SPI Flash subsystem
authorHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Fri, 16 May 2008 09:10:33 +0000 (11:10 +0200)
committerWolfgang Denk <wd@denx.de>
Tue, 3 Jun 2008 18:31:34 +0000 (20:31 +0200)
This adds a new SPI flash subsystem.

Currently, only AT45 DataFlash in non-power-of-two mode is supported,
but some preliminary support for other flash types is in place as
well.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Makefile
drivers/mtd/spi/Makefile [new file with mode: 0644]
drivers/mtd/spi/atmel.c [new file with mode: 0644]
drivers/mtd/spi/spi_flash.c [new file with mode: 0644]
drivers/mtd/spi/spi_flash_internal.h [new file with mode: 0644]
include/spi_flash.h [new file with mode: 0644]

index 30b6aeff7559d2ad72e4a6ff4d5041f3d579aa87..cc988e14e1ea1c286fd3c9652c200f3af2456316 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -224,6 +224,7 @@ LIBS += drivers/mtd/libmtd.a
 LIBS += drivers/mtd/nand/libnand.a
 LIBS += drivers/mtd/nand_legacy/libnand_legacy.a
 LIBS += drivers/mtd/onenand/libonenand.a
+LIBS += drivers/mtd/spi/libspi_flash.a
 LIBS += drivers/net/libnet.a
 LIBS += drivers/net/sk98lin/libsk98lin.a
 LIBS += drivers/pci/libpci.a
@@ -390,6 +391,7 @@ TAG_SUBDIRS += drivers/mtd
 TAG_SUBDIRS += drivers/mtd/nand
 TAG_SUBDIRS += drivers/mtd/nand_legacy
 TAG_SUBDIRS += drivers/mtd/onenand
+TAG_SUBDIRS += drivers/mtd/spi
 TAG_SUBDIRS += drivers/net
 TAG_SUBDIRS += drivers/net/sk98lin
 TAG_SUBDIRS += drivers/pci
diff --git a/drivers/mtd/spi/Makefile b/drivers/mtd/spi/Makefile
new file mode 100644 (file)
index 0000000..af6af97
--- /dev/null
@@ -0,0 +1,47 @@
+#
+# (C) Copyright 2006
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# 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 $(TOPDIR)/config.mk
+
+LIB    := $(obj)libspi_flash.a
+
+COBJS-$(CONFIG_SPI_FLASH)      += spi_flash.o
+COBJS-$(CONFIG_SPI_FLASH_ATMEL)        += atmel.o
+
+COBJS  := $(COBJS-y)
+SRCS   := $(COBJS:.o=.c)
+OBJS   := $(addprefix $(obj),$(COBJS))
+
+all:   $(LIB)
+
+$(LIB): $(obj).depend $(OBJS)
+       $(AR) $(ARFLAGS) $@ $(OBJS)
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/drivers/mtd/spi/atmel.c b/drivers/mtd/spi/atmel.c
new file mode 100644 (file)
index 0000000..fb7a4a9
--- /dev/null
@@ -0,0 +1,362 @@
+/*
+ * Atmel SPI DataFlash support
+ *
+ * Copyright (C) 2008 Atmel Corporation
+ */
+#define DEBUG
+#include <common.h>
+#include <malloc.h>
+#include <spi_flash.h>
+
+#include "spi_flash_internal.h"
+
+/* AT45-specific commands */
+#define CMD_AT45_READ_STATUS           0xd7
+#define CMD_AT45_ERASE_PAGE            0x81
+#define CMD_AT45_LOAD_PROG_BUF1                0x82
+#define CMD_AT45_LOAD_BUF1             0x84
+#define CMD_AT45_LOAD_PROG_BUF2                0x85
+#define CMD_AT45_LOAD_BUF2             0x87
+#define CMD_AT45_PROG_BUF1             0x88
+#define CMD_AT45_PROG_BUF2             0x89
+
+/* AT45 status register bits */
+#define AT45_STATUS_P2_PAGE_SIZE       (1 << 0)
+#define AT45_STATUS_READY              (1 << 7)
+
+/* DataFlash family IDs, as obtained from the second idcode byte */
+#define DF_FAMILY_AT26F                        0
+#define DF_FAMILY_AT45                 1
+#define DF_FAMILY_AT26DF               2       /* AT25DF and AT26DF */
+
+struct atmel_spi_flash_params {
+       u8              idcode1;
+       /* Log2 of page size in power-of-two mode */
+       u8              l2_page_size;
+       u8              pages_per_block;
+       u8              blocks_per_sector;
+       u8              nr_sectors;
+       const char      *name;
+};
+
+struct atmel_spi_flash {
+       const struct atmel_spi_flash_params *params;
+       struct spi_flash flash;
+};
+
+static inline struct atmel_spi_flash *
+to_atmel_spi_flash(struct spi_flash *flash)
+{
+       return container_of(flash, struct atmel_spi_flash, flash);
+}
+
+static const struct atmel_spi_flash_params atmel_spi_flash_table[] = {
+       {
+               .idcode1                = 0x28,
+               .l2_page_size           = 10,
+               .pages_per_block        = 8,
+               .blocks_per_sector      = 32,
+               .nr_sectors             = 32,
+               .name                   = "AT45DB642D",
+       },
+};
+
+static int at45_wait_ready(struct spi_flash *flash, unsigned long timeout)
+{
+       struct spi_slave *spi = flash->spi;
+       unsigned long timebase;
+       int ret;
+       u8 cmd = CMD_AT45_READ_STATUS;
+       u8 status;
+
+       timebase = get_timer(0);
+
+       ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN);
+       if (ret)
+               return -1;
+
+       do {
+               ret = spi_xfer(spi, 8, NULL, &status, 0);
+               if (ret)
