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path: root/drivers/i2c/busses/i2c-rcar.c
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2024-07-12i2c: rcar: ensure Gen3+ reset does not disturb local targetsWolfram Sang1-0/+8
R-Car Gen3+ needs a reset before every controller transfer. That erases configuration of a potentially in parallel running local target instance. To avoid this disruption, avoid controller transfers if a local target is running. Also, disable SMBusHostNotify because it requires being a controller and local target at the same time. Fixes: 3b770017b03a ("i2c: rcar: handle RXDMA HW behaviour on Gen3") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-07-10i2c: rcar: clear NO_RXDMA flag after resettingWolfram Sang1-1/+1
We should allow RXDMA only if the reset was really successful, so clear the flag after the reset call. Fixes: 0e864b552b23 ("i2c: rcar: reset controller is mandatory for Gen3+") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-07-09i2c: rcar: bring hardware to known state when probingWolfram Sang1-5/+12
When probing, the hardware is not brought into a known state. This may be a problem when a hypervisor restarts Linux without resetting the hardware, leaving an old state running. Make sure the hardware gets initialized, especially interrupts should be cleared and disabled. Reported-by: Dirk Behme <dirk.behme@de.bosch.com> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@de.bosch.com Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-01-18i2c: rcar: add FastMode+ support for Gen4Wolfram Sang1-11/+27
To support FM+, we mainly need to turn the SMD constant into a parameter and set it accordingly. That also means we can finally fix SMD to our needs instead of bailing out. A sanity check for SMD then becomes a sanity check for 'x == 0'. After all that, activating the enable bit for FM+ is all we need to do. Tested with a Renesas Falcon board using R-Car V3U. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2024-01-18i2c: rcar: introduce Gen4 devicesWolfram Sang1-6/+7
So far, we treated Gen4 as Gen3. But we are soon adding FM+ as a Gen4 specific feature, so prepare the code for the new devtype. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-09-27i2c: rcar: fix error code in probe()Dan Carpenter1-1/+3
Return an error code if devm_reset_control_get_exclusive() fails. The current code returns success. Fixes: 0e864b552b23 ("i2c: rcar: reset controller is mandatory for Gen3+") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-09-22i2c: rcar: improve accuracy for R-Car Gen3+Wolfram Sang1-39/+89
With some new registers, SCL can be calculated to be closer to the desired rate. Apply the new formula for R-Car Gen3 device types. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-09-22i2c: rcar: reset controller is mandatory for Gen3+Wolfram Sang1-15/+14
Initially, we only needed a reset controller to make sure RXDMA works at least once per transfer. Meanwhile, documentation has been updated. It now says that a reset has to be performed prior every transaction, even if it is non-DMA. So, make the reset controller a requirement instead of being optional. And bail out if resetting fails. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-09-19i2c: rcar: remove open coded DIV_ROUND_CLOSESTWolfram Sang1-4/+3
It improves readability if we use the available helper. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-09-19i2c: rcar: calculate divider instead of brute-forcing itWolfram Sang1-16/+8
Instead of trying all values, we can actually compute it as the comment suggests. It is unclear what the comment means with "involved", it works nicely. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-09-19i2c: rcar: properly format a debug outputWolfram Sang1-1/+1
Use proper types and spacing. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-09-19i2c: rcar: avoid non-standard use of gotoWolfram Sang1-4/+8
Kernel functions goto somewhere on error conditions. Using goto for the default path is irritating. Let's bail out on error instead and use a proper retval. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-08-14I2C: Explicitly include correct DT includesRob Herring1-1/+1
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-08-08i2c: rcar: Remove #ifdef guards for PM related functionsPaul Cercueil1-8/+2
Use the new PM macros for the suspend and resume functions to be automatically dropped by the compiler when CONFIG_PM or CONFIG_PM_SLEEP are disabled, without having to use #ifdef guards. This has the advantage of always compiling these functions in, independently of any Kconfig option. Thanks to that, bugs and other regressions are subsequently easier to catch. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20230722115310.27681-2-paul@crapouillou.net Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2023-06-05i2c: Convert to platform remove callback returning voidUwe Kleine-König1-4/+2
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Alain Volmat <alain.volmat@foss.st.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Baruch Siach <baruch@tkos.co.il> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> Acked-by: Jochen Friedrich <jochen@scram.de> Acked-by: Peter Rosin <peda@axentia.se> Acked-by: Vadim Pasternak <vadimp@nvidia.com> Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reviewed-by: Chris Pringle <chris.pringle@phabrix.com> Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> Reviewed-by: Tali Perry <tali.perry@nuvoton.com> Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-12i2c: move drivers from strlcpy to strscpyWolfram Sang1-1/+1
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>
2022-05-21i2c: rcar: use flags instead of atomic_xferKuninori Morimoto1-10/+10
