serial.c

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/*
 * Generic serial console support
 *
 * Author: Mark A. Greer <[email protected]>
 *
 * Code in serial_edit_cmdline() copied from <file:arch/ppc/boot/simple/misc.c>
 * and was written by Matt Porter <[email protected]>.
 *
 * 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)
{
    int timer = 0, count;
    char ch, *cp;
    struct serial_console_data *scdp = console_ops.data;

    cp = buf;
    count = strlen(buf);
    cp = &buf[count];
    count++;

    while (timer++ < 5*1000) {
        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 */
    }
    *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) {
        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);
    else if (dt_is_compatible(devp, "marvell,mv64360-mpsc"))
        rc = mpsc_console_init(devp, &serial_cd);
    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);
    else if (dt_is_compatible(devp, "fsl,mpc5200-psc-uart"))
        rc = mpc5200_psc_console_init(devp, &serial_cd);
    else if (dt_is_compatible(devp, "xlnx,opb-uartlite-1.00.b") ||
         dt_is_compatible(devp, "xlnx,xps-uartlite-1.00.a"))
        rc = uartlite_console_init(devp, &serial_cd);

    /* 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;
}