/*
 * Atmel DataFlash probing
 *
 * Copyright (C) 2004-2009, 2015 Freescale Semiconductor, Inc.
 * Haikun Wang (haikun.wang@freescale.com)
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <spi.h>
#include <spi_flash.h>
#include <div64.h>
#include <linux/err.h>
#include <linux/math64.h>

#include "sf_internal.h"

/* reads can bypass the buffers */
#define OP_READ_CONTINUOUS      0xE8
#define OP_READ_PAGE            0xD2

/* group B requests can run even while status reports "busy" */
#define OP_READ_STATUS          0xD7    /* group B */

/* move data between host and buffer */
#define OP_READ_BUFFER1         0xD4    /* group B */
#define OP_READ_BUFFER2         0xD6    /* group B */
#define OP_WRITE_BUFFER1        0x84    /* group B */
#define OP_WRITE_BUFFER2        0x87    /* group B */

/* erasing flash */
#define OP_ERASE_PAGE           0x81
#define OP_ERASE_BLOCK          0x50

/* move data between buffer and flash */
#define OP_TRANSFER_BUF1        0x53
#define OP_TRANSFER_BUF2        0x55
#define OP_MREAD_BUFFER1        0xD4
#define OP_MREAD_BUFFER2        0xD6
#define OP_MWERASE_BUFFER1      0x83
#define OP_MWERASE_BUFFER2      0x86
#define OP_MWRITE_BUFFER1       0x88    /* sector must be pre-erased */
#define OP_MWRITE_BUFFER2       0x89    /* sector must be pre-erased */

/* write to buffer, then write-erase to flash */
#define OP_PROGRAM_VIA_BUF1     0x82
#define OP_PROGRAM_VIA_BUF2     0x85

/* compare buffer to flash */
#define OP_COMPARE_BUF1         0x60
#define OP_COMPARE_BUF2         0x61

/* read flash to buffer, then write-erase to flash */
#define OP_REWRITE_VIA_BUF1     0x58
#define OP_REWRITE_VIA_BUF2     0x59

/*
 * newer chips report JEDEC manufacturer and device IDs; chip
 * serial number and OTP bits; and per-sector writeprotect.
 */
#define OP_READ_ID              0x9F
#define OP_READ_SECURITY        0x77
#define OP_WRITE_SECURITY_REVC  0x9A
#define OP_WRITE_SECURITY       0x9B    /* revision D */

struct dataflash {
        uint8_t                 command[16];
        unsigned short          page_offset;    /* offset in flash address */
};

/* Return the status of the DataFlash device */
static inline int dataflash_status(struct spi_slave *spi)
{
        int ret;
        u8 status;
        /*
         * NOTE:  at45db321c over 25 MHz wants to write
         * a dummy byte after the opcode...
         */
        ret = spi_flash_cmd(spi, OP_READ_STATUS, &status, 1);
        return ret ? -EIO : status;
}

/*
 * Poll the DataFlash device until it is READY.
 * This usually takes 5-20 msec or so; more for sector erase.
 * ready: return > 0
 */
static int dataflash_waitready(struct spi_slave *spi)
{
        int status;
        int timeout = 2 * CONFIG_SYS_HZ;
        int timebase;

        timebase = get_timer(0);
        do {
                status = dataflash_status(spi);
                if (status < 0)
                        status = 0;

                if (status & (1 << 7))  /* RDY/nBSY */
                        return status;

                mdelay(3);
        } while (get_timer(timebase) < timeout);

        return -ETIME;
}

/* Erase pages of flash */
static int spi_dataflash_erase(struct udevice *dev, u32 offset, size_t len)
{
        struct dataflash        *dataflash;
        struct spi_flash        *spi_flash;
        struct spi_slave        *spi;
        unsigned                blocksize;
        uint8_t                 *command;
        uint32_t                rem;
        int                     status;

        dataflash = dev_get_priv(dev);
        spi_flash = dev_get_uclass_priv(dev);
        spi = spi_flash->spi;

        blocksize = spi_flash->page_size << 3;

        memset(dataflash->command, 0 , sizeof(dataflash->command));
        command = dataflash->command;

        debug("%s: erase addr=0x%x len 0x%x\n", dev->name, offset, len);

