linux.git/include/linux/mtd, branch v3.9-rc2

mtd: map: BUG() in non handled cases

2013-02-22T07:22:19+00:00

Several map-related functions look like a serie of ifs, checking
widths of map. Those functions do not have any handling for default
case. Instead of fiddling with uninitialized_var in those functions,
let's just add a (correct) BUG() to the default case on those maps. This
will also allow us to catch potential errors in maps setup in future.

Signed-off-by: Dmitry Eremin-Solenikov 
Signed-off-by: Artem Bityutskiy

mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking

2013-02-04T07:27:33+00:00

Currently cfi_cmdset_0002.c does not support PPB locking of sectors. This
patch adds support for this locking/unlocking mechanism. It is needed on
some platforms, since newer U-Boot versions do support this PPB locking
and protect for example their environment sector(s) this way.

This PPB locking/unlocking will be enabled for all devices supported by
cfi_cmdset_0002 reporting 8 in the CFI word 0x49 (Sector Protect/Unprotect
scheme).

Please note that PPB locking does support sector-by-sector locking. But
the whole chip can only be unlocked together. So unlocking one sector
will automatically unlock all sectors of this device. Because of this
chip limitation, the PPB unlocking function saves the current locking
status of all sectors before unlocking the whole device. After unlocking
the saved locking status is re-configured. This way only the addressed
sectors will be unlocked.

To selectively enable this advanced sector protection mechanism, the
device-tree property "use-advanced-sector-protection" has been created.
To enable support for this locking this property needs to be present in the
flash DT node. E.g.:

nor_flash@0,0 {
	compatible = "amd,s29gl256n", "cfi-flash";
	bank-width = <2>;
	use-advanced-sector-protection;
	...

Tested with Spansion S29GL512S10THI and Micron JS28F512M29EWx flash
devices.

Signed-off-by: Stefan Roese 
Tested-by: Holger Brunck 
Signed-off-by: Artem Bityutskiy

mtd: nand: add NAND_BUSWIDTH_AUTO to autodetect bus width

2012-12-03T14:36:52+00:00

The driver call nand_scan_ident in 8 bit mode, then
readid or onfi detection are done (and detect bus width).
The driver should update its bus width before calling nand_scan_tail.

This work because readid and onfi are read work 8 byte mode.

Note that nand_scan_ident send command (NAND_CMD_RESET, NAND_CMD_READID, NAND_CMD_PARAM), address and read data
The ONFI specificication is not very clear for x16 device if high byte of address should be driven to 0,
but according to [1] it should be ok to not drive it during autodetection.

[1]
3.3.2. Target Initialization

[...]
The Read ID and Read Parameter Page commands only use the lower 8-bits of the data bus.
The host shall not issue commands that use a word data width on x16 devices until the host
determines the device supports a 16-bit data bus width in the parameter page.

Signed-off-by: Matthieu CASTET 
Signed-off-by: Artem Bityutskiy

mtd: mtd_blkdevs: Replace request handler kthread with a workqueue

2012-11-21T15:02:23+00:00

By replacing a kthread with a workqueue, the code is now a bit clearer.
There's also a slight reduction of code size (numbers apply for x86):
Before:
   text	   data	    bss	    dec	    hex	filename
   3248	     36	      0	   3284	    cd4	drivers/mtd/mtd_blkdevs.o

After:
   text	   data	    bss	    dec	    hex	filename
   3150	     36	      0	   3186	    c72	drivers/mtd/mtd_blkdevs.o

Due to lack of real hardware, tests have been performed on an emulated
environment with mtdswap and mtdblock over nandsim devices.
Some real testing should be done, before merging this patch.

Signed-off-by: Ezequiel Garcia 
Signed-off-by: Artem Bityutskiy

mtd: uninitialized variable warning in map.h

2012-11-16T08:57:39+00:00

The map_word_load() function initializes exactly
as many words in the buffer as required, but gcc
cannot figure this out and gives a misleading
warning. Marking the local variable as
uninitialized_var shuts up that warning.

