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The Nomadik I2C block was introduced with the Nomadik STn8815
SoC (the STn8810 incidentally is identical to the one named
i2c-stu300.c). However as developments have only been tested
on the DB8500 family, it was not properly working with the
STn8815 anymore.
Rectify this by adding some vendor variant data in the same
manner as other PrimeCells, and switch code path depending
on version.
Tested on the S8815 Nomadik dongle.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Add the compatible string for the Allwinner A10 i2c controller and the
associated register layout.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The Allwinner i2c controller uses the same logic as the Marvell one, but
with slightly different register offsets.
Introduce a structure that will be passed by either the pdata or
associated to the compatible strings, and that holds the various
registers that might be needed.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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These macros make it more comprehensive to access to useful masked and
shifted area of the various registers used.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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This patch adds support for the I2C bus controllers found on Wondermedia
8xxx-series SoCs. Only master-mode is supported.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
[wsa: fixed one macro to shift 8 instead of 16]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The designware block is not always properly disabled in the case of
transfer errors. Interrupts from aborted transfers might be handled
after the data structures for the following transfer are initialised but
before the hardware is set up. This can corrupt the data structures to
the point that the system is stuck in an infinite interrupt loop (where
FIFOs are never emptied because dev->msg_read_idx == dev->msgs_num).
This patch cleanly disables the designware-i2c hardware at the end of
every transfer, be it successful or not.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
[wsa: extended the comment]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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TWI transfer interrupts may be lost when system is heavily handling other
interrupts, while current transfer handler depends on each accurate interrupt
and misses some data in this case. Because there are 2 2-byte FIFOs in blackfin
TWI controller, the occurrence of the data loss can be reduced by reading till
the RX FIFO is empty and writing till the TX FIFO is full.
Reported-by: Bob Maris <mail@maris-ee.eu>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Use the wrapper functions for getting and setting the driver data using
platform_device instead of using dev_{get,set}_drvdata() with &pdev->dev,
so we can directly pass a struct platform_device.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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If a process receives signal while it is waiting for I2C transfer to
complete, an error is returned to the caller and the transfer is aborted.
This can cause the driver to fail subsequent transfers. Also according to
commit d295a86eab2 (i2c: mv64xxx: work around signals causing I2C
transactions to be aborted) I2C drivers aren't supposed to abort
transactions on signals.
To prevent this switch to use wait_for_completion_timeout() instead of
wait_for_completion_interruptible_timeout() in the designware I2C driver.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Since commit ab78029 (drivers/pinctrl: grab default handles from device core),
we can rely on device core for handling pinctrl.
So remove devm_pinctrl_get_select_default() from the driver.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Since commit ab78029 (drivers/pinctrl: grab default handles from device core),
we can rely on device core for handling pinctrl.
So remove devm_pinctrl_get_select_default() from the driver.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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CAVIUM_OCTEON_SOC most place we used to use CPU_CAVIUM_OCTEON. This
allows us to CPU_CAVIUM_OCTEON in places where we have no OCTEON SOC.
Remove CAVIUM_OCTEON_SIMULATOR as it doesn't really do anything, we can
get the same configuration with CAVIUM_OCTEON_SOC.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-ide@vger.kernel.org
Cc: linux-edac@vger.kernel.org
Cc: linux-i2c@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: spi-devel-general@lists.sourceforge.net
Cc: devel@driverdev.osuosl.org
Cc: linux-usb@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Patchwork: https://patchwork.linux-mips.org/patch/5295/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Asking for a multi-part message to be handled by this driver is racy; it
has been observed that the following sequence is possible with this
driver:
- send start
- send address + write
- send data
- send (repeated) start
- send address + write
- send (repeated) start
- send address + read
- unrecoverable bus hang (except by system reset)
The problem is that the interrupt handling sees the next event after the
first repeated start is sent - the IFLG bit is set in the register even
though INTEN is disabled.
