/*
 * (C) Copyright 2003, Psyent Corporation <www.psyent.com>
 * Scott McNutt <smcnutt@psyent.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>

#if defined(CONFIG_NIOS_ASMI)
#include <command.h>
#include <nios-io.h>

#if !defined(CONFIG_SYS_NIOS_ASMIBASE)
#error "*** CONFIG_SYS_NIOS_ASMIBASE not defined ***"
#endif

/*-----------------------------------------------------------------------*/
#define SHORT_HELP\
        "asmi    - read/write Cyclone ASMI configuration device.\n"

#define LONG_HELP\
        "\n"\
        "asmi erase start [end]\n"\
        "    - erase sector start or sectors start through end.\n"\
        "asmi info\n"\
        "    - display ASMI device information.\n"\
        "asmi protect on | off\n"\
        "    - turn device protection on or off.\n"\
        "asmi read addr offset count\n"\
        "    - read count bytes from offset to addr.\n"\
        "asmi write addr offset count\n"\
        "    - write count bytes to offset from addr.\n"\
        "asmi verify addr offset count\n"\
        "    - verify count bytes at offset from addr."


/*-----------------------------------------------------------------------*/
/* Operation codes for serial configuration devices
 */
#define ASMI_WRITE_ENA          0x06    /* Write enable */
#define ASMI_WRITE_DIS          0x04    /* Write disable */
#define ASMI_READ_STAT          0x05    /* Read status */
#define ASMI_READ_BYTES         0x03    /* Read bytes */
#define ASMI_READ_ID            0xab    /* Read silicon id */
#define ASMI_WRITE_STAT         0x01    /* Write status */
#define ASMI_WRITE_BYTES        0x02    /* Write bytes */
#define ASMI_ERASE_BULK         0xc7    /* Erase entire device */
#define ASMI_ERASE_SECT         0xd8    /* Erase sector */

/* Device status register bits
 */
#define ASMI_STATUS_WIP         (1<<0)  /* Write in progress */
#define ASMI_STATUS_WEL         (1<<1)  /* Write enable latch */

static nios_asmi_t *asmi = (nios_asmi_t *)CONFIG_SYS_NIOS_ASMIBASE;

/***********************************************************************
 * Device access
 ***********************************************************************/
static void asmi_cs (int assert)
{
        if (assert) {
                asmi->control |= NIOS_ASMI_SSO;
        } else {
                /* Let all bits shift out */
                while ((asmi->status & NIOS_ASMI_TMT) == 0)
                        ;
                asmi->control &= ~NIOS_ASMI_SSO;
        }
}

static void asmi_tx (unsigned char c)
{
        while ((asmi->status & NIOS_ASMI_TRDY) == 0)
                ;
        asmi->txdata = c;
}

static int asmi_rx (void)
{
        while ((asmi->status & NIOS_ASMI_RRDY) == 0)
                ;
        return (asmi->rxdata);
}

static unsigned char bitrev[] = {
        0x00, 0x08, 0x04, 0x0c, 0x02, 0x0a, 0x06, 0x0e,
        0x01, 0x09, 0x05, 0x0d, 0x03, 0x0b, 0x07, 0x0f
};

static unsigned char asmi_bitrev( unsigned char c )
{
        unsigned char val;

        val  = bitrev[c>>4];
        val |= bitrev[c & 0x0f]<<4;
        return (val);
}

static void asmi_rcv (unsigned char *dst, int len)
{
        while (len--) {
                asmi_tx (0);
                *dst++ = asmi_rx ();
        }
}

static void asmi_rrcv (unsigned char *dst, int len)
{
        while (len--) {
                asmi_tx (0);
                *dst++ = asmi_bitrev (asmi_rx ());
        }
}

static void asmi_snd (unsigned char *src, int len)
{
        while (len--) {
                asmi_tx (*src++);
                asmi_rx ();
        }
}

