Originally, the I2C controller supported by the i2c-mv64xxx driver
requires a lot of software support: an interrupt is generated at each
step of an I2C transaction (after the start bit, after sending the
address, etc.) and the driver is in charge of re-programming the I2C
controller to do the next step of the I2C transaction. This explains
the fairly complex state machine that the driver has.
On Marvell Armada XP and later processors (Armada 375, 38x, etc.), the
I2C controller was extended with a part called the "I2C Bridge", which
allows to offload the I2C transaction completely to the
hardware. Initial support for this mechanism was added in commit
930ab3d403 ("i2c: mv64xxx: Add I2C Transaction Generator support").
However, the implementation done in this commit has two related
issues, which this commit fixes by completely changing how the offload
implementation is done:
* SMBus read transfers, where there is one write to select the
register immediately followed in the same transaction by one read,
were making the processor hang. This was easier visible on the
Marvell Armada XP WRT1900AC platform using a driver for an I2C LED
controller, or on other Armada XP platforms by using a simple
'i2cget' command to read an I2C EEPROM.
* The implementation was based on the fact that the offload engine
was re-programmed to transfer each message of an I2C xfer: this
meant that each message sent with the offload engine was starting
with a normal I2C start sequence. However, the I2C subsystem
assumes that all messages belonging to the same xfer will use the
so-called "repeated start" so that the entire I2C xfer is seen as
one transfer by the I2C devices and cannot be interrupt by other
I2C masters on the same bus.
In fact, the "I2C Bridge" allows to offload three types of xfer:
- xfer of one write message
- xfer of one read message
- xfer of one write message followed by one read message
For all other situations, we have to fallback to not using the "I2C
Bridge" in order to get proper I2C semantics.
Therefore, this commit reworks the offload implementation to put it
not at the message level, but at the xfer level: in the
mv64xxx_i2c_xfer() function, we decide if the transaction can be
offloaded (in which case it is handled by the
mv64xxx_i2c_offload_xfer() function), or otherwise it is handled by
the slow path (implemented in the existing mv64xxx_i2c_execute_msg()).
This allows to simplify the state machine, which no longer needs to
have any state related to the offload implementation: the offload
implementation is now completely separated from the slow path (with
the exception of the interrupt handler, of course).
In summary:
- mv64xxx_i2c_can_offload() will analyze an I2C xfer and decided of
the "I2C Bridge" can be used to offload it or not.
- mv64xxx_i2c_offload_xfer() will actually program the "I2C Bridge"
to offload one xfer (of either one or two messages), and block
using mv64xxx_i2c_wait_for_completion() until the xfer completes.
- The interrupt handler mv64xxx_i2c_intr() is modified to push the
offload related code to a separate function,
mv64xxx_i2c_intr_offload(). It will take care of reading the
received data if needed.
This commit was tested on:
- Armada XP OpenBlocks AX3-4 (EEPROM on I2C and RTC on I2C)
- Armada XP WRT1900AC (LED controller on I2C)
- Armada XP GP (EEPROM on I2C)
Fixes: 930ab3d403 ("i2c: mv64xxx: Add I2C Transaction Generator support")
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[wsa: fixed checkpatch warnings]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes, just
removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There are
some ath9k patches coming in through this tree that have been acked by
the wireless maintainers as they relied on the debugfs changes.
Everything has been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.
Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev_<level>_once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
Pull i2c updates from Wolfram Sang:
"For 3.19, the I2C subsystem has to offer special candy this time.
Right in time for Christmas :)
- I2C slave framework: finally, a generic mechanism for Linux being
an I2C slave (if the bus driver supports that). Docs are still
missing but will come later this cycle, the code is good enough to
go.
- I2C muxes represent their topology in sysfs much more detailed.
This will help users to navigate around much easier.
- irq population of i2c clients is now done at probe time, not device
creation time, to have better support for deferred probing.
- new drivers for Imagination SCB, Amlogic Meson
- DMA support added for Freescale IMX, Renesas SHMobile
- slightly bigger driver updates to OMAP, i801, AT91, and rk3x
(mostly quirk handling, timing updates, and using better kernel
interfaces)
- eeprom driver can now write with byte-access (very slow, but OK to
have)
- and the bunch of smaller fixes, cleanups, ID updates..."
* 'i2c/for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (56 commits)
i2c: sh_mobile: remove unneeded DMA mask
i2c: rcar: add slave support
i2c: slave-eeprom: add eeprom simulator driver
i2c: core changes for slave support
MAINTAINERS: add I2C dt bindings also to I2C realm
i2c: designware: Fix falling time bindings doc
i2c: davinci: switch to use platform_get_irq
Documentation: i2c: Use PM ops instead of legacy suspend/resume
i2c: sh_mobile: optimize irq entry
i2c: pxa: add support for SCCB devices
omap: i2c: don't check bus state IP rev3.3 and earlier
i2c: s3c2410: Handle i2c sys_cfg register in i2c driver
i2c: rk3x: add Kconfig dependency on COMMON_CLK
i2c: omap: add notes related to i2c multimaster mode
i2c: omap: don't reset controller if Arbitration Lost detected
i2c: omap: implement workaround for handling invalid BB-bit values
i2c: omap: cleanup register definitions
i2c: rk3x: handle dynamic clock rate changes correctly
i2c: at91: enable probe deferring on dma channel request
i2c: at91: remove legacy DMA support
...
