Low-level controller enable function __i2c_dw_enable is overloaded to
also handle disabling. What's worse, even though the documentation
requires polling the IC_ENABLE_STATUS register when disabling, this
is not done: polling needs to be requested specifically by calling
__i2c_dw_enable_and_wait, which can also poll on enabling, but that
doesn't work if the IC_ENABLE_STATUS register is not implemented.
This is quite confusing if not in fact backwards.
Especially since the documentation says that disabling should be
followed by polling, the driver should be using a separate function
where it does one-shot disables to make the optimization stand out.
This refactors the two functions so that requested status is given
in the name rather than in a boolean argument. Specifically:
- __i2c_dw_enable: enable without polling (in accordance with docs)
- __i2c_dw_disable: disable and do poll (also as suggested by docs)
- __i2c_dw_disable_nowait: disable without polling (Linux-specific)
No functional change.
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: fixed blank lines in header file]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
"I2C has the following changes for you:
- new flag to mark DMA safe buffers in i2c_msg. Also, some
infrastructure around it. And docs.
- huge refactoring of the at24 driver led by the new maintainer
Bartosz
- update I2C bus recovery to send STOP after recovery
- conversion from gpio to gpiod for I2C bus recovery
- adding a fault-injector to the i2c-gpio driver
- lots of small driver improvements, and bigger ones to
i2c-sh_mobile"
* 'i2c/for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (99 commits)
i2c: mv64xxx: Add myself as maintainer for this driver
i2c: mv64xxx: Fix clock resource by adding an optional bus clock
i2c: mv64xxx: Remove useless test before clk_disable_unprepare
i2c: mxs: use true and false for boolean values
i2c: meson: update doc description to fix build warnings
i2c: meson: add configurable divider factors
dt-bindings: i2c: update documentation for the Meson-AXG
i2c: imx-lpi2c: add runtime pm support
i2c: rcar: fix some trivial typos in comments
i2c: davinci: fix the cpufreq transition
i2c: rk3x: add proper kerneldoc header
i2c: rk3x: account for const type of of_device_id.data
i2c: acorn: remove outdated path from file header
i2c: acorn: add MODULE_LICENSE tag
i2c: rcar: implement bus recovery
i2c: send STOP after successful bus recovery
i2c: ensure SDA is released in recovery if SDA is controllable
i2c: add 'set_sda' to bus_recovery_info
i2c: add identifier in declarations for i2c_bus_recovery
i2c: make kerneldoc about bus recovery more precise
...
Optimize the power management in i2c-designware-platdrv by making it
set the DPM_FLAG_SMART_SUSPEND and DPM_FLAG_LEAVE_SUSPENDED which
allows some code to be dropped from its PM callbacks.
First, setting DPM_FLAG_SMART_SUSPEND causes the intel-lpss driver
to avoid resuming i2c-designware-platdrv devices in its ->prepare
callback, so they can stay in runtime suspend after that point even
if the direct-complete feature is not used for them.
It also causes the ACPI PM domain and the PM core to avoid invoking
"late" and "noirq" suspend callbacks for these devices if they are
in runtime suspend at the beginning of the "late" phase of device
suspend during system suspend. That guarantees dw_i2c_plat_suspend()
to be called for a device only if it is not in runtime suspend.
Moreover, it causes the device's runtime PM status to be set to
"active" after calling dw_i2c_plat_resume() for it, so the
driver doesn't need internal flags to avoid invoking either
dw_i2c_plat_suspend() or dw_i2c_plat_resume() twice in a row.
Second, setting DPM_FLAG_LEAVE_SUSPENDED enables the optimization
allowing the device to stay suspended after system resume under
suitable conditions, so again the driver doesn't need to take
care of that by itself.
Accordingly, the internal "suspended" and "skip_resume" flags
used by the driver are not necessary any more, so drop them and
simplify the driver's PM callbacks.
Additionally, notice that dw_i2c_plat_complete() only needs to
schedule runtime PM resume for the device if platform firmware
has been involved in resuming the system, so make it call
pm_resume_via_firmware() to check that. Also make it check the
runtime PM status of the device instead of its direct_complete
flag which also works if the device remained suspended due to
the DPM_FLAG_LEAVE_SUSPENDED driver flag.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
This patch contains much input from Phil Reid and has been tested
on Intel/Altera Cyclone V SOC Hardware with Altera GPIO's for the
SCL and SDA GPIO's.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tim Sander <tim@krieglstein.org>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For consistency with the rest of the file rename function and parameter to
be consistent with the reset of the common file.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move the i2c_dw_plat_prepare_clk funciton to common file in preparation
for its use also by the master driver.