static void asmi_rsnd (unsigned char *src, int len)
{
        while (len--) {
                asmi_tx (asmi_bitrev (*src++));
                asmi_rx ();
        }
}

static void asmi_wr_enable (void)
{
        asmi_cs (1);
        asmi_tx (ASMI_WRITE_ENA);
        asmi_rx ();
        asmi_cs (0);
}

static unsigned char asmi_status_rd (void)
{
        unsigned char status;

        asmi_cs (1);
        asmi_tx (ASMI_READ_STAT);
        asmi_rx ();
        asmi_tx (0);
        status = asmi_rx ();
        asmi_cs (0);
        return (status);
}

static void asmi_status_wr (unsigned char status)
{
        asmi_wr_enable ();
        asmi_cs (1);
        asmi_tx (ASMI_WRITE_STAT);
        asmi_rx ();
        asmi_tx (status);
        asmi_rx ();
        asmi_cs (0);
        return;
}

/***********************************************************************
 * Device information
 ***********************************************************************/
typedef struct asmi_devinfo_t {
        const char      *name;          /* Device name */
        unsigned char   id;             /* Device silicon id */
        unsigned char   size;           /* Total size log2(bytes)*/
        unsigned char   num_sects;      /* Number of sectors */
        unsigned char   sz_sect;        /* Sector size log2(bytes) */
        unsigned char   sz_page;        /* Page size log2(bytes) */
        unsigned char   prot_mask;      /* Protection mask */
}asmi_devinfo_t;

static struct asmi_devinfo_t devinfo[] = {
        { "EPCS1 ", 0x10, 17, 4, 15, 8, 0x0c },
        { "EPCS4 ", 0x12, 19, 8, 16, 8, 0x1c },
        { 0, 0, 0, 0, 0, 0 }
};

static asmi_devinfo_t *asmi_dev_find (void)
{
        unsigned char buf[4];
        unsigned char id;
        int i;
        struct asmi_devinfo_t *dev = NULL;

        /* Read silicon id requires 3 "dummy bytes" before it's put
         * on the wire.
         */
        buf[0] = ASMI_READ_ID;
        buf[1] = 0;
        buf[2] = 0;
        buf[3] = 0;

        asmi_cs (1);
        asmi_snd (buf,4);
        asmi_rcv (buf,1);
        asmi_cs (0);
        id = buf[0];

        /* Find the info struct */
        i = 0;
        while (devinfo[i].name) {
                if (id == devinfo[i].id) {
                        dev = &devinfo[i];
                        break;
                }
                i++;
        }

        return (dev);
}

/***********************************************************************
 * Misc Utilities
 ***********************************************************************/
static unsigned asmi_cfgsz (void)
{
        unsigned sz = 0;
        unsigned char buf[128];
        unsigned char *p;

        /* Read in the first 128 bytes of the device */
        buf[0] = ASMI_READ_BYTES;
        buf[1] = 0;
        buf[2] = 0;
        buf[3] = 0;

        asmi_cs (1);
        asmi_snd (buf,4);
        asmi_rrcv (buf, sizeof(buf));
        asmi_cs (0);

        /* Search for the starting 0x6a which is followed by the
         * 4-byte 'register' and 4-byte bit-count.
         */
        p = buf;
        while (p < buf + sizeof(buf)-8) {
                if ( *p == 0x6a ) {
                        /* Point to bit count and extract */
                        p += 5;
                        sz = *p++;
                        sz |= *p++ << 8;
                        sz |= *p++ << 16;
                        sz |= *p++ << 24;
                        /* Convert to byte count */
                        sz += 7;
                        sz >>= 3;
                } else if (*p == 0xff) {
                        /* 0xff is ok ... just skip */
                        p++;
                        continue;
                } else {
                        /* Not 0xff or 0x6a ... something's not
                         * right ... report 'unknown' (sz=0).
                         */
                        break;
                }
        }
        return (sz);
}

static int asmi_erase (unsigned start, unsigned end)
{
        unsigned off, sectsz;
        unsigned char buf[4];
        struct asmi_devinfo_t *dev = asmi_dev_find ();

        if (!dev || (start>end))
                return (-1);

