/*
 * (C) Copyright 2007
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * (C) Copyright 2001, 2002
 * DENX Software Engineering
 * Wolfgang Denk, wd@denx.de
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

/* define DEBUG for debugging output (obviously ;-)) */
#if 0
#define DEBUG
#endif

#include <common.h>
#include <i2c.h>
#include <command.h>
#include <console.h>
#include <post.h>
#include <serial.h>
#include <malloc.h>

#include <linux/types.h>
#include <linux/string.h>       /* for strdup */

DECLARE_GLOBAL_DATA_PTR;

static void kbd_init (void);
static int compare_magic (uchar *kbd_data, uchar *str);

/*--------------------- Local macros and constants --------------------*/
#define _NOT_USED_      0xFFFFFFFF

/*------------------------- dspic io expander -----------------------*/
#define DSPIC_PON_STATUS_REG    0x80A
#define DSPIC_PON_INV_STATUS_REG 0x80C
#define DSPIC_PON_KEY_REG       0x810
/*------------------------- Keyboard controller -----------------------*/
/* command codes */
#define KEYBD_CMD_READ_KEYS     0x01
#define KEYBD_CMD_READ_VERSION  0x02
#define KEYBD_CMD_READ_STATUS   0x03
#define KEYBD_CMD_RESET_ERRORS  0x10

/* status codes */
#define KEYBD_STATUS_MASK       0x3F
#define KEYBD_STATUS_H_RESET    0x20
#define KEYBD_STATUS_BROWNOUT   0x10
#define KEYBD_STATUS_WD_RESET   0x08
#define KEYBD_STATUS_OVERLOAD   0x04
#define KEYBD_STATUS_ILLEGAL_WR 0x02
#define KEYBD_STATUS_ILLEGAL_RD 0x01

/* Number of bytes returned from Keyboard Controller */
#define KEYBD_VERSIONLEN        2       /* version information */

/*
 * This is different from the "old" lwmon dsPIC kbd controller
 * implementation. Now the controller still answers with 9 bytes,
 * but the last 3 bytes are always "0x06 0x07 0x08". So we just
 * set the length to compare to 6 instead of 9.
 */
#define KEYBD_DATALEN           6       /* normal key scan data */

/* maximum number of "magic" key codes that can be assigned */

static uchar kbd_addr = CONFIG_SYS_I2C_KEYBD_ADDR;
static uchar dspic_addr = CONFIG_SYS_I2C_DSPIC_IO_ADDR;

static uchar *key_match (uchar *);

#define KEYBD_SET_DEBUGMODE     '#'     /* Magic key to enable debug output */

/***********************************************************************
F* Function:     int board_postclk_init (void) P*A*Z*
 *
P* Parameters:   none
P*
P* Returnvalue:  int
P*                - 0 is always returned.
 *
Z* Intention:    This function is the board_postclk_init() method implementation
Z*               for the lwmon board.
 *
 ***********************************************************************/
int board_postclk_init (void)
{
        kbd_init();

        return (0);
}

static void kbd_init (void)
{
        uchar kbd_data[KEYBD_DATALEN];
        uchar tmp_data[KEYBD_DATALEN];
        uchar val, errcd;
        int i;

        i2c_set_bus_num(0);

        gd->arch.kbd_status = 0;

        /* Forced by PIC. Delays <= 175us loose */
        udelay(1000);

        /* Read initial keyboard error code */
        val = KEYBD_CMD_READ_STATUS;
        i2c_write (kbd_addr, 0, 0, &val, 1);
        i2c_read (kbd_addr, 0, 0, &errcd, 1);
        /* clear unused bits */
        errcd &= KEYBD_STATUS_MASK;
        /* clear "irrelevant" bits. Recommended by Martin Rajek, LWN */
        errcd &= ~(KEYBD_STATUS_H_RESET|KEYBD_STATUS_BROWNOUT);
        if (errcd) {
                gd->arch.kbd_status |= errcd << 8;
        }
        /* Reset error code and verify */
        val = KEYBD_CMD_RESET_ERRORS;
        i2c_write (kbd_addr, 0, 0, &val, 1);
        udelay(1000);   /* delay NEEDED by keyboard PIC !!! */

        val = KEYBD_CMD_READ_STATUS;
        i2c_write (kbd_addr, 0, 0, &val, 1);
        i2c_read (kbd_addr, 0, 0, &val, 1);

        val &= KEYBD_STATUS_MASK;       /* clear unused bits */
        if (val) {                      /* permanent error, report it */
                gd->arch.kbd_status |= val;
                return;
        }