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
As reported by Rajat Jain, there are problems when ACPI operation
region handlers or similar, called at the ->resume_early() time, for
I2C client devices try to access an I2C controller that has already
been suspended at that point. To avoid that, move the suspend/resume
of i2c-designware-platdrv to the late/early stages, respectively.
While at it, avoid resuming the device from runtime suspend in the
driver's ->suspend callback which isn't particularly nice. [A better
approach would be to make the driver track the PM state of the device
so that it doesn't need to resume it in ->suspend, so implement it.]
First, drop dw_i2c_plat_suspend() added by commit a23318feef (i2c:
designware: Fix system suspend) and rename dw_i2c_plat_runtime_suspend()
back to dw_i2c_plat_suspend().
Second, point the driver's ->late_suspend and ->early_resume
callbacks, rather than its ->suspend and ->resume callbacks,
to dw_i2c_plat_suspend() and dw_i2c_plat_resume(), respectively,
so that they are not executed in parallel with each other, for
example if runtime resume of the device takes place during system
suspend.
Finally, add "suspended" and "skip_resume" flags to struct dw_i2c_dev
and make dw_i2c_plat_suspend() and dw_i2c_plat_resume() use them to
avoid suspending or resuming the device twice in a row and to avoid
resuming a previously runtime-suspended device during system resume.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Johannes Stezenbach <js@sig21.net>
Tested-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Only certain system configurations may use the I2C slave mode so let the
support be optional. This allow reducing module size if needed:
text data bss dec hex filename
10328 1336 16 11680 2da0 drivers/i2c/busses/i2c-designware-core.ko
7222 1136 8 8366 20ae drivers/i2c/busses/i2c-designware-core.ko
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Luis Oliveira <lolivei@synopsys.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Recent i2c-designware slave support patches use master or slave HW init
functions through the function pointer so we can declare them static.
While at it, rename i2c_dw_init() as i2c_dw_init_master().
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Luis Oliveira <lolivei@synopsys.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
- Slave mode selected in platform module if the support is detected in
the DT.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
- Changes in Kconfig to enable I2C_DESIGNWARE_SLAVE support
- Slave functions added to core library file
- Slave abort sources added to common source file
- New driver: i2c-designware-slave added
- Changes in the Makefile to compile the I2C_DESIGNWARE_SLAVE module
when supported by the architecture.
All the SLAVE flow is added but it is not enabled via platform
driver.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: made a function static and one-lined a message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
- Definitions were added to core library
- A example was added to designware-core.txt Documentation that shows
how the slave can be setup using DTS
SLAVE related definitions were added to the core of the controller.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
- The functions related to I2C master mode of operation were transformed
in a single driver.
- Common definitions were moved to i2c-designware-core.h
- The i2c-designware-core is now only a library file, the functions
associated are in a source file called i2c-designware-common and
are used by both i2c-designware-master and i2c-designware-slave.
- To decrease noise in namespace common i2c_dw_*() functions are
now using ops to keep them private.
- Designware PCI driver had to be changed to match the previous ops
functions implementation.
Almost all of the "core" source is now part of the "master" source. The
difference is the functions used by both modes and they are in the
"common" source file.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The purpose of this commit is to fix some comments and styling in the
existing code due to the need of reuse this code. What is being made
here is:
- Sorted the headers files
- Corrected some comments style (capital letters, lowcase i2c)
- Reverse tree in the variables declaration
- Add/remove empty lines and tabs where needed
- Fix of misspelled word "endianness" and "transferred"
- Replaced the return variable "r" with the more standard "ret"
The value of this, besides the rules of coding style, is because I
will use this code after and it will make my future patch a lot bigger and
complicated to review. The work here won't bring any additional work to
backported fixes because is just style and reordering.
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Currently we are already setting a pm_runtime_disabled flag and disabling
runtime-pm for i2c-busses used for accessing the system PMIC on x86.
But this is not enough, there are ACPI opregions which may want to access
the PMIC during late-suspend and early-resume, so we need to completely
disable pm to be safe.
