1 files changed, 623 insertions, 0 deletions

diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
new file mode 100644
index 000000000000..a39b3b6b266c
--- /dev/null
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -0,0 +1,623 @@
+/*
+ * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
+ *
+ * Largely derived from at91_dataflash.c:
+ *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
+ *
+ * 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.
+*/
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/flash.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+
+/*
+ * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
+ * each chip, which may be used for double buffered I/O; but this driver
+ * doesn't (yet) use these for any kind of i/o overlap or prefetching.
+ *
+ * Sometimes DataFlash is packaged in MMC-format cards, although the
+ * MMC stack can't use SPI (yet), or distinguish between MMC and DataFlash
+ * protocols during enumeration.
+ */
+
+#define CONFIG_DATAFLASH_WRITE_VERIFY
+
+/* 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       0x9A    /* OTP bits */
+
+
+struct dataflash {
+        u8                      command[4];
+        char                    name[24];
+
+        unsigned                partitioned:1;
+
+        unsigned short          page_offset;    /* offset in flash address */
+        unsigned int            page_size;      /* of bytes per page */
+
+        struct semaphore        lock;
+        struct spi_device       *spi;
+
+        struct mtd_info         mtd;
+};
+
+#ifdef CONFIG_MTD_PARTITIONS
+#define mtd_has_partitions()    (1)
+#else
+#define mtd_has_partitions()    (0)
+#endif
+
+/* ......................................................................... */
+
+/*
+ * Return the status of the DataFlash device.
+ */
+static inline int dataflash_status(struct spi_device *spi)
+{
+        /* NOTE:  at45db321c over 25 MHz wants to write
+         * a dummy byte after the opcode...
+         */
+        return spi_w8r8(spi, OP_READ_STATUS);
+}
+
+/*
+ * Poll the DataFlash device until it is READY.
+ * This usually takes 5-20 msec or so; more for sector erase.
+ */
+static int dataflash_waitready(struct spi_device *spi)
+{
+        int     status;
+
+        for (;;) {
+                status = dataflash_status(spi);
+                if (status < 0) {
+                        DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n",
+                                        spi->dev.bus_id, status);
+                        status = 0;
+                }
+
+                if (status & (1 << 7))  /* RDY/nBSY */
+                        return status;
+
+                msleep(3);
+        }
+}
+
+/* ......................................................................... */
+
+/*
+ * Erase pages of flash.
+ */
+static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+        struct dataflash        *priv = (struct dataflash *)mtd->priv;
+        struct spi_device       *spi = priv->spi;
+        struct spi_transfer     x[1] = { { .tx_dma = 0, }, };
+        struct spi_message      msg;
+        unsigned                blocksize = priv->page_size << 3;
+        u8                      *command;
+
+        DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%x len 0x%x\n",
+                        spi->dev.bus_id,
+                        instr->addr, instr->len);
+
+        /* Sanity checks */
+        if ((instr->addr + instr->len) > mtd->size
+                        || (instr->len % priv->page_size) != 0
+                        || (instr->addr % priv->page_size) != 0)
+                return -EINVAL;
+
+        x[0].tx_buf = command = priv->command;
+        x[0].len = 4;
+        msg.transfers = x;
+        msg.n_transfer = 1;
+
+        down(&priv->lock);
+        while (instr->len > 0) {
+                unsigned int    pageaddr;
+                int             status;
+                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 = instr->addr / priv->page_size;
+                do_block = (pageaddr & 0x7) == 0 && instr->len <= blocksize;
+                pageaddr = pageaddr << priv->page_offset;
+
+                command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
+                command[1] = (u8)(pageaddr >> 16);
+                command[2] = (u8)(pageaddr >> 8);
+                command[3] = 0;
+
+                DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n",
+                        do_block ? "block" : "page",
+                        command[0], command[1], command[2], command[3],
+                        pageaddr);
+
+                status = spi_sync(spi, &msg);
+                (void) dataflash_waitready(spi);
+
+                if (status < 0) {
+                        printk(KERN_ERR "%s: erase %x, err %d\n",
+                                spi->dev.bus_id, pageaddr, status);
+                        /* REVISIT:  can retry instr->retries times; or
+                         * giveup and instr->fail_addr = instr->addr;
+                         */
+                        continue;
+                }
+
+                if (do_block) {
+                        instr->addr += blocksize;
+                        instr->len -= blocksize;
+                } else {
+                        instr->addr += priv->page_size;
+                        instr->len -= priv->page_size;
+                }
+        }
+        up(&priv->lock);
+
+        /* Inform MTD subsystem that erase is complete */
+        instr->state = MTD_ERASE_DONE;
+        mtd_erase_callback(instr);
+
+        return 0;
+}
+
+/*
+ * Read from the DataFlash device.
