Sometimes we would get the following flow when doing an i2cset:
0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4
I2C_SLAVE_WRITE_RECEIVED
0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x714 : INTR_STAT=0x204
I2C_SLAVE_WRITE_REQUESTED
I2C_SLAVE_WRITE_RECEIVED
Documentation/i2c/slave-interface.rst says that I2C_SLAVE_WRITE_REQUESTED,
which is mandatory, should be sent while the data did not arrive yet. It
means in a write-request I2C_SLAVE_WRITE_REQUESTED should be reported
before any I2C_SLAVE_WRITE_RECEIVED.
By the way, I2C_SLAVE_STOP didn't be reported in the above case because
DW_IC_INTR_STAT was not 0x200.
dev->status can be used to record the current state, especially Designware
I2C controller has no interrupts to identify a write-request. This patch
makes not only I2C_SLAVE_WRITE_REQUESTED been reported first when
IC_INTR_RX_FULL is rising and dev->status isn't STATUS_WRITE_IN_PROGRESS
but also I2C_SLAVE_STOP been reported when a STOP condition is received.
Signed-off-by: Michael Wu <michael.wu@vatics.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
If some bits were cleared by i2c_dw_read_clear_intrbits_slave() in
i2c_dw_isr_slave() and not handled immediately, those cleared bits would
not be shown again by later i2c_dw_read_clear_intrbits_slave(). They
therefore were forgotten to be handled.
i2c_dw_read_clear_intrbits_slave() should be called once in an ISR and take
its returned state for all later handlings.
Signed-off-by: Michael Wu <michael.wu@vatics.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Seeing the DW I2C driver is using flags-based accessors with two
conditional clauses it would be better to replace them with the regmap
API IO methods and to initialize the regmap object with read/write
callbacks specific to the controller registers map implementation. This
will be also handy for the drivers with non-standard registers mapping
(like an embedded into the Baikal-T1 System Controller DW I2C block, which
glue-driver is a part of this series).
As before the driver tries to detect the mapping setup at probe stage and
creates a regmap object accordingly, which will be used by the rest of the
code to correctly access the controller registers. In two places it was
appropriate to convert the hand-written read-modify-write and
read-poll-loop design patterns to the corresponding regmap API
ready-to-use methods.
Note the regmap IO methods return value is checked only at the probe
stage. The rest of the code won't do this because basically we have
MMIO-based regmap so non of the read/write methods can fail (this also
won't be needed for the Baikal-T1-specific I2C controller).
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[wsa: fix type of 'rx_valid' and remove outdated kdoc var description]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Move configuration routines to respective modules, i.e. master and slave.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Fix spelling typos in the comments with help of `codespell`.
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 problem with detecting the FIFO depth in the platform driver
is that in order to implement this we have to access the controller
IC_COMP_PARAM_1 register. Currently it's done before the
i2c_dw_set_reg_access() method execution, which is errors prone since
the method determines the registers endianness and access mode and we
can't use dw_readl/dw_writel accessors before this information is
retrieved. We also can't move the i2c_dw_set_reg_access() function
invocation to after the master/slave probe functions call (when endianness
and access mode are determined), since the FIFO depth information is used
by them for initializations. So in order to fix the problem we have no
choice but to move the FIFO size detection methods to the common code and
call it at the probe stage.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Reviewed-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>
Make sure interrupt handler i2c_dw_irq_handler_slave() has finished
before clearing the the dev->slave pointer in i2c_dw_unreg_slave().
There is possibility for a race if i2c_dw_irq_handler_slave() is running
on another CPU while clearing the dev->slave pointer.
Reported-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Reported-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Replace short statement in comment with proper SPDX license tag.
Note, for i2c-desingware-slave.c the identifier is chosen
in accordance with MODULE_LICENSE() macro since it is visible to user.
Another point to this choice is that the header seems to be copy'n'paste
from the other file of this very driver.
Acked-by: Luis Oliveira <Luis.Oliveira@synopsys.com>
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>
SDA hold time configuration is common to both master and slave code. It
is also something that can be done once during probe and do only
register write when HW needs to be reinitialized.
Remove duplication and move SDA hold time configuration to common code.
