linux/drivers/tty/serial/earlycon.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2014 Linaro Ltd.
 * Author: Rob Herring <[email protected]>
 *
 * Based on 8250 earlycon:
 * (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
 *	Bjorn Helgaas <[email protected]>
 */

#define pr_fmt(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>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/acpi.h>

#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/fixmap.h>
#endif

#include <asm/serial.h>

static struct console early_con = …;

static struct earlycon_device early_console_dev = …;

static void __iomem * __init earlycon_map(resource_size_t paddr, size_t size)
{ … }

static void __init earlycon_init(struct earlycon_device *device,
				 const char *name)
{ … }

static void __init earlycon_print_info(struct earlycon_device *device)
{ … }

static int __init parse_options(struct earlycon_device *device, char *options)
{ … }

static int __init register_earlycon(char *buf, const struct earlycon_id *match)
{ … }

/**
 *	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)
{ … }

/*
 * This defers the initialization of the early console until after ACPI has
 * been initialized.
 */
bool earlycon_acpi_spcr_enable __initdata;

/* early_param wrapper for setup_earlycon() */
static int __init param_setup_earlycon(char *buf)
{ … }
early_param(…);

#ifdef CONFIG_OF_EARLY_FLATTREE

int __init of_setup_earlycon(const struct earlycon_id *match,
			     unsigned long node,
			     const char *options)
{ … }

#endif /* CONFIG_OF_EARLY_FLATTREE */