+ *   from   : Start offset in flash device
+ *   len    : Amount to read
+ *   retlen : About of data actually read
+ *   buf    : Buffer containing the data
+ */
+static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
+                               size_t *retlen, u_char *buf)
+{
+        struct dataflash        *priv = (struct dataflash *)mtd->priv;
+        struct spi_transfer     x[2] = { { .tx_dma = 0, }, };
+        struct spi_message      msg;
+        unsigned int            addr;
+        u8                      *command;
+        int                     status;
+
+        DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n",
+                priv->spi->dev.bus_id, (unsigned)from, (unsigned)(from + len));
+
+        *retlen = 0;
+
+        /* Sanity checks */
+        if (!len)
+                return 0;
+        if (from + len > mtd->size)
+                return -EINVAL;
+
+        /* Calculate flash page/byte address */
+        addr = (((unsigned)from / priv->page_size) << priv->page_offset)
+                + ((unsigned)from % priv->page_size);
+
+        command = priv->command;
+
+        DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n",
+                command[0], command[1], command[2], command[3]);
+
+        x[0].tx_buf = command;
+        x[0].len = 8;
+        x[1].rx_buf = buf;
+        x[1].len = len;
+        msg.transfers = x;
+        msg.n_transfer = 2;
+
+        down(&priv->lock);
+
+        /* 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] = (u8)(addr >> 16);
+        command[2] = (u8)(addr >> 8);
+        command[3] = (u8)(addr >> 0);
+        /* plus 4 "don't care" bytes */
+
+        status = spi_sync(priv->spi, &msg);
+        up(&priv->lock);
+
+        if (status >= 0) {
+                *retlen = msg.actual_length - 8;
+                status = 0;
+        } else
+                DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n",
+                        priv->spi->dev.bus_id,
+                        (unsigned)from, (unsigned)(from + len),
+                        status);
+        return status;
+}
+
+/*
+ * Write to the DataFlash device.
+ *   to     : Start offset in flash device
+ *   len    : Amount to write
+ *   retlen : Amount of data actually written
+ *   buf    : Buffer containing the data
+ */
+static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
+                                size_t * retlen, const u_char * buf)
+{
+        struct dataflash        *priv = (struct dataflash *)mtd->priv;
+        struct spi_device       *spi = priv->spi;
+        struct spi_transfer     x[2] = { { .tx_dma = 0, }, };
+        struct spi_message      msg;
+        unsigned int            pageaddr, addr, offset, writelen;
+        size_t                  remaining = len;
+        u_char                  *writebuf = (u_char *) buf;
+        int                     status = -EINVAL;
+        u8                      *command;
+
+        DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n",
+                spi->dev.bus_id, (unsigned)to, (unsigned)(to + len));
+
+        *retlen = 0;
+
+        /* Sanity checks */
+        if (!len)
+                return 0;
+        if ((to + len) > mtd->size)
+                return -EINVAL;
+
+        x[0].tx_buf = command = priv->command;
+        x[0].len = 4;
+        msg.transfers = x;
+
+        pageaddr = ((unsigned)to / priv->page_size);
+        offset = ((unsigned)to % priv->page_size);
+        if (offset + len > priv->page_size)
+                writelen = priv->page_size - offset;
+        else
+                writelen = len;
+
+        down(&priv->lock);
+        while (remaining > 0) {
+                DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n",
