/*
 * (C) Copyright 2006 DENX Software Engineering
 *
 * 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_CMD_NAND)

#include <nand.h>
#include <asm/arch/pxa-regs.h>

#ifdef CONFIG_SYS_DFC_DEBUG1
# define DFC_DEBUG1(fmt, args...) printf(fmt, ##args)
#else
# define DFC_DEBUG1(fmt, args...)
#endif

#ifdef CONFIG_SYS_DFC_DEBUG2
# define DFC_DEBUG2(fmt, args...) printf(fmt, ##args)
#else
# define DFC_DEBUG2(fmt, args...)
#endif

#ifdef CONFIG_SYS_DFC_DEBUG3
# define DFC_DEBUG3(fmt, args...) printf(fmt, ##args)
#else
# define DFC_DEBUG3(fmt, args...)
#endif

/* These really don't belong here, as they are specific to the NAND Model */
static uint8_t scan_ff_pattern[] = { 0xff, 0xff };

static struct nand_bbt_descr delta_bbt_descr = {
        .options = 0,
        .offs = 0,
        .len = 2,
        .pattern = scan_ff_pattern
};

static struct nand_ecclayout delta_oob = {
        .eccbytes = 6,
        .eccpos = {2, 3, 4, 5, 6, 7},
        .oobfree = { {8, 2}, {12, 4} }
};

/*
 * not required for Monahans DFC
 */
static void dfc_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
        return;
}

#if 0
/* read device ready pin */
static int dfc_device_ready(struct mtd_info *mtdinfo)
{
        if(NDSR & NDSR_RDY)
                return 1;
        else
                return 0;
        return 0;
}
#endif

/*
 * Write buf to the DFC Controller Data Buffer
 */
static void dfc_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
        unsigned long bytes_multi = len & 0xfffffffc;
        unsigned long rest = len & 0x3;
        unsigned long *long_buf;
        int i;

        DFC_DEBUG2("dfc_write_buf: writing %d bytes starting with 0x%x.\n", len, *((unsigned long*) buf));
        if(bytes_multi) {
                for(i=0; i<bytes_multi; i+=4) {
                        long_buf = (unsigned long*) &buf[i];
                        NDDB = *long_buf;
                }
        }
        if(rest) {
                printf("dfc_write_buf: ERROR, writing non 4-byte aligned data.\n");
        }
        return;
}


static void dfc_read_buf(struct mtd_info *mtd, u_char* const buf, int len)
{
        int i=0, j;

        /* we have to be carefull not to overflow the buffer if len is
         * not a multiple of 4 */
        unsigned long bytes_multi = len & 0xfffffffc;
        unsigned long rest = len & 0x3;
        unsigned long *long_buf;

        DFC_DEBUG3("dfc_read_buf: reading %d bytes.\n", len);
        /* if there are any, first copy multiple of 4 bytes */
        if(bytes_multi) {
                for(i=0; i<bytes_multi; i+=4) {
                        long_buf = (unsigned long*) &buf[i];
                        *long_buf = NDDB;
                }
        }

        /* ...then the rest */
        if(rest) {
                unsigned long rest_data = NDDB;
                for(j=0;j<rest; j++)
                        buf[i+j] = (u_char) ((rest_data>>j) & 0xff);
        }

        return;
}

/*
 * read a word. Not implemented as not used in NAND code.
 */
static u16 dfc_read_word(struct mtd_info *mtd)
{
        printf("dfc_read_word: UNIMPLEMENTED.\n");
        return 0;
}

/* global var, too bad: mk@tbd: move to ->priv pointer */
static unsigned long read_buf = 0;
static int bytes_read = -1;

/*
 * read a byte from NDDB Because we can only read 4 bytes from NDDB at
 * a time, we buffer the remaining bytes. The buffer is reset when a
 * new command is sent to the chip.
 *
 * WARNING:
 * This function is currently only used to read status and id
 * bytes. For these commands always 8 bytes need to be read from
 * NDDB. So we read and discard these bytes right now. In case this
 * function is used for anything else in the future, we must check
 * what was the last command issued and read the appropriate amount of
 * bytes respectively.
 */
static u_char dfc_read_byte(struct mtd_info *mtd)
{
        unsigned char byte;
        unsigned long dummy;

        if(bytes_read < 0) {
                read_buf = NDDB;
                dummy = NDDB;
                bytes_read = 0;
        }
        byte = (unsigned char) (read_buf>>(8 * bytes_read++));
        if(bytes_read >= 4)
                bytes_read = -1;

