// SPDX-License-Identifier: GPL-2.0
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/bitops.h>
#include <linux/ptrace.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <linux/cuda.h>
#include <linux/of.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/xmon.h>
#include <asm/bootx.h>
#include <asm/errno.h>
#include <asm/pmac_feature.h>
#include <asm/processor.h>
#include <asm/delay.h>
#include <asm/btext.h>
#include <asm/time.h>
#include <asm/udbg.h>

/*
 * This implementation is "special", it can "patch" the current
 * udbg implementation and work on top of it. It must thus be
 * initialized last
 */

static void (*udbg_adb_old_putc)(char c);
static int (*udbg_adb_old_getc)(void);
static int (*udbg_adb_old_getc_poll)(void);

static enum {
        input_adb_none,
        input_adb_pmu,
        input_adb_cuda,
} input_type = input_adb_none;

int xmon_wants_key, xmon_adb_keycode;

static inline void udbg_adb_poll(void)
{
#ifdef CONFIG_ADB_PMU
        if (input_type == input_adb_pmu)
                pmu_poll_adb();
#endif /* CONFIG_ADB_PMU */
#ifdef CONFIG_ADB_CUDA
        if (input_type == input_adb_cuda)
                cuda_poll();
#endif /* CONFIG_ADB_CUDA */
}

#ifdef CONFIG_BOOTX_TEXT

static int udbg_adb_use_btext;
static int xmon_adb_shiftstate;

static unsigned char xmon_keytab[128] =
        "asdfhgzxcv\000bqwer"                           /* 0x00 - 0x0f */
        "yt123465=97-80]o"                              /* 0x10 - 0x1f */
        "u[ip\rlj'k;\\,/nm."                            /* 0x20 - 0x2f */
        "\t `\177\0\033\0\0\0\0\0\0\0\0\0\0"            /* 0x30 - 0x3f */
        "\0.\0*\0+\0\0\0\0\0/\r\0-\0"                   /* 0x40 - 0x4f */
        "\0\0000123456789\0\0\0";                       /* 0x50 - 0x5f */

static unsigned char xmon_shift_keytab[128] =
        "ASDFHGZXCV\000BQWER"                           /* 0x00 - 0x0f */
        "YT!@#$^%+(&_*)}O"                              /* 0x10 - 0x1f */
        "U{IP\rLJ\"K:|<?NM>"                            /* 0x20 - 0x2f */
        "\t ~\177\0\033\0\0\0\0\0\0\0\0\0\0"            /* 0x30 - 0x3f */
        "\0.\0*\0+\0\0\0\0\0/\r\0-\0"                   /* 0x40 - 0x4f */
        "\0\0000123456789\0\0\0";                       /* 0x50 - 0x5f */

static int udbg_adb_local_getc(void)
{
        int k, t, on;

        xmon_wants_key = 1;
        for (;;) {
                xmon_adb_keycode = -1;
                t = 0;
                on = 0;
                k = -1;
                do {
                        if (--t < 0) {
                                on = 1 - on;
                                btext_drawchar(on? 0xdb: 0x20);
                                btext_drawchar('\b');
                                t = 200000;
                        }
                        udbg_adb_poll();
                        if (udbg_adb_old_getc_poll)
                                k = udbg_adb_old_getc_poll();
                } while (k == -1 && xmon_adb_keycode == -1);
                if (on)
                        btext_drawstring(" \b");
                if (k != -1)
                        return k;
                k = xmon_adb_keycode;

                /* test for shift keys */
                if ((k & 0x7f) == 0x38 || (k & 0x7f) == 0x7b) {
                        xmon_adb_shiftstate = (k & 0x80) == 0;
                        continue;
                }
                if (k >= 0x80)
                        continue;       /* ignore up transitions */
                k = (xmon_adb_shiftstate? xmon_shift_keytab: xmon_keytab)[k];
                if (k != 0)
                        break;
        }
        xmon_wants_key = 0;
        return k;
}
#endif /* CONFIG_BOOTX_TEXT */

static int udbg_adb_getc(void)
{
#ifdef CONFIG_BOOTX_TEXT
        if (udbg_adb_use_btext && input_type != input_adb_none)
                return udbg_adb_local_getc();
#endif
        if (udbg_adb_old_getc)
                return udbg_adb_old_getc();
        return -1;
}

/* getc_poll() is not really used, unless you have the xmon-over modem
 * hack that doesn't quite concern us here, thus we just poll the low level
 * ADB driver to prevent it from timing out and call back the original poll
 * routine.
 */
static int udbg_adb_getc_poll(void)
{
        udbg_adb_poll();

        if (udbg_adb_old_getc_poll)
                return udbg_adb_old_getc_poll();
        return -1;
}

static void udbg_adb_putc(char c)
{
#ifdef CONFIG_BOOTX_TEXT
        if (udbg_adb_use_btext)
                btext_drawchar(c);
#endif
        if (udbg_adb_old_putc)
                return udbg_adb_old_putc(c);
}

void __init udbg_adb_init_early(void)
{
#ifdef CONFIG_BOOTX_TEXT
        if (btext_find_display(1) == 0) {
                udbg_adb_use_btext = 1;
                udbg_putc = udbg_adb_putc;
        }
#endif
}

int __init udbg_adb_init(int force_btext)
{
        struct device_node *np;

        /* Capture existing callbacks */
        udbg_adb_old_putc = udbg_putc;
        udbg_adb_old_getc = udbg_getc;
        udbg_adb_old_getc_poll = udbg_getc_poll;

        /* Check if our early init was already called */
        if (udbg_adb_old_putc == udbg_adb_putc)
                udbg_adb_old_putc = NULL;
#ifdef CONFIG_BOOTX_TEXT
        if (udbg_adb_old_putc == btext_drawchar)
                udbg_adb_old_putc = NULL;
#endif

        /* Set ours as output */
        udbg_putc = udbg_adb_putc;
        udbg_getc = udbg_adb_getc;
        udbg_getc_poll = udbg_adb_getc_poll;

#ifdef CONFIG_BOOTX_TEXT
        /* Check if we should use btext output */
        if (btext_find_display(force_btext) == 0)
                udbg_adb_use_btext = 1;
#endif

        /* See if there is a keyboard in the device tree with a parent
         * of type "adb". If not, we return a failure, but we keep the
         * bext output set for now
         */
        for_each_node_by_name(np, "keyboard") {
                struct device_node *parent = of_get_parent(np);
                int found = of_node_is_type(parent, "adb");
                of_node_put(parent);
                if (found)
                        break;
        }
        if (np == NULL)
                return -ENODEV;
        of_node_put(np);

#ifdef CONFIG_ADB_PMU
        if (find_via_pmu())
                input_type = input_adb_pmu;
#endif
#ifdef CONFIG_ADB_CUDA
        if (find_via_cuda())
                input_type = input_adb_cuda;
#endif

        /* Same as above: nothing found, keep btext set for output */
        if (input_type == input_adb_none)
                return -ENODEV;

        return 0;
}