Follow the advice of the below link and prefer 'strscpy'. Conversion is
easy because no driver used the return value and has been done with a
simple sed invocation.
Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
i2c-rcar already has priv->flags. This patch adds a new persistent flag
ID_P_NOT_ATOMIC and uses it to save the extra variable. The negation of
the logic was done to make the code more readable.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
[wsa: negated the logic, rebased, updated the commit message]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Previous refactoring makes it easy now to convert the above flag to a
non-persistent one. This is more appropriate and easier to maintain.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
After moving ICMSR handling to interrupt handlers previously to fix a
race condition, we can now also move ICMSR handling for the first
message out of the function to prepare a message. By introducing a
seperate function to initialize the first message, we can not only
remove some code duplication but the remaining code is also easier to
follow. The function to prepare a message is much simpler without ICMSR
handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
A customer experienced a race condition with 'repeated starts' when a
System Management Interrupt took over for 30us and more. The problem was
that during the SMI a new MAT interrupt came in because we set up the
'repeated start' condition. But the old one was not acknowledged yet.
So, when it was acknowledged after the SMI, the new MAT interrupt was
lost, confusing the state machine of the driver.
The fix consists of two parts. First, we do not clear the status
register for 'repeated starts' when preparing the next message anymore.
The interrupt handlers for sending and receiving data is now solely
responsible for that and it makes the code easier to follow, in fact.
Secondly, clearing the status register is now split up to handle MAT
interrupts independently. This avoids the race condition because the old
MAT interrupt will be now cleared before we initiate the "repeated
start" condition.
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
We have to take care of ID_P_PM_BLOCKED when bailing out during probe.
Fixes: 7ee24eb508 ("i2c: rcar: disable PM in multi-master mode")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
With this feature added, SMBus Block reads and Proc calls are now
supported. This patch is the best of two independent developments by
Wolfram and Bhuvanesh + Andrew, refactored again by Wolfram.
Signed-off-by: Bhuvanesh Surachari <bhuvanesh_surachari@mentor.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Add support for the I2C Bus Interface on R-Car Gen4 SoCs (e.g. R-Car
S4-8) by matching on a family-specific compatible value.
While I2C on R-Car Gen4 does support some extra features (Slave Clock
Stretch Select), for now it is treated the same as I2C on R-Car Gen3.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: removed incorrect "FM+" from commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
dmaengine_terminate_all() is deprecated. When converting the existing
calls, it turned out that the termination in the interrupt handlers was
superfluous and only a side effect of simply calling
rcar_i2c_cleanup_dma(). As either no DMA transfers have been submitted
yet or the last one has successfully completed, there is nothing to
terminate and we can leave it out. So, merge the DMA unmap and cleanup
function to save some code. Then, add a flag if the new cleanup function
needs to terminate DMA. This is only the case for the erorr handling in
the main thread, so we can finally switch from dmaengine_terminate_all()
to dmaengine_terminate_sync() here.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
We want to enable the interrupts _before_ starting the transfer because
it is good programming style and also the proposed order in the R-Car
manual. There is no difference in practice because it doesn't matter in
which order both conditions appear if we wait for both to happen.
Signed-off-by: Ryo Kataoka <ryo.kataoka.wt@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
The compatible value "renesas,i2c-rcar" was deprecated in commit
ad4a8dc3fe ("i2c: rcar: Add per-Generation fallback bindings"),
and never had any users in upstream Linux. Drop its match entry from
the driver.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to devm_request_irq() (which
takes *unsigned* IRQ #), causing it to fail with -EINVAL, overriding
an original error code. Stop calling devm_request_irq() with the
invalid IRQ #s.