+                       return -1;
+
+               if (status & AT45_STATUS_READY)
+                       break;
+       } while (get_timer(timebase) < timeout);
+
+       /* Deactivate CS */
+       spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
+
+       if (status & AT45_STATUS_READY)
+               return 0;
+
+       /* Timed out */
+       return -1;
+}
+
+/*
+ * Assemble the address part of a command for AT45 devices in
+ * non-power-of-two page size mode.
+ */
+static void at45_build_address(struct atmel_spi_flash *asf, u8 *cmd, u32 offset)
+{
+       unsigned long page_addr;
+       unsigned long byte_addr;
+       unsigned long page_size;
+       unsigned int page_shift;
+
+       /*
+        * The "extra" space per page is the power-of-two page size
+        * divided by 32.
+        */
+       page_shift = asf->params->l2_page_size;
+       page_size = (1 << page_shift) + (1 << (page_shift - 5));
+       page_shift++;
+       page_addr = offset / page_size;
+       byte_addr = offset % page_size;
+
+       cmd[0] = page_addr >> (16 - page_shift);
+       cmd[1] = page_addr << (page_shift - 8) | (byte_addr >> 8);
+       cmd[2] = byte_addr;
+}
+
+static int dataflash_read_fast_p2(struct spi_flash *flash,
+               u32 offset, size_t len, void *buf)
+{
+       u8 cmd[5];
+
+       cmd[0] = CMD_READ_ARRAY_FAST;
+       cmd[1] = offset >> 16;
+       cmd[2] = offset >> 8;
+       cmd[3] = offset;
+       cmd[4] = 0x00;
+
+       return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len);
+}
+
+static int dataflash_read_fast_at45(struct spi_flash *flash,
+               u32 offset, size_t len, void *buf)
+{
+       struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
+       u8 cmd[5];
+
+       cmd[0] = CMD_READ_ARRAY_FAST;
+       at45_build_address(asf, cmd + 1, offset);
+       cmd[4] = 0x00;
+
+       return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len);
+}
+
+static int dataflash_write_at45(struct spi_flash *flash,
+               u32 offset, size_t len, const void *buf)
+{
+       struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
+       unsigned long page_addr;
+       unsigned long byte_addr;
+       unsigned long page_size;
+       unsigned int page_shift;
+       size_t chunk_len;
+       size_t actual;
+       int ret;
+       u8 cmd[4];
+
+       page_shift = asf->params->l2_page_size;
+       page_size = (1 << page_shift) + (1 << (page_shift - 5));
+       page_shift++;
+       page_addr = offset / page_size;
+       byte_addr = offset % page_size;
+
+       ret = spi_claim_bus(flash->spi);
+       if (ret) {
+               debug("SF: Unable to claim SPI bus\n");
+               return ret;
+       }
+
+       for (actual = 0; actual < len; actual += chunk_len) {
+               chunk_len = min(len - actual, page_size - byte_addr);
+
+               /* Use the same address bits for both commands */
+               cmd[0] = CMD_AT45_LOAD_BUF1;
+               cmd[1] = page_addr >> (16 - page_shift);
+               cmd[2] = page_addr << (page_shift - 8) | (byte_addr >> 8);
+               cmd[3] = byte_addr;
+
+               ret = spi_flash_cmd_write(flash->spi, cmd, 4,
+                               buf + actual, chunk_len);
+               if (ret < 0) {
+                       debug("SF: Loading AT45 buffer failed\n");
+                       goto out;
+               }
+
+               cmd[0] = CMD_AT45_PROG_BUF1;
+               ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
+               if (ret < 0) {
+                       debug("SF: AT45 page programming failed\n");
+                       goto out;
+               }
+
+               ret = at45_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
+               if (ret < 0) {
+                       debug("SF: AT45 page programming timed out\n");
+                       goto out;
+               }
+
+               page_addr++;
+               byte_addr = 0;
+       }
+
+       debug("SF: AT45: Successfully programmed %u bytes @ 0x%x\n",
+                       len, offset);
+       ret = 0;
+
+out:
+       spi_release_bus(flash->spi);
+       return ret;
+}
+
+int dataflash_erase_at45(struct spi_flash *flash, u32 offset, size_t len)
+{
+       struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
+       unsigned long page_addr;
+       unsigned long page_size;
+       unsigned int page_shift;
+       size_t actual;
+       int ret;
+       u8 cmd[4];
+
+       /*
+        * TODO: This function currently uses page erase only. We can
+        * probably speed things up by using block and/or sector erase
+        * when possible.
