Roel Kluin [Wed, 10 Jun 2009 04:38:52 +0000 (04:38 +0000)]
block/ps3: remove driver_data direct access of struct device
In the near future, the driver core is going to not allow direct access
to the driver_data pointer in struct device. Instead, the functions
dev_get_drvdata() and dev_set_drvdata() should be used. These functions
have been around since the beginning, so are backwards compatible with
all older kernel versions.
[Geert: Use ps3_system_bus_[gs]et_driver_data() for ps3_system_bus_device]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: Jim Paris <jim@jtan.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Introduce bio_list_peek(), to obtain a pointer to the first bio on the bio_list
without actually removing it from the list. This is needed when you want to
serialize based on the list being empty or not.
Paul Mackerras [Fri, 12 Jun 2009 21:10:05 +0000 (21:10 +0000)]
lib: Provide generic atomic64_t implementation
Many processor architectures have no 64-bit atomic instructions, but
we need atomic64_t in order to support the perf_counter subsystem.
This adds an implementation of 64-bit atomic operations using hashed
spinlocks to provide atomicity. For each atomic operation, the address
of the atomic64_t variable is hashed to an index into an array of 16
spinlocks. That spinlock is taken (with interrupts disabled) around the
operation, which can then be coded non-atomically within the lock.
On UP, all the spinlock manipulation goes away and we simply disable
interrupts around each operation. In fact gcc eliminates the whole
atomic64_lock variable as well.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Paul Mackerras [Fri, 12 Jun 2009 02:00:50 +0000 (02:00 +0000)]
powerpc: Add compiler memory barrier to mtmsr macro
On 32-bit non-Book E, local_irq_restore() turns into just mtmsr(),
which doesn't currently have a compiler memory barrier. This means
that accesses to memory inside a local_irq_save/restore section,
or a spin_lock_irqsave/spin_unlock_irqrestore section on UP, can
be reordered by the compiler to occur outside that section.
To fix this, this adds a compiler memory barrier to mtmsr for both
32-bit and 64-bit. Having a compiler memory barrier in mtmsr makes
sense because it will almost always be changing something about the
context in which memory accesses are done, so in general we don't want
memory accesses getting moved from one side of an mtmsr to the other.
With the barrier in mtmsr(), some of the explicit barriers in
hw_irq.h are now redundant, so this removes them.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Ellerman [Thu, 11 Jun 2009 02:18:49 +0000 (02:18 +0000)]
powerpc/iseries: Mark signal_vsp_instruction() as maybe unused
signal_vsp_instruction() is currently only used if CONFIG_PROC_FS
is enabled. However logically it has nothing to do with PROC_FS,
so rather than making it depend on that mark it as maybe unused.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Ellerman [Thu, 11 Jun 2009 02:18:26 +0000 (02:18 +0000)]
powerpc/iseries: Fix unused function warning in iSeries DT code
If CONFIG_BLK_DEV_INITRD is unset dt_prop_u64() is unused, which
causes a warning. We don't really want to tie the definition to
BLK_DEV_INITRD, so mark it as maybe unused.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Ellerman [Thu, 11 Jun 2009 02:12:28 +0000 (02:12 +0000)]
powerpc: Only build prom_init.o when CONFIG_PPC_OF_BOOT_TRAMPOLINE=y
Commit 28794d34 ("powerpc/kconfig: Kill PPC_MULTIPLATFORM"), added
CONFIG_PPC_OF_BOOT_TRAMPOLINE to control the buliding of prom_init.o
However the Makefile still unconditionally builds prom_init_check,
the script that checks prom_init.o for symbol usage, and so in turn
prom_init.o is still always being built. (it's not linked though)
So surround all the prom_init_check logic with an ifeq block testing
if CONFIG_PPC_OF_BOOT_TRAMPOLINE is set.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Ellerman [Wed, 10 Jun 2009 19:05:00 +0000 (19:05 +0000)]
powerpc: Fix warning in setup_64.c when CONFIG_RELOCATABLE=y
When CONFIG_RELOCATABLE is enabled, PHYSICAL_START is actually a
variable of type phys_addr_t. That means to print it we need to
cast to unsigned long long and use llx.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
- Make the IOMMU flags used for mapping main memory into the GPU's I/O space
explicit, instead of relying on the default in the hypervisor,
- Add missing calls to lv1_gpu_context_iomap(..., CBE_IOPTE_M) to unmap the
memory during cleanup.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: Jim Paris <jim@jtan.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
- Make the IOMMU flags used for mapping main memory into the GPU's I/O space
explicit, instead of relying on the default in the hypervisor,
- Add missing calls to lv1_gpu_context_iomap(..., CBE_IOPTE_M) to unmap the
memory during cleanup.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: linux-fbdev-devel@lists.sourceforge.net Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
powerpc/cell: Extract duplicated IOPTE_* to <asm/iommu.h>
Both arch/powerpc/platforms/cell/iommu.c and arch/powerpc/platforms/ps3/mm.c
contain the same Cell IOMMU page table entry definitions. Extract them and move
them to <asm/iommu.h>, while adding a CBE_ prefix.