        div_u64_rem(len, spi_flash->page_size, &rem);
        if (rem) {
                printf("%s: len(0x%x) isn't the multiple of page size(0x%x)\n",
                       dev->name, len, spi_flash->page_size);
                return -EINVAL;
        }
        div_u64_rem(offset, spi_flash->page_size, &rem);
        if (rem) {
                printf("%s: offset(0x%x) isn't the multiple of page size(0x%x)\n",
                       dev->name, offset, spi_flash->page_size);
                return -EINVAL;
        }

        status = spi_claim_bus(spi);
        if (status) {
                debug("dataflash: unable to claim SPI bus\n");
                return status;
        }

        while (len > 0) {
                unsigned int    pageaddr;
                int             do_block;
                /*
                 * Calculate flash page address; use block erase (for speed) if
                 * we're at a block boundary and need to erase the whole block.
                 */
                pageaddr = div_u64(offset, spi_flash->page_size);
                do_block = (pageaddr & 0x7) == 0 && len >= blocksize;
                pageaddr = pageaddr << dataflash->page_offset;

                command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
                command[1] = (uint8_t)(pageaddr >> 16);
                command[2] = (uint8_t)(pageaddr >> 8);
                command[3] = 0;

                debug("%s ERASE %s: (%x) %x %x %x [%d]\n",
                      dev->name, do_block ? "block" : "page",
                      command[0], command[1], command[2], command[3],
                      pageaddr);

                status = spi_flash_cmd_write(spi, command, 4, NULL, 0);
                if (status < 0) {
                        debug("%s: erase send command error!\n", dev->name);
                        return -EIO;
                }

                status = dataflash_waitready(spi);
                if (status < 0) {
                        debug("%s: erase waitready error!\n", dev->name);
                        return status;
                }

                if (do_block) {
                        offset += blocksize;
                        len -= blocksize;
                } else {
                        offset += spi_flash->page_size;
                        len -= spi_flash->page_size;
                }
        }

        spi_release_bus(spi);

        return 0;
}

/*
 * Read from the DataFlash device.
 *   offset : Start offset in flash device
 *   len    : Amount to read
 *   buf    : Buffer containing the data
 */
static int spi_dataflash_read(struct udevice *dev, u32 offset, size_t len,
                              void *buf)
{
        struct dataflash        *dataflash;
        struct spi_flash        *spi_flash;
        struct spi_slave        *spi;
        unsigned int            addr;
        uint8_t                 *command;
        int                     status;

        dataflash = dev_get_priv(dev);
        spi_flash = dev_get_uclass_priv(dev);
        spi = spi_flash->spi;

        memset(dataflash->command, 0 , sizeof(dataflash->command));
        command = dataflash->command;

        debug("%s: erase addr=0x%x len 0x%x\n", dev->name, offset, len);
        debug("READ: (%x) %x %x %x\n",
              command[0], command[1], command[2], command[3]);

        /* Calculate flash page/byte address */
        addr = (((unsigned)offset / spi_flash->page_size)
               << dataflash->page_offset)
               + ((unsigned)offset % spi_flash->page_size);

        status = spi_claim_bus(spi);
        if (status) {
                debug("dataflash: unable to claim SPI bus\n");
                return status;
        }

        /*
         * Continuous read, max clock = f(car) which may be less than
         * the peak rate available.  Some chips support commands with
         * fewer "don't care" bytes.  Both buffers stay unchanged.
         */
        command[0] = OP_READ_CONTINUOUS;
        command[1] = (uint8_t)(addr >> 16);
        command[2] = (uint8_t)(addr >> 8);
        command[3] = (uint8_t)(addr >> 0);

        /* plus 4 "don't care" bytes, command len: 4 + 4 "don't care" bytes */
        status = spi_flash_cmd_read(spi, command, 8, buf, len);

        spi_release_bus(spi);

        return status;
}

/*
 * Write to the DataFlash device.
 *   offset     : Start offset in flash device
 *   len    : Amount to write
 *   buf    : Buffer containing the data
 */
int spi_dataflash_write(struct udevice *dev, u32 offset, size_t len,
                        const void *buf)
{
        struct dataflash        *dataflash;
        struct spi_flash        *spi_flash;
        struct spi_slave        *spi;
        uint8_t                 *command;
        unsigned int            pageaddr, addr, to, writelen;
        size_t                  remaining = len;
        u_char                  *writebuf = (u_char *)buf;
        int                     status = -EINVAL;