+        */
+
+       page_shift = asf->params->l2_page_size;
+       page_size = (1 << page_shift) + (1 << (page_shift - 5));
+       page_shift++;
+       page_addr = offset / page_size;
+
+       if (offset % page_size || len % page_size) {
+               debug("SF: Erase offset/length not multiple of page size\n");
+               return -1;
+       }
+
+       cmd[0] = CMD_AT45_ERASE_PAGE;
+       cmd[3] = 0x00;
+
+       ret = spi_claim_bus(flash->spi);
+       if (ret) {
+               debug("SF: Unable to claim SPI bus\n");
+               return ret;
+       }
+
+       for (actual = 0; actual < len; actual += page_size) {
+               cmd[1] = page_addr >> (16 - page_shift);
+               cmd[2] = page_addr << (page_shift - 8);
+
+               ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
+               if (ret < 0) {
+                       debug("SF: AT45 page erase failed\n");
+                       goto out;
+               }
+
+               ret = at45_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
+               if (ret < 0) {
+                       debug("SF: AT45 page erase timed out\n");
+                       goto out;
+               }
+
+               page_addr++;
+       }
+
+       debug("SF: AT45: Successfully erased %u bytes @ 0x%x\n",
+                       len, offset);
+       ret = 0;
+
+out:
+       spi_release_bus(flash->spi);
+       return ret;
+}
+
+struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode)
+{
+       const struct atmel_spi_flash_params *params;
+       unsigned long page_size;
+       unsigned int family;
+       struct atmel_spi_flash *asf;
+       unsigned int i;
+       int ret;
+       u8 status;
+
+       for (i = 0; i < ARRAY_SIZE(atmel_spi_flash_table); i++) {
+               params = &atmel_spi_flash_table[i];
+               if (params->idcode1 == idcode[1])
+                       break;
+       }
+
+       if (i == ARRAY_SIZE(atmel_spi_flash_table)) {
+               debug("SF: Unsupported DataFlash ID %02x\n",
+                               idcode[1]);
+               return NULL;
+       }
+
+       asf = malloc(sizeof(struct atmel_spi_flash));
+       if (!asf) {
+               debug("SF: Failed to allocate memory\n");
+               return NULL;
+       }
+
+       asf->params = params;
+       asf->flash.spi = spi;
+       asf->flash.name = params->name;
+
+       /* Assuming power-of-two page size initially. */
+       page_size = 1 << params->l2_page_size;
+
+       family = idcode[1] >> 5;
+
+       switch (family) {
+       case DF_FAMILY_AT45:
+               /*
+                * AT45 chips have configurable page size. The status
+                * register indicates which configuration is active.