This also allows them to be used by drivers.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently we are wasting time calling the generic calibrate_delay()
function. We don't need it since our implementation of __delay() is
based on the CPU timebase. So instead, we use our own small
implementation that initializes loops_per_jiffy to something sensible
to make the few users like spinlock debug be happy
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Grant Likely [Sat, 6 Jun 2009 06:39:46 +0000 (06:39 +0000)]
powerpc/install: Bail with error code on error in install script
If anything goes wrong when copying images into the install path, then
the install script should exit with an error code so that 'make' knows
about it and tells the user.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Linus Torvalds [Sun, 14 Jun 2009 21:12:18 +0000 (14:12 -0700)]
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next: (53 commits)
.gitignore: ignore *.lzma files
kbuild: add generic --set-str option to scripts/config
kbuild: simplify argument loop in scripts/config
kbuild: handle non-existing options in scripts/config
kallsyms: generalize text region handling
kallsyms: support kernel symbols in Blackfin on-chip memory
documentation: make version fix
kbuild: fix a compile warning
gitignore: Add GNU GLOBAL files to top .gitignore
kbuild: fix delay in setlocalversion on readonly source
README: fix misleading pointer to the defconf directory
vmlinux.lds.h update
kernel-doc: cleanup perl script
Improve vmlinux.lds.h support for arch specific linker scripts
kbuild: fix headers_exports with boolean expression
kbuild/headers_check: refine extern check
kbuild: fix "Argument list too long" error for "make headers_check",
ignore *.patch files
Remove bashisms from scripts
menu: fix embedded menu presentation
...
Linus Torvalds [Sun, 14 Jun 2009 20:53:22 +0000 (13:53 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
mlx4_core: Don't double-free IRQs when falling back from MSI-X to INTx
IB/mthca: Don't double-free IRQs when falling back from MSI-X to INTx
IB/mlx4: Add strong ordering to local inval and fast reg work requests
IB/ehca: Remove superfluous bitmasks from QP control block
RDMA/cxgb3: Limit fast register size based on T3 limitations
RDMA/cxgb3: Report correct port state and MTU
mlx4_core: Add module parameter for number of MTTs per segment
IB/mthca: Add module parameter for number of MTTs per segment
RDMA/nes: Fix off-by-one bugs in reset_adapter_ne020() and init_serdes()
infiniband: Remove void casts
IB/ehca: Increment version number
IB/ehca: Remove unnecessary memory operations for userspace queue pairs
IB/ehca: Fall back to vmalloc() for big allocations
IB/ehca: Replace vmalloc() with kmalloc() for queue allocation
In addition to KT_DEAD which has limited support for diacriticals,
there is KT_DEAD2 that can support 256 criticals, so let's advertise
it in <linux/keyboard.h>.
