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 */
22 struct 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
readb_outer_space(unsigned long long phys)56 static 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
writeb_outer_space(unsigned long long phys,unsigned char c)80 static 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
prom_putchar(char c)102 void 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