+                */
+               ret = spi_flash_cmd(spi, CMD_AT45_READ_STATUS, &status, 1);
+               if (ret)
+                       goto err;
+
+               debug("SF: AT45 status register: %02x\n", status);
+
+               if (!(status & AT45_STATUS_P2_PAGE_SIZE)) {
+                       asf->flash.read = dataflash_read_fast_at45;
+                       asf->flash.write = dataflash_write_at45;
+                       asf->flash.erase = dataflash_erase_at45;
+                       page_size += 1 << (params->l2_page_size - 5);
+               } else {
+                       asf->flash.read = dataflash_read_fast_p2;
+               }
+
+               break;
+
+       case DF_FAMILY_AT26F:
+       case DF_FAMILY_AT26DF:
+               asf->flash.read = dataflash_read_fast_p2;
+               break;
+
+       default:
+               debug("SF: Unsupported DataFlash family %u\n", family);
+               goto err;
+       }
+
+       asf->flash.size = page_size * params->pages_per_block
+                               * params->blocks_per_sector
+                               * params->nr_sectors;
+
+       debug("SF: Detected %s with page size %u, total %u bytes\n",
+                       params->name, page_size, asf->flash.size);
+
+       return &asf->flash;
+
+err:
+       free(asf);
+       return NULL;
+}
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
new file mode 100644 (file)
index 0000000..d581cb3
--- /dev/null
@@ -0,0 +1,162 @@
+/*
+ * SPI flash interface
+ *
+ * Copyright (C) 2008 Atmel Corporation
+ */
+#define DEBUG
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <spi_flash.h>
+
+#include "spi_flash_internal.h"
+
+int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t len)
+{
+       unsigned long flags = SPI_XFER_BEGIN;
+       int ret;
+
+       if (len == 0)
+               flags |= SPI_XFER_END;
+
+       ret = spi_xfer(spi, 8, &cmd, NULL, flags);
+       if (ret) {
+               debug("SF: Failed to send command %02x: %d\n", cmd, ret);
+               return ret;
+       }
+
+       if (len) {
+               ret = spi_xfer(spi, len * 8, NULL, response, SPI_XFER_END);
+               if (ret)
+                       debug("SF: Failed to read response (%zu bytes): %d\n",
+                                       len, ret);
+       }
+
+       return ret;
+}
+
+int spi_flash_cmd_read(struct spi_slave *spi, const u8 *cmd,
+               size_t cmd_len, void *data, size_t data_len)
+{
+       unsigned long flags = SPI_XFER_BEGIN;
+       int ret;
+
+       if (data_len == 0)
+               flags |= SPI_XFER_END;
+
+       ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, flags);
+       if (ret) {
+               debug("SF: Failed to send read command (%zu bytes): %d\n",
+                               cmd_len, ret);
+       } else if (data_len != 0) {
+               ret = spi_xfer(spi, data_len * 8, NULL, data, SPI_XFER_END);
+               if (ret)
+                       debug("SF: Failed to read %zu bytes of data: %d\n",
+                                       data_len, ret);
+       }
+
+       return ret;
+}
+
+int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
+               const void *data, size_t data_len)
+{
+       unsigned long flags = SPI_XFER_BEGIN;
+       int ret;
+
+       if (data_len == 0)
+               flags |= SPI_XFER_END;
+
+       ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, flags);
+       if (ret) {
+               debug("SF: Failed to send read command (%zu bytes): %d\n",
+                               cmd_len, ret);
+       } else if (data_len != 0) {
+               ret = spi_xfer(spi, data_len * 8, data, NULL, SPI_XFER_END);
+               if (ret)
+                       debug("SF: Failed to read %zu bytes of data: %d\n",
+                                       data_len, ret);
+       }
+
+       return ret;
+}
+
+
+int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
+               size_t cmd_len, void *data, size_t data_len)
+{
+       struct spi_slave *spi = flash->spi;
+       int ret;
+
+       spi_claim_bus(spi);
+       ret = spi_flash_cmd_read(spi, cmd, cmd_len, data, data_len);
+       spi_release_bus(spi);
+
+       return ret;
+}
+
+struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
+               unsigned int max_hz, unsigned int spi_mode)
+{
+       struct spi_slave *spi;
+       struct spi_flash *flash;
+       int ret;
+       u8 idcode[3];
+
+       spi = spi_setup_slave(bus, cs, max_hz, spi_mode);
+       if (!spi) {
+               debug("SF: Failed to set up slave\n");
+               return NULL;
+       }
+
+       ret = spi_claim_bus(spi);
+       if (ret) {
