linux-toradex.git/drivers/i2c/i2c-core-base.c, branch v6.13-rc1

Merge tag 'i2c-host-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-mergewindow

2024-09-21T10:46:00+00:00

The DesignWare and the Renesas I2C drivers have received most of
the changes in this pull request.

The first has has undergone through a series of cleanups that
have been sent to the mailing list a year ago for the first time
and finally get merged in this pull request. They are many, from
typos (e.g. i2/i2c), to cosmetics, to refactoring (e.g. move
inline functions to librarieas) and many others.

Besides that, all the DesignWare Kconfig options have been
grouped under the I2C_DESIGNWARE_CORE and this required some
adaptation in many of the kernel configuration files for
different arm and mips boards.

Follows the list of the rest of the changes grouped by type of
change.

Cleanups
--------
The Qualcomm Geni platform improves the exit path in the runtime
resume function.

The Intel LJCA driver loses "target_addr" parameter in
ljca_i2c_stop() because it was unused.

The MediaTek controller intializes the restart_flag in the
transfer function using the ternary conditional operator ("? :")
instead of initializing it in different parts.

Constified a few global data structures in the virtio driver.

The Renesas driver simplifies the bus speed handling in the init
function making it more readable.

Improved an if/else statement in probe function of the Renesas
R-Car driver.

The iMX/MXC driver switches to using the RUNTIME_PM_OPS() instead
of SET_RUNTIME_PM_OPS().

Still in the iMX/MXC driver a comma ',' has been replaced by a
semicolon ';', while in different drivers the ',' has been
removed from the '{ }' delimiters.

Finally three devm_clk_get_enabled() have been used to simplify
the devm_clk_get/clk_prepare_enable tuple in the Renesas EMEV2,
Ingenic and MPC drivers.

Refactors
---------
The Nuvoton fixes a potential out of boundary array access. This
is not a bug fix because the issue could never occur due to
hardware not having the properties listed in the array. The
change makes the driver more future proof and, at the same time,
silences code analyzers.

Improvements
------------
The Renesas I2C (riic) driver undergoes several patches improving
the runtime power management handling.

The Intel i801 driver uses a more descriptive adapter's name to
show the presence of the IDF feature.

In the Intel Denverton (ismt) adapter the pending transactions
are killed when irq's can't complete their handling, triggering a
timeout. This could have been considered as a bug fix, but
because, standing to Vasily, it's very sporadic, I preferred
considering the patch rather as an improvement.

New Feature
-----------
The Renesas I2C (riic) driver now supports the fast mode plus.

New support
-----------
Added support for:

    - Renesas R9A08G045
    - Rockchip RK3576
    - KEBA I2C
    - Theobroma Systems Mule Multiplexer.

The Keba comes with a new driver, i2c-keba.c.
The Mule is an i2c multiplexer and it also comes with a new
driver, mux/i2c-mux-mule.c.

Core patch
----------
This pull request includes also a patch in the I2C framework, in
i2c-core-base.c where the runtime PM functions have been replaced
in order to allow to be accessed during the device add.

Devicetree
----------
Some cleanups in the devicetree, as well. nVidia and Qualcomm
bindings improve their "if:then:" blocks. While the aspeed
binding loses the "multi-master" property because it was
redundant.

The i2c-sprd binding has been converted to YAML.

i2c: core: Setup i2c_adapter runtime-pm before calling device_add()

2024-09-09T22:36:56+00:00

Platform glue code, which is not build into the kernel and thus cannot
use i2c_register_board_info() may want to use bus_register_notifier()
to listen for i2c-adapters to show up on which the platform code needs
to manually instantiate platform specific i2c_clients.

This results in calling i2c_new_client_device() from the bus notifier
which happens near the device_add() call.

If the i2c-core has not yet setup runtime-pm (specifically the
no-callbacks and ignore-children flags) for the device embedded
inside struct i2c_adapter and the driver for the i2c_client
calls pm_runtime_set_active() this will trigger the following
error inside __pm_runtime_set_status():

"runtime PM trying to activate child device %s but parent (%s) is not active\n"

and the i2c_client's runtime-status will not be updated.

Split the device_register() call for the adapter into device_initialize()
and device_add() and move the pm-runtime init calls inbetween these 2 calls
so that the runtime-status can be correctly set when a driver binds from
the bus-notifier.

Note the moved pm-runtime init calls just override the initial value of
some flags in struct device set by device_initialize() and calling these
before device_add() is safe.

Reviewed-by: Pali Rohár 
Reviewed-by: Andi Shyti 
Signed-off-by: Hans de Goede 
Acked-by: Wolfram Sang 
Signed-off-by: Andi Shyti

i2c: don't use ',' after delimiters

2024-09-09T22:33:52+00:00

Delimiters are meant to be last, no need for a ',' there. Remove a
superfluous newline in the ali1535 driver while here.

Signed-off-by: Wolfram Sang 
Acked-by: Andrew Jeffery 
Signed-off-by: Andi Shyti

i2c: Remove I2C_COMPAT config symbol and related code

2024-09-07T16:31:28+00:00

This code was added with 2bb5095affdb ("i2c: Provide compatibility links
for i2c adapters"). Commit message stated: Provide compatibility links
for [...] the time being. We will remove them after a long transition
period.
15 years should have been a long enough transition period.

