root/arch/mips/boot/compressed/uart-16550.c

DEFINITIONS

1. serial_in
2. serial_out
3. putc

   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_UART0_BASE_ADDR 0x10030000
  23 #define PORT(offset) (CKSEG1ADDR(INGENIC_UART0_BASE_ADDR) + (4 * offset))
  24 #endif
  25 
  26 #ifdef CONFIG_CPU_XLR
  27 #define UART0_BASE  0x1EF14000
  28 #define PORT(offset) (CKSEG1ADDR(UART0_BASE) + (4 * offset))
  29 #define IOTYPE unsigned int
  30 #endif
  31 
  32 #ifdef CONFIG_CPU_XLP
  33 #define UART0_BASE  0x18030100
  34 #define PORT(offset) (CKSEG1ADDR(UART0_BASE) + (4 * offset))
  35 #define IOTYPE unsigned int
  36 #endif
  37 
  38 #ifndef IOTYPE
  39 #define IOTYPE char
  40 #endif
  41 
  42 #ifndef PORT
  43 #error please define the serial port address for your own machine
  44 #endif
  45 
  46 static inline unsigned int serial_in(int offset)
  47 {
  48         return *((volatile IOTYPE *)PORT(offset)) & 0xFF;
  49 }
  50 
  51 static inline void serial_out(int offset, int value)
  52 {
  53         *((volatile IOTYPE *)PORT(offset)) = value & 0xFF;
  54 }
  55 
  56 void putc(char c)
  57 {
  58         int timeout = 1000000;
  59 
  60         while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
  61                 ;
  62 
  63         serial_out(UART_TX, c);
  64 }