Merge remote-tracking branch 'lsk/v3.10/topic/earlycon' into linux-linaro-lsk

This commit is contained in:
Mark Brown 2014-06-05 15:03:37 +01:00
commit f669f023e2
6 changed files with 194 additions and 123 deletions

View File

@ -35,18 +35,8 @@
#include <linux/serial_8250.h>
#include <asm/io.h>
#include <asm/serial.h>
#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/pgtable.h>
#include <asm/fixmap.h>
#endif
struct early_serial8250_device {
struct uart_port port;
char options[16]; /* e.g., 115200n8 */
unsigned int baud;
};
static struct early_serial8250_device early_device;
static struct earlycon_device *early_device;
unsigned int __weak __init serial8250_early_in(struct uart_port *port, int offset)
{
@ -100,7 +90,7 @@ static void __init serial_putc(struct uart_port *port, int c)
static void __init early_serial8250_write(struct console *console,
const char *s, unsigned int count)
{
struct uart_port *port = &early_device.port;
struct uart_port *port = &early_device->port;
unsigned int ier;
/* Save the IER and disable interrupts */
@ -129,7 +119,7 @@ static unsigned int __init probe_baud(struct uart_port *port)
return (port->uartclk / 16) / quot;
}
static void __init init_port(struct early_serial8250_device *device)
static void __init init_port(struct earlycon_device *device)
{
struct uart_port *port = &device->port;
unsigned int divisor;
@ -148,127 +138,32 @@ static void __init init_port(struct early_serial8250_device *device)
serial8250_early_out(port, UART_LCR, c & ~UART_LCR_DLAB);
}
static int __init parse_options(struct early_serial8250_device *device,
char *options)
static int __init early_serial8250_setup(struct earlycon_device *device,
const char *options)
{
struct uart_port *port = &device->port;
int mmio, mmio32, length;
if (!options)
return -ENODEV;
port->uartclk = BASE_BAUD * 16;
mmio = !strncmp(options, "mmio,", 5);
mmio32 = !strncmp(options, "mmio32,", 7);
if (mmio || mmio32) {
port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32);
port->mapbase = simple_strtoul(options + (mmio ? 5 : 7),
&options, 0);
if (mmio32)
port->regshift = 2;
#ifdef CONFIG_FIX_EARLYCON_MEM
set_fixmap_nocache(FIX_EARLYCON_MEM_BASE,
port->mapbase & PAGE_MASK);
port->membase =
(void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
port->membase += port->mapbase & ~PAGE_MASK;
#else
port->membase = ioremap_nocache(port->mapbase, 64);
if (!port->membase) {
printk(KERN_ERR "%s: Couldn't ioremap 0x%llx\n",
__func__,
(unsigned long long) port->mapbase);
return -ENOMEM;
}
#endif
} else if (!strncmp(options, "io,", 3)) {
port->iotype = UPIO_PORT;
port->iobase = simple_strtoul(options + 3, &options, 0);
mmio = 0;
} else
return -EINVAL;
options = strchr(options, ',');
if (options) {
options++;
device->baud = simple_strtoul(options, NULL, 0);
length = min(strcspn(options, " "), sizeof(device->options));
strlcpy(device->options, options, length);
} else {
device->baud = probe_baud(port);
snprintf(device->options, sizeof(device->options), "%u",
device->baud);
}
if (mmio || mmio32)
printk(KERN_INFO
"Early serial console at MMIO%s 0x%llx (options '%s')\n",
mmio32 ? "32" : "",
(unsigned long long)port->mapbase,
device->options);
else
printk(KERN_INFO
"Early serial console at I/O port 0x%lx (options '%s')\n",
port->iobase,
device->options);
return 0;
}
static struct console early_serial8250_console __initdata = {
.name = "uart",
.write = early_serial8250_write,
.flags = CON_PRINTBUFFER | CON_BOOT,
.index = -1,
};
static int __init early_serial8250_setup(char *options)
{
struct early_serial8250_device *device = &early_device;
int err;
if (device->port.membase || device->port.iobase)
if (!(device->port.membase || device->port.iobase))
return 0;
err = parse_options(device, options);
if (err < 0)
return err;
if (!device->baud)
device->baud = probe_baud(&device->port);
init_port(device);
early_device = device;
device->con->write = early_serial8250_write;
return 0;
}
int __init setup_early_serial8250_console(char *cmdline)
{
char *options;
int err;
options = strstr(cmdline, "uart8250,");
if (!options) {
options = strstr(cmdline, "uart,");
if (!options)
return 0;
}
options = strchr(cmdline, ',') + 1;
err = early_serial8250_setup(options);
if (err < 0)
return err;
register_console(&early_serial8250_console);
return 0;
}
EARLYCON_DECLARE(uart8250, early_serial8250_setup);
EARLYCON_DECLARE(uart, early_serial8250_setup);
int serial8250_find_port_for_earlycon(void)
{
struct early_serial8250_device *device = &early_device;
struct uart_port *port = &device->port;
struct earlycon_device *device = early_device;
struct uart_port *port = device ? &device->port : NULL;
int line;
int ret;
if (!device->port.membase && !device->port.iobase)
if (!port || (!port->membase && !port->iobase))
return -ENODEV;
line = serial8250_find_port(port);
@ -283,5 +178,3 @@ int serial8250_find_port_for_earlycon(void)
return ret;
}
early_param("earlycon", setup_early_serial8250_console);

