/*
 * s3c2400 smc disk block device implementation
 *
 * Squidge's SMC Low-level access routines.
 * Inspired and derived from routines provided by Samsung Electronics
 *  M/M R&D Center & FireFly.
 */

#include <rtems.h>
#include <rtems/libio.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>

#include "rtems/blkdev.h"
#include "rtems/diskdevs.h"
#include "smc.h"
#include <rtems/bspIo.h>
#include <s3c24xx.h>

#define SMC_DEVICE_NAME "/dev/smc"
#define SMC_SAMSUNG_ID    0xEC
#define SMC_TOSHIBA_ID    0x98

#define SMC_16MB  0x73
#define SMC_32MB  0x75
#define SMC_64MB  0x76
#define SMC_128MB  0x79

#define LBA_UNUSED      0x80000000
#define LBA_RESERVED    0x80000001

#define BLOCK_UNUSED    0x80000000
#define BLOCK_RESERVED  0x80000001

/* SmartMedia Command */
#define SEQ_DATA_INPUT_CMD   0x80
#define READ1_CMD            0x00
#define READ1_1_CMD          0x01
#define READ2_CMD            0x50
#define READ_ID_CMD          0x90
#define RESET_CMD            0xFF
#define PAGE_PROGRAM_CMD     0x10
#define BLOCK_ERASE_CMD      0x60
#define BLOCK_ERASE_CFM_CMD  0xD0
#define READ_STATUS_CMD      0x70
#define RESET_PTR_CMD        0x00


/* Internal SMC disk descriptor */
struct SMC_INFO {
  uint8_t  id[3];
  uint32_t bytes_per_page;
  uint32_t pages_per_block;
  uint32_t blocks;
  uint32_t mb;
};

/* Ths S3c2410 uses a different register map */
#ifdef CPU_S3C2410
#define rPBDAT rGPBDAT
#define rPBCON rGPBCON
#define rPDDAT rGPDDAT
#define rPEDAT rGPEDAT
#endif


static struct SMC_INFO smc_info;

uint32_t smc_l2p[0x2000];
uint32_t smc_p2l[0x2000];

#define sm_busy() while (!(rPDDAT & 0x200))
#define sm_chip_en() rPDDAT &= (~0x80)
#define sm_chip_dis() rPDDAT |= 0x80
#define sm_cle_en() rPEDAT |= 0x20
#define sm_cle_dis() rPEDAT &= (~0x20)
#define sm_ale_en() rPEDAT |= 0x10
#define sm_ale_dis() rPEDAT &= (~0x10)
#define sm_wp_en() rPDDAT &= (~0x40)
#define sm_wp_dis() rPDDAT |= 0x40
#define sm_read_en() rPBCON &= 0xFFFF0000
#define sm_read_dis() rPBCON = (rPBCON & 0xFFFF0000) | 0x5555
#define sm_write_en() sm_read_dis()
#define sm_write_dis() sm_read_en()

static void sm_write( uint8_t data)
{
  rPBDAT = (rPBDAT & 0xFF00) | data;
  rPEDAT &= (~0x08);
  rPEDAT |= 0x08;
}

static uint8_t sm_read(void)
{
  uint8_t data;

  rPDDAT &= (~0x100);
  data = rPBDAT & 0xFF;
  rPDDAT |= 0x100;
  return data;
}

static void smc_read_id( uint8_t* buf, uint32_t length)
{
  uint32_t i;

  sm_chip_en();

  sm_cle_en();
  sm_write_en();
  sm_write(READ_ID_CMD);
  sm_write_dis();
  sm_cle_dis();

  sm_ale_en();
  sm_write_en();
  sm_write( 0);
  sm_write_dis();
  sm_ale_dis();

  sm_read_en();
  for (i=0;i<length;i++) *(buf+i) = sm_read();
  sm_read_dis();

  sm_chip_dis();
}

/* read an entire logical page of 512 bytes.*/
static uint8_t smc_read_page (uint32_t lpage, uint8_t* buf)
{
  uint32_t block, page, i;