Without this patch, building acs5k_defconfig results in:

drivers/mtd/chips/cfi_cmdset_0002.c: In function 'cfi_amdstd_panic_write':
include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wuninitialized]
drivers/mtd/chips/cfi_cmdset_0002.c: In function 'cfi_amdstd_write_words':
include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wuninitialized]
drivers/mtd/chips/cfi_cmdset_0001.c: In function 'cfi_intelext_write_words':
include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wuninitialized]

Signed-off-by: Arnd Bergmann 
Signed-off-by: Artem Bityutskiy

mtd: diskonchip: use inline functions for DocRead/DocWrite

2012-11-16T08:57:38+00:00

The diskonchip drivers traditionally use home-grown macros for
doing MMIO accesses, which cause a lot of warnings, at least
on ARM machines:

drivers/mtd/devices/doc2000.c: In function 'doc_write':
drivers/mtd/devices/doc2000.c:854:5: warning: value computed is not used [-Wunused-value]
drivers/mtd/devices/doc2000.c: In function 'doc_erase':
drivers/mtd/devices/doc2000.c:1123:5: warning: value computed is not used [-Wunused-value
drivers/mtd/nand/diskonchip.c: In function 'doc2000_read_byte':
drivers/mtd/nand/diskonchip.c:318:3: warning: value computed is not used [-Wunused-value]

A nicer solution is to use the architecture-defined I/O accessors.
Here, we use the __raw_readl/__raw_writel style, instead of the
proper readl/writel ones, in order to preserve the odd semantics
of the existing macros that have their own barrier implementation
and no byte swap. It would be nice to fix this properly and use
the correct accessors as well as make the word size independent
from the architecture, but I guess the hardware is obsolete
enough that we should better not mess the driver an more than
necessary.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Artem Bityutskiy

mtd: map: Fix compilation warning

2012-11-15T17:50:30+00:00

This patch is an attempt to fix following compilation warning.

In file included from drivers/mtd/chips/cfi_cmdset_0001.c:35:0:
drivers/mtd/chips/cfi_cmdset_0001.c: In function 'cfi_intelext_write_words':
include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wmaybe-uninitialized]

I could have used uninitialized_var() too, but didn't used it as the final else
part of map_word_load() is missing. So there is a chance that it might be passed
uninitialized. Better initialize to zero.

Signed-off-by: Viresh Kumar 
Signed-off-by: Artem Bityutskiy

mtd: Fix kernel-doc content to avoid warning.

2012-11-15T13:37:51+00:00

Add missing colons to fix kernel-doc generation warnings.

Signed-off-by: Robert P. J. Day 
Signed-off-by: Artem Bityutskiy

mtd: sh_flctl: Add DMA capabilty

2012-11-15T13:37:50+00:00

The code probes if DMA channels can get allocated and tears them down at
removal/failure if needed.
If available it uses them to transfer the data part (not ECC). On
failure we fall back to PIO mode.

Based on Guennadi Liakhovetski's code from the sh_mmcif driver.

Signed-off-by: Bastian Hecht 
Reviewed-by: Guennadi Liakhovetski 
Signed-off-by: Artem Bityutskiy

mtd: sh_flctl: Minor cleanups

2012-11-15T13:37:50+00:00

Some small fixes to avoid sparse and smatch complain. Other cosmetic fixes
as well.

- Change of the type of the member index in struct sh_flctl from signed
to unsigned. We use index by addressing array members, so unsigned is more
concise here. Adapt functions relying on sh_flctl::index.
- Remove a blurring cast in write_fiforeg().
- Apply consistent naming scheme when refering to the data buffer.
- Shorten some unnecessarily verbose functions.
- Remove spaces at start of lines.

Signed-off-by: Bastian Hecht 
Signed-off-by: Artem Bityutskiy