// SPDX-License-Identifier: GPL-2.0
/* 
 * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
 */

#include <linux/posix_types.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/types.h>
#include <linux/major.h>
#include <linux/kdev_t.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/hardirq.h>
#include <asm/current.h>
#include <asm/irq.h>
#include "stdio_console.h"
#include "chan.h"
#include <irq_user.h>
#include "mconsole_kern.h"
#include <init.h>

#define MAX_TTYS (16)

static void stdio_announce(char *dev_name, int dev)
{
        printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
               dev_name);
}

/* Almost const, except that xterm_title may be changed in an initcall */
static struct chan_opts opts = {
        .announce       = stdio_announce,
        .xterm_title    = "Virtual Console #%d",
        .raw            = 1,
};

static int con_config(char *str, char **error_out);
static int con_get_config(char *dev, char *str, int size, char **error_out);
static int con_remove(int n, char **con_remove);


/* Const, except for .mc.list */
static struct line_driver driver = {
        .name                   = "UML console",
        .device_name            = "tty",
        .major                  = TTY_MAJOR,
        .minor_start            = 0,
        .type                   = TTY_DRIVER_TYPE_CONSOLE,
        .subtype                = SYSTEM_TYPE_CONSOLE,
        .read_irq_name          = "console",
        .write_irq_name         = "console-write",
        .mc  = {
                .list           = LIST_HEAD_INIT(driver.mc.list),
                .name           = "con",
                .config         = con_config,
                .get_config     = con_get_config,
                .id             = line_id,
                .remove         = con_remove,
        },
};

/* The array is initialized by line_init, at initcall time.  The
 * elements are locked individually as needed.
 */
static char *vt_conf[MAX_TTYS];
static char *def_conf;
static struct line vts[MAX_TTYS];

static int con_config(char *str, char **error_out)
{
        return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
}

static int con_get_config(char *dev, char *str, int size, char **error_out)
{
        return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
}

static int con_remove(int n, char **error_out)
{
        return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
}

/* Set in an initcall, checked in an exitcall */
static int con_init_done;

static int con_install(struct tty_driver *driver, struct tty_struct *tty)
{
        return line_install(driver, tty, &vts[tty->index]);
}

static const struct tty_operations console_ops = {
        .open                   = line_open,
        .install                = con_install,
        .close                  = line_close,
        .write                  = line_write,
        .write_room             = line_write_room,
        .chars_in_buffer        = line_chars_in_buffer,
        .flush_buffer           = line_flush_buffer,
        .flush_chars            = line_flush_chars,
        .throttle               = line_throttle,
        .unthrottle             = line_unthrottle,
        .hangup                 = line_hangup,
};

static void uml_console_write(struct console *console, const char *string,
                              unsigned len)
{
        struct line *line = &vts[console->index];
        unsigned long flags;

        spin_lock_irqsave(&line->lock, flags);
        console_write_chan(line->chan_out, string, len);
        spin_unlock_irqrestore(&line->lock, flags);
}

static struct tty_driver *uml_console_device(struct console *c, int *index)
{
        *index = c->index;
        return driver.driver;
}

static int uml_console_setup(struct console *co, char *options)
{
        struct line *line = &vts[co->index];

        return console_open_chan(line, co);
}

/* No locking for register_console call - relies on single-threaded initcalls */
static struct console stdiocons = {
        .name           = "tty",
        .write          = uml_console_write,
        .device         = uml_console_device,
        .setup          = uml_console_setup,
        .flags          = CON_PRINTBUFFER|CON_ANYTIME,
        .index          = -1,
};

static int stdio_init(void)
{
        char *new_title;
        int err;
        int i;

        err = register_lines(&driver, &console_ops, vts,
                                        ARRAY_SIZE(vts));
        if (err)
                return err;

        printk(KERN_INFO "Initialized stdio console driver\n");

        new_title = add_xterm_umid(opts.xterm_title);
        if(new_title != NULL)
                opts.xterm_title = new_title;

        for (i = 0; i < MAX_TTYS; i++) {
                char *error;
                char *s = vt_conf[i];
                if (!s)
                        s = def_conf;
                if (!s)
                        s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
                if (setup_one_line(vts, i, s, &opts, &error))
                        printk(KERN_ERR "setup_one_line failed for "
                               "device %d : %s\n", i, error);
        }

        con_init_done = 1;
        register_console(&stdiocons);
        return 0;
}
late_initcall(stdio_init);

static void console_exit(void)
{
        if (!con_init_done)
                return;
        close_lines(vts, ARRAY_SIZE(vts));
}
__uml_exitcall(console_exit);

static int console_chan_setup(char *str)
{
        if (!strncmp(str, "sole=", 5))  /* console= option specifies tty */
                return 0;

        line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console");
        return 1;
}
__setup("con", console_chan_setup);
__channel_help(console_chan_setup, "con");