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-rw-r--r--arch/ppc64/kernel/udbg_16550.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/udbg_16550.c b/arch/ppc64/kernel/udbg_16550.c
new file mode 100644
index 000000000000..46a23e34f7c9
--- /dev/null
+++ b/arch/ppc64/kernel/udbg_16550.c
@@ -0,0 +1,128 @@
1/*
2 * udbg for for NS16550 compatable serial ports
3 *
4 * Copyright (C) 2001-2005 PPC 64 Team, IBM Corp
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#include <linux/config.h>
12#include <linux/types.h>
13#include <asm/ppcdebug.h>
14#include <asm/processor.h>
15#include <asm/naca.h>
16#include <asm/uaccess.h>
17#include <asm/machdep.h>
18#include <asm/io.h>
19#include <asm/prom.h>
20
21extern u8 real_readb(volatile u8 __iomem *addr);
22extern void real_writeb(u8 data, volatile u8 __iomem *addr);
23
24struct NS16550 {
25 /* this struct must be packed */
26 unsigned char rbr; /* 0 */
27 unsigned char ier; /* 1 */
28 unsigned char fcr; /* 2 */
29 unsigned char lcr; /* 3 */
30 unsigned char mcr; /* 4 */
31 unsigned char lsr; /* 5 */
32 unsigned char msr; /* 6 */
33 unsigned char scr; /* 7 */
34};
35
36#define thr rbr
37#define iir fcr
38#define dll rbr
39#define dlm ier
40#define dlab lcr
41
42#define LSR_DR 0x01 /* Data ready */
43#define LSR_OE 0x02 /* Overrun */
44#define LSR_PE 0x04 /* Parity error */
45#define LSR_FE 0x08 /* Framing error */
46#define LSR_BI 0x10 /* Break */
47#define LSR_THRE 0x20 /* Xmit holding register empty */
48#define LSR_TEMT 0x40 /* Xmitter empty */
49#define LSR_ERR 0x80 /* Error */
50
51static volatile struct NS16550 __iomem *udbg_comport;
52
53static void udbg_550_putc(unsigned char c)
54{
55 if (udbg_comport) {
56 while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0)
57 /* wait for idle */;
58 out_8(&udbg_comport->thr, c);
59 if (c == '\n')
60 udbg_550_putc('\r');
61 }
62}
63
64static int udbg_550_getc_poll(void)
65{
66 if (udbg_comport) {
67 if ((in_8(&udbg_comport->lsr) & LSR_DR) != 0)
68 return in_8(&udbg_comport->rbr);
69 else
70 return -1;
71 }
72 return -1;
73}
74
75static unsigned char udbg_550_getc(void)
76{
77 if (udbg_comport) {
78 while ((in_8(&udbg_comport->lsr) & LSR_DR) == 0)
79 /* wait for char */;
80 return in_8(&udbg_comport->rbr);
81 }
82 return 0;
83}
84
85void udbg_init_uart(void __iomem *comport, unsigned int speed)
86{
87 u16 dll = speed ? (115200 / speed) : 12;
88
89 if (comport) {
90 udbg_comport = (struct NS16550 __iomem *)comport;
91 out_8(&udbg_comport->lcr, 0x00);
92 out_8(&udbg_comport->ier, 0xff);
93 out_8(&udbg_comport->ier, 0x00);
94 out_8(&udbg_comport->lcr, 0x80); /* Access baud rate */
95 out_8(&udbg_comport->dll, dll & 0xff); /* 1 = 115200, 2 = 57600,
96 3 = 38400, 12 = 9600 baud */
97 out_8(&udbg_comport->dlm, dll >> 8); /* dll >> 8 which should be zero
98 for fast rates; */
99 out_8(&udbg_comport->lcr, 0x03); /* 8 data, 1 stop, no parity */
100 out_8(&udbg_comport->mcr, 0x03); /* RTS/DTR */
101 out_8(&udbg_comport->fcr ,0x07); /* Clear & enable FIFOs */
102 ppc_md.udbg_putc = udbg_550_putc;
103 ppc_md.udbg_getc = udbg_550_getc;
104 ppc_md.udbg_getc_poll = udbg_550_getc_poll;
105 }
106}
107
108#ifdef CONFIG_PPC_MAPLE
109void udbg_maple_real_putc(unsigned char c)
110{
111 if (udbg_comport) {
112 while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
113 /* wait for idle */;
114 real_writeb(c, &udbg_comport->thr); eieio();
115 if (c == '\n')
116 udbg_maple_real_putc('\r');
117 }
118}
119
120void udbg_init_maple_realmode(void)
121{
122 udbg_comport = (volatile struct NS16550 __iomem *)0xf40003f8;
123
124 ppc_md.udbg_putc = udbg_maple_real_putc;
125 ppc_md.udbg_getc = NULL;
126 ppc_md.udbg_getc_poll = NULL;
127}
128#endif /* CONFIG_PPC_MAPLE */