Diff: mbed-os/features/filesystem/bd/BlockDevice.h

Revision:

1:9c5af431a1f1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/features/filesystem/bd/BlockDevice.h	Tue May 01 15:47:08 2018 +0000
@@ -0,0 +1,223 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef MBED_BLOCK_DEVICE_H
+#define MBED_BLOCK_DEVICE_H
+
+#include <stdint.h>
+
+
+/** Enum of standard error codes
+ *
+ *  @enum bd_error
+ */
+enum bd_error {
+    BD_ERROR_OK                 = 0,     /*!< no error */
+    BD_ERROR_DEVICE_ERROR       = -4001, /*!< device specific error */
+};
+
+/** Type representing the address of a specific block
+ */
+typedef uint64_t bd_addr_t;
+
+/** Type representing a quantity of 8-bit bytes
+ */
+typedef uint64_t bd_size_t;
+
+
+/** A hardware device capable of writing and reading blocks
+ */
+class BlockDevice
+{
+public:
+    /** Lifetime of a block device
+     */
+    virtual ~BlockDevice() {};
+
+    /** Initialize a block device
+     *
+     *  @return         0 on success or a negative error code on failure
+     */
+    virtual int init() = 0;
+
+    /** Deinitialize a block device
+     *
+     *  @return         0 on success or a negative error code on failure
+     */
+    virtual int deinit() = 0;
+
+    /** Ensure data on storage is in sync with the driver
+     *
+     *  @return         0 on success or a negative error code on failure
+     */
+    virtual int sync()
+    {
+        return 0;
+    }
+
+    /** Read blocks from a block device
+     *
+     *  If a failure occurs, it is not possible to determine how many bytes succeeded
+     *
+     *  @param buffer   Buffer to write blocks to
+     *  @param addr     Address of block to begin reading from
+     *  @param size     Size to read in bytes, must be a multiple of read block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int read(void *buffer, bd_addr_t addr, bd_size_t size) = 0;
+
+    /** Program blocks to a block device
+     *
+     *  The blocks must have been erased prior to being programmed
+     *
+     *  If a failure occurs, it is not possible to determine how many bytes succeeded
+     *
+     *  @param buffer   Buffer of data to write to blocks
+     *  @param addr     Address of block to begin writing to
+     *  @param size     Size to write in bytes, must be a multiple of program block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size) = 0;
+
+    /** Erase blocks on a block device
+     *
+     *  The state of an erased block is undefined until it has been programmed,
+     *  unless get_erase_value returns a non-negative byte value
+     *
+     *  @param addr     Address of block to begin erasing
+     *  @param size     Size to erase in bytes, must be a multiple of erase block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int erase(bd_addr_t addr, bd_size_t size)
+    {
+        return 0;
+    }
+
+    /** Mark blocks as no longer in use
+     *
+     *  This function provides a hint to the underlying block device that a region of blocks
+     *  is no longer in use and may be erased without side effects. Erase must still be called
+     *  before programming, but trimming allows flash-translation-layers to schedule erases when
+     *  the device is not busy.
+     *
+     *  @param addr     Address of block to mark as unused
+     *  @param size     Size to mark as unused in bytes, must be a multiple of erase block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int trim(bd_addr_t addr, bd_size_t size)
+    {
+        return 0;
+    }
+
+    /** Get the size of a readable block
+     *
+     *  @return         Size of a readable block in bytes
+     */
+    virtual bd_size_t get_read_size() const = 0;
+
+    /** Get the size of a programmable block
+     *
+     *  @return         Size of a programmable block in bytes
+     *  @note Must be a multiple of the read size
+     */
+    virtual bd_size_t get_program_size() const = 0;
+
+    /** Get the size of an erasable block
+     *
+     *  @return         Size of an erasable block in bytes
+     *  @note Must be a multiple of the program size
+     */
+    virtual bd_size_t get_erase_size() const
+    {
+        return get_program_size();
+    }
+
+    /** Get the size of an erasable block given address
+     *
+     *  @param addr     Address within the erasable block
+     *  @return         Size of an erasable block in bytes
+     *  @note Must be a multiple of the program size
+     */
+    virtual bd_size_t get_erase_size(bd_addr_t addr) const
+    {
+        return get_erase_size();
+    }
+
+    /** Get the value of storage when erased
+     *
+     *  If get_erase_value returns a non-negative byte value, the underlying
+     *  storage is set to that value when erased, and storage containing
+     *  that value can be programmed without another erase.
+     *
+     *  @return         The value of storage when erased, or -1 if you can't
+     *                  rely on the value of erased storage
+     */
+    virtual int get_erase_value() const
+    {
+        return -1;
+    }
+
+    /** Get the total size of the underlying device
+     *
+     *  @return         Size of the underlying device in bytes
+     */
+    virtual bd_size_t size() const = 0;
+
+    /** Convenience function for checking block read validity
+     *
+     *  @param addr     Address of block to begin reading from
+     *  @param size     Size to read in bytes
+     *  @return         True if read is valid for underlying block device
+     */
+    bool is_valid_read(bd_addr_t addr, bd_size_t size) const
+    {
+        return (
+            addr % get_read_size() == 0 &&
+            size % get_read_size() == 0 &&
+            addr + size <= this->size());
+    }
+
+    /** Convenience function for checking block program validity
+     *
+     *  @param addr     Address of block to begin writing to
+     *  @param size     Size to write in bytes
+     *  @return         True if program is valid for underlying block device
+     */
+    bool is_valid_program(bd_addr_t addr, bd_size_t size) const
+    {
+        return (
+            addr % get_program_size() == 0 &&
+            size % get_program_size() == 0 &&
+            addr + size <= this->size());
+    }
+
+    /** Convenience function for checking block erase validity
+     *
+     *  @param addr     Address of block to begin erasing
+     *  @param size     Size to erase in bytes
+     *  @return         True if erase is valid for underlying block device
+     */
+    bool is_valid_erase(bd_addr_t addr, bd_size_t size) const
+    {
+        return (
+            addr % get_erase_size() == 0 &&
+            size % get_erase_size() == 0 &&
+            addr + size <= this->size());
+    }
+};
+
+
+#endif