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Dan Carpenter f0655a5c8f i2c: rcar: fix error code in probe()
commit 37a672be3ae357a0f87fbc00897fa7fcb3d7d782 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18 13:07:45 +02:00
Wolfram Sang 9877f86792 i2c: rcar: clear NO_RXDMA flag after resetting
[ Upstream commit fea6b5ebb71a2830b042e42de7ae255017ac3ce8 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:07:44 +02:00
Wolfram Sang ec1bba809f i2c: rcar: ensure Gen3+ reset does not disturb local targets
[ Upstream commit ea5ea84c9d3570dc06e8fc5ee2273eaa584aa3ac ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:07:44 +02:00
Wolfram Sang 02268d0264 i2c: rcar: introduce Gen4 devices
[ Upstream commit 2b523c46e81ebd621515ab47117f95de197dfcbf ]

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>
Stable-dep-of: ea5ea84c9d35 ("i2c: rcar: ensure Gen3+ reset does not disturb local targets")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:07:44 +02:00
Wolfram Sang ff7879da53 i2c: rcar: reset controller is mandatory for Gen3+
[ Upstream commit 0e864b552b2302e40b2277629ebac79544a5c433 ]

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>
Stable-dep-of: ea5ea84c9d35 ("i2c: rcar: ensure Gen3+ reset does not disturb local targets")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:07:44 +02:00
Geert Uytterhoeven 504cc00362 i2c: rcar: Add R-Car Gen4 support
[ Upstream commit ea01b71b07 ]

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>
Stable-dep-of: ea5ea84c9d35 ("i2c: rcar: ensure Gen3+ reset does not disturb local targets")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:07:44 +02:00
Wolfram Sang 72dd9b813f i2c: rcar: bring hardware to known state when probing
[ Upstream commit 4e36c0f20cb1c74c7bd7ea31ba432c1c4a989031 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18 13:07:44 +02:00
Kuninori Morimoto b52e192ffd i2c: rcar: fix PM ref counts in probe error paths
[ Upstream commit 3fe2ec59db ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:23:16 +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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 171s5Hs=
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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
Wolfram Sang df576beee5 i2c: rcar: clean up after refactoring i2c_timings
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>
2020-03-31 17:34:29 +02:00
Andy Shevchenko 38a592e266 i2c: rcar: Consolidate timings calls in rcar_i2c_clock_calculate()
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>
2020-03-24 21:59:33 +01:00
Andy Shevchenko 263a5646d8 i2c: core: Allow override timing properties with 0
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>
2020-03-24 21:59:10 +01:00
Geert Uytterhoeven c39511ffb9 i2c: rcar: Remove superfluous call to clk_get_rate()
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>
2019-11-14 21:31:39 +01:00
Wolfram Sang 7b814d852a i2c: rcar: avoid race when unregistering slave client
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>
2019-08-14 14:49:36 +02:00
Wolfram Sang 94e290b0e9 i2c: rcar: wait for data empty before starting DMA
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>
2019-03-20 18:19:20 +01:00
Wolfram Sang 03f85e380f i2c: rcar: let DMA enable routine return success status
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>
2019-03-20 18:19:07 +01:00
Wolfram Sang ed5a81046b i2c: rcar: sanity check for minimal DMA length
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>
2019-03-20 18:18:54 +01:00
Wolfram Sang 7ce98a5591 i2c: rcar: explain the lockless design
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>
2019-03-12 14:09:33 +01:00
Hiromitsu Yamasaki a35ba2f74d i2c: rcar: fix concurrency issue related to ICDMAER
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>
2019-03-12 14:09:16 +01:00
Wolfram Sang 18769445ca i2c: rcar: refactor TCYC handling
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>
2019-02-08 22:30:46 +01:00
Wolfram Sang d0051ca584 i2c: rcar: comment maintenance
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>
2019-02-05 14:31:55 +01:00
Geert Uytterhoeven 81d696c7c4 i2c: rcar: Fix clients using i2c from suspend callback
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>
2019-01-22 23:55:08 +01:00
Wolfram Sang 18569fa89a i2c: rcar: add suspend/resume support
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>
2019-01-08 21:02:52 +01:00
Wolfram Sang 0b57436f15 i2c: rcar: check bus state before reinitializing
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>
2018-11-27 14:00:36 +01:00
Wolfram Sang 31d86033a0 i2c: rcar: cleanup DMA for all kinds of failure
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>
2018-10-20 15:25:59 +02:00
Wolfram Sang 6055af5e1c i2c: use SPDX identifier for Renesas drivers
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>
2018-08-24 14:49:36 +02:00
Wolfram Sang 19358d4488 i2c: rcar: implement STOP and REP_START according to docs
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>
2018-08-20 14:49:41 +02:00
Wolfram Sang b07531acd5 i2c: rcar: refactor private flags
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>
2018-08-20 14:49:24 +02:00
Wolfram Sang 3ef3e5cd72 i2c: rcar: use core to detect 'no zero length' quirk
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>
2018-08-04 23:25:07 +02:00
Wolfram Sang 3b770017b0 i2c: rcar: handle RXDMA HW behaviour on Gen3
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>
2018-07-23 20:10:56 +02:00
Wolfram Sang 4fe10de535 i2c: rcar: use the new get_bus_free callback
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>
2018-07-17 10:47:53 +02:00
Peter Rosin 30a6475744 i2c: busses: make use of i2c_8bit_addr_from_msg
Because it looks neater.

For diolan, this allows factoring out some code that is now common
between if and else.

For eg20t, pch_i2c_writebytes is always called with a write in
msgs->flags, and pch_i2c_readbytes with a read.

For imx, i2c_imx_dma_write and i2c_imx_write are always called with a
write in msgs->flags, and i2c_imx_read with a read.

For qup, qup_i2c_write_tx_fifo_v1 is always called with a write in
qup->msg->flags.

For stu300, also restructure debug output for resends, since that
code as a result is only handling debug output.

Reviewed-by: Guenter Roeck <linux@roeck-us.net> [diolan]
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [efm32 and imx]
Acked-by: Linus Walleij <linus.walleij@linaro.org> [stu300]
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-29 20:30:49 +02:00
Wolfram Sang b1437dcb97 i2c: rcar: enhance comment to avoid regressions
Give a clear testcase for people wishing to change this code. It is also
a reminder for me if people ask about it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 11:14:35 +02:00
Hiromitsu Yamasaki a1de3253a8 i2c: rcar: fix mask value of prohibited bit
According to documentation, Bit 7 of ICMSR is unused and 0 should be
written to it. Fix the mask accordingly.

Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
[wsa: edited commit message]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-24 14:04:38 +01:00