Commit Graph

175 Commits

Author SHA1 Message Date
Wolfram Sang
614b1c3cbf i2c: use inclusive callbacks in struct i2c_algorithm
Convert the I2C subsystem to drop using the 'master_'-prefixed callbacks
in favor of the simplified ones. Fix alignment of '=' while here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2025-06-12 10:05:31 +02:00
Wolfram Sang
093f70c134 i2c: rcar: fix NACK handling when being a target
When this controller is a target, the NACK handling had two issues.
First, the return value from the backend was not checked on the initial
WRITE_REQUESTED. So, the driver missed to send a NACK in this case.
Also, the NACK always arrives one byte late on the bus, even in the
WRITE_RECEIVED case. This seems to be a HW issue. We should then not
rely on the backend to correctly NACK the superfluous byte as well. Fix
both issues by introducing a flag which gets set whenever the backend
requests a NACK and keep sending it until we get a STOP condition.

Fixes: de20d1857d ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2025-01-15 19:37:33 +01:00
Uwe Kleine-König
32a0a94aa0 i2c: Switch back to struct platform_driver::remove()
After commit 0edb555a65 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.

Convert all platform drivers below drivers/i2c to use .remove(), with
the eventual goal to drop struct platform_driver::remove_new(). As
.remove() and .remove_new() have the same prototypes, conversion is done
by just changing the structure member name in the driver initializer.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-11-17 11:58:14 +01:00
Kuninori Morimoto
1bae758922 i2c: rcar: tidyup priv->devtype handling on rcar_i2c_probe()
rcar_i2c_probe() has priv->devtype operation, but handling (A) and (C)
in same place is more understandable ( (A) and (B) are independent).

(A)	if (priv->devtype < I2C_RCAR_GEN3) {
		...
	}

(B)	...

(C)	if (priv->devtype >= I2C_RCAR_GEN3) {
		...
	}

Let's merge it with if-else

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-09-10 00:36:49 +02:00
Linus Torvalds
ef035628c3 The I2C core gains documentation updates for the testunit, a cleanup
regarding unneeded 'driver_data' and more sanity checks in the char
 device.
 
 For the host drivers, this release includes significant updates, with
 the primary change being the renaming from "master/slave" to
 "controller/target" to adhere to I2C v7 and SMBus 3.2 standards.
 
 New Support:
 
  - Added support for Intel Arrow Lake-H.
  - Added I2C support in the Arioha SoC by linking the Mediatek
    I2C controller.
 
 Cleanups:
 
  - Added the MODULE_DESCRIPTION() macro, resolving a modpost
    warning in the ALi 1563 Southbridge driver.
  - Constified the regmap_config declaration in the i2c-designware
    driver.
  - Improved the coding style in the Renesas R-Car driver by
    removing unnecessary semicolons after brackets.
 
 General improvements:
 
  - In the OMAP device, replaced NOIRQ_SYSTEM_SLEEP_PM_OPS with
    RUNTIME_PM_OPS to enable waking up the controller during
    suspend() before suspend_noirq() kicks in.
  - Improved logging in the Xilinx driver.
  - Added a warning (WARN()) in the Renesas R-Car driver for
    spurious interrupts.
 
 DTS Changes:
 
  - Removed address-cell and size-cell from the Atmel at91sam,
    nVidia Tegra 20, and Samsung S3c2410 devices.
  - Fixed Texas Instruments OMAP4 I2C controller to comply with
    the i2c-controller.yaml schema.
  - Improved indentation in DTS examples for several I2C devices.
  - Converted the NXP LPC1788 binding to the dt-schema.
  - Added documentation for the compatible string
    thead,th1520-i2c.
  - Added the "power-domains" property for the Meson I2C driver.
 
 AT24 EEPROM driver changes:
 
  - add support for two new Microchip models
  - document even more new models in DT bindings (those use fallback
    compatibles so no code changes)
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Merge tag 'i2c-for-6.11-rc1-try2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "The I2C core gains documentation updates for the testunit, a cleanup
  regarding unneeded 'driver_data' and more sanity checks in the char
  device.

  For the host drivers, this release includes significant updates, with
  the primary change being the renaming from "master/slave" to
  "controller/target" to adhere to I2C v7 and SMBus 3.2 standards.

  New Support:

   - Added support for Intel Arrow Lake-H
   - Added I2C support in the Arioha SoC by linking the Mediatek I2C
     controller

  Cleanups:

   - Added the MODULE_DESCRIPTION() macro, resolving a modpost warning
     in the ALi 1563 Southbridge driver.
   - Constified the regmap_config declaration in the i2c-designware
     driver.
   - Improved the coding style in the Renesas R-Car driver by removing
     unnecessary semicolons after brackets.

  General improvements:

   - In the OMAP device, replaced NOIRQ_SYSTEM_SLEEP_PM_OPS with
     RUNTIME_PM_OPS to enable waking up the controller during suspend()
     before suspend_noirq() kicks in.
   - Improved logging in the Xilinx driver.
   - Added a warning (WARN()) in the Renesas R-Car driver for spurious
     interrupts.