        dataflash = dev_get_priv(dev);
        spi_flash = dev_get_uclass_priv(dev);
        spi = spi_flash->spi;

        memset(dataflash->command, 0 , sizeof(dataflash->command));
        command = dataflash->command;

        debug("%s: write 0x%x..0x%x\n", dev->name, offset, (offset + len));

        pageaddr = ((unsigned)offset / spi_flash->page_size);
        to = ((unsigned)offset % spi_flash->page_size);
        if (to + len > spi_flash->page_size)
                writelen = spi_flash->page_size - to;
        else
                writelen = len;

        status = spi_claim_bus(spi);
        if (status) {
                debug("dataflash: unable to claim SPI bus\n");
                return status;
        }

        while (remaining > 0) {
                debug("write @ %d:%d len=%d\n", pageaddr, to, writelen);

                /*
                 * REVISIT:
                 * (a) each page in a sector must be rewritten at least
                 *     once every 10K sibling erase/program operations.
                 * (b) for pages that are already erased, we could
                 *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
                 * (c) WRITE to buffer could be done while waiting for
                 *     a previous MWRITE/MWERASE to complete ...
                 * (d) error handling here seems to be mostly missing.
                 *
                 * Two persistent bits per page, plus a per-sector counter,
                 * could support (a) and (b) ... we might consider using
                 * the second half of sector zero, which is just one block,
                 * to track that state.  (On AT91, that sector should also
                 * support boot-from-DataFlash.)
                 */

                addr = pageaddr << dataflash->page_offset;

                /* (1) Maybe transfer partial page to Buffer1 */
                if (writelen != spi_flash->page_size) {
                        command[0] = OP_TRANSFER_BUF1;
                        command[1] = (addr & 0x00FF0000) >> 16;
                        command[2] = (addr & 0x0000FF00) >> 8;
                        command[3] = 0;

                        debug("TRANSFER: (%x) %x %x %x\n",
                              command[0], command[1], command[2], command[3]);

                        status = spi_flash_cmd_write(spi, command, 4, NULL, 0);
                        if (status < 0) {
                                debug("%s: write(<pagesize) command error!\n",
                                      dev->name);
                                return -EIO;
                        }

                        status = dataflash_waitready(spi);
                        if (status < 0) {
                                debug("%s: write(<pagesize) waitready error!\n",
                                      dev->name);
                                return status;
                        }
                }

                /* (2) Program full page via Buffer1 */
                addr += to;
                command[0] = OP_PROGRAM_VIA_BUF1;
                command[1] = (addr & 0x00FF0000) >> 16;
                command[2] = (addr & 0x0000FF00) >> 8;
                command[3] = (addr & 0x000000FF);

                debug("PROGRAM: (%x) %x %x %x\n",
                      command[0], command[1], command[2], command[3]);

                status = spi_flash_cmd_write(spi, command,
                                             4, writebuf, writelen);
                if (status < 0) {
                        debug("%s: write send command error!\n", dev->name);
                        return -EIO;
                }

                status = dataflash_waitready(spi);
                if (status < 0) {
                        debug("%s: write waitready error!\n", dev->name);
                        return status;
                }

#ifdef CONFIG_SPI_DATAFLASH_WRITE_VERIFY
                /* (3) Compare to Buffer1 */
                addr = pageaddr << dataflash->page_offset;
                command[0] = OP_COMPARE_BUF1;
                command[1] = (addr & 0x00FF0000) >> 16;
                command[2] = (addr & 0x0000FF00) >> 8;
                command[3] = 0;

                debug("COMPARE: (%x) %x %x %x\n",
                      command[0], command[1], command[2], command[3]);

                status = spi_flash_cmd_write(spi, command,
                                             4, writebuf, writelen);
                if (status < 0) {
                        debug("%s: write(compare) send command error!\n",
                              dev->name);
                        return -EIO;
                }

                status = dataflash_waitready(spi);

                /* Check result of the compare operation */
                if (status & (1 << 6)) {
                        printf("dataflash: write compare page %u, err %d\n",
                               pageaddr, status);
                        remaining = 0;
                        status = -EIO;
                        break;
                } else {
                        status = 0;
                }