Let's fix this by moving all of the message processing into interrupt
context, rather than having it partly in IRQ and partly in process
context. This allows us to move immediately to the next message in the
interrupt handler and get on with the transfer, rather than incuring a
couple of scheduling switches to get the next message.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Move mv64xxx_i2c_prepare_for_io() higher up in the driver to avoid a
future forward declaration for this function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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As this driver does not advertise protocol mangling support
(I2C_FUNC_PROTOCOL_MANGLING is not set), having code to act on
I2C_M_NOSTART is illogical, and in any case isn't supportable on
anything but the first message - which makes no sense. Remove
the I2C_M_NOSTART code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Propagate the error code from request_irq() rather than ignoring it
entirely.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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As we're changing to using devm_* APIs to fix various problems
in this driver, lets also do devm_kzalloc() while we're here too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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This driver forgets to use clk_put(). Rather than adding clk_put(),
lets instead use devm_clk_get() to obtain this clock so that it's
automatically handled on cleanup.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Eliminate reg_base_p and reg_size, mv64xxx_i2c_unmap_regs() and an
unchecked ioremap() return from this driver by using the devm_*
API for requesting and ioremapping resources.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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mv64xxx_i2c_map_regs() already returns an error code, so lets
propagate that to mv64xxx_i2c_probe()'s caller.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Moorestown support is removed from kernel and Medfield is supported by
i2c-designware-pci. But i2c-intel-mid is still in upstream and community
resources are wasted to maintain it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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To add AMD CZ SMBus controller device ID.
[bhelgaas: drop pci_ids.h update]
Signed-off-by: Shane Huang <shane.huang@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@vger.kernel.org
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This adds device tree support for the ST DDC I2C driver known
as "stu300" in the kernel tree.
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c bugfixes from Wolfram Sang:
"These should have been in rc2 but I missed it due to working on devm
longer than expected.
There is one ID addition, since we are touching the driver anyhow.
And the feature bit documentation is one outcome of a debug session
and will make it easier for users to work around problems. The rest
is typical driver bugfixes."
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: suppress lockdep warning on delete_device
i2c: mv64xxx: work around signals causing I2C transactions to be aborted
i2c: i801: Document feature bits in modinfo
i2c: designware: add Intel BayTrail ACPI ID
i2c: designware: always clear interrupts before enabling them
i2c: designware: fix RX FIFO overrun
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devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Barry Song <Baohua.Song@csr.com>
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Do not use interruptible waits in an I2C driver; if a process uses
signals (eg, Xorg uses SIGALRM and SIGPIPE) then these signals can
cause the I2C driver to abort a transaction in progress by another
driver, which can cause that driver to fail. I2C drivers are not
expected to abort transactions on signals.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Duplicate the feature bits documentation in modinfo, as not every user
will read the driver's source code or documentation file.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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This is the same controller as on Intel Lynxpoint but the ACPI ID is
different (8086F41). Add support for this.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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If the I2C bus is put to a low power state by an ACPI method it might pull
the SDA line low (as its power is removed). Once the bus is put to full
power state again, the SDA line is pulled back to high. This transition
looks like a STOP condition from the controller point-of-view which sets
STOP detected bit in its status register causing the driver to fail
subsequent transfers.
Fix this by always clearing all interrupts before we start a transfer.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
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i2c_dw_xfer_msg() pushes a number of bytes to transmit/receive
to/from the bus into the TX FIFO.
For master-rx transactions, the maximum amount of data that can be
received is calculated depending solely on TX and RX FIFO load.
This is racy - TX FIFO may contain master-rx data yet to be
processed, which will eventually land into the RX FIFO. This
data is not taken into account and the function may request more
data than the controller is actually capable of storing.
This patch ensures the driver takes into account the outstanding
master-rx data in TX FIFO to prevent RX FIFO overrun.
Signed-off-by: Josef Ahmad <josef.ahmad@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
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Pull removal of GENERIC_GPIO from Grant Likely:
"GENERIC_GPIO now synonymous with GPIOLIB. There are no longer any
valid cases for enableing GENERIC_GPIO without GPIOLIB, even though it
is possible to do so which has been causing confusion and breakage.
This branch does the work to completely eliminate GENERIC_GPIO."
* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux:
gpio: update gpio Chinese documentation
Remove GENERIC_GPIO config option
Convert selectors of GENERIC_GPIO to GPIOLIB
blackfin: force use of gpiolib
m68k: coldfire: use gpiolib
mips: pnx833x: remove requirement for GENERIC_GPIO
openrisc: default GENERIC_GPIO to false
avr32: default GENERIC_GPIO to false
xtensa: remove explicit selection of GENERIC_GPIO
sh: replace CONFIG_GENERIC_GPIO by CONFIG_GPIOLIB
powerpc: remove redundant GENERIC_GPIO selection
unicore32: default GENERIC_GPIO to false
unicore32: remove unneeded select GENERIC_GPIO
arm: plat-orion: use GPIO driver on CONFIG_GPIOLIB
arm: remove redundant GENERIC_GPIO selection
mips: alchemy: require gpiolib
mips: txx9: change GENERIC_GPIO to GPIOLIB
mips: loongson: use GPIO driver on CONFIG_GPIOLIB
mips: remove redundant GENERIC_GPIO select
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC device tree updates (part 2) from Arnd Bergmann:
"These are mostly new device tree bindings for existing drivers, as
well as changes to the device tree source files to add support for
those devices, and a couple of new boards, most notably Samsung's
Exynos5 based Chromebook.
