| // SPDX-License-Identifier: BSD-2-Clause |
| /* |
| * Copyright (c) 2015, Linaro Limited |
| */ |
| |
| #include <compiler.h> |
| #include <console.h> |
| #include <drivers/serial8250_uart.h> |
| #include <io.h> |
| #include <keep.h> |
| #include <util.h> |
| #include <kernel/dt.h> |
| |
| /* uart register defines */ |
| #define UART_RHR 0x0 |
| #define UART_THR 0x0 |
| #define UART_IER 0x4 |
| #define UART_ISR 0x8 |
| #define UART_FCR 0x8 |
| #define UART_LCR 0xc |
| #define UART_MCR 0x10 |
| #define UART_LSR 0x14 |
| #define UART_MSR 0x18 |
| #define UART_SPR 0x1c |
| |
| /* uart status register bits */ |
| #define LSR_TEMT 0x40 /* Transmitter empty */ |
| #define LSR_THRE 0x20 /* Transmit-hold-register empty */ |
| #define LSR_EMPTY (LSR_TEMT | LSR_THRE) |
| #define LSR_DR 0x01 /* DATA Ready */ |
| |
| static vaddr_t chip_to_base(struct serial_chip *chip) |
| { |
| struct serial8250_uart_data *pd = |
| container_of(chip, struct serial8250_uart_data, chip); |
| |
| return io_pa_or_va(&pd->base); |
| } |
| |
| static void serial8250_uart_flush(struct serial_chip *chip) |
| { |
| vaddr_t base = chip_to_base(chip); |
| |
| while (1) { |
| uint32_t state = io_read32(base + UART_LSR); |
| |
| /* Wait until transmit FIFO is empty */ |
| if ((state & LSR_EMPTY) == LSR_EMPTY) |
| break; |
| } |
| } |
| |
| static bool serial8250_uart_have_rx_data(struct serial_chip *chip) |
| { |
| vaddr_t base = chip_to_base(chip); |
| |
| return (io_read32(base + UART_LSR) & LSR_DR); |
| } |
| |
| static int serial8250_uart_getchar(struct serial_chip *chip) |
| { |
| vaddr_t base = chip_to_base(chip); |
| |
| while (!serial8250_uart_have_rx_data(chip)) { |
| /* Transmit FIFO is empty, waiting again */ |
| ; |
| } |
| return io_read32(base + UART_RHR) & 0xff; |
| } |
| |
| static void serial8250_uart_putc(struct serial_chip *chip, int ch) |
| { |
| vaddr_t base = chip_to_base(chip); |
| |
| serial8250_uart_flush(chip); |
| |
| /* Write out character to transmit FIFO */ |
| io_write32(base + UART_THR, ch); |
| } |
| |
| static const struct serial_ops serial8250_uart_ops = { |
| .flush = serial8250_uart_flush, |
| .getchar = serial8250_uart_getchar, |
| .have_rx_data = serial8250_uart_have_rx_data, |
| .putc = serial8250_uart_putc, |
| }; |
| KEEP_PAGER(serial8250_uart_ops); |
| |
| void serial8250_uart_init(struct serial8250_uart_data *pd, paddr_t base, |
| uint32_t __unused uart_clk, |
| uint32_t __unused baud_rate) |
| |
| { |
| pd->base.pa = base; |
| pd->chip.ops = &serial8250_uart_ops; |
| |
| /* |
| * do nothing, debug uart(uart0) share with normal world, |
| * everything for uart0 is ready now. |
| */ |
| } |
| |
| #ifdef CFG_DT |
| |
| static struct serial_chip *serial8250_uart_dev_alloc(void) |
| { |
| struct serial8250_uart_data *pd = calloc(1, sizeof(*pd)); |
| |
| if (!pd) |
| return NULL; |
| return &pd->chip; |
| } |
| |
| static int serial8250_uart_dev_init(struct serial_chip *chip, |
| const void *fdt, |
| int offs, |
| const char *parms) |
| { |
| struct serial8250_uart_data *pd = |
| container_of(chip, struct serial8250_uart_data, chip); |
| vaddr_t vbase; |
| paddr_t pbase; |
| size_t size; |
| |
| if (parms && parms[0]) |
| IMSG("serial8250_uart: device parameters ignored (%s)", parms); |
| |
| if (dt_map_dev(fdt, offs, &vbase, &size) < 0) |
| return -1; |
| |
| if (size < SERIAL8250_UART_REG_SIZE) { |
| EMSG("serial8250_uart: register size too small: %zx", size); |
| return -1; |
| } |
| |
| pbase = virt_to_phys((void *)vbase); |
| serial8250_uart_init(pd, pbase, 0, 0); |
| |
| return 0; |
| } |
| |
| static void serial8250_uart_dev_free(struct serial_chip *chip) |
| { |
| struct serial8250_uart_data *pd = |
| container_of(chip, struct serial8250_uart_data, chip); |
| |
| free(pd); |
| } |
| |
| static const struct serial_driver serial8250_driver = { |
| .dev_alloc = serial8250_uart_dev_alloc, |
| .dev_init = serial8250_uart_dev_init, |
| .dev_free = serial8250_uart_dev_free, |
| }; |
| |
| static const struct dt_device_match serial8250_match_table[] = { |
| { .compatible = "snps,dw-apb-uart" }, |
| { 0 } |
| }; |
| |
| const struct dt_driver serial8250_dt_driver __dt_driver = { |
| .name = "serial8250_uart", |
| .match_table = serial8250_match_table, |
| .driver = &serial8250_driver, |
| }; |
| |
| #endif /* CFG_DT */ |