+                        pageaddr, offset, 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 << priv->page_offset;
+
+                /* (1) Maybe transfer partial page to Buffer1 */
+                if (writelen != priv->page_size) {
+                        command[0] = OP_TRANSFER_BUF1;
+                        command[1] = (addr & 0x00FF0000) >> 16;
+                        command[2] = (addr & 0x0000FF00) >> 8;
+                        command[3] = 0;
+
+                        DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n",
+                                command[0], command[1], command[2], command[3]);
+
+                        msg.n_transfer = 1;
+                        status = spi_sync(spi, &msg);
+                        if (status < 0)
+                                DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n",
+                                        spi->dev.bus_id, addr, status);
+
+                        (void) dataflash_waitready(priv->spi);
+                }
+
+                /* (2) Program full page via Buffer1 */
+                addr += offset;
+                command[0] = OP_PROGRAM_VIA_BUF1;
+                command[1] = (addr & 0x00FF0000) >> 16;
+                command[2] = (addr & 0x0000FF00) >> 8;
+                command[3] = (addr & 0x000000FF);
+
+                DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n",
+                        command[0], command[1], command[2], command[3]);
+
+                x[1].tx_buf = writebuf;
+                x[1].len = writelen;
+                msg.n_transfer = 2;
+                status = spi_sync(spi, &msg);
+                if (status < 0)
+                        DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n",
+                                spi->dev.bus_id, addr, writelen, status);
+
+                (void) dataflash_waitready(priv->spi);
+
+#ifdef  CONFIG_DATAFLASH_WRITE_VERIFY
+
+                /* (3) Compare to Buffer1 */
+                addr = pageaddr << priv->page_offset;
+                command[0] = OP_COMPARE_BUF1;
+                command[1] = (addr & 0x00FF0000) >> 16;
+                command[2] = (addr & 0x0000FF00) >> 8;
+                command[3] = 0;
+
+                DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n",
+                        command[0], command[1], command[2], command[3]);
+
+                msg.n_transfer = 1;
+                status = spi_sync(spi, &msg);
+                if (status < 0)
+                        DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n",
+                                spi->dev.bus_id, addr, status);
+
+                status = dataflash_waitready(priv->spi);
+
+                /* Check result of the compare operation */
+                if ((status & (1 << 6)) == 1) {
+                        printk(KERN_ERR "%s: compare page %u, err %d\n",
+                                spi->dev.bus_id, pageaddr, status);
+                        remaining = 0;
+                        status = -EIO;
+                        break;
+                } else
+                        status = 0;
+
+#endif  /* CONFIG_DATAFLASH_WRITE_VERIFY */
+
+                remaining = remaining - writelen;
+                pageaddr++;
+                offset = 0;
+                writebuf += writelen;
+                *retlen += writelen;
+
+                if (remaining > priv->page_size)
+                        writelen = priv->page_size;
+                else
+                        writelen = remaining;
+        }
+        up(&priv->lock);
+
+        return status;
+}
+
+/* ......................................................................... */
+
+/*
+ * Register DataFlash device with MTD subsystem.
