dm: sf: Add Atmel DataFlash spi flash driver

Atmel DataFlash chips have commands different from common spi flash commands. Atmel DataFlash also have special page-size. This driver add support for accessing Atmel DataFlash. It is based on the Driver Model. Example: => sf probe 1:0 SPI DataFlash: Detected AT45DB021B with page size 264 Bytes, erase size 264 Bytes, total 264 KiB, revision d => sf erase 0 42000 SF: 270336 bytes @ 0x0 Erased: OK => mw.l 82000000 45444342 20000 => sf write 82000000 0 42000 SF: 270336 bytes @ 0x0 Written: OK => sf read 83000000 0 42000 SF: 270336 bytes @ 0x0 Read: OK => cmp.b 82000000 83000000 42000 Total of 270336 byte(s) were the same Signed-off-by: Haikun Wang <haikun.wang@freescale.com> Tested-by: Haikun Wang <haikun.wang@freescale.com> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Chakra Divi <cdivi@openedev.com> Reviewed-by: Jagan Teki <jteki@openedev.com>

dm: sf: Add Atmel DataFlash spi flash driver
Atmel DataFlash chips have commands different from common spi flash commands. Atmel DataFlash also have special page-size. This driver add support for accessing Atmel DataFlash. It is based on the Driver Model. Example: => sf probe 1:0 SPI DataFlash: Detected AT45DB021B with page size 264 Bytes, erase size 264 Bytes, total 264 KiB, revision d => sf erase 0 42000 SF: 270336 bytes @ 0x0 Erased: OK => mw.l 82000000 45444342 20000 => sf write 82000000 0 42000 SF: 270336 bytes @ 0x0 Written: OK => sf read 83000000 0 42000 SF: 270336 bytes @ 0x0 Read: OK => cmp.b 82000000 83000000 42000 Total of 270336 byte(s) were the same Signed-off-by: Haikun Wang <haikun.wang@freescale.com> Tested-by: Haikun Wang <haikun.wang@freescale.com> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Chakra Divi <cdivi@openedev.com> Reviewed-by: Jagan Teki <jteki@openedev.com>
Haikun Wang · Jagan Teki
1 parent 7853d76b0b
Showing 2 changed files with 712 additions and 0 deletions Side-by-side Diff
drivers/mtd/spi/Makefile
drivers/mtd/spi/sf_dataflash.c
@@ -15,6 +15,7 @@
 #ifndef CONFIG_DM_SPI
 obj-$(CONFIG_SPI_FLASH) += sf_probe.o
 #endif
+obj-$(CONFIG_SF_DATAFLASH) += sf_dataflash.o
 obj-$(CONFIG_CMD_SF) += sf.o
 obj-$(CONFIG_SPI_FLASH) += sf_ops.o sf_params.o
 obj-$(CONFIG_SPI_FLASH_SANDBOX) += sandbox.o
+/*
+ *
+ * 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"
+
+/*
+ * 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 (yet?) distinguish between MMC and DataFlash
+ * protocols during enumeration.
+ */
+
+/* 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)
+		return -EINVAL;
+	div_u64_rem(offset, spi_flash->page_size, &rem);
+	if (rem)
+		return -EINVAL;
+
+	status = spi_claim_bus(spi);
+	if (status) {
+		debug("SPI 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("SPI 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("SPI 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("SPI 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, u8 *id)
+{
+	int			tmp;
+	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.
+	 */
+	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("SPI 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("SPI DataFlash: Unsupported flash IDs: ");
+	printf("manuf %02x, jedec %04x, ext_jedec %04x\n",
+	       id[0], jedec, id[3] << 8 | id[4]);
+	return NULL;
+}
+
+/*
+ * 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_parentdata(dev);
+	struct spi_flash *spi_flash;
+	struct flash_info *info;
+	u8 idcode[5];
+	int ret, status = 0;
+
+	spi_flash = dev_get_uclass_priv(dev);
+	spi_flash->dev = dev;
+
+	ret = spi_claim_bus(spi);
+	if (ret)
+		return ret;
+
+	ret = spi_flash_cmd(spi, CMD_READ_ID, idcode, sizeof(idcode));
+	if (ret) {
+		printf("SPI DataFlash: Failed to get idcodes\n");
+		goto err_read_cmd;
+	}
+
+	/*
+	 * 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, idcode);
+	if (info != NULL)
+		add_dataflash(dev, info->name, info->nr_pages,
+			      info->pagesize, info->pageoffset,
+			      (info->flags & SUP_POW2PS) ? 'd' : 'c');
+	else {
+		/*
+		* Older chips support only legacy commands, identifing
+		* capacity using bits in the status byte.
+		*/
+		status = dataflash_status(spi);
+		if (status <= 0 || status == 0xff) {
+			printf("SPI DataFlash: read status error %d\n", status);
+			if (status == 0 || status == 0xff)
+				status = -ENODEV;
+			goto err_read_cmd;
+		}
+		/*
+		* 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:
+			dev_info(&spi->dev, "unsupported device (%x)\n",
+				 status & 0x3c);
+			status = -ENODEV;
+			goto err_read_cmd;
+		}
+	}
+
+	/* Assign spi data */
+	spi_flash->spi = spi;
+	spi_flash->memory_map = spi->memory_map;
+	spi_flash->dual_flash = spi->option;
+
+	spi_release_bus(spi);
+
+	return 0;
+
+err_read_cmd:
+	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,
+};
...	...	@@ -15,6 +15,7 @@
15	15	#ifndef CONFIG_DM_SPI
16	16	obj-$(CONFIG_SPI_FLASH) += sf_probe.o
17	17	#endif
	18	+obj-$(CONFIG_SF_DATAFLASH) += sf_dataflash.o
18	19	obj-$(CONFIG_CMD_SF) += sf.o
19	20	obj-$(CONFIG_SPI_FLASH) += sf_ops.o sf_params.o
20	21	obj-$(CONFIG_SPI_FLASH_SANDBOX) += sandbox.o