The intel cfi buffer write has a problem with writing when
the alignment of the buffer in memory is smaller than the
flash bus width.
This patch fixes a alignment problem which may show during this
scenario:
- 32 or 64 attached NOR flash
- flashing an image directly from network to the nor flash
The involved network driver is "smc9111.c".
The data that comes from the network stack and should be written into
the flash isn't 32 bit aligned (at least with this network driver).
This is probably due to the 48 bit wide ethernet addresses.
However the "cfi_flash.c" driver doesn't handle this situation, and
accesses the not-aligned address with a 32 bit pointer.
This patch fixes the problem by reducing the access width if an
aligment problem between source and destination is found.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
'reduce the number of loops by the width of the port' means
a simple len / width. Do not try to be clever by shifting
and doing it wrong.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Fixes:
drivers/usb/gadget/pxa27x_udc.c:1263:13: warning: 'pxa27x_change_interface' defined but not used [-Wunused-function]
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
ISP150x product line have same identifier, we can print these
chips as ISP150x.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Since we do not have ISP1504-related functions, we migrated to ULPI.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Added ULPI detection function.
Same function from isp1504 driver removed.
Used implementation from Linux kernel.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
These registers can be used for any standart ULPI chip,
not only for ISP1504.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Wait until the reset bit is actually cleared instead of some
arbitrary delay (which caused problems with a PHY which was in some
energy saving mode).
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
First check the status at least once, then do timeout checks. Minor
cleanups also.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
We are already setup voltages from capabilities register.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add support for KS8851 16bit MLL chip from Micrel Inc.
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
When programming or erasing a page, don't wait
systematically for 3s, but finish the operation as soon as
the hardware has finished, and timeout if 3 seconds have
passed.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Patch 2c54046510 introduces a private structure
for the S3C based UARTs but still reserves the memory for the smaller
structure which fails at runtime.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This will ensure that we send an other packet only when the first one is send.
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
If a read or write operation encounters an error, the card
might stay in "recv" or "data" state, and never get back to
"tran" state.
In these cases, the host is required to send a CMD12 (end
transmission) to switch the FSM of the card back to "tran"
state, as described in MMC Specification, chapter "Data
Transfer Mode".
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Do not use dev->priv as a register base, but use a driver private
struct instead. Also, remove usage of dev->type_data
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
We currently do not allow to unregister a device when it
has children. However, the return value is seldomly checked.
Also this breaks for hot pluggable devices like USB which we have
to unregister when they disappear. The best way to fix this is to
unregister our children and also the partitions on the unregistered
device.
We unregister the device first and then afterwards the children.
We do this because for example network devices have a miidev as
child which they unregister themselves. So we only have to
unregister the children which are not cleaned up by the drivers,
namely fs devices.
Also, unregister all partitions on a disappearing device.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
As pxafb can rely on a PWM to control backlight, and because
driver dependencies are hard to deal with, remove automatic
enable of PXAFB on probe.
The user should in its environment do a :
- fb0.enable=1
This way, the PWM has been probed and is ready to work, and
the pxafb backlight control works.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add PXA embedded pulse width modulator support. The PWM can
generate signals from 49.6kHz to 1.625MHz.
The driver is for pxa2xx family. The pxa3xx was not handled yet.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add variables to control the duty_ns and period_ns of PWM
chips. When these variables are set, a call to either
pwm_enable() or pwm_config() is performed to enforce the
setup values.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch adds framework support for PWM (pulse width modulation)
devices.
A new pwm can be registered from a hardware driver using
pwmchip_add(). It can then be requested from a client driver using
pwm_request(). A string is used as a unique identifier for the
pwms. It should usually be initialized by the hardware drivers
using dev_name(dev). The client API is the same as currently
in the Linux Kernel.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
First call mii_unregister which is done in the drivers unbind function,
then eth_unregister. Also, remove unregister_device which is done in
eth_unregister.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Whether the controller works in 8bit mode is not only dependent
on the controller but also on the board having wired up 8 data
lines, so put a capabilities field in platform data.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Currently we test the cards capabilities for being 8bit capable.
This does not work since noone ever sets this bit. Unfortunately
there is no bit to test 8bit capability, so we introduce a patch
from the kernel which puts the mmc card into 8bit mode and tests
whether it can succesfully read the ext_csd in this mode.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Too often I have waited to get a reaction from this driver
when something goes wrong. Use timeout loops instead of
inifinite polling loops.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This is quite useful when multiple SD cards are present so spare
some bytes to print this information.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
There will always be the next integer number unless we register
INT_MAX disk devices which is rarely the case.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The mci layer uses pr_debug throughout. Use dev_dbg instead
which is very useful when multiple cards are involved.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The mci layer currently passes around a struct device_d for
its internal use. Apart from being confusing this drops
typesafety for no good reason. Instead, pass around a struct
mci.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The s3c driver passes around a struct device_d * internally in which
it is never interested in. Instead pass around a struct s3c_mci_host
and get rid of all this ugly void * derefs.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Yes, it does make sense. First there will always be the next
hardware which has multiple controllers. Also, we shouldn't
give bad examples to others.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
As we'll need more arguments to set_ios over time put them
in a struct mci_ios like the kernel does.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Whether a card is high capacity is checked in
sd_send_op_cond/mmc_send_op_cond. Remove the wrong check in
mmc_change_freq which wrongly recognizes some eMMC flash
as high capacity.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
When unaligned writes are used, typically doing a cp file /dev/mtdraw0.foo,
the alignement correction code was incorrectly handling such cases, and
didn't return the expected number of written bytes.