        DFC_DEBUG2("dfc_read_byte: byte %u: 0x%x of (0x%x).\n", bytes_read - 1, byte, read_buf);
        return byte;
}

/* calculate delta between OSCR values start and now  */
static unsigned long get_delta(unsigned long start)
{
        unsigned long cur = OSCR;

        if(cur < start) /* OSCR overflowed */
                return (cur + (start^0xffffffff));
        else
                return (cur - start);
}

/* delay function, this doesn't belong here */
static void wait_us(unsigned long us)
{
        unsigned long start = OSCR;
        us = DIV_ROUND_UP(us * OSCR_CLK_FREQ, 1000);

        while (get_delta(start) < us) {
                /* do nothing */
        }
}

static void dfc_clear_nddb(void)
{
        NDCR &= ~NDCR_ND_RUN;
        wait_us(CONFIG_SYS_NAND_OTHER_TO);
}

/* wait_event with timeout */
static unsigned long dfc_wait_event(unsigned long event)
{
        unsigned long ndsr, timeout, start = OSCR;

        if(!event)
                return 0xff000000;
        else if(event & (NDSR_CS0_CMDD | NDSR_CS0_BBD))
                timeout = DIV_ROUND_UP(CONFIG_SYS_NAND_PROG_ERASE_TO
                                        * OSCR_CLK_FREQ, 1000);
        else
                timeout = DIV_ROUND_UP(CONFIG_SYS_NAND_OTHER_TO
                                        * OSCR_CLK_FREQ, 1000);

        while(1) {
                ndsr = NDSR;
                if(ndsr & event) {
                        NDSR |= event;
                        break;
                }
                if(get_delta(start) > timeout) {
                        DFC_DEBUG1("dfc_wait_event: TIMEOUT waiting for event: 0x%lx.\n", event);
                        return 0xff000000;
                }

        }
        return ndsr;
}

/* we don't always wan't to do this */
static void dfc_new_cmd(void)
{
        int retry = 0;
        unsigned long status;

        while(retry++ <= CONFIG_SYS_NAND_SENDCMD_RETRY) {
                /* Clear NDSR */
                NDSR = 0xFFF;

                /* set NDCR[NDRUN] */
                if(!(NDCR & NDCR_ND_RUN))
                        NDCR |= NDCR_ND_RUN;

                status = dfc_wait_event(NDSR_WRCMDREQ);

                if(status & NDSR_WRCMDREQ)
                        return;

                DFC_DEBUG2("dfc_new_cmd: FAILED to get WRITECMDREQ, retry: %d.\n", retry);
                dfc_clear_nddb();
        }
        DFC_DEBUG1("dfc_new_cmd: giving up after %d retries.\n", retry);
}

/* this function is called after Programm and Erase Operations to
 * check for success or failure */
static int dfc_wait(struct mtd_info *mtd, struct nand_chip *this)
{
        unsigned long ndsr=0, event=0;
        int state = this->state;

        if(state == FL_WRITING) {
                event = NDSR_CS0_CMDD | NDSR_CS0_BBD;
        } else if(state == FL_ERASING) {
                event = NDSR_CS0_CMDD | NDSR_CS0_BBD;
        }

        ndsr = dfc_wait_event(event);

        if((ndsr & NDSR_CS0_BBD) || (ndsr & 0xff000000))
                return(0x1); /* Status Read error */
        return 0;
}

/* cmdfunc send commands to the DFC */
static void dfc_cmdfunc(struct mtd_info *mtd, unsigned command,
                        int column, int page_addr)
{
        /* register struct nand_chip *this = mtd->priv; */
        unsigned long ndcb0=0, ndcb1=0, ndcb2=0, event=0;

