tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * 16550 compatible uart based serial debug support for zboot
3 */
4
5#include <linux/types.h>
6#include <linux/serial_reg.h>
7#include <linux/init.h>
8
9#include <asm/addrspace.h>
10
11#if defined(CONFIG_MACH_LOONGSON) || defined(CONFIG_MIPS_MALTA)
12#define UART_BASE 0x1fd003f8
13#define PORT(offset) (CKSEG1ADDR(UART_BASE) + (offset))
14#endif
15
16#ifdef CONFIG_AR7
17#include <ar7.h>
18#define PORT(offset) (CKSEG1ADDR(AR7_REGS_UART0) + (4 * offset))
19#endif
20
21#ifdef CONFIG_MACH_JZ4740
22#define UART0_BASE 0xB0030000
23#define PORT(offset) (UART0_BASE + (4 * offset))
24#endif
25
26#ifndef PORT
27#error please define the serial port address for your own machine
28#endif
29
30static inline unsigned int serial_in(int offset)
31{
32 return *((char *)PORT(offset));
33}
34
35static inline void serial_out(int offset, int value)
36{
37 *((char *)PORT(offset)) = value;
38}
39
40void putc(char c)
41{
42 int timeout = 1024;
43
44 while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
45 ;
46
47 serial_out(UART_TX, c);
48}