A custom recovery function doesn't need these pointers to be populated
because it may work differently internally.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Peter Griffin <peter.griffin@linaro.org>
i2c_bit_quirk_no_clk_stretch is used in i2c-algo-bit.c only, so
declare it as static.
Signed-off-by: Michele Curti <michele.curti@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Disable clock before returning error in tegra_i2c_init() as its leaves
i2c clock ON in case of error and never turns off again as it will have
unbalanced clock enable/disable
Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
With a i2c topology like the following
GPIO ---| ------ BAT1
| v /
I2C -----+----------+---- MUX
| \
EEPROM ------ BAT2
there is a locking problem with the GPIO controller since it is a client
on the same i2c bus that it muxes. Transfers to the mux clients (e.g. BAT1)
will lock the whole i2c bus prior to attempting to switch the mux to the
correct i2c segment. In the above case, the GPIO device is an I/O expander
with an i2c interface, and since the GPIO subsystem knows nothing (and
rightfully so) about the lockless needs of the i2c mux code, this results
in a deadlock when the GPIO driver issues i2c transfers to modify the
mux.
So, observing that while it is needed to have the i2c bus locked during the
actual MUX update in order to avoid random garbage on the slave side, it
is not strictly a must to have it locked over the whole sequence of a full
select-transfer-deselect mux client operation. The mux itself needs to be
locked, so transfers to clients behind the mux are serialized, and the mux
needs to be stable during all i2c traffic (otherwise individual mux slave
segments might see garbage, or worse).
Introduce this new locking concept as "mux-locked" muxes, and call the
pre-existing mux locking scheme "parent-locked".
Modify the i2c mux locking so that muxes that are "mux-locked" locks only
the muxes on the parent adapter instead of the whole i2c bus when there is
a transfer to the slave side of the mux. This lock serializes transfers to
the slave side of the muxes on the parent adapter.
Add code to i2c-mux-gpio and i2c-mux-pinctrl that checks if all involved
gpio/pinctrl devices have a parent that is an i2c adapter in the same
adapter tree that is muxed, and request a "mux-locked mux" if that is the
case.
Modify the select-transfer-deselect code for "mux-locked" muxes so
that each of the select-transfer-deselect ops locks the mux parent
adapter individually.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Instead of checking for i2c parent adapters for every lock/unlock, simply
override the locking for muxes to always lock/unlock the parent adapter
directly.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add i2c_lock_bus() and i2c_unlock_bus(), which call the new lock_bus and
unlock_bus ops in the adapter. These funcs/ops take an additional flags
argument that indicates for what purpose the adapter is locked.
There are two flags, I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT, but they
are both implemented the same. For now. Locking the root adapter means
that the whole bus is locked, locking the segment means that only the
current bus segment is locked (i.e. i2c traffic on the parent side of
a mux is still allowed even if the child side of the mux is locked).
Also support a trylock_bus op (but no function to call it, as it is not
expected to be needed outside of the i2c core).
Implement i2c_lock_adapter/i2c_unlock_adapter in terms of the new locking
scheme (i.e. lock with the I2C_LOCK_ROOT_ADAPTER flag).
Locking the root adapter and locking the segment is the same thing for
all root adapters (e.g. in the normal case of a simple topology with no
i2c muxes). The two locking variants are also the same for traditional
muxes (aka parent-locked muxes). These muxes traverse the tree, locking
each level as they go until they reach the root. This patch is preparatory
for a later patch in the series introducing mux-locked muxes, which behave
differently depending on the requested locking. Since all current users
are using i2c_lock_adapter, which is a wrapper for I2C_LOCK_ROOT_ADAPTER,
we only need to annotate the calls that will not need to lock the root
adapter for mux-locked muxes. I.e. the instances that needs to use
I2C_LOCK_SEGMENT instead of i2c_lock_adapter/I2C_LOCK_ROOT_ADAPTER. Those
instances are in the i2c_transfer and i2c_smbus_xfer functions, so that
mux-locked muxes can single out normal i2c accesses to its slave side
and adjust the locking for those accesses.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When clock support was added to the i2c-mv64xxx, not all clk functions
had stubs when for !CONFIG_HAVE_CLK configurations. However, nowadays,
both "struct clk" and all the clock framework functions have stubs
when CONFIG_HAVE_CLK is not enabled, so it no longer makes sense to
carry such compile-time conditionals in the driver.
This commit was compile tested on both ARM64 (which has both
CONFIG_OF=y and CONFIG_HAVE_CLK=y) and PowerPC c2k_defconfig (which
has CONFIG_OF=y, CONFIG_HAVE_CLK disabled, and the i2c-mv64xxx driver
enabled).