We don't need the mask since we obtain the channels via DT.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The first I2C slave provider using the new generic interface.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The first user of the i2c-slave interface is an eeprom simulator. It is
a shared memory which can be accessed by the remote master via I2C and
locally via sysfs.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Finally(!), make Linux support being an I2C slave. Most of the existing
infrastructure is reused. We mainly add i2c_slave_register/unregister()
calls which tells i2c bus drivers to activate the slave mode. Then, they
also get a callback to report slave events to.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Lots of activity in the devicetree code for v3.18. Most of it is related
to getting all of the overlay support code in place, but there are other
important things in there.
There are a few trivial merge conflicts. They shouldn't give you any
trouble.
Highlights:
- OF_RECONFIG notifiers for SPI, I2C and Platform devices. Those
subsystems can now respond to live changes to the device tree.
- CONFIG_OF_OVERLAY method for applying live changes to the device tree
- Removal of the of_allnodes list. This used to be used to iterate over
all the nodes in the device tree, but it is unnecessary because the
same thing can be done by iterating over the list of child pointers.
Getting rid of of_allnodes saves some memory and avoids the
possibility of of_allnodes being sorted differently from the child
lists.
- Support for retrieving original DTB blob via sysfs. Needed by kexec.
- More unittests
- Documentation and minor bug fixes
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Merge tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux
Pull devicetree changes from Grant Likely:
"Lots of activity in the devicetree code for v3.18. Most of it is
related to getting all of the overlay support code in place, but there
are other important things in there.
Highlights:
- OF_RECONFIG notifiers for SPI, I2C and Platform devices. Those
subsystems can now respond to live changes to the device tree.
- CONFIG_OF_OVERLAY method for applying live changes to the device
tree
- Removal of the of_allnodes list. This used to be used to iterate
over all the nodes in the device tree, but it is unnecessary
because the same thing can be done by iterating over the list of
child pointers. Getting rid of of_allnodes saves some memory and
avoids the possibility of of_allnodes being sorted differently from
the child lists.
- Support for retrieving original DTB blob via sysfs. Needed by
kexec.
- More unittests
- Documentation and minor bug fixes"
* tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux: (42 commits)
of: Delete unnecessary check before calling "of_node_put()"
of: Drop ->next pointer from struct device_node
spi: Check for spi_of_notifier when CONFIG_OF_DYNAMIC=y
of: support passing console options with stdout-path
of: add optional options parameter to of_find_node_by_path()
of: Add bindings for chosen node, stdout-path
of: Remove unneeded and incorrect MODULE_DEVICE_TABLE
ARM: dt: fix up PL011 device tree bindings
of: base, fix of_property_read_string_helper kernel-doc
of: remove select of non-existant OF_DEVICE config symbol
spi/of: Add OF notifier handler
spi/of: Create new device registration method and accessors
i2c/of: Add OF_RECONFIG notifier handler
i2c/of: Factor out Devicetree registration code
of/overlay: Add overlay unittests
of/overlay: Introduce DT overlay support
of/reconfig: Add OF_DYNAMIC notifier for platform_bus_type
of/reconfig: Always use the same structure for notifiers
of/reconfig: Add debug output for OF_RECONFIG notifiers
of/reconfig: Add empty stubs for the of_reconfig methods
...
This time we have some more new material than we used to have during
the last couple of development cycles.
The most important part of it to me is the introduction of a unified
interface for accessing device properties provided by platform
firmware. It works with Device Trees and ACPI in a uniform way and
drivers using it need not worry about where the properties come
from as long as the platform firmware (either DT or ACPI) makes
them available. It covers both devices and "bare" device node
objects without struct device representation as that turns out to
be necessary in some cases. This has been in the works for quite
a few months (and development cycles) and has been approved by
all of the relevant maintainers.
On top of that, some drivers are switched over to the new interface
(at25, leds-gpio, gpio_keys_polled) and some additional changes are
made to the core GPIO subsystem to allow device drivers to manipulate
GPIOs in the "canonical" way on platforms that provide GPIO information
in their ACPI tables, but don't assign names to GPIO lines (in which
case the driver needs to do that on the basis of what it knows about
the device in question). That also has been approved by the GPIO
core maintainers and the rfkill driver is now going to use it.
Second is support for hardware P-states in the intel_pstate driver.
It uses CPUID to detect whether or not the feature is supported by
the processor in which case it will be enabled by default. However,
it can be disabled entirely from the kernel command line if necessary.