        /* Erase the requested sectors. An address is required
         * that lies within the requested sector -- we'll just
         * use the first address in the sector.
         */
        printf ("asmi erasing sector %d ", start);
        if (start != end)
                printf ("to %d ", end);
        sectsz = (1 << dev->sz_sect);
        while (start <= end) {
                off = start * sectsz;
                start++;

                buf[0] = ASMI_ERASE_SECT;
                buf[1] = off >> 16;
                buf[2] = off >> 8;
                buf[3] = off;

                asmi_wr_enable ();
                asmi_cs (1);
                asmi_snd (buf,4);
                asmi_cs (0);

                printf ("."); /* Some user feedback */

                /* Wait for erase to complete */
                while (asmi_status_rd() & ASMI_STATUS_WIP)
                        ;
        }
        printf (" done.\n");
        return (0);
}

static int asmi_read (ulong addr, ulong off, ulong cnt)
{
        unsigned char buf[4];

        buf[0] = ASMI_READ_BYTES;
        buf[1] = off >> 16;
        buf[2] = off >> 8;
        buf[3] = off;

        asmi_cs (1);
        asmi_snd (buf,4);
        asmi_rrcv ((unsigned char *)addr, cnt);
        asmi_cs (0);

        return (0);
}

static
int asmi_write (ulong addr, ulong off, ulong cnt)
{
        ulong wrcnt;
        unsigned pgsz;
        unsigned char buf[4];
        struct asmi_devinfo_t *dev = asmi_dev_find ();

        if (!dev)
                return (-1);

        pgsz = (1<<dev->sz_page);
        while (cnt) {
                if (off % pgsz)
                        wrcnt = pgsz - (off % pgsz);
                else
                        wrcnt = pgsz;
                wrcnt = (wrcnt > cnt) ? cnt : wrcnt;

                buf[0] = ASMI_WRITE_BYTES;
                buf[1] = off >> 16;
                buf[2] = off >> 8;
                buf[3] = off;

                asmi_wr_enable ();
                asmi_cs (1);
                asmi_snd (buf,4);
                asmi_rsnd ((unsigned char *)addr, wrcnt);
                asmi_cs (0);

                /* Wait for write to complete */
                while (asmi_status_rd() & ASMI_STATUS_WIP)
                        ;

                cnt -= wrcnt;
                off += wrcnt;
                addr += wrcnt;
        }

        return (0);
}

static
int asmi_verify (ulong addr, ulong off, ulong cnt, ulong *err)
{
        ulong rdcnt;
        unsigned char buf[256];
        unsigned char *start,*end;
        int i;

        start = end = (unsigned char *)addr;
        while (cnt) {
                rdcnt = (cnt>sizeof(buf)) ? sizeof(buf) : cnt;
                asmi_read ((ulong)buf, off, rdcnt);
                for (i=0; i<rdcnt; i++) {
                        if (*end != buf[i]) {
                                *err = end - start;
                                return(-1);
                        }
                        end++;
                }
                cnt -= rdcnt;
                off += rdcnt;
        }
        return (0);
}

static int asmi_sect_erased (int sect, unsigned *offset,
                struct asmi_devinfo_t *dev)
{
        unsigned char buf[128];
        unsigned off, end;
        unsigned sectsz;
        int i;

        sectsz = (1 << dev->sz_sect);
        off = sectsz * sect;
        end = off + sectsz;

        while (off < end) {
                asmi_read ((ulong)buf, off, sizeof(buf));
                for (i=0; i < sizeof(buf); i++) {
                        if (buf[i] != 0xff) {
                                *offset = off + i;
                                return (0);
                        }
                }
                off += sizeof(buf);
        }
        return (1);
}


