1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/*
* Copyright (C) 2014 Linaro Ltd.
* Author: Rob Herring <robh@kernel.org>
*
* Based on 8250 earlycon:
* (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
* Bjorn Helgaas <bjorn.helgaas@hp.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/serial_core.h>
#include <linux/sizes.h>
#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/fixmap.h>
#endif
#include <asm/serial.h>
static struct console early_con = {
.name = "uart", /* 8250 console switch requires this name */
.flags = CON_PRINTBUFFER | CON_BOOT,
.index = -1,
};
static struct earlycon_device early_console_dev = {
.con = &early_con,
};
static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
{
void __iomem *base;
#ifdef CONFIG_FIX_EARLYCON_MEM
set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK);
base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
base += paddr & ~PAGE_MASK;
#else
base = ioremap(paddr, size);
#endif
if (!base)
pr_err("%s: Couldn't map 0x%llx\n", __func__,
(unsigned long long)paddr);
return base;
}
static int __init parse_options(struct earlycon_device *device, char *options)
{
struct uart_port *port = &device->port;
int length;
unsigned long addr;
if (uart_parse_earlycon(options, &port->iotype, &addr, &options))
return -EINVAL;
switch (port->iotype) {
case UPIO_MEM:
port->mapbase = addr;
break;
case UPIO_MEM16:
port->regshift = 1;
port->mapbase = addr;
break;
case UPIO_MEM32:
case UPIO_MEM32BE:
port->regshift = 2;
port->mapbase = addr;
break;
case UPIO_PORT:
port->iobase = addr;
break;
default:
return -EINVAL;
}
if (options) {
device->baud = simple_strtoul(options, NULL, 0);
length = min(strcspn(options, " ") + 1,
(size_t)(sizeof(device->options)));
strlcpy(device->options, options, length);
}
if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM16 ||
port->iotype == UPIO_MEM32 || port->iotype == UPIO_MEM32BE)
pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n",
(port->iotype == UPIO_MEM) ? "" :
(port->iotype == UPIO_MEM16) ? "16" :
(port->iotype == UPIO_MEM32) ? "32" : "32be",
(unsigned long long)port->mapbase,
device->options);
else
pr_info("Early serial console at I/O port 0x%lx (options '%s')\n",
port->iobase,
device->options);
return 0;
}
static int __init register_earlycon(char *buf, const struct earlycon_id *match)
{
int err;
struct uart_port *port = &early_console_dev.port;
/* On parsing error, pass the options buf to the setup function */
if (buf && !parse_options(&early_console_dev, buf))
buf = NULL;
spin_lock_init(&port->lock);
port->uartclk = BASE_BAUD * 16;
if (port->mapbase)
port->membase = earlycon_map(port->mapbase, 64);
early_console_dev.con->data = &early_console_dev;
err = match->setup(&early_console_dev, buf);
if (err < 0)
return err;
if (!early_console_dev.con->write)
return -ENODEV;
register_console(early_console_dev.con);
return 0;
}
/**
* setup_earlycon - match and register earlycon console
* @buf: earlycon param string
*
* Registers the earlycon console matching the earlycon specified
* in the param string @buf. Acceptable param strings are of the form
* <name>,io|mmio|mmio32|mmio32be,<addr>,<options>
* <name>,0x<addr>,<options>
* <name>,<options>
* <name>
*
* Only for the third form does the earlycon setup() method receive the
* <options> string in the 'options' parameter; all other forms set
* the parameter to NULL.
*
* Returns 0 if an attempt to register the earlycon was made,
* otherwise negative error code
*/
int __init setup_earlycon(char *buf)
{
const struct earlycon_id *match;
if (!buf || !buf[0])
return -EINVAL;
if (early_con.flags & CON_ENABLED)
return -EALREADY;
for (match = __earlycon_table; match < __earlycon_table_end; match++) {
size_t len = strlen(match->name);
if (strncmp(buf, match->name, len))
continue;
if (buf[len]) {
if (buf[len] != ',')
continue;
buf += len + 1;
} else
buf = NULL;
return register_earlycon(buf, match);
}
return -ENOENT;
}
/* early_param wrapper for setup_earlycon() */
static int __init param_setup_earlycon(char *buf)
{
int err;
/*
* Just 'earlycon' is a valid param for devicetree earlycons;
* don't generate a warning from parse_early_params() in that case
*/
if (!buf || !buf[0])
return 0;
err = setup_earlycon(buf);
if (err == -ENOENT || err == -EALREADY)
return 0;
return err;
}
early_param("earlycon", param_setup_earlycon);
#ifdef CONFIG_OF_EARLY_FLATTREE
int __init of_setup_earlycon(unsigned long addr,
int (*setup)(struct earlycon_device *, const char *))
{
int err;
struct uart_port *port = &early_console_dev.port;
spin_lock_init(&port->lock);
port->iotype = UPIO_MEM;
port->mapbase = addr;
port->uartclk = BASE_BAUD * 16;
port->membase = earlycon_map(addr, SZ_4K);
early_console_dev.con->data = &early_console_dev;
err = setup(&early_console_dev, NULL);
if (err < 0)
return err;
if (!early_console_dev.con->write)
return -ENODEV;
register_console(early_console_dev.con);
return 0;
}
#endif /* CONFIG_OF_EARLY_FLATTREE */
|