Next is support for a platform firmware interface based on ACPI
operation regions used by the PMIC (Power Management Integrated
Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
That interface is used for manipulating power resources and for
thermal management: sensor temperature reporting, trip point setting
and so on.
Also the ACPI core is now going to support the _DEP configuration
information in a limited way. Basically, _DEP it supposed to reflect
off-the-hierarchy dependencies between devices which may be very
indirect, like when AML for one device accesses locations in an
operation region handled by another device's driver (usually, the
device depended on this way is a serial bus or GPIO controller).
The support added this time is sufficient to make the ACPI battery
driver work on Asus T100A, but it is general enough to be able to
cover some other use cases in the future.
Finally, we have a new cpufreq driver for the Loongson1B processor.
In addition to the above, there are fixes and cleanups all over the
place as usual and a traditional ACPICA update to a recent upstream
release.
As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver
for Intel platforms should be able to handle power management of
the DMA engine correctly, the cpufreq-dt driver should interact
with the thermal subsystem in a better way and the ACPI backlight
driver should handle some more corner cases, among other things.
On top of the ACPICA update there are fixes for race conditions
in the ACPICA's interrupt handling code which might lead to some
random and strange looking failures on some systems.
In the cleanups department the most visible part is the series
of commits targeted at getting rid of the CONFIG_PM_RUNTIME
configuration option. That was triggered by a discussion
regarding the generic power domains code during which we realized
that trying to support certain combinations of PM config options
was painful and not really worth it, because nobody would use them
in production anyway. For this reason, we decided to make
CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and that lead to the
conclusion that the latter became redundant and CONFIG_PM could
be used instead of it. The material here makes that replacement
in a major part of the tree, but there will be at least one more
batch of that in the second part of the merge window.
Specifics:
- Support for retrieving device properties information from ACPI
_DSD device configuration objects and a unified device properties
interface for device drivers (and subsystems) on top of that.
As stated above, this works with Device Trees and ACPI and allows
device drivers to be written in a platform firmware (DT or ACPI)
agnostic way. The at25, leds-gpio and gpio_keys_polled drivers
are now going to use this new interface and the GPIO subsystem
is additionally modified to allow device drivers to assign names
to GPIO resources returned by ACPI _CRS objects (in case _DSD is
not present or does not provide the expected data). The changes
in this set are mostly from Mika Westerberg, Rafael J Wysocki,
Aaron Lu, and Darren Hart with some fixes from others (Fabio Estevam,
Geert Uytterhoeven).
- Support for Hardware Managed Performance States (HWP) as described
in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
driver. CPUID is used to detect whether or not the feature is
supported by the processor. If supported, it will be enabled
automatically unless the intel_pstate=no_hwp switch is present in
the kernel command line. From Dirk Brandewie.
- New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).
- Support for firmware interface based on ACPI operation regions
used by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
platforms for power resource control and thermal management
(Aaron Lu).
- Limited support for retrieving off-the-hierarchy dependencies
between devices from ACPI _DEP device configuration objects
and deferred probing support for the ACPI battery driver based
on the _DEP information to make that driver work on Asus T100A
(Lan Tianyu).
- New cpufreq driver for the Loongson1B processor (Kelvin Cheung).
- ACPICA update to upstream revision 20141107 which only affects
tools (Bob Moore).
- Fixes for race conditions in the ACPICA's interrupt handling
code and in the ACPI code related to system suspend and resume
(Lv Zheng and Rafael J Wysocki).
- ACPI core fix for an RCU-related issue in the ioremap() regions
management code that slowed down significantly after CPUs had
been allowed to enter idle states even if they'd had RCU callbakcs
queued and triggered some problems in certain proprietary graphics
driver (and elsewhere). The fix replaces synchronize_rcu() in
that code with synchronize_rcu_expedited() which makes the issue
go away. From Konstantin Khlebnikov.
- ACPI LPSS (Low-Power Subsystem) driver fix to handle power
management of the DMA engine included into the LPSS correctly.
The problem is that the DMA engine doesn't have ACPI PM support
of its own and it simply is turned off when the last LPSS device
having ACPI PM support goes into D3cold. To work around that,
the PM domain used by the ACPI LPSS driver is redesigned so at
least one device with ACPI PM support will be on as long as the
DMA engine is in use. From Andy Shevchenko.
- ACPI backlight driver fix to avoid using it on "Win8-compatible"
systems where it doesn't work and where it was used by default by
mistake (Aaron Lu).
- Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and
Ashwin Chaugule (mostly related to the upcoming ARM64 support).
- Intel RAPL (Running Average Power Limit) power capping driver
fixes and improvements including new processor IDs (Jacob Pan).
- Generic power domains modification to power up domains after
attaching devices to them to meet the expectations of device
drivers and bus types assuming devices to be accessible at
probe time (Ulf Hansson).
- Preliminary support for controlling device clocks from the
generic power domains core code and modifications of the
ARM/shmobile platform to use that feature (Ulf Hansson).
- Assorted minor fixes and cleanups of the generic power
domains core code (Ulf Hansson, Geert Uytterhoeven).