This was tested on a 528 block size.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Currently, we can only print the phy_status. Factor out the routine to
get the status, so we can query it from fec drivers and configure
accordingly. Needed because mx28 needs a special bit set for 10Mbit.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Q: "the linux driver add these bits, why not we?"
A: Because nobody activated the bits?
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Introduce a variable which gets updated when needed and only written
once. Will make further additions easier.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
remove double include, remove unused (and double in case of RCNTRL)
defines, sort the includes at least somewhat.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The timings of the poller calling have changed, digging out
a latent bug in pxa27x udc controller.
The polling routine is called before the probe function is
called, and the driver internal are not initialized at that
time. This triggers a NULL pointer exception.
Fix it by moving poller registration after driver probe.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Adding overlay support for i.MX3 sdc.
Foreground channel only works when background is also enabled.
The foreground video mode is always the same as the background.
Also added alpha command to set the alpha value of the foreground.
Tested on a phyCORE-i.MX35.
Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The offset for the IPU Clock in the CGR1 register is 18 not 22.
See MCIMX35RM table 14-17.
Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Make support of multiple video modes possible for i.MX3 boards.
Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The document "PC16550D Universal Asynchronous
Receiver Transmitter with FIFOs" (vers. June 1995,
http://www.national.com/ds/PC/PC16550D.pdf) states
that IER (Interrupt Enable Register) is accessible
if the bit DLAB = 0 (DLAB is bit 7 in LCR; in barebox
DLAB known as LCR_BKSE).
So before IER access we need set DLAB to 0.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
cherry-picked from U-Boot.
commit 69716c1900274a89bd5cbd1b0bb276ceaaa04f61
Author: Jason Kridner <jkridner@beagleboard.org>
Date: Wed Apr 20 08:54:16 2011 -0500
USB: Remove __attribute__ ((packed)) for struct ehci_hccr and ehci_hcor
Remove __attribute__ ((packed)) to prevent byte access to soc
registers in some gcc versions.
Having patches to enable ehci for the BeagleBoard lying around for
several months, this one was the show-stopper.
Switched to align(4), rather than remove the attribute, per suggestion
from Alexander.
Credits have to go to Laine Walker-Avina <lwalkera@ieee.org> for
finding the problem.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
commit 30de24d79fc6e659d0070f6e863ae0e53567ba0e param: add config to disable it
removes param support for xloader configurations. Set param eccmode calls
omap_gpmc_eccmode and so nand_scan_tail. So nand fails without param support
Call omap_gpmc_eccmode directly if CONFIG_PARAMETER is not enabled
to fix that.
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
in commit commit f60f6c58e
atmel_mci: check for device id we use to address the right slot
the driver use the dev_id to detect the slot which is wrong on 9263 as we have
2 devices with 2 slots
use slot_b paramter to specify the slot as done in linux
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Support added for ioctl of ECCGETSTATS and MEMGETREGIONINFO.
Fix default handling in core.c to return -EINVAL, if request
was unknown.
Signed-off-by: Alexander Aring <a.aring@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Without num_modes the imx fb driver won't work. Specify this
in the boards and also bail out in the driver when num_modes
is unspecified.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Change dependencies in Kconfig for twl devices.
Signed-off-by: Alexander Aring <a.aring@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
- add a usbserial command to enable/disable the serial gadget
- allow dfu and usbserial to cohexist in the same barebox
- add a timeout in u_serial so that we don't get locked if the user
enable usbserial from a UART console but doesn't consume the data
on the usbserial port created on the PC
- remove debug or verbose printf
- tested on i.MX25 & i.MX35 & usb-a926x
Signed-off-by: Eric Bénard <eric@eukrea.com>
Tested-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
- bwPollTimeout is set to 10 ms, from the DFU spec, this
is the minimum time, in milliseconds, that the host should
wait before sending a subsequent DFU_GETSTATUS request.
Without this, I get 25 seconds value and dfu-util waits twice 25s
during download
- when in IDLE and receiving DETACH, first return 0 to make
dfu-util happy, then use a dfudetach variable to exit dfu
(without an USB reset as per the comment on line 425) and
return to runtime mode.
- tested on i.MX25 & i.MX35 & usb-a926x
Signed-off-by: Eric Bénard <eric@eukrea.com>
Tested-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
- this patch sync fsl_udc.c with linux's driver,
- add a poller on usb_gadget_poll to get serial gadget working,
- return -EIO in usb_gadget_poll when udc is stopped (do detect
cable disonnection)
- tested on i.MX25 & i.MX35
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
While we are here: do not follow the change of the file name, because there is
no GPIO dependency in this driver.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Commit 88ce7ef769 has changed the API and commit
b29b8f43d5 has moved the S3C24xx NAND driver
file. With the move the API change in the S3C24xx NAND driver was lost.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Commit 88ce7ef769 introduces an additional
parameter to the function add_mtd_device(). It seems one of the callers was
left.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
To get rid of:
(MTD_OOB_DEVICE && MTD_RAW_DEVICE) selects NAND_READ_OOB which has unmet direct dependencies (MTD && NAND)
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The UART is one of the units which differs only slightly inside the S3C family.
Prepare this driver to share it with more recent CPUs.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
There are major differences in the clock tree of the S3C24xx family and the
more recent CPUs of the S3C family. Keep the S3C24XX clock routines separate to
avoid an ifdef hell. But also use generic function names to be able to
share drivers among the S3C family.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This LCD driver is for the LCD controller in the S3C2410/S3C2440 CPUs only.
Change its name to reflect its usage and free the way to add LCD controller
drivers for more recent Samsung CPUs.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The aready existing NAND controller driver in Barebox is for the S3C24XX family
only. Change the name of the file to reflect this fact (and free the way to add
more recent Samsung NAND controllers)
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Start with renaming files to share them in the S3C CPU family,
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Bit errors in the ECC itself are not beeing taken into account.
In this cases the number of detected errors != number of corrected errors and
chien search returns an error.
This patch adds detection of bit errors in the ECC.
Signed-off-by: Steve Schefter <steve@scheftech.com>
Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The clock rate was incorrectly calculated, leading to a
frequency of 19.5MHz / 64 instead of 19.5Mz for the host
controller.
with the fix applied, a copy of a file of 230 kB shrinks
from 6000ms to 123ms.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add the MSystem disk-on-chip G3 support, taken from the
linux kernel with few amendments to bring it into barebox.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
For PIO NAND access functions, we use the features of the SMC:
- no need to take into account the NAND bus width: SMC will deal with this
- use of an IO memcpy on the NAND chip-select space is able to generate
proper SMC behavior.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
introduced in commit f76ad819e4
drivers/mtd: cosmetic changes
it's supposed to the invert of the writesize - 1
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The flags in struct console_device have to be initialized
to zero. Otherwise the following can happen:
- console_register sets the initial baudrate of a new console
before we set the global console init state to CONSOLE_INIT_FULL.
- In console_baudrate_set we test whether the current console is
active which may be true because of unitialized flags.
- we then call getc() to wait for the user to accept the new settings
and we are stuck because of the CONSOLE_UNINITIALIZED state
we will never get anything from getc().
Looking back this explains some cases for me when barebox refused
to start and I really wonder why this did not become a more visible
problem before.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add a device to read and write to MTD data and oob
(/dev/mtdraw<N>).
The device is constrained in a separate source file, so that
further improvement of commands (such as nandwrite) could
make it useless, and easy to remove.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Split /dev/mtd and /dev/mtdoob devices.
Remove from mtd structure the mtdoob character device.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
If multiple MTD devices were registered, an exception
occured, as they all wanted id 0. Let the driver code choose
the device number dynamically.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Change NAND_WRITE into MTD_WRITE.
Change "page_shift" references in the core, which are purely
NAND, into mtd->writesize which is MTD generic.
Rename all "info" (struct mtd_info) into "mtd".
Also provide a parameter to add_mtd_device() so that legacy
nand devices still appear as nand<N>.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Fix whitespace, replace all debug() by dev_dbg(), and fix
line length to 80 characters.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Support the setup of the mmc voltage, when booting OMAP4 with twl6030
from nand.
Signed-off-by: Alexander Aring <a.aring@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Add a general twl device driver twlcore to call i2c send/write
functions.
Abstract twl4030 to call twlcore functions.
Fixed some code-styling issues pointed out by checkpatch.
Signed-off-by: Alexander Aring <a.aring@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Added i2c support for omap4. Tested on pcm049.
Driver based on linux kernel implementation.
Also added a shift to access 16-bit registers
to make support for OMAP730/850 possible.
If accessing a non existing slave the bus will go into arbitration mode.
It's unable to recover from it.
Signed-off-by: Alexander Aring <a.aring@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Increase pxa reading performance by reading 4 bytes at a
time instead of 4 reads of 1 byte.
As the mci controller FIFO accepts reads on bytes, halfwords
or words, use words whenether possible.
The boost is for a 250KBytes file read and display (bmp):
- before: 6900ms
- after: 6000ms
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The write data timeout is too small for old cards,
especially the Transcend 256MBytes SD card. Increase it from
10ms to 100ms.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
As PXA cpus suffer from a silicon bug which prevents them
from being compound devices, forbid use_acm=1 for PXAs.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The NAND_READ_OOB Kconfig option is used to
a) creating a cdev for reading OOB data
b) compiling in mtd->read_oob support
The former was intended and that's also what the Kconfig help
says. The latter though was implicit and wrong. mtd->read_oob
is also used by the bbt code which resulted in a NULL pointer
deref when compiled with BBT but without NAND_READ_OOB.
To fix this, split the option into two. The now invisible
option NAND_OOB_DEVICE is only responsible for b) and gets
selected when necessary.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>