453 lines
10 KiB
C
453 lines
10 KiB
C
/*
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* Copyright (c) 2017 Jean-Paul Etienne <fractalclone@gmail.com>
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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/**
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* @brief UART driver for the SiFive Freedom E310 Processor
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*/
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#include <kernel.h>
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#include <arch/cpu.h>
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#include <uart.h>
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#include <board.h>
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#define RXDATA_EMPTY (1 << 31) /* Receive FIFO Empty */
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#define RXDATA_MASK 0xFF /* Receive Data Mask */
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#define TXDATA_FULL (1 << 31) /* Transmit FIFO Full */
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#define TXCTRL_TXEN (1 << 0) /* Activate Tx Channel */
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#define RXCTRL_RXEN (1 << 0) /* Activate Rx Channel */
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#define IE_TXWM (1 << 0) /* TX Interrupt Enable/Pending */
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#define IE_RXWM (1 << 1) /* RX Interrupt Enable/Pending */
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/*
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* RX/TX Threshold count to generate TX/RX Interrupts.
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* Used by txctrl and rxctrl registers
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*/
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#define CTRL_CNT(x) (((x) & 0x07) << 16)
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struct uart_fe310_regs_t {
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u32_t tx;
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u32_t rx;
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u32_t txctrl;
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u32_t rxctrl;
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u32_t ie;
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u32_t ip;
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u32_t div;
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};
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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typedef void (*irq_cfg_func_t)(void);
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#endif
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struct uart_fe310_device_config {
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u32_t port;
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u32_t sys_clk_freq;
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u32_t baud_rate;
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u32_t rxcnt_irq;
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u32_t txcnt_irq;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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irq_cfg_func_t cfg_func;
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#endif
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};
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struct uart_fe310_data {
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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uart_irq_callback_t callback;
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#endif
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};
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#define DEV_CFG(dev) \
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((const struct uart_fe310_device_config * const) \
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(dev)->config->config_info)
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#define DEV_UART(dev) \
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((struct uart_fe310_regs_t *)(DEV_CFG(dev))->port)
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#define DEV_DATA(dev) \
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((struct uart_fe310_data * const)(dev)->driver_data)
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/**
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* @brief Output a character in polled mode.
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*
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* Writes data to tx register if transmitter is not full.
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*
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* @param dev UART device struct
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* @param c Character to send
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*
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* @return Sent character
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*/
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static unsigned char uart_fe310_poll_out(struct device *dev,
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unsigned char c)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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/* Wait while TX FIFO is full */
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while (uart->tx & TXDATA_FULL)
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;
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uart->tx = (int)c;
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return c;
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}
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/**
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* @brief Poll the device for input.
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*
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* @param dev UART device struct
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* @param c Pointer to character
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*
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* @return 0 if a character arrived, -1 if the input buffer if empty.
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*/
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static int uart_fe310_poll_in(struct device *dev, unsigned char *c)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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u32_t val = uart->rx;
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if (val & RXDATA_EMPTY)
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return -1;
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*c = (unsigned char)(val & RXDATA_MASK);
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return 0;
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}
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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/**
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* @brief Fill FIFO with data
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*
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* @param dev UART device struct
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* @param tx_data Data to transmit
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* @param size Number of bytes to send
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*
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* @return Number of bytes sent
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*/
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static int uart_fe310_fifo_fill(struct device *dev,
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const u8_t *tx_data,
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int size)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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int i;
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for (i = 0; i < size && !(uart->tx & TXDATA_FULL); i++)
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uart->tx = (int)tx_data[i];
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return i;
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}
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/**
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* @brief Read data from FIFO
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*
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* @param dev UART device struct
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* @param rxData Data container
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* @param size Container size
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*
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* @return Number of bytes read
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*/
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static int uart_fe310_fifo_read(struct device *dev,
