463 lines
10 KiB
C
463 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 Processor
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*/
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#define DT_DRV_COMPAT sifive_uart0
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#include <zephyr/kernel.h>
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#include <zephyr/arch/cpu.h>
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#include <zephyr/drivers/uart.h>
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#include <zephyr/drivers/pinctrl.h>
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#include <soc.h>
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#include <zephyr/irq.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_sifive_regs_t {
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uint32_t tx;
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uint32_t rx;
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uint32_t txctrl;
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uint32_t rxctrl;
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uint32_t ie;
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uint32_t ip;
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uint32_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_sifive_device_config {
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uintptr_t port;
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uint32_t sys_clk_freq;
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uint32_t baud_rate;
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uint32_t rxcnt_irq;
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uint32_t txcnt_irq;
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const struct pinctrl_dev_config *pcfg;
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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_sifive_data {
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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uart_irq_callback_user_data_t callback;
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void *cb_data;
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#endif
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};
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#define DEV_UART(dev) \
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((struct uart_sifive_regs_t *) \
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((const struct uart_sifive_device_config * const)(dev)->config)->port)
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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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static void uart_sifive_poll_out(const struct device *dev,
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unsigned char c)
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{
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volatile struct uart_sifive_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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}
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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_sifive_poll_in(const struct device *dev, unsigned char *c)
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{
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volatile struct uart_sifive_regs_t *uart = DEV_UART(dev);
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uint32_t val = uart->rx;
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if (val & RXDATA_EMPTY) {
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return -1;
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}
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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_sifive_fifo_fill(const struct device *dev,
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const uint8_t *tx_data,
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int size)
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{
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volatile struct uart_sifive_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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}
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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_sifive_fifo_read(const struct device *dev,
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uint8_t *rx_data,
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const int size)
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{
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volatile struct uart_sifive_regs_t *uart = DEV_UART(dev);
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int i;
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uint32_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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}
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rx_data[i] = (uint8_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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static void uart_sifive_irq_tx_enable(const struct device *dev)
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{
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volatile struct uart_sifive_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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static void uart_sifive_irq_tx_disable(const struct device *dev)
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{
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volatile struct uart_sifive_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_sifive_irq_tx_ready(const struct device *dev)
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{
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volatile struct uart_sifive_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_sifive_irq_tx_complete(const struct device *dev)
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{
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volatile struct uart_sifive_regs_t *uart = DEV_UART(dev);
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/*
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* No TX EMPTY 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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static void uart_sifive_irq_rx_enable(const struct device *dev)
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{
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volatile struct uart_sifive_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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static void uart_sifive_irq_rx_disable(const struct device *dev)
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{
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volatile struct uart_sifive_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_sifive_irq_rx_ready(const struct device *dev)
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{
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volatile struct uart_sifive_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_sifive_irq_err_enable(const 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_sifive_irq_err_disable(const 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_sifive_irq_is_pending(const struct device *dev)
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{
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volatile struct uart_sifive_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_sifive_irq_update(const 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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static void uart_sifive_irq_callback_set(const struct device *dev,
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uart_irq_callback_user_data_t cb,
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void *cb_data)
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{
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struct uart_sifive_data *data = dev->data;
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data->callback = cb;
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data->cb_data = cb_data;
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}
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static void uart_sifive_irq_handler(const struct device *dev)
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{
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struct uart_sifive_data *data = dev->data;
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if (data->callback) {
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data->callback(dev, data->cb_data);
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}