Signed-off-by: Heiner Kallweit 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Wolfram Sang

i2c: core: Lock address during client device instantiation

2024-08-26T13:20:02+00:00

Krzysztof reported an issue [0] which is caused by parallel attempts to
instantiate the same I2C client device. This can happen if driver
supports auto-detection, but certain devices are also instantiated
explicitly.
The original change isn't actually wrong, it just revealed that I2C core
isn't prepared yet to handle this scenario.
Calls to i2c_new_client_device() can be nested, therefore we can't use a
simple mutex here. Parallel instantiation of devices at different addresses
is ok, so we just have to prevent parallel instantiation at the same address.
We can use a bitmap with one bit per 7-bit I2C client address, and atomic
bit operations to set/check/clear bits.
Now a parallel attempt to instantiate a device at the same address will
result in -EBUSY being returned, avoiding the "sysfs: cannot create duplicate
filename" splash.

Note: This patch version includes small cosmetic changes to the Tested-by
      version, only functional change is that address locking is supported
      for slave addresses too.

[0] https://lore.kernel.org/linux-i2c/9479fe4e-eb0c-407e-84c0-bd60c15baf74@ans.pl/T/#m12706546e8e2414d8f1a0dc61c53393f731685cc

Fixes: caba40ec3531 ("eeprom: at24: Probe for DDR3 thermal sensor in the SPD case")
Cc: stable@vger.kernel.org
Tested-by: Krzysztof Piotr Oledzki 
Signed-off-by: Heiner Kallweit 
Signed-off-by: Wolfram Sang

Merge tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2024-07-25T17:42:22+00:00

Pull driver core updates from Greg KH:
 "Here is the big set of driver core changes for 6.11-rc1.

  Lots of stuff in here, with not a huge diffstat, but apis are evolving
  which required lots of files to be touched. Highlights of the changes
  in here are:

   - platform remove callback api final fixups (Uwe took many releases
     to get here, finally!)

   - Rust bindings for basic firmware apis and initial driver-core
     interactions.

     It's not all that useful for a "write a whole driver in rust" type
     of thing, but the firmware bindings do help out the phy rust
     drivers, and the driver core bindings give a solid base on which
     others can start their work.

     There is still a long way to go here before we have a multitude of
     rust drivers being added, but it's a great first step.

   - driver core const api changes.

     This reached across all bus types, and there are some fix-ups for
     some not-common bus types that linux-next and 0-day testing shook
     out.

     This work is being done to help make the rust bindings more safe,
     as well as the C code, moving toward the end-goal of allowing us to
     put driver structures into read-only memory. We aren't there yet,
     but are getting closer.

   - minor devres cleanups and fixes found by code inspection

   - arch_topology minor changes

   - other minor driver core cleanups

  All of these have been in linux-next for a very long time with no
  reported problems"

* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
  ARM: sa1100: make match function take a const pointer
  sysfs/cpu: Make crash_hotplug attribute world-readable
  dio: Have dio_bus_match() callback take a const *
  zorro: make match function take a const pointer
  driver core: module: make module_[add|remove]_driver take a const *
  driver core: make driver_find_device() take a const *
  driver core: make driver_[create|remove]_file take a const *
  firmware_loader: fix soundness issue in `request_internal`
  firmware_loader: annotate doctests as `no_run`
  devres: Correct code style for functions that return a pointer type
  devres: Initialize an uninitialized struct member
  devres: Fix memory leakage caused by driver API devm_free_percpu()
  devres: Fix devm_krealloc() wasting memory
  driver core: platform: Switch to use kmemdup_array()
  driver core: have match() callback in struct bus_type take a const *
  MAINTAINERS: add Rust device abstractions to DRIVER CORE
  device: rust: improve safety comments
  MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
  MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
  firmware: rust: improve safety comments
  ...

Merge tag 'i2c-for-6.11-rc1-try2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

2024-07-19T23:46:26+00:00

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
  ...

i2c: mark HostNotify target address as used

2024-07-11T09:27:30+00:00

I2C core handles the local target for receiving HostNotify alerts. There
is no separate driver bound to that address. That means userspace can
access it if desired, leading to further complications if controllers
are not capable of reading their own local target. Bind the local target
to the dummy driver so it will be marked as "handled by the kernel" if
the HostNotify feature is used. That protects aginst userspace access
and prevents other drivers binding to it.

Fixes: 2a71593da34d ("i2c: smbus: add core function handling SMBus host-notify")
Signed-off-by: Wolfram Sang

i2c: add debug message for detected HostNotify alerts

2024-07-10T06:31:59+00:00

Setting up HostNotify can be tricky. Support debugging by stating
when a HostNotify alert was received independent of the irq being
mapped. Especially useful with the in-kernel i2c testunit. Update
documentation as well.

Signed-off-by: Wolfram Sang 
Reviewed-by: Andi Shyti

driver core: have match() callback in struct bus_type take a const *

2024-07-03T13:16:54+00:00

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki 
Reviewed-by: Alex Elder 
Acked-by: Sumit Garg 
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman