Current situation with 4K sectors is quite messy. First of all, some
MTD "users" don't work with such small size. An example may be UBIFS
which requires 15 KiB erase blocks as a minimum. In theory spi-nor
should provide multiple erase regions and MTD "users" should use the
one they need. Unforunately that is not implemented.
In the result our flashes database in spi-nor is hackish. For some
flashes we pretend they don't support 4K sectors just because some
distribution uses UBIFS on it. This ofc leads to conflicts, like
Samsung using w25q128 with 4K sectors vs. OpenWrt requiring it to
pretend it's 64 KiB blocks only.
My idea (plan?) for fixing this situation:
1) Use real hw info (this requires a way for disabling 4K for now)
2) Provide detailed info about erase regions
3) Make UBIFS work with devices that support 4K sectors
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
There's no reason this can't be a module. Also, give SPI-NOR its own
submenu.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
(0) What is the QuadSPI controller?
The QuadSPI(Quad Serial Peripheral Interface) acts as an interface to
one single or two external serial flash devices, each with up to 4
bidirectional data lines.
(1) The QuadSPI controller is driven by the LUT(Look-up Table) registers.
The LUT registers are a look-up-table for sequences of instructions.
A valid sequence consists of four LUT registers.
(2) The definition of the LUT register shows below:
---------------------------------------------------
| INSTR1 | PAD1 | OPRND1 | INSTR0 | PAD0 | OPRND0 |
---------------------------------------------------
There are several types of INSTRx, such as:
CMD : the SPI NOR command.
ADDR : the address for the SPI NOR command.
DUMMY : the dummy cycles needed by the SPI NOR command.
....
There are several types of PADx, such as:
PAD1 : use a singe I/O line.
PAD2 : use two I/O lines.
PAD4 : use quad I/O lines.
....
(3) Test this driver with the JFFS2 and UBIFS:
For jffs2:
-------------
#flash_eraseall /dev/mtd0
#mount -t jffs2 /dev/mtdblock0 tmp
#bonnie++ -d tmp -u 0 -s 10 -r 5
For ubifs:
-------------
#flash_eraseall /dev/mtd0
#ubiattach /dev/ubi_ctrl -m 0
#ubimkvol /dev/ubi0 -N test -m
#mount -t ubifs ubi0:test tmp
#bonnie++ -d tmp -u 0 -s 10 -r 5
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This patch cloned most of the m25p80.c. In theory, it adds a new spi-nor layer.
Before this patch, the layer is like:
MTD
------------------------
m25p80
------------------------
spi bus driver
------------------------
SPI NOR chip
After this patch, the layer is like:
MTD
------------------------
spi-nor
------------------------
m25p80
------------------------
spi bus driver
------------------------
SPI NOR chip
With the spi-nor controller driver(Freescale Quadspi), it looks like:
MTD
------------------------
spi-nor
------------------------
fsl-quadspi
------------------------
SPI NOR chip
New APIs:
spi_nor_scan: used to scan a spi-nor flash.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
[Brian: rebased to include additional m25p_ids[] entry]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