This lets userland know abut the drivers/char/keyboard.c function
k_dead2, which supports more than the few trivial ones that k_dead
supports.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 14 Jun 2009 20:46:57 +0000 (13:46 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc: (25 commits)
atmel-mci: add MCI2 register definitions
atmel-mci: Integrate AT91 specific definition in header file
tmio_mmc: allow compilation for ASIC3
mmc_block: do not DMA to stack
sdhci: Print ADMA status and pointer on debug
tmio_mmc: fix clock setup
tmio_mmc: map SD control registers after enabling the MFD cell
tmio_mmc: correct probe return value for num_resources != 3
tmio_mmc: don't use set_irq_type
tmio_mmc: add bus_shift support
MFD,mmc: tmio_mmc: make HCLK configurable
mmc_spi: don't use EINVAL for possible transmission errors
cb710: more cleanup for the DEBUG case.
sdhci: platform driver for SDHCI
mxcmmc: remove frequency workaround
cb710: handle DEBUG define in Makefile
cb710: add missing parenthesis
cb710: fix printk format string
mmc: Driver for CB710/720 memory card reader (MMC part)
pxamci: add regulator support.
...
Linus Torvalds [Sun, 14 Jun 2009 20:45:49 +0000 (13:45 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: fix inverted wheel for bluetooth version of apple mighty mouse
HID: no more reinitializtion is needed in post_reset
HID: hidraw -- fix comment about accepted devices
HID: Multitouch support for the N-Trig touchscreen
HID: add new multitouch and digitizer contants
HID: autocentering support for Logitech Force 3D Pro
HID: fix hid-ff drivers so that devices work even without ff support
HID: force feedback support for SmartJoy PLUS PS2/USB adapter
HID: Wacom Graphire Bluetooth driver
HID: autocentering support for Logitech G25 Racing Wheel
Robin Getz [Mon, 10 Jul 2006 06:25:40 +0000 (06:25 +0000)]
kallsyms: support kernel symbols in Blackfin on-chip memory
The Blackfin arch has a discontiguous .text layout due to having on-chip
instruction memory and no virtual memory support. As such, we need to
add explicit checks for these additional .text regions.
Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Linus Torvalds [Sun, 14 Jun 2009 20:42:43 +0000 (13:42 -0700)]
Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (417 commits)
MAINTAINERS: EB110ATX is not ebsa110
MAINTAINERS: update Eric Miao's email address and status
fb: add support of LCD display controller on pxa168/910 (base layer)
[ARM] 5552/1: ep93xx get_uart_rate(): use EP93XX_SYSCON_PWRCNT and EP93XX_SYSCON_PWRCN
[ARM] pxa/sharpsl_pm: zaurus needs generic pxa suspend/resume routines
[ARM] 5544/1: Trust PrimeCell resource sizes
[ARM] pxa/sharpsl_pm: cleanup of gpio-related code.
[ARM] pxa/sharpsl_pm: drop set_irq_type calls
[ARM] pxa/sharpsl_pm: merge pxa-specific code into generic one
[ARM] pxa/sharpsl_pm: merge the two sharpsl_pm.c since it's now pxa specific
[ARM] sa1100: remove unused collie_pm.c
[ARM] pxa: fix the conflicting non-static declarations of global_gpios[]
[ARM] 5550/1: Add default configure file for w90p910 platform
[ARM] 5549/1: Add clock api for w90p910 platform.
[ARM] 5548/1: Add gpio api for w90p910 platform
[ARM] 5551/1: Add multi-function pin api for w90p910 platform.
[ARM] Make ARM_VIC_NR depend on ARM_VIC
[ARM] 5546/1: ARM PL022 SSP/SPI driver v3
ARM: OMAP4: SMP: Update defconfig for OMAP4430
ARM: OMAP4: SMP: Enable SMP support for OMAP4430
...
The Makefiles in the build directories use the internal make variable
MAKEFILE_LIST which is available from make 3.80 only. (The patch would be
valid back to 2.6.25)
Signed-off-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Roland Dreier [Sun, 14 Jun 2009 20:30:45 +0000 (13:30 -0700)]
mlx4_core: Don't double-free IRQs when falling back from MSI-X to INTx
When both MSI-X and legacy INTx fail to generate an interrupt, the
driver frees the MSI-X interrupts twice. Fix this by clearing the
have_irq flag for the MSI-X interrupts when they are freed the first
time. This is the same bug that was reported in ib_mthca by Yinghai
Lu <yhlu.kernel@gmail.com>.