Fixes: 6ccbe60713 ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
V3U creates spurious interrupts which we need to handle. This costs time
until BUS_PHASE_DATA can be activated which is problematic for Gen2 SoCs
and earlier. Because of this we introduce two interrupt handlers here
which will call a generic main irq function once the timing critical
stuff is done.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Ensure this irq runs as fast as possible.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
'flags' and 'io' are needed first, so they should be at the beginning of
the private struct.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
To avoid the HW race condition on R-Car Gen2 and earlier, we need to
write to ICMCR as soon as possible in the interrupt handler. We can
improve this by writing a static value instead of masking out bits.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Pull i2c updates from Wolfram Sang:
- if a host can be a client, too, the I2C core can now use it to
emulate SMBus HostNotify support (STM32 and R-Car added this so far)
- also for client mode, a testunit has been added. It can create rare
situations on the bus, so host controllers can be tested
- a binding has been added to mark the bus as "single-master". This
allows for better timeout detections
- new driver for Mellanox Bluefield
- massive refactoring of the Tegra driver
- EEPROMs recognized by the at24 driver can now have custom names
- rest is driver updates
* 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (80 commits)
Documentation: i2c: add testunit docs to index
i2c: tegra: Improve driver module description
i2c: tegra: Clean up whitespaces, newlines and indentation
i2c: tegra: Clean up and improve comments
i2c: tegra: Clean up printk messages
i2c: tegra: Clean up variable names
i2c: tegra: Improve formatting of variables
i2c: tegra: Check errors for both positive and negative values
i2c: tegra: Factor out hardware initialization into separate function
i2c: tegra: Factor out register polling into separate function
i2c: tegra: Factor out packet header setup from tegra_i2c_xfer_msg()
i2c: tegra: Factor out error recovery from tegra_i2c_xfer_msg()
i2c: tegra: Rename wait/poll functions
i2c: tegra: Remove "dma" variable from tegra_i2c_xfer_msg()
i2c: tegra: Remove redundant check in tegra_i2c_issue_bus_clear()
i2c: tegra: Remove likely/unlikely from the code
i2c: tegra: Remove outdated barrier()
i2c: tegra: Clean up variable types
i2c: tegra: Reorder location of functions in the code
i2c: tegra: Clean up probe function
...
The I2C core can now utilize a slave interface to handle SMBus
HostNotify events. Enable it in this driver.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
LOOP_TIMEOUT was only used back then because we didn't want to introduce
another constant. The timeout value can easily be a magnitude shorter
because the typical range is 3us - 8us. Refactor the code to use the
poll_timeout helper, use a specific timeout value and get rid of the
ugly LOOP_TIMEOUT constant.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
I2C doesn't define a timeout for bus busy, so an arbitrary value like
LOOP_TIMEOUT is not a good idea. Let's use the timeout value in struct
adapter which is meant for such cases and is user-configurable (via
IOCTL). To reduce the load, wait 10us instead of 1us which is good
enough for the slow frequencies used by I2C. Finally, use the
poll_timeout helper instead of open coding it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Currently, a NACK in slave mode is set/cleared when SCL is held low by
the IP core right before the bit is about to be pushed out. This is too
late for clearing and then a NACK from the previous byte is still used
for the current one. Now, let's clear the NACK right after we detected
the STOP condition following the NACK.
Fixes: de20d1857d ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Due to the lockless design of the driver, it is theoretically possible
to access a NULL pointer, if a slave interrupt was running while we were
unregistering the slave. To make this rock solid, disable the interrupt
for a short time while we are clearing the interrupt_enable register.
This patch is purely based on code inspection. The OOPS is super-hard to
trigger because clearing SAR (the address) makes interrupts even more
unlikely to happen as well. While here, reinit SCR to SDBS because this
bit should always be set according to documentation. There is no effect,
though, because the interface is disabled.
Fixes: 7b814d852a ("i2c: rcar: avoid race when unregistering slave client")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
When the SSR interrupt is activated, it will detect every STOP condition
on the bus, not only the ones after we have been addressed. So, enable
this interrupt only after we have been addressed, and disable it
otherwise.
Fixes: de20d1857d ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
On R-Car Gen2, we get a timeout when reading from the address set in
ICSAR, even though the slave interface is disabled. Clearing it fixes
this situation. Note that Gen3 is not affected.
To reproduce: bind and undbind an I2C slave on some bus, run
'i2cdetect' on that bus.
Fixes: de20d1857d ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
use devm_platform_get_and_ioremap_resource() to simplify code, which
contains platform_get_resource() and devm_ioremap_resource(), it also
get the resource for use by the following code.
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The pointer is not really needed anymore since we have the timings
struct available in the function itself now. Remove the pointer and
access the struct directly.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move i2c_parse_fw_timings() to rcar_i2c_clock_calculate() to consolidate
timings calls in one place.
While here, replace hard coded values with standard bus frequency definitions.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Some drivers may allow to override properties with 0 value when defaults
are not in use, thus, replace memset() with corresponding per property
update.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Variable "rate" already contains the current clock rate, so use that
rather than calling clk_get_rate() again.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
After we disabled interrupts, there might still be an active one
running. Sync before clearing the pointer to the slave device.
Fixes: de20d1857d ("i2c: rcar: add slave support")
Reported-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When sending with DMA, the driver transfers the first byte with PIO (as
documented). However, it started DMA right after the first byte was
written. This worked, but was not according to the datasheet which
suggests to wait until data register was empty again. Implement this.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We will need to know if enabling DMA was successful in a later patch.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use a macro for the hardcoded value and apply a build check. If it is
not met, the driver logic will not work anymore.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
To make sure people can understand the lockless design of this driver
without the need to dive into git history, add a comment giving an
overview of the situation.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch fixes the problem that an interrupt may set up a new I2C
message and the DMA callback overwrites this setup.