- Assorted minor fixes and cleanups of the device clocks control
code in the PM core (Geert Uytterhoeven, Grygorii Strashko).
- Consolidation of device power management Kconfig options by making
CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
which is now redundant (Rafael J Wysocki and Kevin Hilman). That
is the first batch of the changes needed for this purpose.
- Core device runtime power management support code cleanup related
to the execution of callbacks (Andrzej Hajda).
- cpuidle ARM support improvements (Lorenzo Pieralisi).
- cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and
a new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
Bartlomiej Zolnierkiewicz).
- New cpufreq driver callback (->ready) to be executed when the
cpufreq core is ready to use a given policy object and cpufreq-dt
driver modification to use that callback for cooling device
registration (Viresh Kumar).
- cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu,
James Geboski, Tomeu Vizoso).
- Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
Stefan Wahren, Petr Cvek).
- OPP (Operating Performance Points) framework modification to
allow OPPs to be removed too and update of a few cpufreq drivers
(cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
during initialization) on driver removal (Viresh Kumar).
- Hibernation core fixes and cleanups (Tina Ruchandani and
Markus Elfring).
- PM Kconfig fix related to CPU power management (Pankaj Dubey).
- cpupower tool fix (Prarit Bhargava).
/
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Merge tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
"This time we have some more new material than we used to have during
the last couple of development cycles.
The most important part of it to me is the introduction of a unified
interface for accessing device properties provided by platform
firmware. It works with Device Trees and ACPI in a uniform way and
drivers using it need not worry about where the properties come from
as long as the platform firmware (either DT or ACPI) makes them
available. It covers both devices and "bare" device node objects
without struct device representation as that turns out to be necessary
in some cases. This has been in the works for quite a few months (and
development cycles) and has been approved by all of the relevant
maintainers.
On top of that, some drivers are switched over to the new interface
(at25, leds-gpio, gpio_keys_polled) and some additional changes are
made to the core GPIO subsystem to allow device drivers to manipulate
GPIOs in the "canonical" way on platforms that provide GPIO
information in their ACPI tables, but don't assign names to GPIO lines
(in which case the driver needs to do that on the basis of what it
knows about the device in question). That also has been approved by
the GPIO core maintainers and the rfkill driver is now going to use
it.
Second is support for hardware P-states in the intel_pstate driver.
It uses CPUID to detect whether or not the feature is supported by the
processor in which case it will be enabled by default. However, it
can be disabled entirely from the kernel command line if necessary.
Next is support for a platform firmware interface based on ACPI
operation regions used by the PMIC (Power Management Integrated
Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
That interface is used for manipulating power resources and for
thermal management: sensor temperature reporting, trip point setting
and so on.
Also the ACPI core is now going to support the _DEP configuration
information in a limited way. Basically, _DEP it supposed to reflect
off-the-hierarchy dependencies between devices which may be very
indirect, like when AML for one device accesses locations in an
operation region handled by another device's driver (usually, the
device depended on this way is a serial bus or GPIO controller). The
support added this time is sufficient to make the ACPI battery driver
work on Asus T100A, but it is general enough to be able to cover some
other use cases in the future.
Finally, we have a new cpufreq driver for the Loongson1B processor.
In addition to the above, there are fixes and cleanups all over the
place as usual and a traditional ACPICA update to a recent upstream
release.
As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver for
Intel platforms should be able to handle power management of the DMA
engine correctly, the cpufreq-dt driver should interact with the
thermal subsystem in a better way and the ACPI backlight driver should
handle some more corner cases, among other things.
On top of the ACPICA update there are fixes for race conditions in the
ACPICA's interrupt handling code which might lead to some random and
strange looking failures on some systems.
In the cleanups department the most visible part is the series of
commits targeted at getting rid of the CONFIG_PM_RUNTIME configuration
option. That was triggered by a discussion regarding the generic
power domains code during which we realized that trying to support
certain combinations of PM config options was painful and not really
worth it, because nobody would use them in production anyway. For
this reason, we decided to make CONFIG_PM_SLEEP select
CONFIG_PM_RUNTIME and that lead to the conclusion that the latter
became redundant and CONFIG_PM could be used instead of it. The
material here makes that replacement in a major part of the tree, but
there will be at least one more batch of that in the second part of
the merge window.
Specifics:
- Support for retrieving device properties information from ACPI _DSD
device configuration objects and a unified device properties
interface for device drivers (and subsystems) on top of that. As
stated above, this works with Device Trees and ACPI and allows
device drivers to be written in a platform firmware (DT or ACPI)
agnostic way. The at25, leds-gpio and gpio_keys_polled drivers are
now going to use this new interface and the GPIO subsystem is
additionally modified to allow device drivers to assign names to
GPIO resources returned by ACPI _CRS objects (in case _DSD is not
present or does not provide the expected data). The changes in
this set are mostly from Mika Westerberg, Rafael J Wysocki, Aaron
Lu, and Darren Hart with some fixes from others (Fabio Estevam,
Geert Uytterhoeven).