        /* clear the ugly byte read buffer */
        bytes_read = -1;
        read_buf = 0;

        switch (command) {
        case NAND_CMD_READ0:
                DFC_DEBUG3("dfc_cmdfunc: NAND_CMD_READ0, page_addr: 0x%x, column: 0x%x.\n", page_addr, (column>>1));
                dfc_new_cmd();
                ndcb0 = (NAND_CMD_READ0 | (4<<16));
                column >>= 1; /* adjust for 16 bit bus */
                ndcb1 = (((column>>1) & 0xff) |
                         ((page_addr<<8) & 0xff00) |
                         ((page_addr<<8) & 0xff0000) |
                         ((page_addr<<8) & 0xff000000)); /* make this 0x01000000 ? */
                event = NDSR_RDDREQ;
                goto write_cmd;
        case NAND_CMD_READ1:
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_READ1 unimplemented!\n");
                goto end;
        case NAND_CMD_READOOB:
                DFC_DEBUG1("dfc_cmdfunc: NAND_CMD_READOOB unimplemented!\n");
                goto end;
        case NAND_CMD_READID:
                dfc_new_cmd();
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_READID.\n");
                ndcb0 = (NAND_CMD_READID | (3 << 21) | (1 << 16)); /* addr cycles*/
                event = NDSR_RDDREQ;
                goto write_cmd;
        case NAND_CMD_PAGEPROG:
                /* sent as a multicommand in NAND_CMD_SEQIN */
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_PAGEPROG empty due to multicmd.\n");
                goto end;
        case NAND_CMD_ERASE1:
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_ERASE1,  page_addr: 0x%x, column: 0x%x.\n", page_addr, (column>>1));
                dfc_new_cmd();
                ndcb0 = (0xd060 | (1<<25) | (2<<21) | (1<<19) | (3<<16));
                ndcb1 = (page_addr & 0x00ffffff);
                goto write_cmd;
        case NAND_CMD_ERASE2:
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_ERASE2 empty due to multicmd.\n");
                goto end;
        case NAND_CMD_SEQIN:
                /* send PAGE_PROG command(0x1080) */
                dfc_new_cmd();
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_SEQIN/PAGE_PROG,  page_addr: 0x%x, column: 0x%x.\n", page_addr, (column>>1));
                ndcb0 = (0x1080 | (1<<25) | (1<<21) | (1<<19) | (4<<16));
                column >>= 1; /* adjust for 16 bit bus */
                ndcb1 = (((column>>1) & 0xff) |
                         ((page_addr<<8) & 0xff00) |
                         ((page_addr<<8) & 0xff0000) |
                         ((page_addr<<8) & 0xff000000)); /* make this 0x01000000 ? */
                event = NDSR_WRDREQ;
                goto write_cmd;
        case NAND_CMD_STATUS:
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_STATUS.\n");
                dfc_new_cmd();
                ndcb0 = NAND_CMD_STATUS | (4<<21);
                event = NDSR_RDDREQ;
                goto write_cmd;
        case NAND_CMD_RESET:
                DFC_DEBUG2("dfc_cmdfunc: NAND_CMD_RESET.\n");
                ndcb0 = NAND_CMD_RESET | (5<<21);
                event = NDSR_CS0_CMDD;
                goto write_cmd;
        default:
                printk("dfc_cmdfunc: error, unsupported command.\n");
                goto end;
        }

 write_cmd:
        NDCB0 = ndcb0;
        NDCB0 = ndcb1;
        NDCB0 = ndcb2;

        /*  wait_event: */
        dfc_wait_event(event);
 end:
        return;
}

static void dfc_gpio_init(void)
{
        DFC_DEBUG2("Setting up DFC GPIO's.\n");

        /* no idea what is done here, see zylonite.c */
        GPIO4 = 0x1;

