xref: /linux/arch/mips/boot/compressed/uart-16550.c (revision 67faad74352d1ce0c1f411f92fdb1e0c0f3c9380)
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 #include "decompress.h"
12 
13 #if defined(CONFIG_MACH_LOONGSON64) || defined(CONFIG_MIPS_MALTA)
14 #define UART_BASE 0x1fd003f8
15 #define PORT(offset) (CKSEG1ADDR(UART_BASE) + (offset))
16 #endif
17 
18 #ifdef CONFIG_MACH_INGENIC
19 #define INGENIC_UART_BASE_ADDR	(0x10030000 + 0x1000 * CONFIG_ZBOOT_INGENIC_UART)
20 #define PORT(offset) (CKSEG1ADDR(INGENIC_UART_BASE_ADDR) + (4 * offset))
21 #endif
22 
23 #ifdef CONFIG_ECONET
24 #define EN75_UART_BASE	0x1fbf0003
25 #define PORT(offset)	(CKSEG1ADDR(EN75_UART_BASE) + (4 * (offset)))
26 #endif
27 
28 #ifndef IOTYPE
29 #define IOTYPE char
30 #endif
31 
32 #ifndef PORT
33 #error please define the serial port address for your own machine
34 #endif
35 
serial_in(int offset)36 static inline unsigned int serial_in(int offset)
37 {
38 	return *((volatile IOTYPE *)PORT(offset)) & 0xFF;
39 }
40 
serial_out(int offset,int value)41 static inline void serial_out(int offset, int value)
42 {
43 	*((volatile IOTYPE *)PORT(offset)) = value & 0xFF;
44 }
45 
putc(char c)46 void putc(char c)
47 {
48 	int timeout = 1000000;
49 
50 	while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
51 		;
52 
53 	serial_out(UART_TX, c);
54 }
55