  DTS Changes:

   - Removed address-cell and size-cell from the Atmel at91sam, nVidia
     Tegra 20, and Samsung S3c2410 devices.
   - Fixed Texas Instruments OMAP4 I2C controller to comply with the
     i2c-controller.yaml schema.
   - Improved indentation in DTS examples for several I2C devices.
   - Converted the NXP LPC1788 binding to the dt-schema.
   - Added documentation for the compatible string thead,th1520-i2c.
   - Added the "power-domains" property for the Meson I2C driver.

  AT24 EEPROM driver changes:

   - add support for two new Microchip models
   - document even more new models in DT bindings (those use fallback
     compatibles so no code changes)"

* tag 'i2c-for-6.11-rc1-try2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (87 commits)
  i2c: document new callbacks in i2c_algorithm
  dt-bindings: i2c: amlogic,meson6-i2c: add optional power-domains
  dt-bindings: i2c: at91: Add sama7d65 compatible string
  i2c: st: reword according to newest specification
  i2c: cpm: reword according to newest specification
  i2c: virtio: reword according to newest specification
  i2c: nvidia-gpu: reword according to newest specification
  i2c: viai2c: reword according to newest specification
  i2c: viperboard: reword according to newest specification
  i2c: uniphier: reword according to newest specification
  i2c: uniphier-f: reword according to newest specification
  i2c: tiny-usb: reword according to newest specification
  i2c: thunderx-pcidrv: reword according to newest specification
  i2c: tegra-bpmp: reword according to newest specification
  i2c: taos-evm: reword according to newest specification
  i2c: sun6i-p2wi: reword according to newest specification
  i2c: stm32f4: reword according to newest specification
  i2c: sprd: reword according to newest specification
  i2c: sis5595: reword according to newest specification
  i2c: rzv2m: reword according to newest specification
  ...
2024-07-19 16:46:26 -07:00
Wolfram Sang
ea5ea84c9d i2c: rcar: ensure Gen3+ reset does not disturb local targets
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: 3b770017b0 ("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>
2024-07-12 01:45:08 +02:00
Wolfram Sang
fea6b5ebb7 i2c: rcar: clear NO_RXDMA flag after resetting
We should allow RXDMA only if the reset was really successful, so clear
the flag after the reset call.

Fixes: 0e864b552b ("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>
2024-07-10 22:52:30 +02:00
Wolfram Sang
2a1bd7a180 i2c: rcar: minor changes to adhere to coding style
A newline was missing and closing braces of functions do not need a
semicolon.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-07-10 09:58:18 +02:00
Wolfram Sang
3291d2327e i2c: rcar: WARN about spurious irqs
The FIXME is very old and probably needed because of some driver bug
like insufficient initialization. It may well be that it was fixed
meanwhile but we never know because the spurious irq is silently
ignored. Add now a call trace when this happens so we have more
information in case the issue still exists.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-07-10 09:57:49 +02:00
Wolfram Sang
4e36c0f20c i2c: rcar: bring hardware to known state when probing
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: 6ccbe60713 ("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>
2024-07-09 01:18:29 +02:00
Wolfram Sang
d0520eb3ed i2c: rcar: add FastMode+ support for Gen4
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>
2024-01-18 21:10:42 +01:00
Wolfram Sang
2b523c46e8 i2c: rcar: introduce Gen4 devices
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>
2024-01-18 21:10:42 +01:00
Dan Carpenter
37a672be3a i2c: rcar: fix error code in probe()
Return an error code if devm_reset_control_get_exclusive() fails.
The current code returns success.