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u8_t *rx_data,
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const int size)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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int i;
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u32_t val;
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for (i = 0; i < size; i++) {
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val = uart->rx;
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if (val & RXDATA_EMPTY)
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break;
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rx_data[i] = (u8_t)(val & RXDATA_MASK);
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}
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return i;
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}
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/**
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* @brief Enable TX interrupt in ie register
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*
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* @param dev UART device struct
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*
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* @return N/A
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*/
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static void uart_fe310_irq_tx_enable(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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uart->ie |= IE_TXWM;
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}
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/**
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* @brief Disable TX interrupt in ie register
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*
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* @param dev UART device struct
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*
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* @return N/A
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*/
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static void uart_fe310_irq_tx_disable(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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uart->ie &= ~IE_TXWM;
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}
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/**
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* @brief Check if Tx IRQ has been raised
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*
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* @param dev UART device struct
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*
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* @return 1 if an IRQ is ready, 0 otherwise
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*/
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static int uart_fe310_irq_tx_ready(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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return !!(uart->ip & IE_TXWM);
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}
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/**
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* @brief Check if nothing remains to be transmitted
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*
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* @param dev UART device struct
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*
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* @return 1 if nothing remains to be transmitted, 0 otherwise
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*/
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static int uart_fe310_irq_tx_complete(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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/*
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* No TX EMTPY flag for this controller,
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* just check if TX FIFO is not full
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*/
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return !(uart->tx & TXDATA_FULL);
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}
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/**
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* @brief Enable RX interrupt in ie register
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*
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* @param dev UART device struct
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*
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* @return N/A
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*/
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static void uart_fe310_irq_rx_enable(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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uart->ie |= IE_RXWM;
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}
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/**
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* @brief Disable RX interrupt in ie register
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*
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* @param dev UART device struct
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*
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* @return N/A
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*/
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static void uart_fe310_irq_rx_disable(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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uart->ie &= ~IE_RXWM;
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}
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/**
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* @brief Check if Rx IRQ has been raised
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*
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* @param dev UART device struct
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*
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* @return 1 if an IRQ is ready, 0 otherwise
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*/
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static int uart_fe310_irq_rx_ready(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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return !!(uart->ip & IE_RXWM);
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}
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/* No error interrupt for this controller */
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static void uart_fe310_irq_err_enable(struct device *dev)
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{
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ARG_UNUSED(dev);
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}
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static void uart_fe310_irq_err_disable(struct device *dev)
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{
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ARG_UNUSED(dev);
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}
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/**
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* @brief Check if any IRQ is pending
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*
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* @param dev UART device struct
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*
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* @return 1 if an IRQ is pending, 0 otherwise
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*/
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static int uart_fe310_irq_is_pending(struct device *dev)
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{
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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return !!(uart->ip & (IE_RXWM | IE_TXWM));
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}
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static int uart_fe310_irq_update(struct device *dev)
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{
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return 1;
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}
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/**
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* @brief Set the callback function pointer for IRQ.
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*
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* @param dev UART device struct
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* @param cb Callback function pointer.
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*
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* @return N/A
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*/
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static void uart_fe310_irq_callback_set(struct device *dev,