The changes depend on earlier platform specific updates and touch the
usual platforms: omap, exynos, tegra, mxs, mvebu and davinci."
* tag 'dt-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (169 commits)
ARM: exynos: dts: cros5250: add EC device
ARM: dts: Add sbs-battery for exynos5250-snow
ARM: dts: Add i2c-arbitrator bus for exynos5250-snow
ARM: dts: add mshc controller node for Exynos4x12 SoCs
ARM: dts: Add chip-id controller node on Exynos4/5 SoC
ARM: EXYNOS: Create virtual I/O mapping for Chip-ID controller using device tree
ARM: davinci: da850-evm: add SPI flash support
ARM: davinci: da850: override SPI DT node device name
ARM: davinci: da850: add SPI1 DT node
spi/davinci: add DT binding documentation
spi/davinci: no wildcards in DT compatible property
ARM: dts: mvebu: Convert mvebu device tree files to 64 bits
ARM: dts: mvebu: introduce internal-regs node
ARM: dts: mvebu: Convert all the mvebu files to use the range property
ARM: dts: mvebu: move all peripherals inside soc
ARM: dts: mvebu: fix cpus section indentation
ARM: davinci: da850: add EHRPWM & ECAP DT node
ARM/dts: OMAP3: fix pinctrl-single configuration
ARM: dts: Add OMAP3430 SDP NOR flash memory binding
ARM: dts: Add NOR flash bindings for OMAP2420 H4
...
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This is support for the ARM Chromebook, originally scheduled
as a "late" pull request. Since it's already late now, we
can combine this into the existing next/dt2 branch.
* late/dt:
ARM: exynos: dts: cros5250: add EC device
ARM: dts: Add sbs-battery for exynos5250-snow
ARM: dts: Add i2c-arbitrator bus for exynos5250-snow
ARM: dts: Add chip-id controller node on Exynos4/5 SoC
ARM: EXYNOS: Create virtual I/O mapping for Chip-ID controller using device tree
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c changes from Wolfram Sang:
- an arbitration driver. While the driver is quite simple, it caused
discussion if we need additional arbitration on top of the one
specified in the I2C standard. Conclusion is that I accept a few
generic mechanisms, but not very specific ones.
- the core lost the detach_adapter() call. It has no users anymore and
was in the way for other cleanups. attach_adapter() is sadly still
there since there are users waiting to be converted.
- the core gained a bus recovery infrastructure. I2C defines a way to
recover if the data line is stalled. This mechanism is now in the
core and drivers can now pass some data to make use of it.
- bigger driver cleanups for designware, s3c2410
- removing superfluous refcounting from drivers
- removing Ben Dooks as second maintainer due to inactivity. Thanks
for all your work so far, Ben!
- bugfixes, feature additions, devicetree fixups, simplifications...
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (38 commits)
i2c: xiic: must always write 16-bit words to TX_FIFO
i2c: octeon: use HZ in timeout value
i2c: octeon: Fix i2c fail problem when a process is terminated by a signal
i2c: designware-pci: drop superfluous {get|put}_device
i2c: designware-plat: drop superfluous {get|put}_device
i2c: davinci: drop superfluous {get|put}_device
MAINTAINERS: Ben Dooks is inactive regarding I2C
i2c: mux: Add i2c-arb-gpio-challenge 'mux' driver
i2c: at91: convert to dma_request_slave_channel_compat()
i2c: mxs: do error checking and handling in PIO mode
i2c: mxs: remove races in PIO code
i2c-designware: switch to use runtime PM autosuspend
i2c-designware: use usleep_range() in the busy-loop
i2c-designware: enable/disable the controller properly
i2c-designware: use dynamic adapter numbering on Lynxpoint
i2c-designware-pci: use managed functions pcim_* and devm_*
i2c-designware-pci: use dev_err() instead of printk()
i2c-designware: move to managed functions (devm_*)
i2c: remove CONFIG_HOTPLUG ifdefs
i2c: s3c2410: Add SMBus emulation for block read
...