- Support for Hardware Managed Performance States (HWP) as described
in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
driver. CPUID is used to detect whether or not the feature is
supported by the processor. If supported, it will be enabled
automatically unless the intel_pstate=no_hwp switch is present in
the kernel command line. From Dirk Brandewie.
- New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).
- Support for firmware interface based on ACPI operation regions used
by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
platforms for power resource control and thermal management (Aaron
Lu).
- Limited support for retrieving off-the-hierarchy dependencies
between devices from ACPI _DEP device configuration objects and
deferred probing support for the ACPI battery driver based on the
_DEP information to make that driver work on Asus T100A (Lan
Tianyu).
- New cpufreq driver for the Loongson1B processor (Kelvin Cheung).
- ACPICA update to upstream revision 20141107 which only affects
tools (Bob Moore).
- Fixes for race conditions in the ACPICA's interrupt handling code
and in the ACPI code related to system suspend and resume (Lv Zheng
and Rafael J Wysocki).
- ACPI core fix for an RCU-related issue in the ioremap() regions
management code that slowed down significantly after CPUs had been
allowed to enter idle states even if they'd had RCU callbakcs
queued and triggered some problems in certain proprietary graphics
driver (and elsewhere). The fix replaces synchronize_rcu() in that
code with synchronize_rcu_expedited() which makes the issue go
away. From Konstantin Khlebnikov.
- ACPI LPSS (Low-Power Subsystem) driver fix to handle power
management of the DMA engine included into the LPSS correctly. The
problem is that the DMA engine doesn't have ACPI PM support of its
own and it simply is turned off when the last LPSS device having
ACPI PM support goes into D3cold. To work around that, the PM
domain used by the ACPI LPSS driver is redesigned so at least one
device with ACPI PM support will be on as long as the DMA engine is
in use. From Andy Shevchenko.
- ACPI backlight driver fix to avoid using it on "Win8-compatible"
systems where it doesn't work and where it was used by default by
mistake (Aaron Lu).
- Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and Ashwin
Chaugule (mostly related to the upcoming ARM64 support).
- Intel RAPL (Running Average Power Limit) power capping driver fixes
and improvements including new processor IDs (Jacob Pan).
- Generic power domains modification to power up domains after
attaching devices to them to meet the expectations of device
drivers and bus types assuming devices to be accessible at probe
time (Ulf Hansson).
- Preliminary support for controlling device clocks from the generic
power domains core code and modifications of the ARM/shmobile
platform to use that feature (Ulf Hansson).
- Assorted minor fixes and cleanups of the generic power domains core
code (Ulf Hansson, Geert Uytterhoeven).
- Assorted minor fixes and cleanups of the device clocks control code
in the PM core (Geert Uytterhoeven, Grygorii Strashko).
- Consolidation of device power management Kconfig options by making
CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
which is now redundant (Rafael J Wysocki and Kevin Hilman). That
is the first batch of the changes needed for this purpose.
- Core device runtime power management support code cleanup related
to the execution of callbacks (Andrzej Hajda).
- cpuidle ARM support improvements (Lorenzo Pieralisi).
- cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and a
new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
Bartlomiej Zolnierkiewicz).
- New cpufreq driver callback (->ready) to be executed when the
cpufreq core is ready to use a given policy object and cpufreq-dt
driver modification to use that callback for cooling device
registration (Viresh Kumar).
- cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu, James
Geboski, Tomeu Vizoso).
- Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
Stefan Wahren, Petr Cvek).
- OPP (Operating Performance Points) framework modification to allow
OPPs to be removed too and update of a few cpufreq drivers
(cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
during initialization) on driver removal (Viresh Kumar).
- Hibernation core fixes and cleanups (Tina Ruchandani and Markus
Elfring).
- PM Kconfig fix related to CPU power management (Pankaj Dubey).
- cpupower tool fix (Prarit Bhargava)"
* tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (120 commits)
i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
tools: cpupower: fix return checks for sysfs_get_idlestate_count()
drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
leds: leds-gpio: Fix multiple instances registration without 'label' property
iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
PM: Merge the SET*_RUNTIME_PM_OPS() macros
...
* acpi-scan:
ACPI: Add _DEP support to fix battery issue on Asus T100TA
* acpi-pm:
ACPI / sleep: Drain outstanding events after disabling multiple GPEs
ACPI / PM: Fixed a typo in a comment
* acpi-lpss:
dmaengine: dw: enable runtime PM
ACPI / LPSS: introduce a 'proxy' device to power on LPSS for DMA
ACPI / LPSS: allow to use specific PM domain during ->probe()
ACPI / LPSS: add all LPSS devices to the specific power domain
* acpi-processor:
ACPI / cpuidle: avoid assigning signed errno to acpi_status
ACPI / processor: remove unused variabled from acpi_processor_power structure
ACPI / processor: Update the comments in processor.h
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so some #ifdef blocks
depending on CONFIG_PM_RUNTIME may be dropped now.