+               debug("SF: Failed to claim SPI bus: %d\n", ret);
+               goto err_claim_bus;
+       }
+
+       /* Read the ID codes */
+       ret = spi_flash_cmd(spi, CMD_READ_ID, &idcode, sizeof(idcode));
+       if (ret)
+               goto err_read_id;
+
+       debug("SF: Got idcode %02x %02x %02x\n", idcode[0],
+                       idcode[1], idcode[2]);
+
+       switch (idcode[0]) {
+#ifdef CONFIG_SPI_FLASH_SPANSION
+       case 0x01:
+               flash = spi_flash_probe_spansion(spi, idcode);
+               break;
+#endif
+#ifdef CONFIG_SPI_FLASH_ATMEL
+       case 0x1F:
+               flash = spi_flash_probe_atmel(spi, idcode);
+               break;
+#endif
+       default:
+               debug("SF: Unsupported manufacturer %02X\n", idcode[0]);
+               flash = NULL;
+               break;
+       }
+
+       if (!flash)
+               goto err_manufacturer_probe;
+
+       spi_release_bus(spi);
+
+       return flash;
+
+err_manufacturer_probe:
+err_read_id:
+       spi_release_bus(spi);
+err_claim_bus:
+       spi_free_slave(spi);
+       return NULL;
+}
+
+void spi_flash_free(struct spi_flash *flash)
+{
+       spi_free_slave(flash->spi);
+       free(flash);
+}
diff --git a/drivers/mtd/spi/spi_flash_internal.h b/drivers/mtd/spi/spi_flash_internal.h
new file mode 100644 (file)
index 0000000..1438050
--- /dev/null
@@ -0,0 +1,45 @@
+/*
+ * SPI flash internal definitions
+ *
+ * Copyright (C) 2008 Atmel Corporation
+ */
+
+/* Common parameters */
+#define SPI_FLASH_PROG_TIMEOUT         ((10 * CFG_HZ) / 1000)
+#define SPI_FLASH_PAGE_ERASE_TIMEOUT   ((50 * CFG_HZ) / 1000)
+#define SPI_FLASH_SECTOR_ERASE_TIMEOUT (10 * CFG_HZ)
+
+/* Common commands */
+#define CMD_READ_ID                    0x9f
+
+#define CMD_READ_ARRAY_SLOW            0x03
+#define CMD_READ_ARRAY_FAST            0x0b
+#define CMD_READ_ARRAY_LEGACY          0xe8
+
+/* Send a single-byte command to the device and read the response */
+int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t len);
+
+/*
+ * Send a multi-byte command to the device and read the response. Used
+ * for flash array reads, etc.
+ */
+int spi_flash_cmd_read(struct spi_slave *spi, const u8 *cmd,
+               size_t cmd_len, void *data, size_t data_len);
+
+/*
+ * Send a multi-byte command to the device followed by (optional)
+ * data. Used for programming the flash array, etc.
+ */
+int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
+               const void *data, size_t data_len);
+
+/*
+ * Same as spi_flash_cmd_read() except it also claims/releases the SPI
+ * bus. Used as common part of the ->read() operation.
+ */
+int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
+               size_t cmd_len, void *data, size_t data_len);
+
+/* Manufacturer-specific probe functions */
+struct spi_flash *spi_flash_probe_spansion(struct spi_slave *spi, u8 *idcode);
+struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode);
diff --git a/include/spi_flash.h b/include/spi_flash.h
new file mode 100644 (file)
index 0000000..de4f174
--- /dev/null
@@ -0,0 +1,70 @@
+/*
+ * Interface to SPI flash
+ *
+ * Copyright (C) 2008 Atmel Corporation
+ *
+ * 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
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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
+ */
+#ifndef _SPI_FLASH_H_
+#define _SPI_FLASH_H_
+
+#include <spi.h>
+
+struct spi_flash_region {
+       unsigned int    count;
+       unsigned int    size;
+};
+
+struct spi_flash {
+       struct spi_slave *spi;
+
+       const char      *name;
+
+       u32             size;
+
+       int             (*read)(struct spi_flash *flash, u32 offset,
+                               size_t len, void *buf);
+       int             (*write)(struct spi_flash *flash, u32 offset,
+                               size_t len, const void *buf);
+       int             (*erase)(struct spi_flash *flash, u32 offset,
+                               size_t len);
+};
+
+struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
+               unsigned int max_hz, unsigned int spi_mode);
+void spi_flash_free(struct spi_flash *flash);
+
+static inline int spi_flash_read(struct spi_flash *flash, u32 offset,
+               size_t len, void *buf)
+{
+       return flash->read(flash, offset, len, buf);
+}
+
+static inline int spi_flash_write(struct spi_flash *flash, u32 offset,
+               size_t len, const void *buf)
+{
+       return flash->write(flash, offset, len, buf);
+}
+
+static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
+               size_t len)
+{
+       return flash->erase(flash, offset, len);
+}
+
+#endif /* _SPI_FLASH_H_ */