https://github.com/torvalds/linux
Tip revision: 5816b3e6577eaa676ceb00a848f0fd65fe2adc29 authored by Linus Torvalds on 26 September 2021, 21:08:19 UTC
Linux 5.15-rc3
Linux 5.15-rc3
Tip revision: 5816b3e
serial.c
/*
* Generic serial console support
*
* Author: Mark A. Greer <mgreer@mvista.com>
*
* Code in serial_edit_cmdline() copied from <file:arch/ppc/boot/simple/misc.c>
* and was written by Matt Porter <mporter@kernel.crashing.org>.
*
* 2001,2006 (c) MontaVista Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
#include <stdarg.h>
#include <stddef.h>
#include "types.h"
#include "string.h"
#include "stdio.h"
#include "io.h"
#include "ops.h"
static int serial_open(void)
{
struct serial_console_data *scdp = console_ops.data;
return scdp->open();
}
static void serial_write(const char *buf, int len)
{
struct serial_console_data *scdp = console_ops.data;
while (*buf != '\0')
scdp->putc(*buf++);
}
static void serial_edit_cmdline(char *buf, int len, unsigned int timeout)
{
int timer = 0, count;
char ch, *cp;
struct serial_console_data *scdp = console_ops.data;
cp = buf;
count = strlen(buf);
cp = &buf[count];
count++;
do {
if (scdp->tstc()) {
while (((ch = scdp->getc()) != '\n') && (ch != '\r')) {
/* Test for backspace/delete */
if ((ch == '\b') || (ch == '\177')) {
if (cp != buf) {
cp--;
count--;
printf("\b \b");
}
/* Test for ^x/^u (and wipe the line) */
} else if ((ch == '\030') || (ch == '\025')) {
while (cp != buf) {
cp--;
count--;
printf("\b \b");
}
} else if (count < len) {
*cp++ = ch;
count++;
scdp->putc(ch);
}
}
break; /* Exit 'timer' loop */
}
udelay(1000); /* 1 msec */
} while (timer++ < timeout);
*cp = 0;
}
static void serial_close(void)
{
struct serial_console_data *scdp = console_ops.data;
if (scdp->close)
scdp->close();
}
static void *serial_get_stdout_devp(void)
{
void *devp;
char devtype[MAX_PROP_LEN];
char path[MAX_PATH_LEN];
devp = finddevice("/chosen");
if (devp == NULL)
goto err_out;
if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0 ||
getprop(devp, "stdout-path", path, MAX_PATH_LEN) > 0) {
devp = finddevice(path);
if (devp == NULL)
goto err_out;
if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
&& !strcmp(devtype, "serial"))
return devp;
}
err_out:
return NULL;
}
static struct serial_console_data serial_cd;
/* Node's "compatible" property determines which serial driver to use */
int serial_console_init(void)
{
void *devp;
int rc = -1;
devp = serial_get_stdout_devp();
if (devp == NULL)
goto err_out;
if (dt_is_compatible(devp, "ns16550") ||
dt_is_compatible(devp, "pnpPNP,501"))
rc = ns16550_console_init(devp, &serial_cd);
#ifdef CONFIG_CPM
else if (dt_is_compatible(devp, "fsl,cpm1-scc-uart") ||
dt_is_compatible(devp, "fsl,cpm1-smc-uart") ||
dt_is_compatible(devp, "fsl,cpm2-scc-uart") ||
dt_is_compatible(devp, "fsl,cpm2-smc-uart"))
rc = cpm_console_init(devp, &serial_cd);
#endif
#ifdef CONFIG_PPC_MPC52xx
else if (dt_is_compatible(devp, "fsl,mpc5200-psc-uart"))
rc = mpc5200_psc_console_init(devp, &serial_cd);
#endif
#ifdef CONFIG_PPC64_BOOT_WRAPPER
else if (dt_is_compatible(devp, "ibm,opal-console-raw"))
rc = opal_console_init(devp, &serial_cd);
#endif
/* Add other serial console driver calls here */
if (!rc) {
console_ops.open = serial_open;
console_ops.write = serial_write;
console_ops.close = serial_close;
console_ops.data = &serial_cd;
if (serial_cd.getc)
console_ops.edit_cmdline = serial_edit_cmdline;
return 0;
}
err_out:
return -1;
}