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git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
"Usual stuff, mostly comment fixes, typo fixes, printk fixes and small
code cleanups"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (45 commits)
mm: Convert print_symbol to %pSR
gfs2: Convert print_symbol to %pSR
m32r: Convert print_symbol to %pSR
iostats.txt: add easy-to-find description for field 6
x86 cmpxchg.h: fix wrong comment
treewide: Fix typo in printk and comments
doc: devicetree: Fix various typos
docbook: fix 8250 naming in device-drivers
pata_pdc2027x: Fix compiler warning
treewide: Fix typo in printks
mei: Fix comments in drivers/misc/mei
treewide: Fix typos in kernel messages
pm44xx: Fix comment for "CONFIG_CPU_IDLE"
doc: Fix typo "CONFIG_CGROUP_CGROUP_MEMCG_SWAP"
mmzone: correct "pags" to "pages" in comment.
kernel-parameters: remove outdated 'noresidual' parameter
Remove spurious _H suffixes from ifdef comments
sound: Remove stray pluses from Kconfig file
radio-shark: Fix printk "CONFIG_LED_CLASS"
doc: put proper reference to CONFIG_MODULE_SIG_ENFORCE
...
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The TX_FIFO register is 10 bits wide. The lower 8 bits are the data to be
written, while the upper two bits are flags to indicate stop/start.
The driver apparently attempted to optimize write access, by only writing a
byte in those cases where the stop/start bits are zero. However, we have
seen cases where the lower byte is duplicated onto the upper byte by the
hardware, which causes inadvertent stop/starts.
This patch changes the write access to the transmit FIFO to always be 16 bits
wide.
Signed off by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
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HZ based value is better than a magic number.
Signed-off-by: Eunbong Song <eunb.song@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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I've been debugging the abnormal operation of i2c on octeon. If a process is
terminated by signal in the middle of i2c operation, next i2c read operation
which is done by another process was failed. So i changed to ignore signal in
the middle of i2c operation. After that the problem was not reproduced.
Signed-off-by: Eunbong Song <eunb.song@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Sekhar Nori <nsekhar@ti.com>
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GENERIC_GPIO is now equivalent to GPIOLIB and features that depended on
GENERIC_GPIO can now depend on GPIOLIB to allow removal of this option.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
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Use generic DMA DT helper. Platforms booting with or without DT populated are
both supported.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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In PIO mode we can end up with the same errors as in DMA mode, but as IRQs
are disabled there we have to check for them manually after each command.
Also don't use the big controller reset hammer when receiving a NAK from a
slave. It's sufficient to tell the controller to continue at a clean state.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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This commit fixes the three following races in PIO code:
- The CTRL0 register is racy in itself, when programming transfer state and
run bit in the same cycle the hardware sometimes ends up using the state
from the last transfer. Fix this by programming state in one cycle, make
sure the write is flushed down APBX bus by reading back the reg and only
then trigger the run bit.
- Only clear the DMAREQ bit in DEBUG0 after the read/write to the data reg
happened. Otherwise we are racing with the hardware about who touches
the data reg first.
- When checking for completion of a transfer it's not sufficient to check
if the data engine finished, but also a check for i2c bus idle is needed.
In PIO mode we are really fast to program the next transfer after a finished
one, so the controller possibly tries to start a new transfer while the
clkgen engine is still busy writing the NAK/STOP from the last transfer to
the bus.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Using autosuspend helps to reduce the resume latency in situations where
another I2C message is going to be started soon. For example with HID over
I2C touch panels we get several messages in a short period of time while
the touch panel is in use.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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This is not an atomic context so there is no need to use mdelay() but
instead use usleep_range().
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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The correct way to disable or enable the controller is to wait until the
DW_IC_ENABLE_STATUS register bit matches the bit we program into DW_IC_ENABLE
register. This procedure is described in the DesignWare I2C databook.
By doing this we can be sure that the controller is in correct state once
the function returns.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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It is not good idea to mix static and dynamic I2C adapter numbering. In
this particular case on Lynxpoint we had graphics I2C adapter which took
the first numbers preventing the designware I2C driver from using the
adapter numbers it preferred.
Since Lynxpoint support was just introduced and there is no hardware available
outside Intel we can fix this by switching to use dynamic adapter numbering
instead of static.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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