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_AR7
17 #include <ar7.h>
18 #define PORT(offset) (CKSEG1ADDR(AR7_REGS_UART0) + (4 * offset))
19 #endif
20 
21 #ifdef CONFIG_MACH_INGENIC
22 #define INGENIC_UART_BASE_ADDR	(0x10030000 + 0x1000 * CONFIG_ZBOOT_INGENIC_UART)
23 #define PORT(offset) (CKSEG1ADDR(INGENIC_UART_BASE_ADDR) + (4 * offset))
24 #endif
25 
26 #ifndef IOTYPE
27 #define IOTYPE char
28 #endif
29 
30 #ifndef PORT
31 #error please define the serial port address for your own machine
32 #endif
33 
34 static inline unsigned int serial_in(int offset)
35 {
36 	return *((volatile IOTYPE *)PORT(offset)) & 0xFF;
37 }
38 
39 static inline void serial_out(int offset, int value)
40 {
41 	*((volatile IOTYPE *)PORT(offset)) = value & 0xFF;
42 }
43 
44 void putc(char c)
45 {
46 	int timeout = 1000000;
47 
48 	while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
49 		;
50 
51 	serial_out(UART_TX, c);
52 }
53