Do that in drivers/i2c/busses/i2c-omap.c.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Cadence I2C controller has bug wherein it generates invalid read transactions
after timeout in master receiver mode. This driver does not use the HW
timeout and this interrupt is disabled but the feature itself cannot be
disabled. Hence, this patch writes the maximum value (0xFF) to this register.
This is one of the workarounds to this bug and it will not avoid the issue
completely but reduces the chances of error.
Signed-off-by: Vishnu Motghare <vishnum@xilinx.com>
Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
According to I2C specification the NACK should be handled as follows:
"When SDA remains HIGH during this ninth clock pulse, this is defined as the Not
Acknowledge signal. The master can then generate either a STOP condition to
abort the transfer, or a repeated START condition to start a new transfer."
[I2C spec Rev. 6, 3.1.6: http://www.nxp.com/documents/user_manual/UM10204.pdf]
Currently the Davinci i2c driver interrupts the transfer on receipt of a
NACK but fails to send a STOP in some situations and so makes the bus
stuck until next I2C IP reset (idle/enable).
For example, the issue will happen during SMBus read transfer which
consists from two i2c messages write command/address and read data:
S Slave Address Wr A Command Code A Sr Slave Address Rd A D1..Dn A P
<--- write -----------------------> <--- read --------------------->
The I2C client device will send NACK if it can't recognize "Command Code"
and it's expected from I2C master to generate STP in this case.
But now, Davinci i2C driver will just exit with -EREMOTEIO and STP will
not be generated.
Hence, fix it by generating Stop condition (STP) always when NACK is received.
This patch fixes Davinci I2C in the same way it was done for OMAP I2C
commit cda2109a26 ("i2c: omap: query STP always when NACK is received").
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reported-by: Hein Tibosch <hein_tibosch@yahoo.es>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Switch Davinci I2C driver to use platform_get_irq(), because
it is not recommened to use platform_get_resource(pdev, IORESOURCE_IRQ, ..)
for requesting IRQ resources any more, as they can be not ready yet
in case of DT-boot.
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We can simply pass the pointer to the private structure to the irq
routine instead of passing the platform device and looking up its
driver_data.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The SET_PM_RUNTIME_PM_OPS() and SET_RUNTIME_PM_OPS() macros are
identical except that one of them is not empty for CONFIG_PM set,
while the other one is not empty for CONFIG_PM_RUNTIME set,
respectively.
However, after commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if
PM_SLEEP is selected) PM_RUNTIME is always set if PM is set, so one
of these macros is now redundant.
For this reason, replace SET_PM_RUNTIME_PM_OPS() with
SET_RUNTIME_PM_OPS() everywhere and redefine the SET_PM_RUNTIME_PM_OPS
symbol as SET_RUNTIME_PM_OPS in case new code is starting to use the
macro being removed here.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add support for SCCB by implementing I2C_M_IGNORE_NAK and I2C_M_STOP
flags and advertising functionality flag I2C_FUNC_PROTOCOL_MANGLING.
Also fixed missing functionality flag I2C_FUNC_NOSTART.
Signed-off-by: Petr Cvek <petr.cvek@tul.cz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Commit 0f5768bf89 ("i2c: omap: implement workaround for handling
invalid BB-bit values") introduce the error result in boot test fault on
OMAP3530 boards.
The patch fix the error (disable i2c bus test for OMAP3530).
Reported-by: Kevin Hilman <khilman@kernel.org>
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Fixes: 0f5768bf89 ("i2c: omap: implement workaround for handling invalid BB-bit values")
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
CONFIG_OF_DYNAMIC enables runtime changes to the device tree which in
turn may trigger addition or removal of devices from Linux. Add an
OF_RECONFIG notifier handler to receive tree change events and to
creating or destroy i2c devices as required.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[grant.likely: clean up #ifdefs and drop unneeded error handling]
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-i2c@vger.kernel.org
Dynamically inserting i2c client device nodes requires the use
of a single device registration method. Factor out the loop body of
of_i2c_register_devices() so that it can be called for individual
device_nodes instead of for all the children of a node.
Note: The diff of this commit looks far more complicated than it
actually is due the indentation being changed for a large block of code.
When viewed using the diff -w flag to ignore whitespace changes it can
be seen that the change is actually quite simple.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[grant.likely: Made new function static and removed changes to header]
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-i2c@vger.kernel.org
Let's handle i2c interrupt re-configuration in i2c driver. This will
help us in removing some soc specific checks from machine files and
will help in removing static iomapping of SYS register in exynos.c
Also handle saving and restoring of SYS_I2C_CFG register during
suspend and resume of i2c driver.
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Now that we are using the clk notifier framework we get compile errors
without COMMON_CLK. But the driver fails to probe without COMMON_CLK
anyways, so just add that as a Kconfig dependency.
Signed-off-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
ACPI 5.0 introduces _DEP (Operation Region Dependencies) to designate
device objects that OSPM should assign a higher priority in start
ordering due to future operation region accesses.
