1 /*
2 * arch/ppc/kernel/gen550_dbg.c
3 *
4 * A library of polled 16550 serial routines. These are intended to
5 * be used to support progress messages, xmon, kgdb, etc. on a
6 * variety of platforms.
7 *
8 * Adapted from lots of code ripped from the arch/ppc/boot/ polled
9 * 16550 support.
10 *
11 * Matt Porter <mporter@mvista.com>
12 *
13 * Copyright 2002 MontaVista Software Inc.
14 *
15 * This program is free software; you can redistribute it and/or modify it
16 * under the terms of the GNU General Public License as published by the
17 * Free Software Foundation; either version 2 of the License, or (at your
18 * option) any later version.
19 */
20
21 #include <linux/config.h>
22 #include <linux/serialP.h>
23 #include <linux/serial_reg.h>
24 #include <asm/serial.h>
25 #include <asm/io.h>
26
27 #define SERIAL_BAUD 9600
28
29 extern struct serial_state rs_table[];
30
31 static void (*serial_outb)(unsigned long, unsigned char);
32 static unsigned long (*serial_inb)(unsigned long);
33
34 static int shift;
35
direct_inb(unsigned long addr)36 unsigned long direct_inb(unsigned long addr)
37 {
38 return readb(addr);
39 }
40
direct_outb(unsigned long addr,unsigned char val)41 void direct_outb(unsigned long addr, unsigned char val)
42 {
43 writeb(val, addr);
44 }
45
io_inb(unsigned long port)46 unsigned long io_inb(unsigned long port)
47 {
48 return inb(port);
49 }
50
io_outb(unsigned long port,unsigned char val)51 void io_outb(unsigned long port, unsigned char val)
52 {
53 outb(val, port);
54 }
55
serial_init(int chan,void * ignored)56 unsigned long serial_init(int chan, void *ignored)
57 {
58 unsigned long com_port;
59 unsigned char lcr, dlm;
60
61 /* We need to find out which type io we're expecting. If it's
62 * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
63 * If it's 'SERIAL_IO_MEM', we can the exact location. -- Tom */
64 switch (rs_table[chan].io_type) {
65 case SERIAL_IO_PORT:
66 com_port = rs_table[chan].port;
67 serial_outb = io_outb;
68 serial_inb = io_inb;
69 break;
70 case SERIAL_IO_MEM:
71 com_port = (unsigned long)rs_table[chan].iomem_base;
72 serial_outb = direct_outb;
73 serial_inb = direct_inb;
74 break;
75 default:
76 /* We can't deal with it. */
77 return -1;
78 }
79
80 /* How far apart the registers are. */
81 shift = rs_table[chan].iomem_reg_shift;
82
83 /* save the LCR */
84 lcr = serial_inb(com_port + (UART_LCR << shift));
85
86 /* Access baud rate */
87 serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB);
88 dlm = serial_inb(com_port + (UART_DLM << shift));
89
90 /*
91 * Test if serial port is unconfigured
92 * We assume that no-one uses less than 110 baud or
93 * less than 7 bits per character these days.
94 * -- paulus.
95 */
96 if ((dlm <= 4) && (lcr & 2)) {
97 /* port is configured, put the old LCR back */
98 serial_outb(com_port + (UART_LCR << shift), lcr);
99 }
100 else {
101 /* Input clock. */
102 serial_outb(com_port + (UART_DLL << shift),
103 (rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF);
104 serial_outb(com_port + (UART_DLM << shift),
105 (rs_table[chan].baud_base / SERIAL_BAUD) >> 8);
106 /* 8 data, 1 stop, no parity */
107 serial_outb(com_port + (UART_LCR << shift), 0x03);
108 /* RTS/DTR */
109 serial_outb(com_port + (UART_MCR << shift), 0x03);
110
111 /* Clear & enable FIFOs */
112 serial_outb(com_port + (UART_FCR << shift), 0x07);
113 }
114
115 return (com_port);
116 }
117
118 void
serial_putc(unsigned long com_port,unsigned char c)119 serial_putc(unsigned long com_port, unsigned char c)
120 {
121 while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
122 ;
123 serial_outb(com_port, c);
124 }
125
126 unsigned char
serial_getc(unsigned long com_port)127 serial_getc(unsigned long com_port)
128 {
129 while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
130 ;
131 return serial_inb(com_port);
132 }
133
134 int
serial_tstc(unsigned long com_port)135 serial_tstc(unsigned long com_port)
136 {
137 return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
138 }
139
140 void
serial_close(unsigned long com_port)141 serial_close(unsigned long com_port)
142 {
143 }
144
145 void
gen550_init(int i,struct serial_struct * serial_req)146 gen550_init(int i, struct serial_struct *serial_req)
147 {
148 rs_table[i].io_type = serial_req->io_type;
149 rs_table[i].port = serial_req->port;
150 rs_table[i].iomem_base = serial_req->iomem_base;
151 rs_table[i].iomem_reg_shift = serial_req->iomem_reg_shift;
152 }
153
154 #ifdef CONFIG_SERIAL_TEXT_DEBUG
155 void
gen550_progress(char * s,unsigned short hex)156 gen550_progress(char *s, unsigned short hex)
157 {
158 volatile unsigned int progress_debugport;
159 volatile char c;
160
161 progress_debugport = serial_init(0, NULL);
162
163 serial_putc(progress_debugport, '\r');
164
165 while ((c = *s++) != 0)
166 serial_putc(progress_debugport, c);
167
168 serial_putc(progress_debugport, '\n');
169 serial_putc(progress_debugport, '\r');
170 }
171 #endif /* CONFIG_SERIAL_TEXT_DEBUG */
172