// SPDX-License-Identifier: GPL-2.0
/* 
 * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
 */

#include <linux/fs.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/major.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/console.h>
#include <asm/termbits.h>
#include <asm/irq.h>
#include "chan.h"
#include <init.h>
#include <irq_user.h>
#include "mconsole_kern.h"

static const int ssl_version = 1;

#define NR_PORTS 64

static void ssl_announce(char *dev_name, int dev)
{
        printk(KERN_INFO "Serial line %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       = ssl_announce,
        .xterm_title    = "Serial Line #%d",
        .raw            = 1,
};

static int ssl_config(char *str, char **error_out);
static int ssl_get_config(char *dev, char *str, int size, char **error_out);
static int ssl_remove(int n, char **error_out);


/* Const, except for .mc.list */
static struct line_driver driver = {
        .name                   = "UML serial line",
        .device_name            = "ttyS",
        .major                  = TTY_MAJOR,
        .minor_start            = 64,
        .type                   = TTY_DRIVER_TYPE_SERIAL,
        .subtype                = 0,
        .read_irq_name          = "ssl",
        .write_irq_name         = "ssl-write",
        .mc  = {
                .list           = LIST_HEAD_INIT(driver.mc.list),
                .name           = "ssl",
                .config         = ssl_config,
                .get_config     = ssl_get_config,
                .id             = line_id,
                .remove         = ssl_remove,
        },
};

/* The array is initialized by line_init, at initcall time.  The
 * elements are locked individually as needed.
 */
static char *conf[NR_PORTS];
static char *def_conf = CONFIG_SSL_CHAN;
static struct line serial_lines[NR_PORTS];

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

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

static int ssl_remove(int n, char **error_out)
{
        return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
                           error_out);
}

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

static const struct tty_operations ssl_ops = {
        .open                   = line_open,
        .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,
        .install                = ssl_install,
        .hangup                 = line_hangup,
};

/* Changed by ssl_init and referenced by ssl_exit, which are both serialized
 * by being an initcall and exitcall, respectively.
 */
static int ssl_init_done;

static void ssl_console_write(struct console *c, const char *string,
                              unsigned len)
{
        struct line *line = &serial_lines[c->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 *ssl_console_device(struct console *c, int *index)
{
        *index = c->index;
        return driver.driver;
}

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

        return console_open_chan(line, co);
}

/* No locking for register_console call - relies on single-threaded initcalls */
static struct console ssl_cons = {
        .name           = "ttyS",
        .write          = ssl_console_write,
        .device         = ssl_console_device,
        .setup          = ssl_console_setup,
        .flags          = CON_PRINTBUFFER|CON_ANYTIME,
        .index          = -1,
};

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

        printk(KERN_INFO "Initializing software serial port version %d\n",
               ssl_version);

        err = register_lines(&driver, &ssl_ops, serial_lines,
                                    ARRAY_SIZE(serial_lines));
        if (err)
                return err;

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

        for (i = 0; i < NR_PORTS; i++) {
                char *error;
                char *s = conf[i];
                if (!s)
                        s = def_conf;
                if (setup_one_line(serial_lines, i, s, &opts, &error))
                        printk(KERN_ERR "setup_one_line failed for "
                               "device %d : %s\n", i, error);
        }

        ssl_init_done = 1;
        register_console(&ssl_cons);
        return 0;
}
late_initcall(ssl_init);

static void ssl_exit(void)
{
        if (!ssl_init_done)
                return;
        close_lines(serial_lines, ARRAY_SIZE(serial_lines));
}
__uml_exitcall(ssl_exit);

static int ssl_chan_setup(char *str)
{
        line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
        return 1;
}

__setup("ssl", ssl_chan_setup);
__channel_help(ssl_chan_setup, "ssl");

static int ssl_non_raw_setup(char *str)
{
        opts.raw = 0;
        return 1;
}
__setup("ssl-non-raw", ssl_non_raw_setup);
__uml_help(ssl_non_raw_setup,
"ssl-non-raw\n"
"    Set serial lines to non-raw mode.\n\n"
);