#endif  /* CONFIG_SPI_DATAFLASH_WRITE_VERIFY */
                remaining = remaining - writelen;
                pageaddr++;
                to = 0;
                writebuf += writelen;

                if (remaining > spi_flash->page_size)
                        writelen = spi_flash->page_size;
                else
                        writelen = remaining;
        }

        spi_release_bus(spi);

        return 0;
}

static int add_dataflash(struct udevice *dev, char *name, int nr_pages,
                             int pagesize, int pageoffset, char revision)
{
        struct spi_flash *spi_flash;
        struct dataflash *dataflash;

        dataflash = dev_get_priv(dev);
        spi_flash = dev_get_uclass_priv(dev);

        dataflash->page_offset = pageoffset;

        spi_flash->name = name;
        spi_flash->page_size = pagesize;
        spi_flash->size = nr_pages * pagesize;
        spi_flash->erase_size = pagesize;

#ifndef CONFIG_SPL_BUILD
        printf("SPI DataFlash: Detected %s with page size ", spi_flash->name);
        print_size(spi_flash->page_size, ", erase size ");
        print_size(spi_flash->erase_size, ", total ");
        print_size(spi_flash->size, "");
        printf(", revision %c", revision);
        puts("\n");
#endif

        return 0;
}

struct flash_info {
        char            *name;

        /*
         * JEDEC id has a high byte of zero plus three data bytes:
         * the manufacturer id, then a two byte device id.
         */
        uint32_t        jedec_id;

        /* The size listed here is what works with OP_ERASE_PAGE. */
        unsigned        nr_pages;
        uint16_t        pagesize;
        uint16_t        pageoffset;

        uint16_t        flags;
#define SUP_POW2PS      0x0002          /* supports 2^N byte pages */
#define IS_POW2PS       0x0001          /* uses 2^N byte pages */
};

static struct flash_info dataflash_data[] = {
        /*
         * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
         * one with IS_POW2PS and the other without.  The entry with the
         * non-2^N byte page size can't name exact chip revisions without
         * losing backwards compatibility for cmdlinepart.
         *
         * Those two entries have different name spelling format in order to
         * show their difference obviously.
         * The upper case refer to the chip isn't in normal 2^N bytes page-size
         * mode.
         * The lower case refer to the chip is in normal 2^N bytes page-size
         * mode.
         *
         * These newer chips also support 128-byte security registers (with
         * 64 bytes one-time-programmable) and software write-protection.
         */
        { "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
        { "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},

        { "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
        { "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},

        { "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
        { "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},

        { "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
        { "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},

        { "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
        { "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},

        { "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},           /* rev C */

        { "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
        { "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},

        { "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
        { "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
};

static struct flash_info *jedec_probe(struct spi_slave *spi)
{
        int                     tmp;
        uint8_t                 id[5];
        uint32_t                jedec;
        struct flash_info       *info;
        int status;

        /*
         * JEDEC also defines an optional "extended device information"
         * string for after vendor-specific data, after the three bytes
         * we use here.  Supporting some chips might require using it.
         *
         * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
         * That's not an error; only rev C and newer chips handle it, and
         * only Atmel sells these chips.
         */
        tmp = spi_flash_cmd(spi, CMD_READ_ID, id, sizeof(id));
        if (tmp < 0) {
                printf("dataflash: error %d reading JEDEC ID\n", tmp);
                return ERR_PTR(tmp);
        }
        if (id[0] != 0x1f)
                return NULL;

        jedec = id[0];
        jedec = jedec << 8;
        jedec |= id[1];
        jedec = jedec << 8;
        jedec |= id[2];

        for (tmp = 0, info = dataflash_data;
                        tmp < ARRAY_SIZE(dataflash_data);
                        tmp++, info++) {
                if (info->jedec_id == jedec) {
                        if (info->flags & SUP_POW2PS) {
                                status = dataflash_status(spi);
                                if (status < 0) {
                                        debug("dataflash: status error %d\n",
                                              status);
                                        return NULL;
                                }
                                if (status & 0x1) {
                                        if (info->flags & IS_POW2PS)
                                                return info;
                                } else {
                                        if (!(info->flags & IS_POW2PS))
                                                return info;
                                }
                        } else {
                                return info;
                        }
                }
        }