On Asus T100TA, ACPI battery info are read from a I2C slave device via
I2C operation region. Before I2C operation region handler is installed,
battery _STA always returns 0. There is a _DEP method of designating
start order under battery device node.
This patch is to implement _DEP feature to fix battery issue on the
Asus T100TA. Introducing acpi_dep_list and adding dep_unmet count
in struct acpi_device. During ACPI namespace scan, create struct
acpi_dep_data for a valid pair of master (device pointed to by _DEP)/
slave(device with _DEP), record master's and slave's ACPI handle in
it and put it into acpi_dep_list. The dep_unmet count will increase
by one if there is a device under its _DEP. Driver's probe() should
return EPROBE_DEFER when find dep_unmet is larger than 0. When I2C
operation region handler is installed, remove all struct acpi_dep_data
on the acpi_dep_list whose master is pointed to I2C host controller
and decrease slave's dep_unmet. When dep_unmet decreases to 0, all
_DEP conditions are met and then do acpi_bus_attach() for the device
in order to resolve battery _STA issue on the Asus T100TA.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=69011
Tested-by: Jan-Michael Brummer <jan.brummer@tabos.org>
Tested-by: Adam Williamson <adamw@happyassassin.net>
Tested-by: Michael Shigorin <shigorin@gmail.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
No functional changes.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Arbitration Lost is an expected situation in a multimaster
environment. I2C controller (IP) correctly detect and report AL.
The only one visible reason for resetting IP in the AL case is
to avoid advisory 1.94 (omap3) and errata i595 (omap4): "I2C:
After an Arbitration is Lost the Module Incorrectly Starts
the Next Transfer".
Errata workaround states: "The MST and STT bits inside I2C_CON
should be set to 1 at the same moment (avoid setting the MST bit
to 1 while STT = 0)." The driver never set MST and STT bits
separately and doesn't create condition for errata. So the reset
is not necessary.
Also corrected return value for AL to -EAGAIN.
Tested on Beagleboard XM C.
Tested on BBB and AM437x Starter Kit by Felipe Balbi.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Tested-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In a multimaster environment, after IP software reset, BB-bit value doesn't
correspond to the current bus state. It may happen what BB-bit will be 0,
while the bus is busy due to another I2C master activity.
Any transfer started when BB=0 and bus is busy wouldn't be completed by IP
and results in controller timeout. More over, in some cases IP could
interrupt another master's transfer and corrupt data on wire.
The commit implement method allowing to prevent IP from entering into
"controller timeout" state and from "data corruption" state.
The one drawback is the need to wait for 10ms before the first transfer.
Tested on Beagleboard XM C.
Tested on BBB and AM437x Starter Kit by Felipe Balbi.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Tested-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Delete STAT_AD0 mask as unrelated to current IP (omap1?).
Delete DEBUG conditional around SYSTEST masks group.
Add SYSTEST functional mode masks for SCL and SDA.
Add STAT_BF mask.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Tested-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The i2c input clock can change dynamically, e.g. on the RK3066 where
pclk_i2c0 and pclk_i2c1 are connected to the armclk, which changes
rate on cpu frequency scaling.
Until now, we incorrectly called clk_get_rate() while holding the
i2c->lock in rk3x_i2c_xfer() to adapt to clock rate changes.
Thanks to Huang Tao for reporting this issue.
Do it properly now using the clk notifier framework. The callback
logic was taken from i2c-cadence.c.
Also rename all misleading "i2c_rate" variables to "clk_rate", as they
describe the *input* clk rate.
Signed-off-by: Max Schwarz <max.schwarz@online.de>
Tested-by: Doug Anderson <dianders@chromium.org> on RK3288
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
commit 6d9939f651 (i2c: omap: split out [XR]DR
and [XR]RDY) changed the way how errata i207 (I2C: RDR Flag May Be Incorrectly
Set) get handled. 6d9939f651 code doesn't correspond to workaround provided by
errata.
According to errata ISR must filter out spurious RDR before data read not after.
ISR must read RXSTAT to get number of bytes available to read. Because RDR
could be set while there could no data in the receive FIFO.
Restored pre 6d9939f651 way of handling errata.
Found by code review. Real impact haven't seen.
Tested on Beagleboard XM C.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Fixes: 6d9939f651 i2c: omap: split out [XR]DR and [XR]RDY
Tested-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Since at91sam9g45 is now DT-only, all DMA capable users of this driver
are using the DT case, and the legacy support can be removed.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If the Designware core is configured with IC_EMPTYFIFO_HOLD_MASTER_EN
set to zero, allowing the TX FIFO to become empty causes a STOP
condition to be generated on the I2C bus. If the transmit FIFO
threshold is set too high, an erroneous STOP condition can be
generated on long transfers - particularly where the interrupt
latency is extended.
Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
commit 1d7afc9594 (i2c: omap: ack IRQ in parts)
changed the interrupt handler to complete transfers without clearing
XRDY (AL case) and ARDY (NACK case) flags. XRDY or ARDY interrupts will be
fired again. As a result, ISR keep processing transfer after it was already
complete (from the driver code point of view).
A didn't see real impacts of the 1d7afc9, but it is really bad idea to
have ISR running on user data after transfer was complete.
It looks, what 1d7afc9 violate TI specs in what how AL and NACK should be
handled (see Note 1, sprugn4r, Figure 17-31 and Figure 17-32).
According to specs (if I understood correctly), in case of NACK and AL driver
must reset NACK, AL, ARDY, RDR, and RRDY (Master Receive Mode), and
NACK, AL, ARDY, and XDR (Master Transmitter Mode).
All that is done down the code under the if condition:
if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) ...
The patch restore pre 1d7afc9 logic of handling NACK and AL interrupts, so
no interrupts is fired after ISR informs the rest of driver what transfer
complete.
Note: instead of removing break under NACK case, we could just replace 'break'
with 'continue' and allow NACK transfer to finish using ARDY event. I found
that NACK and ARDY bits usually set together. That case confirm TI wiki:
http://processors.wiki.ti.com/index.php/I2C_Tips#Detecting_and_handling_NACK
In order if someone interested in the event traces for NACK and AL cases,
I sent them to mailing list.
Tested on Beagleboard XM C.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Fixes: 1d7afc9 i2c: omap: ack IRQ in parts
Cc: <stable@vger.kernel.org> # v3.7+
Acked-by: Felipe Balbi <balbi@ti.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This fixes the following kbuild test robot warning:
>> drivers/i2c/busses/i2c-dln2.c:70:1-4: WARNING: end returns can be simplified if negative or 0 value
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
It should be the DMA device, not the platform device.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The SCB is present on IMG SoCs other than the META-based TZ1090,
such as the MIPS-based Pistachio SoC. Relax the Kconfig dependency
so that it can be built on any MIPS or META machine.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This is a driver for the I2C controller found in Amlogic Meson SoCs.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This makes the topology clearer. For instance, by adding a pca9547
device with address 0x70 to bus i2c-0, you get:
/sys/class/i2c-dev/i2c-0/device/0-0070/channel-0 -> i2c-1
...
/sys/class/i2c-dev/i2c-0/device/0-0070/channel-7 -> i2c-8
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
[wsa: simplified sysfs-usage and fixed format string usage]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Martin Belanger <martin.belanger@cyaninc.com>
Acked-by: Danielle Costantino <danielle.costantino@gmail.com>
The current implementation creates muxed i2c-<n> busses as immediate
children of their i2c-<n> parent bus. In case of multiple muxes on one
bus, it is impossible to determine which muxed bus comes from which mux.
It could be argued that the parent device should be changed from the
parent adapter to the mux device. This has pros and cons. To improve the
topology, simply add a "mux_device" symlink pointing to the actual
muxing device, so we can distinguish muxed busses. Doing it this way, we
don't break the ABI.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
No need to initialize 'ret' if it gets assigned directly after that.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
DMA is optional, even DMA request unsuccessfully, i2c can also work well.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If the inlcude headers aren't sorted alphabetically, then the
logical choice is to append new ones, however that creates a
lot of potential for conflicts or duplicates because every change
will then add new includes in the same location.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Since commit 2fd36c5526 ("i2c: core: Map OF IRQ at probe time"),
i2c slaves without interrupts (e.g. da9210 and at24 on r8a7791/koelsch)
fail to probe:
at24: probe of 2-0050 failed with error -22
da9210: probe of 6-0068 failed with error -22
This happens because the call to of_irq_get() in i2c_device_probe()
returns -EINVAL.
If a device node does not have an "interrupts" property,
of_irq_parse_one() fails. Unlike irq_of_parse_and_map(), of_irq_get()
does not ignore errors from of_irq_parse_one(), but forwards them.
Make i2c_device_probe() ignore all errors but -EPROBE_DEFER to fix this,
just like platform_get_irq() and platform_get_irq_byname() already do.
Fixes: 2fd36c5526 ("i2c: core: Map OF IRQ at probe time")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add support for the IMG I2C Serial Control Bus (SCB) found on the
Pistachio and TZ1090 SoCs.
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
[Ezequiel: code cleaning and rebasing]
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The driver tried to access device registers with the (little-endian)
iowrite/ioread functions. While this worked on little-endian machines
(e.g. Microblaze with AXI bus), it made the driver unusable on
big-endian machines (e.g. PPC405 with PLB).
During the probe function, the driver tried to write a 32-bit reset mask
into the reset register. This caused an error interrupt on big-endian
systems, because the device detected an invalid (byte-swapped) reset
mask. The result was an Oops.
The patch implements an endianness detection similar to the one used in
other Xilinx drivers like drivers/spi/spi-xilinx.c. It was tested on a
PPC405/PLB system.
Signed-off-by: Thomas Gessler <Thomas.Gessler@exp2.physik.uni-giessen.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
