// SPDX-License-Identifier: GPL-2.0
/* suncore.c
 *
 * Common SUN serial routines.  Based entirely
 * upon drivers/sbus/char/sunserial.c which is:
 *
 * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
 *
 * Adaptation to new UART layer is:
 *
 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
 */

#include <linux/kernel.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/serial_core.h>
#include <linux/sunserialcore.h>
#include <linux/init.h>

#include <asm/prom.h>


static int sunserial_current_minor = 64;

int sunserial_register_minors(struct uart_driver *drv, int count)
{
        int err = 0;

        drv->minor = sunserial_current_minor;
        drv->nr += count;
        /* Register the driver on the first call */
        if (drv->nr == count)
                err = uart_register_driver(drv);
        if (err == 0) {
                sunserial_current_minor += count;
                drv->tty_driver->name_base = drv->minor - 64;
        }
        return err;
}
EXPORT_SYMBOL(sunserial_register_minors);

void sunserial_unregister_minors(struct uart_driver *drv, int count)
{
        drv->nr -= count;
        sunserial_current_minor -= count;

        if (drv->nr == 0)
                uart_unregister_driver(drv);
}
EXPORT_SYMBOL(sunserial_unregister_minors);

int sunserial_console_match(struct console *con, struct device_node *dp,
                            struct uart_driver *drv, int line, bool ignore_line)
{
        if (!con)
                return 0;

        drv->cons = con;

        if (of_console_device != dp)
                return 0;

        if (!ignore_line) {
                int off = 0;

                if (of_console_options &&
                    *of_console_options == 'b')
                        off = 1;

                if ((line & 1) != off)
                        return 0;
        }

        if (!console_set_on_cmdline) {
                con->index = line;
                add_preferred_console(con->name, line, NULL);
        }
        return 1;
}
EXPORT_SYMBOL(sunserial_console_match);

void sunserial_console_termios(struct console *con, struct device_node *uart_dp)
{
        const char *mode, *s;
        char mode_prop[] = "ttyX-mode";
        int baud, bits, stop, cflag;
        char parity;

        if (of_node_name_eq(uart_dp, "rsc") ||
            of_node_name_eq(uart_dp, "rsc-console") ||
            of_node_name_eq(uart_dp, "rsc-control")) {
                mode = of_get_property(uart_dp,
                                       "ssp-console-modes", NULL);
                if (!mode)
                        mode = "115200,8,n,1,-";
        } else if (of_node_name_eq(uart_dp, "lom-console")) {
                mode = "9600,8,n,1,-";
        } else {
                struct device_node *dp;
                char c;

                c = 'a';
                if (of_console_options)
                        c = *of_console_options;

                mode_prop[3] = c;

                dp = of_find_node_by_path("/options");
                mode = of_get_property(dp, mode_prop, NULL);
                if (!mode)
                        mode = "9600,8,n,1,-";
                of_node_put(dp);
        }

        cflag = CREAD | HUPCL | CLOCAL;

        s = mode;
        baud = simple_strtoul(s, NULL, 0);
        s = strchr(s, ',');
        bits = simple_strtoul(++s, NULL, 0);
        s = strchr(s, ',');
        parity = *(++s);
        s = strchr(s, ',');
        stop = simple_strtoul(++s, NULL, 0);
        s = strchr(s, ',');
        /* XXX handshake is not handled here. */

        switch (baud) {
                case 150: cflag |= B150; break;
                case 300: cflag |= B300; break;
                case 600: cflag |= B600; break;
                case 1200: cflag |= B1200; break;
                case 2400: cflag |= B2400; break;
                case 4800: cflag |= B4800; break;
                case 9600: cflag |= B9600; break;
                case 19200: cflag |= B19200; break;
                case 38400: cflag |= B38400; break;
                case 57600: cflag |= B57600; break;
                case 115200: cflag |= B115200; break;
                case 230400: cflag |= B230400; break;
                case 460800: cflag |= B460800; break;
                default: baud = 9600; cflag |= B9600; break;
        }

        switch (bits) {
                case 5: cflag |= CS5; break;
                case 6: cflag |= CS6; break;
                case 7: cflag |= CS7; break;
                case 8: cflag |= CS8; break;
                default: cflag |= CS8; break;
        }

        switch (parity) {
                case 'o': cflag |= (PARENB | PARODD); break;
                case 'e': cflag |= PARENB; break;
                case 'n': default: break;
        }

        switch (stop) {
                case 2: cflag |= CSTOPB; break;
                case 1: default: break;
        }

        con->cflag = cflag;
}

/* Sun serial MOUSE auto baud rate detection.  */
static struct mouse_baud_cflag {
        int baud;
        unsigned int cflag;
} mouse_baud_table[] = {
        { 1200, B1200 },
        { 2400, B2400 },
        { 4800, B4800 },
        { 9600, B9600 },
        { -1, ~0 },
        { -1, ~0 },
};

unsigned int suncore_mouse_baud_cflag_next(unsigned int cflag, int *new_baud)
{
        int i;

        for (i = 0; mouse_baud_table[i].baud != -1; i++)
                if (mouse_baud_table[i].cflag == (cflag & CBAUD))
                        break;

        i += 1;
        if (mouse_baud_table[i].baud == -1)
                i = 0;

        *new_baud = mouse_baud_table[i].baud;
        return mouse_baud_table[i].cflag;
}

EXPORT_SYMBOL(suncore_mouse_baud_cflag_next);

/* Basically, when the baud rate is wrong the mouse spits out
 * breaks to us.
 */
int suncore_mouse_baud_detection(unsigned char ch, int is_break)
{
        static int mouse_got_break = 0;
        static int ctr = 0;

        if (is_break) {
                /* Let a few normal bytes go by before we jump the gun
                 * and say we need to try another baud rate.
                 */
                if (mouse_got_break && ctr < 8)
                        return 1;

                /* Ok, we need to try another baud. */
                ctr = 0;
                mouse_got_break = 1;
                return 2;
        }
        if (mouse_got_break) {
                ctr++;
                if (ch == 0x87) {
                        /* Correct baud rate determined. */
                        mouse_got_break = 0;
                }
                return 1;
        }
        return 0;
}

EXPORT_SYMBOL(suncore_mouse_baud_detection);

static int __init suncore_init(void)
{
        return 0;
}
device_initcall(suncore_init);

#if 0 /* ..def MODULE ; never supported as such */
MODULE_AUTHOR("Eddie C. Dost, David S. Miller");
MODULE_DESCRIPTION("Sun serial common layer");
MODULE_LICENSE("GPL");
#endif