        /*
         * Read current keyboard state.
         *
         * After the error reset it may take some time before the
         * keyboard PIC picks up a valid keyboard scan - the total
         * scan time is approx. 1.6 ms (information by Martin Rajek,
         * 28 Sep 2002). We read a couple of times for the keyboard
         * to stabilize, using a big enough delay.
         * 10 times should be enough. If the data is still changing,
         * we use what we get :-(
         */

        memset (tmp_data, 0xFF, KEYBD_DATALEN); /* impossible value */
        for (i=0; i<10; ++i) {
                val = KEYBD_CMD_READ_KEYS;
                i2c_write (kbd_addr, 0, 0, &val, 1);
                i2c_read (kbd_addr, 0, 0, kbd_data, KEYBD_DATALEN);

                if (memcmp(kbd_data, tmp_data, KEYBD_DATALEN) == 0) {
                        /* consistent state, done */
                        break;
                }
                /* remeber last state, delay, and retry */
                memcpy (tmp_data, kbd_data, KEYBD_DATALEN);
                udelay (5000);
        }
}


/* Read a register from the dsPIC. */
int _dspic_read(ushort reg, ushort *data)
{
        uchar buf[sizeof(*data)];
        int rval;

        if (i2c_read(dspic_addr, reg, 2, buf, 2))
                return -1;

        rval = i2c_read(dspic_addr, reg, sizeof(reg), buf, sizeof(*data));
        *data = (buf[0] << 8) | buf[1];

        return rval;
}


/***********************************************************************
F* Function:     int misc_init_r (void) P*A*Z*
 *
P* Parameters:   none
P*
P* Returnvalue:  int
P*                - 0 is always returned, even in the case of a keyboard
P*                    error.
 *
Z* Intention:    This function is the misc_init_r() method implementation
Z*               for the lwmon board.
Z*               The keyboard controller is initialized and the result
Z*               of a read copied to the environment variable "keybd".
Z*               If KEYBD_SET_DEBUGMODE is defined, a check is made for
Z*               this key, and if found display to the LCD will be enabled.
Z*               The keys in "keybd" are checked against the magic
Z*               keycommands defined in the environment.
Z*               See also key_match().
 *
D* Design:       wd@denx.de
C* Coding:       wd@denx.de
V* Verification: dzu@denx.de
 ***********************************************************************/
int misc_init_r_kbd (void)
{
        uchar kbd_data[KEYBD_DATALEN];
        char keybd_env[2 * KEYBD_DATALEN + 1];
        uchar kbd_init_status = gd->arch.kbd_status >> 8;
        uchar kbd_status = gd->arch.kbd_status;
        uchar val;
        ushort data, inv_data;
        char *str;
        int i;

        if (kbd_init_status) {
                printf ("KEYBD: Error %02X\n", kbd_init_status);
        }
        if (kbd_status) {               /* permanent error, report it */
                printf ("*** Keyboard error code %02X ***\n", kbd_status);
                sprintf (keybd_env, "%02X", kbd_status);
                setenv ("keybd", keybd_env);
                return 0;
        }

        /*
         * Now we know that we have a working  keyboard,  so  disable
         * all output to the LCD except when a key press is detected.
         */

        if ((console_assign (stdout, "serial") < 0) ||
                (console_assign (stderr, "serial") < 0)) {
                printf ("Can't assign serial port as output device\n");
        }

        /* Read Version */
        val = KEYBD_CMD_READ_VERSION;
        i2c_write (kbd_addr, 0, 0, &val, 1);
        i2c_read (kbd_addr, 0, 0, kbd_data, KEYBD_VERSIONLEN);
        printf ("KEYBD: Version %d.%d\n", kbd_data[0], kbd_data[1]);

        /* Read current keyboard state */
        val = KEYBD_CMD_READ_KEYS;
        i2c_write (kbd_addr, 0, 0, &val, 1);
        i2c_read (kbd_addr, 0, 0, kbd_data, KEYBD_DATALEN);