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}
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#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
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static int uart_sifive_init(const struct device *dev)
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{
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const struct uart_sifive_device_config * const cfg = dev->config;
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volatile struct uart_sifive_regs_t *uart = DEV_UART(dev);
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#ifdef CONFIG_PINCTRL
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int ret;
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#endif
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/* Enable TX and RX channels */
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uart->txctrl = TXCTRL_TXEN | CTRL_CNT(cfg->txcnt_irq);
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uart->rxctrl = RXCTRL_RXEN | CTRL_CNT(cfg->rxcnt_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 = 0U;
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/* Setup IRQ handler */
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cfg->cfg_func();
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#endif
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#ifdef CONFIG_PINCTRL
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ret = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
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if (ret < 0) {
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return ret;
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}
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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_sifive_driver_api = {
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.poll_in = uart_sifive_poll_in,
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.poll_out = uart_sifive_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_sifive_fifo_fill,
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.fifo_read = uart_sifive_fifo_read,
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.irq_tx_enable = uart_sifive_irq_tx_enable,
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.irq_tx_disable = uart_sifive_irq_tx_disable,
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.irq_tx_ready = uart_sifive_irq_tx_ready,
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.irq_tx_complete = uart_sifive_irq_tx_complete,
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.irq_rx_enable = uart_sifive_irq_rx_enable,
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.irq_rx_disable = uart_sifive_irq_rx_disable,
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.irq_rx_ready = uart_sifive_irq_rx_ready,
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.irq_err_enable = uart_sifive_irq_err_enable,
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.irq_err_disable = uart_sifive_irq_err_disable,
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.irq_is_pending = uart_sifive_irq_is_pending,
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.irq_update = uart_sifive_irq_update,
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.irq_callback_set = uart_sifive_irq_callback_set,
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#endif
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};
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#ifdef CONFIG_UART_SIFIVE_PORT_0
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static struct uart_sifive_data uart_sifive_data_0;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_sifive_irq_cfg_func_0(void);
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#endif
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PINCTRL_DT_INST_DEFINE(0);
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static const struct uart_sifive_device_config uart_sifive_dev_cfg_0 = {
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.port = DT_INST_REG_ADDR(0),
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.sys_clk_freq = SIFIVE_PERIPHERAL_CLOCK_FREQUENCY,
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.baud_rate = DT_INST_PROP(0, current_speed),
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.rxcnt_irq = CONFIG_UART_SIFIVE_PORT_0_RXCNT_IRQ,
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.txcnt_irq = CONFIG_UART_SIFIVE_PORT_0_TXCNT_IRQ,
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.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(0),
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.cfg_func = uart_sifive_irq_cfg_func_0,
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#endif
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};
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DEVICE_DT_INST_DEFINE(0,
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uart_sifive_init,
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NULL,
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&uart_sifive_data_0, &uart_sifive_dev_cfg_0,
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PRE_KERNEL_1, CONFIG_SERIAL_INIT_PRIORITY,
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(void *)&uart_sifive_driver_api);
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_sifive_irq_cfg_func_0(void)
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{
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IRQ_CONNECT(DT_INST_IRQN(0), DT_INST_IRQ(0, priority),
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uart_sifive_irq_handler, DEVICE_DT_INST_GET(0),
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0);
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irq_enable(DT_INST_IRQN(0));
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}
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#endif
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#endif /* CONFIG_UART_SIFIVE_PORT_0 */
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#ifdef CONFIG_UART_SIFIVE_PORT_1
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static struct uart_sifive_data uart_sifive_data_1;
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_sifive_irq_cfg_func_1(void);
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#endif
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PINCTRL_DT_INST_DEFINE(1);
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static const struct uart_sifive_device_config uart_sifive_dev_cfg_1 = {
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.port = DT_INST_REG_ADDR(1),
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.sys_clk_freq = SIFIVE_PERIPHERAL_CLOCK_FREQUENCY,
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.baud_rate = DT_INST_PROP(1, current_speed),
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.rxcnt_irq = CONFIG_UART_SIFIVE_PORT_1_RXCNT_IRQ,
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.txcnt_irq = CONFIG_UART_SIFIVE_PORT_1_TXCNT_IRQ,
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.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(1),
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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.cfg_func = uart_sifive_irq_cfg_func_1,
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#endif
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};
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DEVICE_DT_INST_DEFINE(1,
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uart_sifive_init,
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NULL,
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&uart_sifive_data_1, &uart_sifive_dev_cfg_1,
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PRE_KERNEL_1, CONFIG_SERIAL_INIT_PRIORITY,
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(void *)&uart_sifive_driver_api);
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#ifdef CONFIG_UART_INTERRUPT_DRIVEN
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static void uart_sifive_irq_cfg_func_1(void)
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{
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IRQ_CONNECT(DT_INST_IRQN(1), DT_INST_IRQ(1, priority),
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uart_sifive_irq_handler, DEVICE_DT_INST_GET(1),
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0);
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irq_enable(DT_INST_IRQN(1));
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}
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#endif
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#endif /* CONFIG_UART_SIFIVE_PORT_1 */
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