| // SPDX-License-Identifier: GPL-2.0-or-later |
| * 8250/16550-type serial ports prom_putchar() |
| * Copyright (C) 2010 Yoichi Yuasa <yuasa@linux-mips.org> |
| #include <linux/serial_core.h> |
| #include <linux/serial_reg.h> |
| static void __iomem *serial8250_base; |
| static unsigned int serial8250_reg_shift; |
| static unsigned int serial8250_tx_timeout; |
| void setup_8250_early_printk_port(unsigned long base, unsigned int reg_shift, |
| serial8250_base = (void __iomem *)base; |
| serial8250_reg_shift = reg_shift; |
| serial8250_tx_timeout = timeout; |
| static inline u8 serial_in(int offset) |
| return readb(serial8250_base + (offset << serial8250_reg_shift)); |
| static inline void serial_out(int offset, char value) |
| writeb(value, serial8250_base + (offset << serial8250_reg_shift)); |
| void prom_putchar(char c) |
| timeout = serial8250_tx_timeout; |
| bits = UART_LSR_TEMT | UART_LSR_THRE; |
| status = serial_in(UART_LSR); |
| } while ((status & bits) != bits); |