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>
2022-05-21i2c: rcar: REP_AFTER_RD is not a persistent flagWolfram Sang1-9/+8
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>
2022-05-21i2c: rcar: use BIT macro consistentlyWolfram Sang1-35/+35
Easier to read and ensures proper types. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-05-21i2c: rcar: refactor handling of first messageWolfram Sang1-27/+23
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>
2022-05-21i2c: rcar: avoid race condition with SMIsWolfram Sang1-11/+17
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>
2022-05-21i2c: rcar: fix PM ref counts in probe error pathsKuninori Morimoto1-6/+9
We have to take care of ID_P_PM_BLOCKED when bailing out during probe. Fixes: 7ee24eb508d6 ("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>
2022-04-16i2c: rcar: add support for I2C_M_RECV_LENWolfram Sang1-4/+27
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>
2022-02-11i2c: rcar: Add R-Car Gen4 supportGeert Uytterhoeven1-0/+1
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>
2021-12-17i2c: rcar: update to new DMAENGINE API when terminatingWolfram Sang1-17/+9
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>
2021-09-30i2c: rcar: enable interrupts before starting transferWolfram Sang1-3/+3
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>
2021-05-28i2c: rcar: Drop "renesas,i2c-rcar"Geert Uytterhoeven1-1/+0
The compatible value "renesas,i2c-rcar" was deprecated in commit ad4a8dc3fec6485b ("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>
2021-04-14i2c: rcar: add IRQ checkSergey Shtylyov1-1/+4
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: 6ccbe607132b ("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>
2021-03-18i2c: rcar: implement atomic transfersUlrich Hecht1-6/+78
Implements atomic transfers. Tested by rebooting an r8a7790 Lager board after connecting the i2c-rcar controller to the PMIC in arch/arm/boot/dts/r8a7790-lager.dts like so: compatible = "i2c-demux-pinctrl"; pinctrl-names = "default"; pinctrl-0 = <&pmic_irq_pins>; - i2c-parent = <&iic3>, <&i2c3>; + i2c-parent = <&i2c3>, <&iic3>; i2c-bus-name = "i2c-pwr"; #address-cells = <1>; #size-cells = <0>; Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-01-05i2c: rcar: protect against supurious interrupts on V3UWolfram Sang1-14/+43
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>
2021-01-05i2c: rcar: make sure irq is not threaded on Gen2 and earlierWolfram Sang1-1/+5
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>
2021-01-05i2c: rcar: optimize cacheline to minimize HW race conditionWolfram Sang1-1/+1
'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>
2021-01-05i2c: rcar: faster irq code to minimize HW race conditionWolfram Sang1-7/+4
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>
2020-10-21Merge branch 'i2c/for-5.10' of ↵Linus Torvalds1-24/+41
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 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 ...
2020-09-21i2c: rcar: add HostNotify supportWolfram Sang1-3/+28
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>
2020-09-19i2c: rcar: refactor and shorten timeout when resettingWolfram Sang1-12/+3
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>
2020-09-19i2c: rcar: improve bus busy detectionWolfram Sang1-9/+10
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>
2020-08-25i2c: rcar: in slave mode, clear NACK earlierWolfram Sang1-0/+1
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: de20d1857dd6 ("i2c: rcar: add slave support") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-07-31i2c: rcar: avoid race when unregistering slaveWolfram Sang1-3/+5
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: 7b814d852af6 ("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>
2020-07-31Merge tag 'v5.8-rc7' into i2c/for-5.9Wolfram Sang1-0/+3
2020-07-26i2c: rcar: slave: only send STOP event when we have been addressedWolfram Sang1-3/+4
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: de20d1857dd6 ("i2c: rcar: add slave support") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-07-23i2c: rcar: always clear ICSAR to avoid side effectsWolfram Sang1-0/+3
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: de20d1857dd6 ("i2c: rcar: add slave support") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-04-15i2c: busses: convert to devm_platform_get_and_ioremap_resourceDejin Zheng1-3/+1
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>
2020-03-31i2c: rcar: clean up after refactoring i2c_timingsWolfram Sang1-6/+6
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>
2020-03-24i2c: rcar: Consolidate timings calls in rcar_i2c_clock_calculate()Andy Shevchenko1-9/+9
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>
2020-03-24i2c: core: Allow override timing properties with 0Andy Shevchenko1-1/+1
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>
2019-11-14i2c: rcar: Remove superfluous call to clk_get_rate()Geert Uytterhoeven1-1/+1
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>
2019-08-14i2c: rcar: avoid race when unregistering slave clientWolfram Sang1-4/+7
After we disabled interrupts, there might still be an active one running. Sync before clearing the pointer to the slave device. Fixes: de20d1857dd6 ("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>
2019-03-20i2c: rcar: wait for data empty before starting DMAWolfram Sang1-7/+4
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>
2019-03-20i2c: rcar: let DMA enable routine return success statusWolfram Sang1-5/+6
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>
generated by cgit v1.2.3 (git 2.39.0) at 2024-08-09 11:22:13 +0300