It will be called from slave probe and for master code from a new
i2c_dw_set_timings_master() to where we will populate more probe time
timing parameter setting.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move register access detection out from master and slave HW
initialization code to common code. Motivation for this is to have
register access configured before HW initialization and remove
duplicated code.
This allows to do further separation between probe time initialization
and runtime reinitialization code.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Commit 43df43e6ba ("i2c: designware: Don't set SCL timings and speed
mode when in slave mode") made variable comp_param1 needless in
i2c_dw_init_slave(). Remove it now.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
According to data sheet SCL timing parameters and DW_IC_CON SPEED mode
bits are not used when operating in slave mode.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Luis Oliveira <lolivei@synopsys.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Pull i2c updates from Wolfram Sang:
- new drivers for Spreadtrum I2C, Intel Cherry Trail Whiskey Cove SMBUS
- quite some driver updates
- cleanups for the i2c-mux subsystem
- some subsystem-wide constification
- further cleanup of include/linux/i2c
* 'i2c/for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (50 commits)
i2c: sprd: Fix undefined reference errors
i2c: nomadik: constify amba_id
i2c: versatile: Make i2c_algo_bit_data const
i2c: busses: make i2c_adapter_quirks const
i2c: busses: make i2c_adapter const
i2c: busses: make i2c_algorithm const
i2c: Add Spreadtrum I2C controller driver
dt-bindings: i2c: Add Spreadtrum I2C controller documentation
i2c-cht-wc: make cht_wc_i2c_adap_driver static
MAINTAINERS: Add entry for drivers/i2c/busses/i2c-cht-wc.c
i2c: aspeed: Retain delay/setup/hold values when configuring bus frequency
dt-bindings: i2c: eeprom: Document vendor to be used and deprecated ones
i2c: i801: Restore the presence state of P2SB PCI device after reading BAR
MAINTAINERS: drop entry for Blackfin I2C and Sonic's email
blackfin: merge the two TWI header files
i2c: davinci: Preserve return value of devm_clk_get
i2c: mediatek: Add i2c compatible for MediaTek MT7622
dt-bindings: i2c: Add MediaTek MT7622 i2c binding
dt-bindings: i2c: modify information formats
i2c: mux: i2c-arb-gpio-challenge: allow compiling w/o OF support
...
I2C slave controller must be powered and active all the time when I2C
slave backend is registered in order to let master address and
communicate with us.
Now if the controller is runtime PM capable it will be suspended after
probe and cannot ever respond to the master or generate interrupts.
Fix this by resuming the controller when I2C slave backend is registered
and let it suspend after unregistering.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I guess pm_runtime_put_noidle() call in i2c_dw_probe_slave() was copied
by accident from similar master mode adapter registration code. It is
unbalanced due missing pm_runtime_get_noresume() but harmless since it
doesn't decrease dev->power.usage_count below zero.
In theory we can hit similar needless runtime suspend/resume cycle
during slave mode adapter registration that was happening when
registering the master mode adapter. See commit cd998ded5c ("i2c:
designware: Prevent runtime suspend during adapter registration").
However, since we are slave, we can consider it as a wrong configuration
if we have other slaves attached under this adapter and can omit the
pm_runtime_get_noresume()/pm_runtime_put_noidle() calls for simplicity.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When i2c-designware is initialized in slave mode the
i2c-designware-slave.c: i2c_dw_irq_handler_slave() can hit a NULL
pointer dereference when I2C slave backend is not registered but code is
accessing the struct dw_i2c_dev.slave without testing is it NULL.
We might get spurious interrupts from other devices or from IRQ core
during unloading the driver when CONFIG_DEBUG_SHIRQ is set. Existing
check for enable and IRQ status is not enough since device can be power
gated and those bits may read 1.
Fix this by handling the interrupt only when also struct dw_i2c_dev.slave
is set.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Check for i2c_algorithm and i2c_adapter_quirks structures that are only
stored in the algo and quirks fields of an i2c_adapter structure
correspondingly. These fields are declared const, so i2c_algorithm and
i2c_adapter_quirks structures that have this property can be declared
as const also.
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (for designware)
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>
Trivial fixes to spelling mistakes in dev_dbg message
"STAUTS" -> "STATUS"
"SLAVE_ACTTVITY" -> "SLAVE_ACTIVITY"
Signed-off-by: Colin Ian King <colin.king@canonical.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>