/***********************************************************************
 * Commands
 ***********************************************************************/
static
void do_asmi_info (struct asmi_devinfo_t *dev, int argc, char *argv[])
{
        int i;
        unsigned char stat;
        unsigned tmp;
        int erased;

        /* Basic device info */
        printf ("%s: %d kbytes (%d sectors x %d kbytes,"
                " %d bytes/page)\n",
                dev->name, 1 << (dev->size-10),
                dev->num_sects, 1 << (dev->sz_sect-10),
                1 << dev->sz_page );

        /* Status -- for now protection is all-or-nothing */
        stat = asmi_status_rd();
        printf ("status: 0x%02x (WIP:%d, WEL:%d, PROT:%s)\n",
                stat,
                (stat & ASMI_STATUS_WIP) ? 1 : 0,
                (stat & ASMI_STATUS_WEL) ? 1 : 0,
                (stat & dev->prot_mask) ? "on" : "off" );

        /* Configuration  */
        tmp = asmi_cfgsz ();
        if (tmp) {
                printf ("config: 0x%06x (%d) bytes\n", tmp, tmp );
        } else {
                printf ("config: unknown\n" );
        }

        /* Sector info */
        for (i=0; i<dev->num_sects; i++) {
                erased = asmi_sect_erased (i, &tmp, dev);
                printf ("     %d: %06x ",
                        i, i*(1<<dev->sz_sect) );
                if (erased)
                        printf ("erased\n");
                else
                        printf ("data @ 0x%06x\n", tmp);
        }

        return;
}

static
void do_asmi_erase (struct asmi_devinfo_t *dev, int argc, char *argv[])
{
        unsigned start,end;

        if ((argc < 3) || (argc > 4)) {
                printf ("USAGE: asmi erase sect [end]\n");
                return;
        }
        if ((asmi_status_rd() & dev->prot_mask) != 0) {
                printf ( "asmi: device protected.\n");
                return;
        }

        start = simple_strtoul (argv[2], NULL, 10);
        if (argc > 3)
                end = simple_strtoul (argv[3], NULL, 10);
        else
                end = start;
        if ((start >= dev->num_sects) || (start > end)) {
                printf ("asmi: invalid sector range: [%d:%d]\n",
                        start, end );
                return;
        }

        asmi_erase (start, end);

        return;
}

static
void do_asmi_protect (struct asmi_devinfo_t *dev, int argc, char *argv[])
{
        unsigned char stat;

        /* For now protection is all-or-nothing to keep things
         * simple. The protection bits don't map in a linear
         * fashion ... and we would rather protect the bottom
         * of the device since it contains the config data and
         * leave the top unprotected for app use. But unfortunately
         * protection works from top-to-bottom so it does
         * really help very much from a software app point-of-view.
         */
        if (argc < 3) {
                printf ("USAGE: asmi protect on | off\n");
                return;
        }
        if (!dev)
                return;

        /* Protection on/off is just a matter of setting/clearing
         * all protection bits in the status register.
         */
        stat = asmi_status_rd ();
        if (strcmp ("on", argv[2]) == 0) {
                stat |= dev->prot_mask;
        } else if (strcmp ("off", argv[2]) == 0 ) {
                stat &= ~dev->prot_mask;
        } else {
                printf ("asmi: unknown protection: %s\n", argv[2]);
                return;
        }
        asmi_status_wr (stat);
        return;
}

static
void do_asmi_read (struct asmi_devinfo_t *dev, int argc, char *argv[])
{
        ulong addr,off,cnt;
        ulong sz;

        if (argc < 5) {
                printf ("USAGE: asmi read addr offset count\n");
                return;
        }

        sz = 1 << dev->size;
        addr = simple_strtoul (argv[2], NULL, 16);
        off  = simple_strtoul (argv[3], NULL, 16);
        cnt  = simple_strtoul (argv[4], NULL, 16);
        if (off > sz) {
                printf ("offset is greater than device size"
                        "... aborting.\n");
                return;
        }
        if ((off + cnt) > sz) {
                printf ("request exceeds device size"
                        "... truncating.\n");
                cnt = sz - off;
        }
        printf ("asmi: read %08lx <- %06lx (0x%lx bytes)\n",
                        addr, off, cnt);
        asmi_read (addr, off, cnt);