The only non-trivial change is in the mv64xxx_of_config() function,
which was returning -ENODEV unconditionally if CONFIG_HAVE_CLK was
disabled. Simply removing this condition works fine because the first
test done by the function is to verify if drv_data->clk points to a
valid clock, and if it doesn't, we return -ENODEV. When
CONFIG_HAVE_CLK is disabled, devm_clk_get() unconditionally returns
NULL, so mv64xxx_of_config() will return -ENODEV when no clock is
provided, which is the intended behavior.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Instead of separately calling clk_prepare()/clk_enable(), use
clk_prepare_enable(), and instead of calling
clk_disable()/clk_unprepare(), use clk_disable_unprepare(). Those
handy shortcuts have been introduced specifically to simplify the
numerous call sites were both functions were called in sequence.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If a clock is registered by a platform driver and not by the
OF_CLK_DECLARE() mechanism, it might show up after the first attempt
to probe i2c-mv64xxx. In order to solve this, we need to handle
-EPROBE_PREFER as a special return value of devm_clk_get(), and return
the same error code from probe().
This gives us three situations:
- There is no reference to a clock in the DT. In this case,
devm_clk_get() returns an error that is not -EPROBE_DEFER
(something like -ENODEV), and we continue the probing without
enabling the clock.
- There is a reference to the clock in the DT, and the clock is
ready. devm_clk_get() returns a valid reference to the clock, and
we prepare/enable it.
- There is a reference to the clock in the DT, but the clock is not
ready. devm_clk_get() returns -EPROBE_DEFER, and we exit from
probe() with the same error code so that probe() is tried again
later.
This is needed for Marvell Armada 7K/8K, where the clock driver is a
platform driver.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The new ARM64 Marvell Armada 7K/8K SoC family is using the same I2C
controller as the 32-bits Marvell EBU SoCs, so this commit allows
mv64xxx to be enabled when ARCH_MVEBU=y.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either
built-in or as a module, use that macro instead of open coding the same.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
There is a race between the TWSI interrupt and the condition
that is required before proceeding:
Low-level: interrupt flag bit must be set
High-level controller: valid bit must be clear
If the interrupt comes too early and the condition is not met
the wait will time out, and the transfer is aborted leading
to very poor performance.
To avoid this race retry for the condition ~80 µs later.
The retry is avoided on the very first invocation of
wait_event_timeout() (which tests the condition before entering
the wait and is therefore always wrong in this case).
EEPROM reads on 100kHz i2c now measure ~5.2kB/s, about 1/2 what's
achievable, and much better than the worst-case 100 bytes/sec before.
While at it remove the debug print from the low-level wait function.
Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Zero-length message support (SMBUS QUICK or i2c) never worked with
the Octeon hardware. Disable SMBUS QUICK support and bail out in
case of a zero-length i2c request.
After this change 'i2c-detect -q' will return an error on Octeon but
the previously reported results were wrong anyway.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The clk_prepare_enable() function can fail so check the return
value and propagate the error in case of a failure.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The driver not always prints the error code in case of a failure but this
information can be very useful for debugging. So let's print if available.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Improve the readability by:
- fixing indentation,
- switching to proper block comments,
- removing spurious blank lines,
- checkpatch: void function return statements are not generally useful,
- checkpatch: braces {} are not necessary for any arm of this
statement,
- checkpatch: missing a blank line after declarations.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cleanup the weird function-level comments and remove obvious
documentation for probe/remove.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If during probe() the s3c24xx_i2c_init() failed, the clock was left in
disabled but prepared state.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
cn78xx has a different interrupt architecture, so we have to manage
the interrupts differently.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use High-Level Controller (HLC) when possible. The HLC can read/write
up to 8 bytes and is completely optional. The most important difference
of the HLC is that it only requires one interrupt for a transfer
(up to 8 bytes) where the low-level read/write requires 2 interrupts
plus one interrupt per transferred byte. Since the interrupts are costly
using the HLC improves the performance. Also, the HLC provides improved
error handling.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
[wsa: fixed trivial checkpatch warnings]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add helper function that reads back a value after writing to
make sure the write is finished and use it in octeon_i2c_write_int().
Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Switch to the i2c bus recovery framework using generic SCL recovery.
If this fails try to reset the hardware. The recovery is triggered
during START on timeout of the interrupt or failure to reach
the START / repeated-START condition.
The START function is moved to xfer and while at it remove the
xfer debug message (i2c core already provides a debug message
for this).
Signed-off-by: Jan Glauber <jglauber@cavium.com>
[wsa: removed one empty line]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Introduce a function that checks for valid status codes depending
on the phase of a transmit or receive. Also add all existing status
codes and improve error handling for various states.
The Octeon TWSI has an "assert acknowledge" bit (TWSI_CTL_AAK) that
is required to be set in master receive mode until the last byte is
requested. The state check needs to consider if this bit was set.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS to simplify the code.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS to simplify the code.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The lock is taken while reading two registers. On RT the first lock is
taken in hard irq where it might sleep and in the threaded irq.
The threaded irq runs in oneshot mode so the hard irq does not run until
the thread the completes so there is no reason to grab the lock.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[grygorii.strashko@ti.com: drop locking from isr completely and remove
lock field from struct omap_i2c_dev]
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Share the ACPI companion for the platform device with the
i2c adapter, so that the adapter has access to the properties
defined in ACPI tables.
Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
All i2c mux users are using an explicit i2c mux core, drop support
for implicit i2c mux cores.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Add a mask to handle the case where not all child adapters should
cause a mux deselect to happen, now that there is a common deselect op
for all child adapters.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
All i2c-muxes have a parent adapter and one or many child
adapters. A mux also has some means of selection. Previously,
this was stored per child adapter, but it is only needed
to keep track of this per mux.
Add an i2c mux core, that keeps track of this consistently.
Also add some glue for users of the old interface, which will
create one implicit mux core per child adapter.
Signed-off-by: Peter Rosin <peda@axentia.se>
Tested-by: Antti Palosaari <crope@iki.fi>
Tested-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Switch to the new generic functions: i2c_parse_fw_timings().
Signed-off-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Add helper functions for control, data and status register access.
This simplifies the code and makes the purpose of the register
access clearer.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Rename the [read|write]_sw functions to make it clearer they access
the TWSI registers.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
No functional change, just moving the functions upward in
preparation of improving the recovery.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Convert the adapter timeout to 2 ms independently of depending on CONFIG_HZ.
CONFIG_HZ is 100 for MIPS Cavium-Octeon so the timeout value is not changed.
Also set retries to 5 to improve robustness.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Enable multi-master mode in I2C_CNFG reg based on hw features.
Using single/multi-master mode bit introduced for Tegra210,
whereas multi-master mode is enabled by default in HW for T124 and
earlier Tegra SOC. Enabling this bit doesn't explicitly start
treating the bus has having multiple masters, but will start
checking for arbitration lost and reporting when it occurs.
The Tegra210 I2C controller supports single/multi master mode.
Add chipdata for Tegra210 and its compatibility string so that
Tegra210 will select data that enables multi master mode correctly.
Do below prerequisites for multi-master bus if "multi-master"
dt property entry is added.
1. Enable 1st level clock always set.
2. Disable 2nd level clock gating (slcg which
is supported from T124 SOC and later chips)
Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Allow runtime PM so that PM and PCI core can put the device into low-power
state when idle and resume it back when needed in those platforms that
support PM for i801 device.
Enable also autosuspend with 1 second delay in order to not needlessly
toggle power state on and off if there are multiple transactions during
short time.
Device is resumed at the beginning of bus access and marked idle ready
for autosuspend at the end of it.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Stop using legacy PCI PM support and convert to standard dev_pm_ops.
This provides more straightforward path to add runtime PM.
While at it remove explicit PCI power state control and configuration space
save/restore as the PCI core does it.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When using a certain I2C device with runtime PM enabled on
a certain I2C bus adaper the following happens:
struct amba_device *foo
\
struct i2c_adapter *bar
\
struct i2c_client *baz
The AMBA device foo has its device PM struct set to ignore
children with pm_suspend_ignore_children(&foo->dev, true).
This makes runtime PM work just fine locally in the driver:
the fact that devices on the bus are suspended or resumed
individually does not affect its operation, and the hardware
does not power up unless transferring messages.
However this child ignorance property is not inherited into
the struct i2c_adapter *bar.
On system suspend things will work fine.
On system resume the following annoying phenomenon occurs:
- In the pm_runtime_force_resume() path of
struct i2c_client *baz, pm_runtime_set_active(&baz->dev); is
eventually called.
- This becomes __pm_runtime_set_status(&baz->dev, RPM_ACTIVE);
- __pm_runtime_set_status() detects that RPM state is changed,
and checks whether the parent is:
not active (RPM_ACTIVE) and not ignoring its children
If this happens it concludes something is wrong, because
a parent that is not ignoring its children must be active
before any children activate.
- Since the struct i2c_adapter *bar does not ignore
its children, the PM core thinks that it must indeed go
online before its children, the check bails out with
-EBUSY, i.e. the i2c_client *baz thinks it can't work
because it's parent is not online, and it respects its
parent.
- In the driver the .resume() callback returns -EBUSY from
the runtime_force_resume() call as per above. This leaves
the device in a suspended state, leading to bad behaviour
later when the device is used. The following debug
print is made with an extra printg patch but illustrates
the problem:
[ 17.040832] bh1780 2-0029: parent (i2c-2) is not active
parent->power.ignore_children = 0
[ 17.040832] bh1780 2-0029: pm_runtime_force_resume:
pm_runtime_set_active() failed (-16)
[ 17.040863] dpm_run_callback():
pm_runtime_force_resume+0x0/0x88 returns -16
[ 17.040863] PM: Device 2-0029 failed to resume: error -16
Fix this by letting all struct i2c_adapter:s ignore their
children: i2c children have no business doing keeping
their parents awake: they are completely autonomous
devices that just use their parent to talk, a usecase
which must be power managed in the host on a per-message
basis.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Wolfram Sang