flash

Documentation

Overview

Package flash provides higher-level functions such as reading, erasing, writing and programming the flash chip.

Index

• type Flash
  • func New(spi SPI) (*Flash, error)
  • func (f *Flash) EraseAt(n int64, off int64) (int64, error)
  • func (f *Flash) FillFromSFDP() error
  • func (f *Flash) ProgramAt(p []byte, off int64) (int, error)
  • func (f *Flash) ReadAt(p []byte, off int64) (int, error)
  • func (f *Flash) ReadJEDECID() (uint32, error)
  • func (f *Flash) SFDP() *sfdp.SFDP
  • func (f *Flash) SFDPReader() *SFDPReader
  • func (f *Flash) Size() int64
  • func (f *Flash) WriteAt(p []byte, off int64) (int, error)
• type SFDPReader
  • func (f *SFDPReader) ReadAt(p []byte, off int64) (int, error)
• type SPI

Types

type Flash

type Flash struct {

	// Chip is derived from SFDP or looking up
	// the chip via the ID.
	chips.Chip
	// contains filtered or unexported fields
}

Flash provides operations for SPI flash chips.

func New

func New(spi SPI) (*Flash, error)

New creates a new flash device from a SPI interface.

func (*Flash) EraseAt

func (f *Flash) EraseAt(n int64, off int64) (int64, error)

EraseAt erases n bytes from offset off. Both parameters must be aligned to sectorSize.

func (*Flash) FillFromSFDP

func (f *Flash) FillFromSFDP() error

FillFromSFDP fills the Flash struct with parameters from the SFDP. Querying the SFDP is a bit messy, for each type of parameter, so this code pulls the SFDP parameters into struct members. It also makes the creation of chips a bit easier, when we do not have an SFDP.

func (*Flash) ProgramAt

func (f *Flash) ProgramAt(p []byte, off int64) (int, error)

func (*Flash) ReadAt

func (f *Flash) ReadAt(p []byte, off int64) (int, error)

ReadAt reads from the flash chip.

func (*Flash) ReadJEDECID

func (f *Flash) ReadJEDECID() (uint32, error)

ReadJEDECID reads the flash chip's JEDEC ID.

func (*Flash) SFDP

func (f *Flash) SFDP() *sfdp.SFDP

SFDP returns all the SFDP tables from the flash chip. The value is cached.

func (*Flash) SFDPReader

func (f *Flash) SFDPReader() *SFDPReader

SFDPReader is used to read from the SFDP address space.

func (*Flash) Size

func (f *Flash) Size() int64

Size returns the size of the flash chip in bytes.

func (*Flash) WriteAt

func (f *Flash) WriteAt(p []byte, off int64) (int, error)

WriteAt writes to the flash chip.

For optimal performance, call this function on boundaries of pageSize.

NOTE: This will not erase before writing! The ProgramAt function is probably what you want instead!

type SFDPReader

type SFDPReader Flash

SFDPReader is a wrapper around Flash where the ReadAt function reads from the SFDP address space.

func (*SFDPReader) ReadAt

func (f *SFDPReader) ReadAt(p []byte, off int64) (int, error)

ReadAt reads from the given offset in the SFDP address space.

type SPI

type SPI interface {
	Transfer(transfers []spidev.Transfer) error
	ID() (chips.ID, error)
	Status() (op.Status, error)
}

SPI interface for the underlying calls to the SPI driver.