  /* convert logical block to physical block
     and then convert into page suitable for read1 command...
  */
  block = lpage >> 5;
  if (smc_l2p[block] < LBA_UNUSED) {
    page = smc_l2p[block] << 5;
    page += (lpage & 0x1F);
  }
  else
    return 0;

  sm_chip_en();

  sm_cle_en();
  sm_write_en();
  sm_write(READ1_CMD);
  sm_write_dis();
  sm_cle_dis();

  sm_ale_en();
  sm_write_en();
  sm_write( 0x00);
  sm_write( (uint8_t)(page >> 0));
  sm_write( (uint8_t)(page >> 8));
  if (smc_info.mb >= 64)
    sm_write( (uint8_t)(page >> 16));
  sm_write_dis();
  sm_ale_dis();

  sm_busy();

  sm_read_en();
  for (i = 0; i < 512; i++) {
    *buf = sm_read();
    buf++;
  }
  sm_read_dis();
  sm_chip_dis();

  sm_busy();
  return 1;
}

static void smc_read_spare( uint32_t page, uint8_t* buf, uint8_t length)
{
  uint32_t i;

  sm_chip_en();

  sm_cle_en();
  sm_read_dis();
  sm_write(READ2_CMD);
  sm_read_en();
  sm_cle_dis();

  sm_ale_en();
  sm_read_dis();
  sm_write( 0x00);
  sm_write( (uint8_t)(page >> 0));
  sm_write( (uint8_t)(page >> 8));
  if (smc_info.mb >= 64)
    sm_write( (uint8_t)(page >> 16));
  sm_read_en();
  sm_ale_dis();

  sm_busy();

  sm_read_en();
  for (i=0;i<length;i++)
    *(buf+i) = sm_read();
  sm_read_dis();

  sm_chip_dis();

}

static void smc_make_l2p(void)
{
  uint32_t pblock, i, j, lblock, zone, count;
  uint8_t data[512];

  for (i=0;i<0x2000;i++) {
    smc_l2p[i] = LBA_RESERVED;
    smc_p2l[i] = BLOCK_RESERVED;
  }

  for (pblock=0;pblock<smc_info.blocks;pblock++) {
    /* read physical block - first page */
    smc_read_spare( pblock*smc_info.pages_per_block, (uint8_t*)&data, 16);

    zone = pblock >> 10; /* divide by 1024 to get zone */
    if ((data[5] == 0xFF) && ((data[6]&0xF8) == 0x10)) {
      lblock = ((((data[6]<<8)|(data[7]<<0)) >> 1) & 0x03FF) + (zone * 1000);
      smc_l2p[lblock] = pblock;
      smc_p2l[pblock] = lblock;
    } else {
      count = 0;
      for (j=0;j<16;j++) {
        if (data[j] == 0xFF) count++;
      }
      if (count == 16) {
        smc_p2l[pblock] = BLOCK_UNUSED;
      } else {
        smc_p2l[pblock] = BLOCK_RESERVED;
      }
    }
  }
}


static void smc_detect( uint8_t id1, uint8_t id2, uint8_t id3)
{
  smc_info.id[0] = id1;
  smc_info.id[1] = id2;
  smc_info.id[2] = id3;
  smc_info.mb    = 0;
  smc_info.bytes_per_page  = 0;
  smc_info.pages_per_block = 0;
  smc_info.blocks          = 0;

  switch (id1) {
    case SMC_SAMSUNG_ID:
    case SMC_TOSHIBA_ID: {
      switch (id2) {
        case SMC_16MB  : smc_info.mb = 16; break;
        case SMC_32MB  : smc_info.mb = 32; break;
        case SMC_64MB  : smc_info.mb = 64; break;
        case SMC_128MB : smc_info.mb = 128; break;
      }
      break;
    }
  }

  switch (smc_info.mb) {
    case 16  : smc_info.bytes_per_page = 512; smc_info.pages_per_block = 32; smc_info.blocks = 0x0400; break;
    case 32  : smc_info.bytes_per_page = 512; smc_info.pages_per_block = 32; smc_info.blocks = 0x0800; break;
    case 64  : smc_info.bytes_per_page = 512; smc_info.pages_per_block = 32; smc_info.blocks = 0x1000; break;
    case 128 : smc_info.bytes_per_page = 512; smc_info.pages_per_block = 32; smc_info.blocks = 0x2000; break;
  }
}

static void smc_init( void)
{
  unsigned char buf[32];
  int i;