        return;
}

static
void do_asmi_write (struct asmi_devinfo_t *dev, int argc, char *argv[])
{
        ulong addr,off,cnt;
        ulong sz;
        ulong err;

        if (argc < 5) {
                printf ("USAGE: asmi write addr offset count\n");
                return;
        }
        if ((asmi_status_rd() & dev->prot_mask) != 0) {
                printf ( "asmi: device protected.\n");
                return;
        }

        sz = 1 << dev->size;
        addr = simple_strtoul (argv[2], NULL, 16);
        off  = simple_strtoul (argv[3], NULL, 16);
        cnt  = simple_strtoul (argv[4], NULL, 16);
        if (off > sz) {
                printf ("offset is greater than device size"
                        "... aborting.\n");
                return;
        }
        if ((off + cnt) > sz) {
                printf ("request exceeds device size"
                        "... truncating.\n");
                cnt = sz - off;
        }
        printf ("asmi: write %08lx -> %06lx (0x%lx bytes)\n",
                        addr, off, cnt);
        asmi_write (addr, off, cnt);
        if (asmi_verify (addr, off, cnt, &err) != 0)
                printf ("asmi: write error at offset %06lx\n", err);

        return;
}

static
void do_asmi_verify (struct asmi_devinfo_t *dev, int argc, char *argv[])
{
        ulong addr,off,cnt;
        ulong sz;
        ulong err;

        if (argc < 5) {
                printf ("USAGE: asmi verify addr offset count\n");
                return;
        }

        sz = 1 << dev->size;
        addr = simple_strtoul (argv[2], NULL, 16);
        off  = simple_strtoul (argv[3], NULL, 16);
        cnt  = simple_strtoul (argv[4], NULL, 16);
        if (off > sz) {
                printf ("offset is greater than device size"
                        "... aborting.\n");
                return;
        }
        if ((off + cnt) > sz) {
                printf ("request exceeds device size"
                        "... truncating.\n");
                cnt = sz - off;
        }
        printf ("asmi: verify %08lx -> %06lx (0x%lx bytes)\n",
                        addr, off, cnt);
        if (asmi_verify (addr, off, cnt, &err) != 0)
                printf ("asmi: verify error at offset %06lx\n", err);

        return;
}

/*-----------------------------------------------------------------------*/
int do_asmi (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
        int len;
        struct asmi_devinfo_t *dev = asmi_dev_find ();

        if (argc < 2) {
                printf ("Usage:%s", LONG_HELP);
                return (0);
        }

        if (!dev) {
                printf ("asmi: device not found.\n");
                return (0);
        }

        len = strlen (argv[1]);
        if (strncmp ("info", argv[1], len) == 0) {
                do_asmi_info ( dev, argc, argv);
        } else if (strncmp ("erase", argv[1], len) == 0) {
                do_asmi_erase (dev, argc, argv);
        } else if (strncmp ("protect", argv[1], len) == 0) {
                do_asmi_protect (dev, argc, argv);
        } else if (strncmp ("read", argv[1], len) == 0) {
                do_asmi_read (dev, argc, argv);
        } else if (strncmp ("write", argv[1], len) == 0) {
                do_asmi_write (dev, argc, argv);
        } else if (strncmp ("verify", argv[1], len) == 0) {
                do_asmi_verify (dev, argc, argv);
        } else {
                printf ("asmi: unknown operation: %s\n", argv[1]);
        }

        return (0);
}

/*-----------------------------------------------------------------------*/


U_BOOT_CMD( asmi, 5, 0, do_asmi, SHORT_HELP, LONG_HELP );

#endif /* CONFIG_NIOS_ASMI */