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@ -62,6 +62,7 @@ config SERIAL_8250_CONSOLE
bool "Console on 8250/16550 and compatible serial port"
depends on SERIAL_8250=y
select SERIAL_CORE_CONSOLE
select SERIAL_EARLYCON
---help---
If you say Y here, it will be possible to use a serial port as the
system console (the system console is the device which receives all

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@ -7,6 +7,13 @@ if TTY
menu "Serial drivers"
depends on HAS_IOMEM && GENERIC_HARDIRQS
config SERIAL_EARLYCON
bool
help
Support for early consoles with the earlycon parameter. This enables
the console before standard serial driver is probed. The console is
enabled when early_param is processed.
source "drivers/tty/serial/8250/Kconfig"
comment "Non-8250 serial port support"

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@ -5,6 +5,8 @@
obj-$(CONFIG_SERIAL_CORE) += serial_core.o
obj-$(CONFIG_SERIAL_21285) += 21285.o
obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o
# These Sparc drivers have to appear before others such as 8250
# which share ttySx minor node space. Otherwise console device
# names change and other unplesantries.

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@ -0,0 +1,152 @@
/*
* 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, ret;
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;
ret = kstrtoul(options, 0, &addr);
if (ret)
return ret;
port->mapbase = addr;
if (mmio32)
port->regshift = 2;
} else if (!strncmp(options, "io,", 3)) {
port->iotype = UPIO_PORT;
options += 3;
ret = kstrtoul(options, 0, &addr);
if (ret)
return ret;
port->iobase = addr;
mmio = 0;
} else if (!strncmp(options, "0x", 2)) {
port->iotype = UPIO_MEM;
ret = kstrtoul(options, 0, &addr);
if (ret)
return ret;
port->mapbase = addr;
} else {
return -EINVAL;
}
port->uartclk = BASE_BAUD * 16;
options = strchr(options, ',');
if (options) {
options++;
ret = kstrtouint(options, 0, &device->baud);
if (ret)
return ret;
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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@ -279,6 +279,22 @@ static inline int uart_poll_timeout(struct uart_port *port)
/*
* Console helpers.
*/
struct earlycon_device {
struct console *con;
struct uart_port port;
char options[16]; /* e.g., 115200n8 */
unsigned int baud;
};
int setup_earlycon(char *buf, const char *match,
int (*setup)(struct earlycon_device *, const char *));
#define EARLYCON_DECLARE(name, func) \
static int __init name ## _setup_earlycon(char *buf) \
{ \
return setup_earlycon(buf, __stringify(name), func); \
} \
early_param("earlycon", name ## _setup_earlycon);
struct uart_port *uart_get_console(struct uart_port *ports, int nr,
struct console *c);
void uart_parse_options(char *options, int *baud, int *parity, int *bits,