1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 2001, 2002, 2004 Ralf Baechle 7 */ 8#include <linux/init.h> 9#include <linux/console.h> 10#include <linux/kdev_t.h> 11#include <linux/major.h> 12#include <linux/termios.h> 13#include <linux/sched.h> 14#include <linux/tty.h> 15 16#include <linux/serial.h> 17#include <linux/serial_core.h> 18#include <asm/serial.h> 19#include <asm/io.h> 20 21/* SUPERIO uart register map */ 22struct yo_uartregs { 23 union { 24 volatile u8 rbr; /* read only, DLAB == 0 */ 25 volatile u8 thr; /* write only, DLAB == 0 */ 26 volatile u8 dll; /* DLAB == 1 */ 27 } u1; 28 union { 29 volatile u8 ier; /* DLAB == 0 */ 30 volatile u8 dlm; /* DLAB == 1 */ 31 } u2; 32 union { 33 volatile u8 iir; /* read only */ 34 volatile u8 fcr; /* write only */ 35 } u3; 36 volatile u8 iu_lcr; 37 volatile u8 iu_mcr; 38 volatile u8 iu_lsr; 39 volatile u8 iu_msr; 40 volatile u8 iu_scr; 41} yo_uregs_t; 42 43#define iu_rbr u1.rbr 44#define iu_thr u1.thr 45#define iu_dll u1.dll 46#define iu_ier u2.ier 47#define iu_dlm u2.dlm 48#define iu_iir u3.iir 49#define iu_fcr u3.fcr 50 51#define ssnop() __asm__ __volatile__("sll $0, $0, 1\n"); 52#define ssnop_4() do { ssnop(); ssnop(); ssnop(); ssnop(); } while (0) 53 54#define IO_BASE_64 0x9000000000000000ULL 55 56static unsigned char readb_outer_space(unsigned long long phys) 57{ 58 unsigned long long vaddr = IO_BASE_64 | phys; 59 unsigned char res; 60 unsigned int sr; 61 62 sr = read_c0_status(); 63 write_c0_status((sr | ST0_KX) & ~ ST0_IE); 64 ssnop_4(); 65 66 __asm__ __volatile__ ( 67 " .set mips3 \n" 68 " ld %0, %1 \n" 69 " lbu %0, (%0) \n" 70 " .set mips0 \n" 71 : "=r" (res) 72 : "m" (vaddr)); 73 74 write_c0_status(sr); 75 ssnop_4(); 76 77 return res; 78} 79 80static void writeb_outer_space(unsigned long long phys, unsigned char c) 81{ 82 unsigned long long vaddr = IO_BASE_64 | phys; 83 unsigned long tmp; 84 unsigned int sr; 85 86 sr = read_c0_status(); 87 write_c0_status((sr | ST0_KX) & ~ ST0_IE); 88 ssnop_4(); 89 90 __asm__ __volatile__ ( 91 " .set mips3 \n" 92 " ld %0, %1 \n" 93 " sb %2, (%0) \n" 94 " .set mips0 \n" 95 : "=&r" (tmp) 96 : "m" (vaddr), "r" (c)); 97 98 write_c0_status(sr); 99 ssnop_4(); 100} 101 102void prom_putchar(char c) 103{ 104 unsigned long lsr = 0xfd000008ULL + offsetof(struct yo_uartregs, iu_lsr); 105 unsigned long thr = 0xfd000008ULL + offsetof(struct yo_uartregs, iu_thr); 106 107 while ((readb_outer_space(lsr) & 0x20) == 0); 108 writeb_outer_space(thr, c); 109} 110