Nicolas Pitre [Fri, 12 Jun 2009 02:09:29 +0000 (03:09 +0100)]
[ARM] 5545/2: add flush_kernel_dcache_page() for ARM
Without this, the default implementation is a no op which is completely
wrong with a VIVT cache, and usage of sg_copy_buffer() produces
unpredictable results.
Tested-by: Sebastian Andrzej Siewior <bigeasy@breakpoint.cc> CC: stable@kernel.org Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Roland Dreier [Sat, 13 Jun 2009 22:14:09 +0000 (15:14 -0700)]
IB/mthca: Don't double-free IRQs when falling back from MSI-X to INTx
When both MSI-X and legacy INTx fail to generate an interrupt, the
driver frees the MSI-X interrupts twice. Fix this by clearing the
have_irq flag for the MSI-X interrupts when they are freed the first
time.
Reported-by: Yinghai Lu <yhlu.kernel@gmail.com> Tested-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
Ben Dooks [Mon, 8 Jun 2009 22:33:57 +0000 (23:33 +0100)]
mmc_block: do not DMA to stack
In the write recovery routine, the data to get from the card
is allocated from the stack. The DMA mapping documentation says
explicitly stack memory is not mappable by any of the DMA calls.
Change to using kmalloc() to allocate the memory for the result
from the card and then free it once we've finished with the
transaction.
[ Changed to GFP_KERNEL allocation - Pierre Ossman ]
Signed-off-by: Ben Dooks <ben@simtec.co.uk> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Ian Molton [Fri, 12 Jun 2009 20:53:05 +0000 (21:53 +0100)]
tmio_mmc: fix clock setup
This patch fixes the clock setup in tmio_mmc.
* Incorrect divider setting
* Cruft written to the clock registers (seemingly harmless but Not
Good (tm))
It also eliminates some unnecessary ifs and tidies the loop syntax.
Thanks to Philipp Zabel who discovered the divider issue, commenting
"Except for the SDCLK = HCLK (divider bypassed) case, the clock
setting resulted in double the requested frequency.
The smallest possible frequency (f_max/512) is configured with
a divider setting 0x80, not 0x40."
Signed-off-by: Ian Molton <ian@mnementh.co.uk> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Philipp Zabel [Thu, 4 Jun 2009 18:12:32 +0000 (20:12 +0200)]
tmio_mmc: add bus_shift support
Some ASIC3 devices in the wild are connected with the address bus shifted
by one line, so that its 16-bit registers appear 32-bit aligned in host
memory space.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com> Acked-by: Ian Molton <ian@mnementh.co.uk> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Philipp Zabel [Thu, 4 Jun 2009 18:12:31 +0000 (20:12 +0200)]
MFD,mmc: tmio_mmc: make HCLK configurable
The Toshiba parts all have a 24 MHz HCLK, but HTC ASIC3 has a 24.576 MHz HCLK
and AMD Imageon w228x's HCLK is 80 MHz. With this patch, the MFD driver
provides the HCLK frequency to tmio_mmc via mfd_cell->driver_data.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com> Acked-by: Ian Molton <ian@mnementh.co.uk> Acked-by: Samuel Ortiz <sameo@openedhand.com> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Wolfgang Muees [Tue, 26 May 2009 07:56:19 +0000 (08:56 +0100)]
mmc_spi: don't use EINVAL for possible transmission errors
This patch changes the reported error code for the responses
to a command from EINVAL to EFAULT/ENOSYS, as EINVAL is reserved
for non-recoverable host errors, and the responses from
the SD/MMC card may be because of recoverable transmission
errors in the command or in the response. Response codes
in SPI mode are NOT protected by a checksum, so don't trust them.
Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de> Acked-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Michał Mirosław [Fri, 22 May 2009 18:33:59 +0000 (20:33 +0200)]
mmc: Driver for CB710/720 memory card reader (MMC part)
The code is divided in two parts. There is a virtual 'bus' driver
that handles PCI device and registers three new devices one per card
reader type. The other driver handles SD/MMC part of the reader.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Daniel Ribeiro [Thu, 21 May 2009 11:54:18 +0000 (08:54 -0300)]
pxamci: add regulator support.
Changes pxamci.c to use the regulator subsystem. Uses the regulator case
CONFIG_REGULATOR is defined and a matching is regulator is provided, or
falls back to pdata->setpower otherwise. A warning is displayed case
both a valid regulator and pdata is set, and the regulator is used.
Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com> Acked-by: Eric Miao <eric.miao@marvell.com> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
mmc/omap: make mmci-omap using platform_driver_probe
A pointer to mmc_omap_probe which lives in .init.text is passed to the
core via platform_driver_register and so the kernel might oops if probe
is called after the init code is discarded.
As requested by David Brownell platform_driver_probe is used instead of
moving the probe function to .devinit.text. This saves some memory, but
might have the downside that a device being registered after the call to
mmc_omap_init but before the init sections are discarded will not be
bound anymore to the driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Wolfgang Muees [Wed, 8 Apr 2009 09:14:07 +0000 (10:14 +0100)]
mmc_spi: speedup for slow cards, less wear-out
Speedup for slow cards by transfering more data at once.
This patch also reduces the amount of wear-out of the flash
blocks because fewer partial blocks are written.
Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
Jorg Schummer [Tue, 31 Mar 2009 14:51:21 +0000 (17:51 +0300)]
mmc: mmc_rescan detects card change in one run
With this patch, mmc_rescan can detect the removal of an mmc card and
the insertion of (possibly another) card in the same run. This means
that a card change can be detected without having to call
mmc_detect_change multiple times.
This change generalises the core such that it can be easily used by
hosts which provide a mechanism to detect only the presence of a card
reader cover, which has to be taken off in order to insert a card. Other
hosts ("card detect" or "MMC_CAP_NEEDS_POLL") each receive an event when
a card is removed and when a card is inserted, so it is sufficient for
them if mmc_rescan handles only one event at a time. "Cover detect"
hosts, however, only receive events about the cover status. This means
that between 2 subsequent events, both a card removal and a card
insertion can occur. In this case, the pre-patch version of mmc_rescan
would only detect the removal of the previous card but not the insertion
of the new card.
Signed-off-by: Jorg Schummer <ext-jorg.2.schummer@nokia.com> Signed-off-by: Pierre Ossman <pierre@ossman.eu>
* git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6:
avr32: Fix oops on unaligned user access
avr32: Add support for Mediama RMTx add-on board for ATNGW100
avr32: Change Atmel ATNGW100 config to add choice of add-on board
Fix MIMC200 board LCD init
avr32: Fix clash in ATMEL_USART_ flags
avr32: remove obsolete hw_interrupt_type
avr32: Solves problem with inverted MCI detect pin on Merisc board
atmel-mci: Add support for inverted detect pin
The problem is that asm/signal.h has been made to include asm-generic/signal.h,
but the redundant stuff from asm/signal.h has not been discarded, leading to
multiple redefinitions.
Linus Torvalds [Sat, 13 Jun 2009 20:15:59 +0000 (13:15 -0700)]
Merge branch 'next-i2c' of git://aeryn.fluff.org.uk/bjdooks/linux
* 'next-i2c' of git://aeryn.fluff.org.uk/bjdooks/linux:
i2c-ocores: Can add I2C devices to the bus
i2c-s3c2410: move to using platform idtable to match devices
i2c: OMAP3: Better noise suppression for fast/standard modes
i2c: OMAP2/3: Fix scll/sclh calculations
i2c: Blackfin TWI: implement I2C_FUNC_SMBUS_I2C_BLOCK functionality
i2c: Blackfin TWI: fix transfer errors with repeat start
i2c: Blackfin TWI: fix REPEAT START mode doesn't repeat
i2c: Blackfin TWI: make sure we don't end up with a CLKDIV=0