By disabling the DMA Enable Register(ICDMAER), rcar_i2c_dma_unmap()
enables interrupts for register settings (such as Master Control
Register(ICMCR)) and advances the I2C transfer sequence.
If an interrupt occurs immediately after ICDMAER is disabled, the
callback handler later continues and overwrites the previous settings
from the interrupt. So, disable ICDMAER at the end of the callback to
ensure other interrupts are masked until then.
Note that this driver needs to work lock-free because there are IP cores
with a HW race condition which prevent us from using a spinlock in the
interrupt handler.
Reproduction test:
1. Add a delay after disabling ICDMAER. (It is expected to generate an
interrupt of rcar_i2c_irq())
void rcar_i2c_dma_unmap(struct rcar_i2c_priv *priv)
{
...
rcar_i2c_write(priv, ICDMAER, 0);
usleep_range(500, 800)
...
priv->dma_direction = DMA_NONE;
}
2. Execute DMA transfers
$ i2ctransfer -y 4 w9@0x6a 1 1+ r16
3. A log message of BUG_ON() will be displayed.
Fixes: 73e8b05283 ("i2c: rcar: add DMA support")
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[wsa: updated test case to be more reliable, added note to comment]
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The latest documentation made it clear that we need to initialize the
TCYC value independently of DMA. The old code used TCYC06 (wrongly) for
non-DMA transfers. The new code sets TCYC up independently from DMA.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Update copyright years and remove a comment which grew incorrect and
useless over time.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When doing s2idle/s2ram on Salvator-X(S):
WARNING: CPU: 2 PID: 971 at drivers/i2c/i2c-core-base.c:1869 __i2c_transfer+0x608/0x910
[...]
Call trace:
__i2c_transfer+0x608/0x910
i2c_smbus_xfer_emulated+0x158/0x5b0
__i2c_smbus_xfer+0x17c/0x818
i2c_smbus_xfer+0x64/0x98
i2c_smbus_read_byte_data+0x40/0x70
cs2000_bset.isra.1+0x2c/0x68
__cs2000_set_rate.constprop.7+0x80/0x148
cs2000_resume+0x18/0x20
dpm_run_callback+0x74/0x330
device_resume_early+0xd4/0x120
dpm_resume_early+0x158/0x4f8
suspend_devices_and_enter+0x36c/0xd98
[...]
On second resume, the sound driver fails with:
cs2000-cp 2-004f: pll lock failed
rcar_sound ec500000.sound: can't use clk 1
As the CS2000 clock driver needs to send I2C messages during suspend,
the I2C controller driver should be suspended later, and resumed
earlier. Fix this by using the noirq sleep ops instead of the normal
sleep ops, which are called after the late sleep ops, as used by the
CS2000 clock driver.
Fixes: 18569fa89a ("i2c: rcar: add suspend/resume support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Because the adapter will be set up before every transaction anyhow, we
just need to mark it as suspended to the I2C core.
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We should check the bus state before reinitializing the IP core.
Otherwise, the internal bus busy state which also tracks multi-master
activity is lost.
Credits go to the Renesas BSP team for suggesting this change.
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Fixes: ae481cc139 ("i2c: rcar: fix resume by always initializing registers before transfer")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
DMA needs to be cleaned up not only on timeout, but on all errors where
it has been setup before.
Fixes: 73e8b05283 ("i2c: rcar: add DMA support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
When doing a REP_START after a read message, the driver used to trigger
a STOP first which would then be overwritten by REP_START. This was the
only stable method found when doing the last refactoring. However, this
was not in accordance with the documentation.
After research from our BSP team and myself, we now can implement a
version which works and is according to the documentation. The new
approach ensures the ICMCR register is only changed when really needed.
Tested on a R-Car Gen2 (H2) and Gen3 with DMA (M3N).
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use BIT macro to avoid shift-31-problem, indent a little more and use
GENMASK to make it easier to add new flags.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
And don't reimplement in the driver.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
On Gen3, we can only do RXDMA once per transfer reliably. For that, we
must reset the device, then we can have RXDMA once. This patch
implements this. When there is no reset controller or the reset fails,
RXDMA will be blocked completely. Otherwise, it will be disabled after
the first RXDMA transfer. Based on a commit from the BSP by Hiromitsu
Yamasaki, yet completely refactored to handle multiple read messages
within one transfer.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
To break out of recovery as early as possible, feed back the bus_free
logic state.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