        DF_ALE_WE1 = 0x00000001;
        DF_ALE_WE2 = 0x00000001;
        DF_nCS0 = 0x00000001;
        DF_nCS1 = 0x00000001;
        DF_nWE = 0x00000001;
        DF_nRE = 0x00000001;
        DF_IO0 = 0x00000001;
        DF_IO8 = 0x00000001;
        DF_IO1 = 0x00000001;
        DF_IO9 = 0x00000001;
        DF_IO2 = 0x00000001;
        DF_IO10 = 0x00000001;
        DF_IO3 = 0x00000001;
        DF_IO11 = 0x00000001;
        DF_IO4 = 0x00000001;
        DF_IO12 = 0x00000001;
        DF_IO5 = 0x00000001;
        DF_IO13 = 0x00000001;
        DF_IO6 = 0x00000001;
        DF_IO14 = 0x00000001;
        DF_IO7 = 0x00000001;
        DF_IO15 = 0x00000001;

        DF_nWE = 0x1901;
        DF_nRE = 0x1901;
        DF_CLE_NOE = 0x1900;
        DF_ALE_WE1 = 0x1901;
        DF_INT_RnB = 0x1900;
}

/*
 * Board-specific NAND initialization. The following members of the
 * argument are board-specific (per include/linux/mtd/nand_new.h):
 * - IO_ADDR_R?: address to read the 8 I/O lines of the flash device
 * - IO_ADDR_W?: address to write the 8 I/O lines of the flash device
 * - hwcontrol: hardwarespecific function for accesing control-lines
 * - dev_ready: hardwarespecific function for  accesing device ready/busy line
 * - enable_hwecc?: function to enable (reset)  hardware ecc generator. Must
 *   only be provided if a hardware ECC is available
 * - ecc.mode: mode of ecc, see defines
 * - chip_delay: chip dependent delay for transfering data from array to
 *   read regs (tR)
 * - options: various chip options. They can partly be set to inform
 *   nand_scan about special functionality. See the defines for further
 *   explanation
 * Members with a "?" were not set in the merged testing-NAND branch,
 * so they are not set here either.
 */
int board_nand_init(struct nand_chip *nand)
{
        unsigned long tCH, tCS, tWH, tWP, tRH, tRP, tRP_high, tR, tWHR, tAR;

        /* set up GPIO Control Registers */
        dfc_gpio_init();

        /* turn on the NAND Controller Clock (104 MHz @ D0) */
        CKENA |= (CKENA_4_NAND | CKENA_9_SMC);

#undef CONFIG_SYS_TIMING_TIGHT
#ifndef CONFIG_SYS_TIMING_TIGHT
        tCH = MIN(((unsigned long) (NAND_TIMING_tCH * DFC_CLK_PER_US) + 1),
                  DFC_MAX_tCH);
        tCS = MIN(((unsigned long) (NAND_TIMING_tCS * DFC_CLK_PER_US) + 1),
                  DFC_MAX_tCS);
        tWH = MIN(((unsigned long) (NAND_TIMING_tWH * DFC_CLK_PER_US) + 1),
                  DFC_MAX_tWH);
        tWP = MIN(((unsigned long) (NAND_TIMING_tWP * DFC_CLK_PER_US) + 1),
                  DFC_MAX_tWP);
        tRH = MIN(((unsigned long) (NAND_TIMING_tRH * DFC_CLK_PER_US) + 1),
                  DFC_MAX_tRH);
        tRP = MIN(((unsigned long) (NAND_TIMING_tRP * DFC_CLK_PER_US) + 1),
                  DFC_MAX_tRP);
        tR = MIN(((unsigned long) (NAND_TIMING_tR * DFC_CLK_PER_US) + 1),
                 DFC_MAX_tR);
        tWHR = MIN(((unsigned long) (NAND_TIMING_tWHR * DFC_CLK_PER_US) + 1),
                   DFC_MAX_tWHR);
        tAR = MIN(((unsigned long) (NAND_TIMING_tAR * DFC_CLK_PER_US) + 1),
                  DFC_MAX_tAR);
#else /* this is the tight timing */