        /* read out start key from bse01 received via can */
        _dspic_read(DSPIC_PON_STATUS_REG, &data);
        /* check highbyte from status register */
        if (data > 0xFF) {
                _dspic_read(DSPIC_PON_INV_STATUS_REG, &inv_data);

                /* check inverse data */
                if ((data+inv_data) == 0xFFFF) {
                        /* don't overwrite local key */
                        if (kbd_data[1] == 0) {
                                /* read key value */
                                _dspic_read(DSPIC_PON_KEY_REG, &data);
                                str = (char *)&data;
                                /* swap bytes */
                                kbd_data[1] = str[1];
                                kbd_data[2] = str[0];
                                printf("CAN received startkey: 0x%X\n", data);
                        }
                }
        }

        for (i = 0; i < KEYBD_DATALEN; ++i) {
                sprintf (keybd_env + i + i, "%02X", kbd_data[i]);
        }

        setenv ("keybd", keybd_env);

        str = strdup ((char *)key_match (kbd_data));    /* decode keys */
#ifdef KEYBD_SET_DEBUGMODE
        if (kbd_data[0] == KEYBD_SET_DEBUGMODE) {       /* set debug mode */
                if ((console_assign (stdout, "lcd") < 0) ||
                        (console_assign (stderr, "lcd") < 0)) {
                        printf ("Can't assign LCD display as output device\n");
                }
        }
#endif /* KEYBD_SET_DEBUGMODE */
#ifdef CONFIG_PREBOOT   /* automatically configure "preboot" command on key match */
        setenv ("preboot", str);        /* set or delete definition */
#endif /* CONFIG_PREBOOT */
        if (str != NULL) {
                free (str);
        }
        return (0);
}

#ifdef CONFIG_PREBOOT

static uchar kbd_magic_prefix[] = "key_magic";
static uchar kbd_command_prefix[] = "key_cmd";

static int compare_magic (uchar *kbd_data, uchar *str)
{
        uchar compare[KEYBD_DATALEN-1];
        char *nxt;
        int i;

        /* Don't include modifier byte */
        memcpy (compare, kbd_data+1, KEYBD_DATALEN-1);

        for (; str != NULL; str = (*nxt) ? (uchar *)(nxt+1) : (uchar *)nxt) {
                uchar c;
                int k;

                c = (uchar) simple_strtoul ((char *)str, (char **) (&nxt), 16);

                if (str == (uchar *)nxt) {      /* invalid character */
                        break;
                }

                /*
                 * Check if this key matches the input.
                 * Set matches to zero, so they match only once
                 * and we can find duplicates or extra keys
                 */
                for (k = 0; k < sizeof(compare); ++k) {
                        if (compare[k] == '\0') /* only non-zero entries */
                                continue;
                        if (c == compare[k]) {  /* found matching key */
                                compare[k] = '\0';
                                break;
                        }
                }
                if (k == sizeof(compare)) {
                        return -1;              /* unmatched key */
                }
        }

        /*
         * A full match leaves no keys in the `compare' array,
         */
        for (i = 0; i < sizeof(compare); ++i) {
                if (compare[i])
                {
                        return -1;
                }
        }

        return 0;
}

/***********************************************************************
F* Function:     static uchar *key_match (uchar *kbd_data) P*A*Z*
 *
P* Parameters:   uchar *kbd_data
P*                - The keys to match against our magic definitions
P*
P* Returnvalue:  uchar *
P*                - != NULL: Pointer to the corresponding command(s)
P*                     NULL: No magic is about to happen
 *
Z* Intention:    Check if pressed key(s) match magic sequence,
Z*               and return the command string associated with that key(s).
Z*
Z*               If no key press was decoded, NULL is returned.
Z*
Z*               Note: the first character of the argument will be
Z*                     overwritten with the "magic charcter code" of the
Z*                     decoded key(s), or '\0'.
Z*
Z*               Note: the string points to static environment data
Z*                     and must be saved before you call any function that
Z*                     modifies the environment.
 *
D* Design:       wd@denx.de
C* Coding:       wd@denx.de
V* Verification: dzu@denx.de
 ***********************************************************************/
static uchar *key_match (uchar *kbd_data)
{
        char magic[sizeof (kbd_magic_prefix) + 1];
        uchar *suffix;
        char *kbd_magic_keys;