Fixes: 0e864b552b ("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>
2023-09-27 21:54:25 +02:00
Wolfram Sang
54c76ed330 i2c: rcar: improve accuracy for R-Car Gen3+
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>
2023-09-22 11:54:48 +02:00
Wolfram Sang
0e864b552b i2c: rcar: reset controller is mandatory for Gen3+
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>
2023-09-22 11:54:38 +02:00
Wolfram Sang
3c417c947c i2c: rcar: remove open coded DIV_ROUND_CLOSEST
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>
2023-09-19 11:11:02 +02:00
Wolfram Sang
47280af872 i2c: rcar: calculate divider instead of brute-forcing it
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>
2023-09-19 11:10:54 +02:00
Wolfram Sang
d72857907a i2c: rcar: properly format a debug output
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>
2023-09-19 11:10:47 +02:00
Wolfram Sang
be944ceb67 i2c: rcar: avoid non-standard use of goto
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>
2023-09-19 11:10:28 +02:00
Rob Herring
59738ab266 I2C: Explicitly include correct DT includes
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>
2023-08-14 17:47:21 +02:00
Paul Cercueil
941b99ac57 i2c: rcar: Remove #ifdef guards for PM related functions
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>
2023-08-08 15:36:51 +02:00
Uwe Kleine-König
e190a0c389 i2c: Convert to platform remove callback returning void
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>
2023-06-05 09:47:37 +02:00
Wolfram Sang
ea1558ce14 i2c: move drivers from strlcpy to strscpy
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>
2022-08-11 23:02:51 +02:00
Kuninori Morimoto
e35fb41889 i2c: rcar: use flags instead of atomic_xfer
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>
2022-05-21 12:55:32 +02:00
Wolfram Sang
f0f0e07685 i2c: rcar: REP_AFTER_RD is not a persistent flag
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>
2022-05-21 12:55:07 +02:00
Wolfram Sang
4c278db7be i2c: rcar: use BIT macro consistently
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>
2022-05-21 12:54:50 +02:00
Wolfram Sang
238904dd64 i2c: rcar: refactor handling of first message
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>
2022-05-21 08:37:01 +02:00
Wolfram Sang
a0fb48c9bd i2c: rcar: avoid race condition with SMIs
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>
2022-05-21 08:36:53 +02:00
Kuninori Morimoto
3fe2ec59db i2c: rcar: fix PM ref counts in probe error paths
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>
2022-05-21 08:16:40 +02:00
Wolfram Sang
633c0e7559 i2c: rcar: add support for I2C_M_RECV_LEN
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>
2022-04-15 23:36:18 +02:00
Geert Uytterhoeven
ea01b71b07 i2c: rcar: Add R-Car Gen4 support
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>
2022-02-11 18:32:02 +01:00
Wolfram Sang
a5f7cf953f i2c: rcar: update to new DMAENGINE API when terminating
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>
2021-12-16 22:22:56 +01:00
Wolfram Sang
e7f4264821 i2c: rcar: enable interrupts before starting transfer
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>
2021-09-29 23:02:59 +02:00
Geert Uytterhoeven
7475d2fbca i2c: rcar: Drop "renesas,i2c-rcar"
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>
2021-05-28 09:50:43 +02:00
Sergey Shtylyov
147178cf03 i2c: rcar: add IRQ check
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>
2021-04-14 10:21:16 +02:00
Ulrich Hecht
82531dfdf1 i2c: rcar: implement atomic transfers
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>
2021-03-18 11:59:00 +01:00
Wolfram Sang
9c975c432b i2c: rcar: protect against supurious interrupts on V3U
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>
2021-01-05 16:29:46 +01:00
Wolfram Sang
24c6d4bc56 i2c: rcar: make sure irq is not threaded on Gen2 and earlier
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>
2021-01-05 16:29:32 +01:00
Wolfram Sang
25c2e0fb5f i2c: rcar: optimize cacheline to minimize HW race condition
'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>
2021-01-05 16:29:19 +01:00
Wolfram Sang
c7b514ec97 i2c: rcar: faster irq code to minimize HW race condition
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>
2021-01-05 16:29:06 +01:00
Linus Torvalds
b5df4b5c28 Merge branch 'i2c/for-5.10' of 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
  ...
2020-10-21 10:54:05 -07:00
Wolfram Sang
c4651f11d0 i2c: rcar: add HostNotify support
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>
2020-09-21 11:06:52 +02:00
Wolfram Sang
74779f6eeb i2c: rcar: refactor and shorten timeout when resetting
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>
2020-09-18 23:02:02 +02:00
Wolfram Sang
9374ed1dfe i2c: rcar: improve bus busy detection
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>
2020-09-18 23:02:02 +02:00
Wolfram Sang
914a7b3563 i2c: rcar: in slave mode, clear NACK earlier
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>
2020-08-25 09:42:51 +02:00
Wolfram Sang
c7c9e914f9 i2c: rcar: avoid race when unregistering slave
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>
2020-07-31 15:56:32 +02:00
Wolfram Sang
073d398dc4 Linux 5.8-rc7
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 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGd0sH/2iktYhMwPxzzpnb
 eI3OuTX/mRn4vUFOfpx9dmGVleMfKkpbvnn3IY7wA62Qfv7J7lkFRa1Bd1DlqXfW
 yyGTGDSKG5chiRCOU3s9ni92M4xIzFlrojyt/dIK2lUGMzUPI9FGlZRGQLKqqwLh
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 171s5Hs=
 =BQIl
 -----END PGP SIGNATURE-----

Merge tag 'v5.8-rc7' into i2c/for-5.9
2020-07-31 15:54:27 +02:00
Wolfram Sang
314139f9f0 i2c: rcar: slave: only send STOP event when we have been addressed
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>
2020-07-26 14:32:46 +02:00
Wolfram Sang
eb01597158 i2c: rcar: always clear ICSAR to avoid side effects
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>
2020-07-23 22:25:18 +02:00
Dejin Zheng
c02fb2b806 i2c: busses: convert to devm_platform_get_and_ioremap_resource
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>
2020-04-15 12:12:52 +02:00