
| * |
| * @return N/A |
| */ |
| static void uart_sifive_irq_tx_disable(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| uart->ie &= ~IE_TXWM; |
| } |
| |
| /** |
| * @brief Check if Tx IRQ has been raised |
| * |
| * @param dev UART device struct |
| * |
| * @return 1 if an IRQ is ready, 0 otherwise |
| */ |
| static int uart_sifive_irq_tx_ready(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| return !!(uart->ip & IE_TXWM); |
| } |
| |
| /** |
| * @brief Check if nothing remains to be transmitted |
| * |
| * @param dev UART device struct |
| * |
| * @return 1 if nothing remains to be transmitted, 0 otherwise |
| */ |
| static int uart_sifive_irq_tx_complete(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| /* |
| * No TX EMPTY flag for this controller, |
| * just check if TX FIFO is not full |
| */ |
| return !(uart->tx & TXDATA_FULL); |
| } |
| |
| /** |
| * @brief Enable RX interrupt in ie register |
| * |
| * @param dev UART device struct |
| * |
| * @return N/A |
| */ |
| static void uart_sifive_irq_rx_enable(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| uart->ie |= IE_RXWM; |
| } |
| |
| /** |
| * @brief Disable RX interrupt in ie register |
| * |
| * @param dev UART device struct |
| * |
| * @return N/A |
| */ |
| static void uart_sifive_irq_rx_disable(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| uart->ie &= ~IE_RXWM; |
| } |
| |
| /** |
| * @brief Check if Rx IRQ has been raised |
| * |
| * @param dev UART device struct |
| * |
| * @return 1 if an IRQ is ready, 0 otherwise |
| */ |
| static int uart_sifive_irq_rx_ready(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| return !!(uart->ip & IE_RXWM); |
| } |
| |
| /* No error interrupt for this controller */ |
| static void uart_sifive_irq_err_enable(const struct device *dev) |
| { |
| ARG_UNUSED(dev); |
| } |
| |
| static void uart_sifive_irq_err_disable(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_sifive_irq_is_pending(const struct device *dev) |
| { |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| return !!(uart->ip & (IE_RXWM | IE_TXWM)); |
| } |
| |
| static int uart_sifive_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. |
| * |
| * @return N/A |
| */ |
| static void uart_sifive_irq_callback_set(const struct device *dev, |
| uart_irq_callback_user_data_t cb, |
| void *cb_data) |
| { |
| struct uart_sifive_data *data = DEV_DATA(dev); |
| |
| data->callback = cb; |
| data->cb_data = cb_data; |
| } |
| |
| static void uart_sifive_irq_handler(const struct device *dev) |
| { |
| struct uart_sifive_data *data = DEV_DATA(dev); |
| |
| if (data->callback) |
| data->callback(dev, data->cb_data); |
| } |
| |
| #endif /* CONFIG_UART_INTERRUPT_DRIVEN */ |
| |
| |
| static int uart_sifive_init(const struct device *dev) |
| { |
| const struct uart_sifive_device_config * const cfg = DEV_CFG(dev); |
| volatile struct uart_sifive_regs_t *uart = DEV_UART(dev); |
| |
| /* Enable TX and RX channels */ |
| uart->txctrl = TXCTRL_TXEN | CTRL_CNT(cfg->txcnt_irq); |
| uart->rxctrl = RXCTRL_RXEN | CTRL_CNT(cfg->rxcnt_irq); |
| |
| /* Set baud rate */ |
| uart->div = cfg->sys_clk_freq / cfg->baud_rate - 1; |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| /* Ensure that uart IRQ is disabled initially */ |
| uart->ie = 0U; |
| |
| /* Setup IRQ handler */ |