This commit renames the flag from pm_runtime_disabled to pm_disabled and
adds the following new behavior if the flag is set:
1) Call dev_pm_syscore_device(dev, true) which disables normal suspend /
resume and remove the pm_runtime_disabled check from dw_i2c_plat_resume
since that will now never get called. This fixes suspend_late handlers
which use ACPI PMIC opregions causing errors like these:
PM: Suspending system (freeze)
PM: suspend of devices complete after 1127.751 msecs
i2c_designware 808622C1:06: timeout waiting for bus ready
ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion]
acpi 80860F14:02: Failed to change power state to D3hot
PM: late suspend of devices failed
2) Set IRQF_NO_SUSPEND irq flag. This fixes resume_early handlers which
handlers which use ACPI PMIC opregions causing errors like these:
PM: resume from suspend-to-idle
i2c_designware 808622C1:06: controller timed out
ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull immutable branch as a common base for further development:
"Baytrail PMIC vs. PMU race fixes from Hans de Goede
This time the right version (v4), with the compile fix."
Some platforms like hi3660 need do reset first to allow accessing registers
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Ramiro Oliveira <ramiro.oliveira@synopsys.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The cherrytrail punit has the pmic i2c bus access semaphore at a
different register address.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-9-hdegoede@redhat.com
On my cherrytrail tablet with axp288 pmic, just doing a bunch of repeated
reads from the pmic, e.g. "i2cdump -y 14 0x34" would lookup the tablet in
1 - 3 runs guaranteed.
This seems to be causes by the cpu trying to enter C6 or C7 while we hold
the punit bus semaphore, at which point everything just hangs.
Avoid this by disallowing the CPU to enter C6 or C7 before acquiring the
punit bus semaphore.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109051
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-7-hdegoede@redhat.com
Rename accessor_flags to flags, so that we can use the field for
other flags too. This is a preparation patch for adding cherrytrail
support to the punit semaphore code.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-4-hdegoede@redhat.com
This reverts commit 63d0f0a695.
It caused a regression on platforms where I2C controller is synthesized
with dynamic TAR update disabled. Detection code is testing is bit
DW_IC_CON_10BITADDR_MASTER in register DW_IC_CON read-only but fails to
restore original value in case bit is read-write.
Instead of fixing this we revert the commit since it was preparation for
the commit 0317e6c0f1 ("i2c: designware: do not disable adapter after
transfer") which was also reverted.
Reported-by: Shah Nehal-Bakulchandra <Nehal-bakulchandra.Shah@amd.com>
Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Acked-By: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: <stable@vger.kernel.org> # v4.9+
Fixes: 63d0f0a695 ("i2c: designware: detect when dynamic tar update is possible")
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use a common place for default functionality bits for both platform
and pci driver.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This adapter can be synthesized with dynamic tar update enabled or disabled.
When enabled it is not necessary to disable the adapter to change the slave
address in some situations, which saves some time per transaction.
There is no direct register to know if this feature is enabled but we can do it
indirectly by writing to the 10BIT_ADDR field in IC_CON: this field is
read only when dynamic tar update is enabled.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Christian Ruppert <christian.ruppert@alitech.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch enabled high speed mode. High speed mode can be turn on by
setting the clk_freq to 3400000. High speed HCNT and LCNT are needed
as there is no default value provided.
Signed-off-by: Weifeng Voon <weifeng.voon@intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I2C designware controller can run at fast mode plus and high speed. This
patch adds the capability to get the HCNT, LCNT configuration via
FPCN (fast plus) and HSCN (high speed) ACPI method.
Signed-off-by: Weifeng Voon <weifeng.voon@intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I2c designware controller operate speed is configured in the register
IC_CON. Previously the operate speed is determined by a local variable
clk_freq. This patch will move the local variable clk_freq into struct
dw_i2c_dev. This change will ease the set and get of the clk_freq.
Signed-off-by: Weifeng Voon <weifeng.voon@intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
On some platforms, such as Intel Medfield, the I2C slave devices are enumerated
through SFI tables where bus numbering is expected to be defined in the OS.
Make the bus number allocation robust for such platforms.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The per adapter bus_lock already projects from concurrent calls to the
master_xfer callback. No need to add a driver internal lock.
Also, rephrase a comment to drop mention of this lock.
Reported-by: Rongrong Zou <zourongrong@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Because of some hardware limitation, AMD I2C controller can't
trigger pending interrupt if interrupt status has been changed
after clearing interrupt status bits. Then, I2C will lost
interrupt and IO timeout.
According to hardware design, this patch implements a workaround
to disable i2c controller interrupt and re-enable i2c interrupt
before exiting ISR.
To reduce the performance impacts on other vendors, use unlikely
function to check flag in ISR.
