[deliverable/linux.git] / drivers / tty / serial / earlycon.c

/*
 * 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>
#include <linux/sizes.h>
#include <linux/mod_devicetable.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 const struct of_device_id __earlycon_of_table_sentinel
	__used __section(__earlycon_of_table_end);

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 (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM32)
		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;
}

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;

	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;
}
Commit	Line	Data
9aac5887 RH	1	/*
	2	* Copyright (C) 2014 Linaro Ltd.
	3	* Author: Rob Herring <robh@kernel.org>
	4	*
	5	* Based on 8250 earlycon:
	6	* (c) Copyright 2004 Hewlett-Packard Development Company, L.P.
	7	* Bjorn Helgaas <bjorn.helgaas@hp.com>
	8	*
	9	* This program is free software: you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13	#include <linux/console.h>
	14	#include <linux/kernel.h>
	15	#include <linux/init.h>
	16	#include <linux/io.h>
	17	#include <linux/serial_core.h>
b0b6abd3 RH	18	#include <linux/sizes.h>
b0b6abd3 RH	19	#include <linux/mod_devicetable.h>
9aac5887 RH	20
	21	#ifdef CONFIG_FIX_EARLYCON_MEM
	22	#include <asm/fixmap.h>
	23	#endif
	24
	25	#include <asm/serial.h>
	26
	27	static struct console early_con = {
60efcf04	28	.name = "uart", /* 8250 console switch requires this name */
9aac5887 RH	29	.flags = CON_PRINTBUFFER \| CON_BOOT,
	30	.index = -1,
	31	};
	32
	33	static struct earlycon_device early_console_dev = {
	34	.con = &early_con,
	35	};
	36
b0b6abd3 RH	37	static const struct of_device_id __earlycon_of_table_sentinel
	38	__used __section(__earlycon_of_table_end);
	39
9aac5887 RH	40	static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
	41	{
	42	void __iomem *base;
	43	#ifdef CONFIG_FIX_EARLYCON_MEM
	44	set_fixmap_io(FIX_EARLYCON_MEM_BASE, paddr & PAGE_MASK);
	45	base = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
	46	base += paddr & ~PAGE_MASK;
	47	#else
	48	base = ioremap(paddr, size);
	49	#endif
	50	if (!base)
	51	pr_err("%s: Couldn't map 0x%llx\n", __func__,
	52	(unsigned long long)paddr);
	53
	54	return base;
	55	}
	56
	57	static int __init parse_options(struct earlycon_device *device,
	58	char *options)
	59	{
	60	struct uart_port *port = &device->port;
e26f1db9	61	int mmio, mmio32, length;
9aac5887 RH	62	unsigned long addr;
	63
	64	if (!options)
	65	return -ENODEV;
	66
	67	mmio = !strncmp(options, "mmio,", 5);
	68	mmio32 = !strncmp(options, "mmio32,", 7);
	69	if (mmio \|\| mmio32) {
	70	port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32);
	71	options += mmio ? 5 : 7;
e26f1db9	72	addr = simple_strtoul(options, NULL, 0);
9aac5887 RH	73	port->mapbase = addr;
	74	if (mmio32)
	75	port->regshift = 2;
	76	} else if (!strncmp(options, "io,", 3)) {
	77	port->iotype = UPIO_PORT;
	78	options += 3;
e26f1db9	79	addr = simple_strtoul(options, NULL, 0);
9aac5887 RH	80	port->iobase = addr;
	81	mmio = 0;
	82	} else if (!strncmp(options, "0x", 2)) {
	83	port->iotype = UPIO_MEM;
e26f1db9	84	addr = simple_strtoul(options, NULL, 0);
9aac5887 RH	85	port->mapbase = addr;
	86	} else {
	87	return -EINVAL;
	88	}
	89
	90	port->uartclk = BASE_BAUD * 16;
	91
	92	options = strchr(options, ',');
	93	if (options) {
	94	options++;
e26f1db9	95	device->baud = simple_strtoul(options, NULL, 0);
9aac5887 RH	96	length = min(strcspn(options, " ") + 1,
	97	(size_t)(sizeof(device->options)));
	98	strlcpy(device->options, options, length);
	99	}
	100
fe655de1	101	if (port->iotype == UPIO_MEM \|\| port->iotype == UPIO_MEM32)
9aac5887 RH	102	pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n",
	103	mmio32 ? "32" : "",
	104	(unsigned long long)port->mapbase,
	105	device->options);
	106	else
	107	pr_info("Early serial console at I/O port 0x%lx (options '%s')\n",
	108	port->iobase,
	109	device->options);
	110
	111	return 0;
	112	}
	113
	114	int __init setup_earlycon(char buf, const char match,
	115	int (setup)(struct earlycon_device , const char *))
	116	{
	117	int err;
	118	size_t len;
	119	struct uart_port *port = &early_console_dev.port;
	120
	121	if (!buf \|\| !match \|\| !setup)
	122	return 0;
	123
	124	len = strlen(match);
	125	if (strncmp(buf, match, len))
	126	return 0;
	127	if (buf[len] && (buf[len] != ','))
	128	return 0;
	129
	130	buf += len + 1;
	131
	132	err = parse_options(&early_console_dev, buf);
	133	/* On parsing error, pass the options buf to the setup function */
	134	if (!err)
	135	buf = NULL;
	136
	137	if (port->mapbase)
	138	port->membase = earlycon_map(port->mapbase, 64);
	139
	140	early_console_dev.con->data = &early_console_dev;
	141	err = setup(&early_console_dev, buf);
	142	if (err < 0)
	143	return err;
	144	if (!early_console_dev.con->write)
	145	return -ENODEV;
	146
	147	register_console(early_console_dev.con);
	148	return 0;
	149	}
b0b6abd3 RH	150
	151	int __init of_setup_earlycon(unsigned long addr,
	152	int (setup)(struct earlycon_device , const char *))
	153	{
	154	int err;
	155	struct uart_port *port = &early_console_dev.port;
	156
	157	port->iotype = UPIO_MEM;
	158	port->mapbase = addr;
	159	port->uartclk = BASE_BAUD * 16;
	160	port->membase = earlycon_map(addr, SZ_4K);
	161
	162	early_console_dev.con->data = &early_console_dev;
	163	err = setup(&early_console_dev, NULL);
	164	if (err < 0)
	165	return err;
	166	if (!early_console_dev.con->write)
	167	return -ENODEV;
	168
	169
	170	register_console(early_console_dev.con);
	171	return 0;
	172	}