| cfg->cfg_func(); |
| #endif |
| |
| return 0; |
| } |
| |
| static const struct uart_driver_api uart_sifive_driver_api = { |
| .poll_in = uart_sifive_poll_in, |
| .poll_out = uart_sifive_poll_out, |
| .err_check = NULL, |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| .fifo_fill = uart_sifive_fifo_fill, |
| .fifo_read = uart_sifive_fifo_read, |
| .irq_tx_enable = uart_sifive_irq_tx_enable, |
| .irq_tx_disable = uart_sifive_irq_tx_disable, |
| .irq_tx_ready = uart_sifive_irq_tx_ready, |
| .irq_tx_complete = uart_sifive_irq_tx_complete, |
| .irq_rx_enable = uart_sifive_irq_rx_enable, |
| .irq_rx_disable = uart_sifive_irq_rx_disable, |
| .irq_rx_ready = uart_sifive_irq_rx_ready, |
| .irq_err_enable = uart_sifive_irq_err_enable, |
| .irq_err_disable = uart_sifive_irq_err_disable, |
| .irq_is_pending = uart_sifive_irq_is_pending, |
| .irq_update = uart_sifive_irq_update, |
| .irq_callback_set = uart_sifive_irq_callback_set, |
| #endif |
| }; |
| |
| #ifdef CONFIG_UART_SIFIVE_PORT_0 |
| |
| static struct uart_sifive_data uart_sifive_data_0; |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| static void uart_sifive_irq_cfg_func_0(void); |
| #endif |
| |
| static const struct uart_sifive_device_config uart_sifive_dev_cfg_0 = { |
| .port = DT_INST_REG_ADDR(0), |
| .sys_clk_freq = DT_INST_PROP(0, clock_frequency), |
| .baud_rate = DT_INST_PROP(0, current_speed), |
| .rxcnt_irq = CONFIG_UART_SIFIVE_PORT_0_RXCNT_IRQ, |
| .txcnt_irq = CONFIG_UART_SIFIVE_PORT_0_TXCNT_IRQ, |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| .cfg_func = uart_sifive_irq_cfg_func_0, |
| #endif |
| }; |
| |
| DEVICE_DT_INST_DEFINE(0, |
| uart_sifive_init, |
| NULL, |
| &uart_sifive_data_0, &uart_sifive_dev_cfg_0, |
| PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, |
| (void *)&uart_sifive_driver_api); |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| static void uart_sifive_irq_cfg_func_0(void) |
| { |
| IRQ_CONNECT(DT_INST_IRQN(0), DT_INST_IRQ(0, priority), |
| uart_sifive_irq_handler, DEVICE_DT_INST_GET(0), |
| 0); |
| |
| irq_enable(DT_INST_IRQN(0)); |
| } |
| #endif |
| |
| #endif /* CONFIG_UART_SIFIVE_PORT_0 */ |
| |
| #ifdef CONFIG_UART_SIFIVE_PORT_1 |
| |
| static struct uart_sifive_data uart_sifive_data_1; |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| static void uart_sifive_irq_cfg_func_1(void); |
| #endif |
| |
| static const struct uart_sifive_device_config uart_sifive_dev_cfg_1 = { |
| .port = DT_INST_REG_ADDR(1), |
| .sys_clk_freq = DT_INST_PROP(1, clock_frequency), |
| .baud_rate = DT_INST_PROP(1, current_speed), |
| .rxcnt_irq = CONFIG_UART_SIFIVE_PORT_1_RXCNT_IRQ, |
| .txcnt_irq = CONFIG_UART_SIFIVE_PORT_1_TXCNT_IRQ, |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| .cfg_func = uart_sifive_irq_cfg_func_1, |
| #endif |
| }; |
| |
| DEVICE_DT_INST_DEFINE(1, |
| uart_sifive_init, |
| NULL, |
| &uart_sifive_data_1, &uart_sifive_dev_cfg_1, |
| PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, |
| (void *)&uart_sifive_driver_api); |
| |
| #ifdef CONFIG_UART_INTERRUPT_DRIVEN |
| static void uart_sifive_irq_cfg_func_1(void) |
| { |
| IRQ_CONNECT(DT_INST_IRQN(1), DT_INST_IRQ(1, priority), |
| uart_sifive_irq_handler, DEVICE_DT_INST_GET(1), |
| 0); |
| |
| irq_enable(DT_INST_IRQN(1)); |
| } |
| #endif |
| |
| #endif /* CONFIG_UART_SIFIVE_PORT_1 */ |