        /*
         * The following string defines the characters that can pe appended
         * to "key_magic" to form the names of environment variables that
         * hold "magic" key codes, i. e. such key codes that can cause
         * pre-boot actions. If the string is empty (""), then only
         * "key_magic" is checked (old behaviour); the string "125" causes
         * checks for "key_magic1", "key_magic2" and "key_magic5", etc.
         */
        if ((kbd_magic_keys = getenv ("magic_keys")) == NULL)
                kbd_magic_keys = "";

        /* loop over all magic keys;
         * use '\0' suffix in case of empty string
         */
        for (suffix=(uchar *)kbd_magic_keys; *suffix || suffix==(uchar *)kbd_magic_keys; ++suffix) {
                sprintf (magic, "%s%c", kbd_magic_prefix, *suffix);
                debug ("### Check magic \"%s\"\n", magic);
                if (compare_magic(kbd_data, (uchar *)getenv(magic)) == 0) {
                        char cmd_name[sizeof (kbd_command_prefix) + 1];
                        char *cmd;

                        sprintf (cmd_name, "%s%c", kbd_command_prefix, *suffix);

                        cmd = getenv (cmd_name);
                        debug ("### Set PREBOOT to $(%s): \"%s\"\n",
                                        cmd_name, cmd ? cmd : "<<NULL>>");
                        *kbd_data = *suffix;
                        return ((uchar *)cmd);
                }
        }
        debug ("### Delete PREBOOT\n");
        *kbd_data = '\0';
        return (NULL);
}
#endif /* CONFIG_PREBOOT */

/***********************************************************************
F* Function:     int do_kbd (cmd_tbl_t *cmdtp, int flag,
F*                           int argc, char * const argv[]) P*A*Z*
 *
P* Parameters:   cmd_tbl_t *cmdtp
P*                - Pointer to our command table entry
P*               int flag
P*                - If the CMD_FLAG_REPEAT bit is set, then this call is
P*                  a repetition
P*               int argc
P*                - Argument count
P*               char * const argv[]
P*                - Array of the actual arguments
P*
P* Returnvalue:  int
P*                - 0 is always returned.
 *
Z* Intention:    Implement the "kbd" command.
Z*               The keyboard status is read.  The result is printed on
Z*               the console and written into the "keybd" environment
Z*               variable.
 *
D* Design:       wd@denx.de
C* Coding:       wd@denx.de
V* Verification: dzu@denx.de
 ***********************************************************************/
int do_kbd (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
        uchar kbd_data[KEYBD_DATALEN];
        char keybd_env[2 * KEYBD_DATALEN + 1];
        uchar val;
        int i;

#if 0 /* Done in kbd_init */
        i2c_init (CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
#endif

        /* Read keys */
        val = KEYBD_CMD_READ_KEYS;
        i2c_write (kbd_addr, 0, 0, &val, 1);
        i2c_read (kbd_addr, 0, 0, kbd_data, KEYBD_DATALEN);

        puts ("Keys:");
        for (i = 0; i < KEYBD_DATALEN; ++i) {
                sprintf (keybd_env + i + i, "%02X", kbd_data[i]);
                printf (" %02x", kbd_data[i]);
        }
        putc ('\n');
        setenv ("keybd", keybd_env);
        return 0;
}

U_BOOT_CMD(
        kbd,    1,      1,      do_kbd,
        "read keyboard status",
        ""
);

/*----------------------------- Utilities -----------------------------*/

#ifdef CONFIG_POST
/*
 * Returns 1 if keys pressed to start the power-on long-running tests
 * Called from board_init_f().
 */
int post_hotkeys_pressed(void)
{
        uchar kbd_data[KEYBD_DATALEN];
        uchar val;

        /* Read keys */
        val = KEYBD_CMD_READ_KEYS;
        i2c_write (kbd_addr, 0, 0, &val, 1);
        i2c_read (kbd_addr, 0, 0, kbd_data, KEYBD_DATALEN);

        return (compare_magic(kbd_data, (uchar *)CONFIG_POST_KEY_MAGIC) == 0);
}
#endif