Signed-off-by: Xiangliang Yu <Xiangliang.Yu@amd.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
There is some code duplication in i2c-designware-platdrv and
i2c-designware-pcidrv probe functions. What is even worse that duplication
requires i2c_dw_xfer(), i2c_dw_func() and i2c_dw_isr() i2c-designware-core
functions to be exported.
Therefore move common code into new i2c_dw_probe() and make functions above
local to i2c-designware-core.
While merging the code patch does following functional changes:
- I2C Adapter name will be "Synopsys DesignWare I2C adapter". Previously it
was used for platform and ACPI devices but PCI device used
"i2c-designware-pci".
- Using device name for interrupt name. Previous it was platform device name,
ACPI device name or "i2c-designware-pci".
- Error code from devm_request_irq() and i2c_add_numbered_adapter() will be
printed in case of error.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
dw_readl() and dw_writel() are not used outside of i2c-designware-core and
they are not exported so make them static and remove their forward
declaration.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c_dw_is_enabled() became unused by the commit be58eda775
("i2c: designware-pci: Cleanup driver power management") and
i2c_dw_enable() by the commit 3a48d1c08f ("i2c: prevent spurious
interrupt on Designware controllers").
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There is no need to clear interrupts in i2c_dw_pci_probe() since only place
where interrupts are unmasked is i2c_dw_xfer_init() and there interrupts
are always cleared after commit 2a2d95e9d6 ("i2c: designware: always
clear interrupts before enabling them").
This allows to cleanup the code and replace i2c_dw_clear_int() in
i2c_dw_xfer_init() by direct register read as there are no other callers.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch implements an I2C bus sharing mechanism between the host and platform
hardware on select Intel BayTrail SoC platforms using the X-Powers AXP288 PMIC.
On these platforms access to the PMIC must be shared with platform hardware. The
hardware unit assumes full control of the I2C bus and the host must request
access through a special semaphore. Hardware control of the bus also makes it
necessary to disable runtime pm to avoid interfering with hardware transactions.
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Adds support for acquiring and releasing a hardware bus lock in the i2c
designware core transfer function. This is needed for i2c bus controllers
that are shared with but not controlled by the kernel.
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch allows to set independantly SCL and SDA falling times.
The tLOW period is computed by taking into account the SCL falling time.
The tHIGH period is computed by taking into account the SDA falling time.
For instance in case the margin on tLOW is considered too small, it can
be increased by increasing the SCL falling time which is by default set
at 300ns.
The same applies for tHIGH period with the help of SDA falling time.
Signed-off-by: Romain Baeriswyl <romainba@abilis.com>
Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com>
Acked-by: Shinya Kuribayashi <skuribay@pobox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The DesignWare I2C controller has high count (HCNT) and low count (LCNT)
registers for each of the I2C speed modes (standard and fast). These
registers are programmed based on the input clock speed in the driver.
The current code calculates these values based on the input clock speed and
tries hard to meet the I2C bus timing requirements. This could result
non-optimal values with regarding to the bus speed. For example on Intel
BayTrail we get bus speed of 315.41kHz which is ~20% slower than we would
expect (400kHz) in fast mode (even though the timing requirements are met).
This patch makes it possible for the platform code to pass more optimal
HCNT/LCNT values to the core driver if they are known beforehand. If these
are not set we use the calculated and more conservative values.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Shinya Kuribayashi <skuribay@pobox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch makes the SDA hold time configurable through device tree.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com> for arch/arc bits
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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
The STM SPEAr platform can only access the i2c controller register
via 16bit read/write functions. This patch adds support to
automatically detect this 16bit access mode.
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Add runtime power management to the PCI driver.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Move all register manipulation code into the core, also move register
offset definitions to i2c-designware-core.c since the bus specific
portions of the driver no longer need/use them.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
With multiple I2C adapters possible in the system each running at
(possibly) different speeds we need to move the controller
configuration bit field to the adapter.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The functionality of the adapter depends on the configuration of the
IP block at silicon compile time and is adapter specific.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The clock frequecy supplied to the IP core is specific to a single
instance of the driver. This patch makes it possible to have multiple
Designware I2C cores in the system possibly running at different core
frequencies.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This patch splits i2c-designware.c into three pieces:
i2c-designware-core.c, contains the code that interacts directly
with the core.
i2c-designware-platdrv.c, contains the code specific to the
platform driver using the core.
i2c-designware-core.h contains the definitions and declareations
shared by i2c-designware-core.c and i2c-designware-platdrv.c.
This patch is the first in a set to allow multiple instances of the
designware I2C core in the system.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
