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/*
* 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.
*/
#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/serial_core.h>
#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/fixmap.h>
#endif
#include <asm/serial.h>
static struct console early_con = {
.name = "earlycon",
.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 mmio, mmio32, length;
unsigned long addr;
if (!options)
return -ENODEV;
mmio = !strncmp(options, "mmio,", 5);
mmio32 = !strncmp(options, "mmio32,", 7);
if (mmio || mmio32) {
port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32);
options += mmio ? 5 : 7;
addr = simple_strtoul(options, NULL, 0);
port->mapbase = addr;
if (mmio32)
port->regshift = 2;
} else if (!strncmp(options, "io,", 3)) {
port->iotype = UPIO_PORT;
options += 3;
addr = simple_strtoul(options, NULL, 0);
port->iobase = addr;
mmio = 0;
} else if (!strncmp(options, "0x", 2)) {
port->iotype = UPIO_MEM;
addr = simple_strtoul(options, NULL, 0);
port->mapbase = addr;
} else {
return -EINVAL;
}
port->uartclk = BASE_BAUD * 16;
options = strchr(options, ',');
if (options) {
options++;
device->baud = simple_strtoul(options, NULL, 0);
length = min(strcspn(options, " ") + 1,
(size_t)(sizeof(device->options)));
strlcpy(device->options, options, length);
}
if (mmio || mmio32)
pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n",
mmio32 ? "32" : "",
(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;
}
int __init setup_earlycon(char *buf, const char *match,
int (*setup)(struct earlycon_device *, const char *))
{
int err;
size_t len;
struct uart_port *port = &early_console_dev.port;
if (!buf || !match || !setup)
return 0;
len = strlen(match);
if (strncmp(buf, match, len))
return 0;
if (buf[len] && (buf[len] != ','))
return 0;
buf += len + 1;
err = parse_options(&early_console_dev, buf);
/* On parsing error, pass the options buf to the setup function */
if (!err)
buf = NULL;
if (port->mapbase)
port->membase = earlycon_map(port->mapbase, 64);
early_console_dev.con->data = &early_console_dev;
err = 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;
}
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