+ */
+static int __devinit
+add_dataflash(struct spi_device *spi, char *name,
+                int nr_pages, int pagesize, int pageoffset)
+{
+        struct dataflash                *priv;
+        struct mtd_info                 *device;
+        struct flash_platform_data      *pdata = spi->dev.platform_data;
+
+        priv = (struct dataflash *) kzalloc(sizeof *priv, GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        init_MUTEX(&priv->lock);
+        priv->spi = spi;
+        priv->page_size = pagesize;
+        priv->page_offset = pageoffset;
+
+        /* name must be usable with cmdlinepart */
+        sprintf(priv->name, "spi%d.%d-%s",
+                        spi->master->bus_num, spi->chip_select,
+                        name);
+
+        device = &priv->mtd;
+        device->name = (pdata && pdata->name) ? pdata->name : priv->name;
+        device->size = nr_pages * pagesize;
+        device->erasesize = pagesize;
+        device->owner = THIS_MODULE;
+        device->type = MTD_DATAFLASH;
+        device->flags = MTD_CAP_NORFLASH;
+        device->erase = dataflash_erase;
+        device->read = dataflash_read;
+        device->write = dataflash_write;
+        device->priv = priv;
+
+        dev_info(&spi->dev, "%s (%d KBytes)\n", name, device->size/1024);
+        dev_set_drvdata(&spi->dev, priv);
+
+        if (mtd_has_partitions()) {
+                struct mtd_partition    *parts;
+                int                     nr_parts = 0;
+
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+                static const char *part_probes[] = { "cmdlinepart", NULL, };
+
+                nr_parts = parse_mtd_partitions(device, part_probes, &parts, 0);
+#endif
+
+                if (nr_parts <= 0 && pdata && pdata->parts) {
+                        parts = pdata->parts;
+                        nr_parts = pdata->nr_parts;
+                }
+
+                if (nr_parts > 0) {
+                        priv->partitioned = 1;
+                        return add_mtd_partitions(device, parts, nr_parts);
+                }
+        } else if (pdata->nr_parts)
+                dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
+                                pdata->nr_parts, device->name);
+
+        return add_mtd_device(device) == 1 ? -ENODEV : 0;
+}
+
+/*
+ * Detect and initialize DataFlash device:
+ *
+ *   Device      Density         ID code          #Pages PageSize  Offset
+ *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
+ *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1025    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 __devinit dataflash_probe(struct spi_device *spi)
+{
+        int status;
+
+        status = dataflash_status(spi);
+        if (status <= 0 || status == 0xff) {
+                DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n",
+                                spi->dev.bus_id, status);
+                if (status == 0xff)
+                        status = -ENODEV;
+                return status;
+        }
+
+        /* 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(spi, "AT45DB011B", 512, 264, 9);
+                break;
+        case 0x14:      /* 0 1 0 1 x x */
+                status = add_dataflash(spi, "AT45DB021B", 1025, 264, 9);
+                break;
+        case 0x1c:      /* 0 1 1 1 x x */
+                status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
+                break;
+        case 0x24:      /* 1 0 0 1 x x */
+                status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
+                break;
+        case 0x2c:      /* 1 0 1 1 x x */
+                status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
+                break;
+        case 0x34:      /* 1 1 0 1 x x */
+                status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
+                break;
+        case 0x38:      /* 1 1 1 x x x */
+        case 0x3c:
+                status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
+                break;
+        /* obsolete AT45DB1282 not (yet?) supported */
+        default:
+                DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n",
+                                spi->dev.bus_id, status & 0x3c);
+                status = -ENODEV;
+        }
+
+        if (status < 0)
+                DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n",
+                                spi->dev.bus_id, status);
+
+        return status;
+}
+
+static int __devexit dataflash_remove(struct spi_device *spi)
+{
+        struct dataflash        *flash = dev_get_drvdata(&spi->dev);
+        int                     status;
+
+        DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", spi->dev.bus_id);
+
+        if (mtd_has_partitions() && flash->partitioned)
+                status = del_mtd_partitions(&flash->mtd);
+        else
+                status = del_mtd_device(&flash->mtd);
+        if (status == 0)
+                kfree(flash);
+        return status;
+}
+
+static struct spi_driver dataflash_driver = {
+        .driver = {
+                .name           = "mtd_dataflash",
+                .bus            = &spi_bus_type,
+                .owner          = THIS_MODULE,
+        },
+
+        .probe          = dataflash_probe,
+        .remove         = __devexit_p(dataflash_remove),
+
+        /* FIXME:  investigate suspend and resume... */
+};
+
+static int __init dataflash_init(void)
+{
+        return spi_register_driver(&dataflash_driver);
+}
+module_init(dataflash_init);
+
+static void __exit dataflash_exit(void)
+{
+        spi_unregister_driver(&dataflash_driver);
+}
+module_exit(dataflash_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrew Victor, David Brownell");
+MODULE_DESCRIPTION("MTD DataFlash driver");