nuttx/Documentation/components/drivers/special/mtd.rst

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Memory Technology Device Drivers
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- ``include/nuttx/mtd/mtd.h``. All structures and APIs needed
to work with MTD drivers are provided in this header file.
- ``struct mtd_dev_s``. Each MTD device driver must implement
an instance of ``struct mtd_dev_s``. That structure defines a
call table with the following methods:
Erase the specified erase blocks (units are erase blocks):
Read/write from the specified read/write blocks:
Some devices may support byte oriented reads (optional). Most
MTD devices are inherently block oriented so byte-oriented
accesses are not supported. It is recommended that low-level
drivers not support read() if it requires buffering.
Some devices may also support byte oriented writes (optional).
Most MTD devices are inherently block oriented so byte-oriented
accesses are not supported. It is recommended that low-level
drivers not support read() if it requires buffering. This
interface is only available if ``CONFIG_MTD_BYTE_WRITE`` is
defined.
Support other, less frequently used commands:
- ``MTDIOC_GEOMETRY``: Get MTD geometry
- ``MTDIOC_XIPBASE:``: Convert block to physical address for
eXecute-In-Place
- ``MTDIOC_BULKERASE``: Erase the entire device
is provided via a single ``ioctl`` method (see
``include/nuttx/fs/ioctl.h``):
- **Binding MTD Drivers**. MTD drivers are not normally directly
accessed by user code, but are usually bound to another, higher
level device driver. In general, the binding sequence is:
#. Get an instance of ``struct mtd_dev_s`` from the
hardware-specific MTD device driver, and
#. Provide that instance to the initialization method of the
higher level device driver.
- **Examples**: ``drivers/mtd/m25px.c`` and ``drivers/mtd/ftl.c``