tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * 16550 compatible uart based serial debug support for zboot
4 */
5
6#include <linux/types.h>
7#include <linux/serial_reg.h>
8
9#include <asm/addrspace.h>
10
11#if defined(CONFIG_MACH_LOONGSON64) || defined(CONFIG_MIPS_MALTA)
12#define UART_BASE 0x1fd003f8
13#define PORT(offset) (CKSEG1ADDR(UART_BASE) + (offset))
14#endif
15
16#ifdef CONFIG_MACH_INGENIC
17#define INGENIC_UART_BASE_ADDR (0x10030000 + 0x1000 * CONFIG_ZBOOT_INGENIC_UART)
18#define PORT(offset) (CKSEG1ADDR(INGENIC_UART_BASE_ADDR) + (4 * offset))
19#endif
20
21#ifndef IOTYPE
22#define IOTYPE char
23#endif
24
25#ifndef PORT
26#error please define the serial port address for your own machine
27#endif
28
29static inline unsigned int serial_in(int offset)
30{
31 return *((volatile IOTYPE *)PORT(offset)) & 0xFF;
32}
33
34static inline void serial_out(int offset, int value)
35{
36 *((volatile IOTYPE *)PORT(offset)) = value & 0xFF;
37}
38
39void putc(char c)
40{
41 int timeout = 1000000;
42
43 while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
44 ;
45
46 serial_out(UART_TX, c);
47}