        tCH = MIN(((unsigned long) (NAND_TIMING_tCH * DFC_CLK_PER_US)),
                  DFC_MAX_tCH);
        tCS = MIN(((unsigned long) (NAND_TIMING_tCS * DFC_CLK_PER_US)),
                  DFC_MAX_tCS);
        tWH = MIN(((unsigned long) (NAND_TIMING_tWH * DFC_CLK_PER_US)),
                  DFC_MAX_tWH);
        tWP = MIN(((unsigned long) (NAND_TIMING_tWP * DFC_CLK_PER_US)),
                  DFC_MAX_tWP);
        tRH = MIN(((unsigned long) (NAND_TIMING_tRH * DFC_CLK_PER_US)),
                  DFC_MAX_tRH);
        tRP = MIN(((unsigned long) (NAND_TIMING_tRP * DFC_CLK_PER_US)),
                  DFC_MAX_tRP);
        tR = MIN(((unsigned long) (NAND_TIMING_tR * DFC_CLK_PER_US) - tCH - 2),
                 DFC_MAX_tR);
        tWHR = MIN(((unsigned long) (NAND_TIMING_tWHR * DFC_CLK_PER_US) - tCH - 2),
                   DFC_MAX_tWHR);
        tAR = MIN(((unsigned long) (NAND_TIMING_tAR * DFC_CLK_PER_US) - 2),
                  DFC_MAX_tAR);
#endif /* CONFIG_SYS_TIMING_TIGHT */


        DFC_DEBUG2("tCH=%u, tCS=%u, tWH=%u, tWP=%u, tRH=%u, tRP=%u, tR=%u, tWHR=%u, tAR=%u.\n", tCH, tCS, tWH, tWP, tRH, tRP, tR, tWHR, tAR);

        /* tRP value is split in the register */
        if(tRP & (1 << 4)) {
                tRP_high = 1;
                tRP &= ~(1 << 4);
        } else {
                tRP_high = 0;
        }

        NDTR0CS0 = (tCH << 19) |
                (tCS << 16) |
                (tWH << 11) |
                (tWP << 8) |
                (tRP_high << 6) |
                (tRH << 3) |
                (tRP << 0);

        NDTR1CS0 = (tR << 16) |
                (tWHR << 4) |
                (tAR << 0);

        /* If it doesn't work (unlikely) think about:
         *  - ecc enable
         *  - chip select don't care
         *  - read id byte count
         *
         * Intentionally enabled by not setting bits:
         *  - dma (DMA_EN)
         *  - page size = 512
         *  - cs don't care, see if we can enable later!
         *  - row address start position (after second cycle)
         *  - pages per block = 32
         *  - ND_RDY : clears command buffer
         */
        /* NDCR_NCSX |          /\* Chip select busy don't care *\/ */

        NDCR = (NDCR_SPARE_EN |         /* use the spare area */
                NDCR_DWIDTH_C |         /* 16bit DFC data bus width  */
                NDCR_DWIDTH_M |         /* 16 bit Flash device data bus width */
                (2 << 16) |             /* read id count = 7 ???? mk@tbd */
                NDCR_ND_ARB_EN |        /* enable bus arbiter */
                NDCR_RDYM |             /* flash device ready ir masked */
                NDCR_CS0_PAGEDM |       /* ND_nCSx page done ir masked */
                NDCR_CS1_PAGEDM |
                NDCR_CS0_CMDDM |        /* ND_CSx command done ir masked */
                NDCR_CS1_CMDDM |
                NDCR_CS0_BBDM |         /* ND_CSx bad block detect ir masked */
                NDCR_CS1_BBDM |
                NDCR_DBERRM |           /* double bit error ir masked */
                NDCR_SBERRM |           /* single bit error ir masked */
                NDCR_WRDREQM |          /* write data request ir masked */
                NDCR_RDDREQM |          /* read data request ir masked */
                NDCR_WRCMDREQM);        /* write command request ir masked */


        /* wait 10 us due to cmd buffer clear reset */
        /*      wait(10); */


        nand->cmd_ctrl = dfc_hwcontrol;
/*      nand->dev_ready = dfc_device_ready; */
        nand->ecc.mode = NAND_ECC_SOFT;
        nand->ecc.layout = &delta_oob;
        nand->options = NAND_BUSWIDTH_16;
        nand->waitfunc = dfc_wait;
        nand->read_byte = dfc_read_byte;
        nand->read_word = dfc_read_word;
        nand->read_buf = dfc_read_buf;
        nand->write_buf = dfc_write_buf;

        nand->cmdfunc = dfc_cmdfunc;
        nand->badblock_pattern = &delta_bbt_descr;
        return 0;
}

#endif