        /*
         * Treat other chips as errors ... we won't know the right page
         * size (it might be binary) even when we can tell which density
         * class is involved (legacy chip id scheme).
         */
        printf("dataflash: JEDEC id %06x not handled\n", jedec);
        return ERR_PTR(-ENODEV);
}

/*
 * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
 * or else the ID code embedded in the status bits:
 *
 *   Device      Density         ID code          #Pages PageSize  Offset
 *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
 *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
 *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
 *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
 *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
 *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
 *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
 *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
 */
static int spi_dataflash_probe(struct udevice *dev)
{
        struct spi_slave *spi = dev_get_parent_priv(dev);
        struct spi_flash *spi_flash;
        struct flash_info *info;
        int status;

        spi_flash = dev_get_uclass_priv(dev);
        spi_flash->spi = spi;
        spi_flash->dev = dev;

        status = spi_claim_bus(spi);
        if (status)
                return status;

        /*
         * Try to detect dataflash by JEDEC ID.
         * If it succeeds we know we have either a C or D part.
         * D will support power of 2 pagesize option.
         * Both support the security register, though with different
         * write procedures.
         */
        info = jedec_probe(spi);
        if (IS_ERR(info))
                goto err_jedec_probe;
        if (info != NULL) {
                status = add_dataflash(dev, info->name, info->nr_pages,
                                info->pagesize, info->pageoffset,
                                (info->flags & SUP_POW2PS) ? 'd' : 'c');
                if (status < 0)
                        goto err_status;
        }

       /*
        * Older chips support only legacy commands, identifing
        * capacity using bits in the status byte.
        */
        status = dataflash_status(spi);
        if (status <= 0 || status == 0xff) {
                printf("dataflash: read status error %d\n", status);
                if (status == 0 || status == 0xff)
                        status = -ENODEV;
                goto err_jedec_probe;
        }

       /*
        * if there's a device there, assume it's dataflash.
        * board setup should have set spi->max_speed_max to
        * match f(car) for continuous reads, mode 0 or 3.
        */
        switch (status & 0x3c) {
        case 0x0c:      /* 0 0 1 1 x x */
                status = add_dataflash(dev, "AT45DB011B", 512, 264, 9, 0);
                break;
        case 0x14:      /* 0 1 0 1 x x */
                status = add_dataflash(dev, "AT45DB021B", 1024, 264, 9, 0);
                break;
        case 0x1c:      /* 0 1 1 1 x x */
                status = add_dataflash(dev, "AT45DB041x", 2048, 264, 9, 0);
                break;
        case 0x24:      /* 1 0 0 1 x x */
                status = add_dataflash(dev, "AT45DB081B", 4096, 264, 9, 0);
                break;
        case 0x2c:      /* 1 0 1 1 x x */
                status = add_dataflash(dev, "AT45DB161x", 4096, 528, 10, 0);
                break;
        case 0x34:      /* 1 1 0 1 x x */
                status = add_dataflash(dev, "AT45DB321x", 8192, 528, 10, 0);
                break;
        case 0x38:      /* 1 1 1 x x x */
        case 0x3c:
                status = add_dataflash(dev, "AT45DB642x", 8192, 1056, 11, 0);
                break;
        /* obsolete AT45DB1282 not (yet?) supported */
        default:
                printf("dataflash: unsupported device (%x)\n", status & 0x3c);
                status = -ENODEV;
                goto err_status;
        }

        return status;

err_status:
        spi_free_slave(spi);
err_jedec_probe:
        spi_release_bus(spi);
        return status;
}

static const struct dm_spi_flash_ops spi_dataflash_ops = {
        .read = spi_dataflash_read,
        .write = spi_dataflash_write,
        .erase = spi_dataflash_erase,
};

static const struct udevice_id spi_dataflash_ids[] = {
        { .compatible = "atmel,at45", },
        { .compatible = "atmel,dataflash", },
        { }
};

U_BOOT_DRIVER(spi_dataflash) = {
        .name           = "spi_dataflash",
        .id             = UCLASS_SPI_FLASH,
        .of_match       = spi_dataflash_ids,
        .probe          = spi_dataflash_probe,
        .priv_auto_alloc_size = sizeof(struct dataflash),
        .ops            = &spi_dataflash_ops,
};