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uart_irq_callback_t cb)
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{
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struct uart_fe310_data *data = DEV_DATA(dev);
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data->callback = cb;
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}
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static void uart_fe310_irq_handler(void *arg)
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{
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struct device *dev = (struct device *)arg;
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struct uart_fe310_data *data = DEV_DATA(dev);
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if (data->callback)
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data->callback(dev);
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}
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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static int uart_fe310_init(struct device *dev)
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{
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const struct uart_fe310_device_config * const cfg = DEV_CFG(dev);
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volatile struct uart_fe310_regs_t *uart = DEV_UART(dev);
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/* Enable TX and RX channels */
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uart->txctrl = TXCTRL_TXEN | CTRL_CNT(cfg->rxcnt_irq);
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uart->rxctrl = RXCTRL_RXEN | CTRL_CNT(cfg->txcnt_irq);
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/* Set baud rate */
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uart->div = cfg->sys_clk_freq / cfg->baud_rate - 1;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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/* Ensure that uart IRQ is disabled initially */
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uart->ie = 0;
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/* Setup IRQ handler */
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cfg->cfg_func();
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#endif
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return 0;
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}
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static const struct uart_driver_api uart_fe310_driver_api = {
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.poll_in = uart_fe310_poll_in,
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.poll_out = uart_fe310_poll_out,
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.err_check = NULL,
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.fifo_fill = uart_fe310_fifo_fill,
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.fifo_read = uart_fe310_fifo_read,
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.irq_tx_enable = uart_fe310_irq_tx_enable,
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.irq_tx_disable = uart_fe310_irq_tx_disable,
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.irq_tx_ready = uart_fe310_irq_tx_ready,
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.irq_tx_complete = uart_fe310_irq_tx_complete,
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.irq_rx_enable = uart_fe310_irq_rx_enable,
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.irq_rx_disable = uart_fe310_irq_rx_disable,
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.irq_rx_ready = uart_fe310_irq_rx_ready,
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.irq_err_enable = uart_fe310_irq_err_enable,
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.irq_err_disable = uart_fe310_irq_err_disable,
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.irq_is_pending = uart_fe310_irq_is_pending,
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.irq_update = uart_fe310_irq_update,
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.irq_callback_set = uart_fe310_irq_callback_set,
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#endif
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};
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#ifdef CONFIG_UART_FE310_PORT_0
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static struct uart_fe310_data uart_fe310_data_0;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_fe310_irq_cfg_func_0(void);
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#endif
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static const struct uart_fe310_device_config uart_fe310_dev_cfg_0 = {
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.port = FE310_UART_0_BASE_ADDR,
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.sys_clk_freq = uart_fe310_port_0_clk_freq,
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.baud_rate = CONFIG_UART_FE310_PORT_0_BAUD_RATE,
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.rxcnt_irq = CONFIG_UART_FE310_PORT_0_RXCNT_IRQ,
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.txcnt_irq = CONFIG_UART_FE310_PORT_0_TXCNT_IRQ,
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.cfg_func = uart_fe310_irq_cfg_func_0,
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#endif
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};
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DEVICE_AND_API_INIT(uart_fe310_0, CONFIG_UART_FE310_PORT_0_NAME,
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uart_fe310_init,
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&uart_fe310_data_0, &uart_fe310_dev_cfg_0,
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PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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(void *)&uart_fe310_driver_api);
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_fe310_irq_cfg_func_0(void)
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{
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IRQ_CONNECT(FE310_UART_0_IRQ,
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CONFIG_UART_FE310_PORT_0_IRQ_PRIORITY,
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uart_fe310_irq_handler, DEVICE_GET(uart_fe310_0),
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0);
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irq_enable(FE310_UART_0_IRQ);
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}
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#endif
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#endif /* CONFIG_FE310_UART_0 */
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#ifdef CONFIG_UART_FE310_PORT_1
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static struct uart_fe310_data uart_fe310_data_1;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_fe310_irq_cfg_func_1(void);
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#endif
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static const struct uart_fe310_device_config uart_fe310_dev_cfg_1 = {
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.port = FE310_UART_1_BASE_ADDR,
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.sys_clk_freq = uart_fe310_port_1_clk_freq,
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.baud_rate = CONFIG_UART_FE310_PORT_1_BAUD_RATE,
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.rxcnt_irq = CONFIG_UART_FE310_PORT_1_RXCNT_IRQ,
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.txcnt_irq = CONFIG_UART_FE310_PORT_1_TXCNT_IRQ,
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.cfg_func = uart_fe310_irq_cfg_func_1,
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#endif
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};
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DEVICE_AND_API_INIT(uart_fe310_1, CONFIG_UART_FE310_PORT_1_NAME,
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uart_fe310_init,
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&uart_fe310_data_1, &uart_fe310_dev_cfg_1,
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PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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(void *)&uart_fe310_driver_api);
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_fe310_irq_cfg_func_1(void)
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{
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IRQ_CONNECT(FE310_UART_1_IRQ,
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CONFIG_UART_FE310_PORT_1_IRQ_PRIORITY,
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uart_fe310_irq_handler, DEVICE_GET(uart_fe310_1),
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0);
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irq_enable(FE310_UART_1_IRQ);
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}
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#endif
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#endif /* CONFIG_FE310_UART_1 */
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