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