  /* reset smc */
  sm_chip_en();
  sm_cle_en();
  sm_write_en();
  sm_write(0xFF);
  sm_write_dis();
  sm_cle_dis();
  for(i=0;i<10;i++);
  sm_busy();
  sm_chip_dis();

  smc_read_id (buf, 4);
  smc_detect (buf[0], buf[1], buf[2]);
  printk ("SMC: [%02X-%02X-%02X-%02X]\n", buf[0], buf[1], buf[2], buf[3]);
  printk ("SMC size: %" PRIu32 "MB detected\n",smc_info.mb);
  smc_make_l2p();
}

/* smc_write --
 * write stub
 */
static int smc_write(rtems_blkdev_request *req)
{
  rtems_blkdev_request_done(req, RTEMS_SUCCESSFUL);
  return 0;
}


/* smc_read --
 * PARAMETERS:
 *     req - pointer to the READ block device request info
 *
 * RETURNS:
 *     ioctl return value
 */
static int
smc_read(rtems_blkdev_request *req)
{
    uint32_t   i;
    rtems_blkdev_sg_buffer *sg;
    uint32_t   remains;

    remains = smc_info.bytes_per_page * req->bufnum;
    sg = req->bufs;
    for (i = 0; (remains > 0) && (i < req->bufnum); i++, sg++)
    {
        int count = sg->length;
        if (count > remains)
            count = remains;
        smc_read_page(sg->block,sg->buffer);
        remains -= count;
    }
    rtems_blkdev_request_done(req, RTEMS_SUCCESSFUL);
    return 0;
}

/* smc_ioctl --
 *     IOCTL handler for SMC device.
 *
 * PARAMETERS:
 *      dev  - device number (major, minor number)
 *      req  - IOCTL request code
 *      argp - IOCTL argument
 *
 * RETURNS:
 *     IOCTL return value
 */
static int
smc_ioctl(rtems_disk_device *dd, uint32_t req, void *argp)
{
    switch (req)
    {
        case RTEMS_BLKIO_REQUEST:
        {
            rtems_blkdev_request *r = argp;
            switch (r->req)
            {
                case RTEMS_BLKDEV_REQ_READ:
                    return smc_read(r);
                case RTEMS_BLKDEV_REQ_WRITE:
                    return smc_write(r);
                default:
                    errno = EINVAL;
                    return -1;
            }
            break;
        }

        default:
            errno = EINVAL;
            return -1;
    }
}

/* smc_initialize --
 *     RAM disk device driver initialization. Run through RAM disk
 *     configuration information and configure appropriate RAM disks.
 *
 * PARAMETERS:
 *     major - RAM disk major device number
 *     minor - minor device number, not applicable
 *     arg   - initialization argument, not applicable
 *
 * RETURNS:
 *     none
 */
rtems_device_driver
smc_initialize(
    rtems_device_major_number major,
    rtems_device_minor_number minor,
    void *arg)
{
    rtems_status_code rc;
    dev_t dev;
    uint32_t block_num;

    rc = rtems_disk_io_initialize();
    if (rc != RTEMS_SUCCESSFUL)
        return rc;

    smc_init();
    block_num = smc_info.blocks << 5;

    dev = rtems_filesystem_make_dev_t(major, 0);
    rc = rtems_disk_create_phys(dev, 512, block_num,
                                    smc_ioctl, NULL, SMC_DEVICE_NAME);

    return RTEMS_SUCCESSFUL;
}