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 30 static inline unsigned int serial_in(int offset) 31 { 32 return *((char *)PORT(offset)); 33 } 34 35 static inline void serial_out(int offset, int value) 36 { 37 *((char *)PORT(offset)) = value; 38 } 39 40 void 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 } 49