i2c: Introduce i2c_10bit_addr_*_from_msg() helpers

There are already a lot of drivers that have been using
i2c_8bit_addr_from_msg() for 7-bit addresses, now it's time
to have the similar for 10-bit

i2c: Introduce i2c_10bit_addr_*_from_msg() helpers

There are already a lot of drivers that have been using
i2c_8bit_addr_from_msg() for 7-bit addresses, now it's time
to have the similar for 10-bit addresses.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Andi Shyti <[email protected]>

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i2c: Unexport i2c_of_match_device()

i2c_of_match_device() is not used anymore outside of I²C framework,
unexport it.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by:

i2c: Unexport i2c_of_match_device()

i2c_of_match_device() is not used anymore outside of I²C framework,
unexport it.

Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Vladimir Zapolskiy <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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Revert "i2c: Replace list-based mechanism for handling auto-detected clients"

This reverts commit 56a50667cbcfaf95eea9128d5676af94e54b51a8. Mux
handling is not sufficiently implemented. It needs mor

Revert "i2c: Replace list-based mechanism for handling auto-detected clients"

This reverts commit 56a50667cbcfaf95eea9128d5676af94e54b51a8. Mux
handling is not sufficiently implemented. It needs more time.

Signed-off-by: Wolfram Sang <[email protected]>

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Revert "i2c: Replace list-based mechanism for handling userspace-created clients"

This reverts commit 3cfe39b3a845593a485ab1c716615979004ef9f6. Mux
handling is not sufficiently implemented. It needs

Revert "i2c: Replace list-based mechanism for handling userspace-created clients"

This reverts commit 3cfe39b3a845593a485ab1c716615979004ef9f6. Mux
handling is not sufficiently implemented. It needs more time.

Signed-off-by: Wolfram Sang <[email protected]>

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i2c: add kdoc for the new debugfs entry of clients

When adding the new debugfs entry, its kdoc equivalent was forgotten.
Add it now.

Fixes: d06905d68610 ("i2c: add core-managed per-client directory

i2c: add kdoc for the new debugfs entry of clients

When adding the new debugfs entry, its kdoc equivalent was forgotten.
Add it now.

Fixes: d06905d68610 ("i2c: add core-managed per-client directory in debugfs")
Reported-by: Stephen Rothwell <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: add core-managed per-client directory in debugfs

More and more I2C client drivers use debugfs entries and currently they
need to manage a subdir for their files on their own. This means
inconsi

i2c: add core-managed per-client directory in debugfs

More and more I2C client drivers use debugfs entries and currently they
need to manage a subdir for their files on their own. This means
inconsistent naming for these subdirs and they are scattered all over
the debugfs-tree as well. Not to mention the duplicated code.

Let the I2C core provide and maintain a proper directory per client.

Note: It was considered to save the additional pointer in 'struct
i2c_client' and only provide a subdir when requested via a helper
function. When sketching this approach, more and more corner cases
appeared, though, so the current solution with its simple and unabiguous
code was chosen.

Signed-off-by: Wolfram Sang <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]>

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i2c: Replace list-based mechanism for handling userspace-created clients

Similar to the list of auto-detected clients, we can also replace the
list of userspace-created clients with flagging such cl

i2c: Replace list-based mechanism for handling userspace-created clients

Similar to the list of auto-detected clients, we can also replace the
list of userspace-created clients with flagging such client devices.

Signed-off-by: Heiner Kallweit <[email protected]>
[wsa: fixed description of the new flag; reordered new code in
'device_store' to have single exit point; fixed whitespace errors;
folded cleanup patch into this one]
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: Replace list-based mechanism for handling auto-detected clients

So far a list is used to track auto-detected clients per driver.
The same functionality can be achieved much simpler by flagging

i2c: Replace list-based mechanism for handling auto-detected clients

So far a list is used to track auto-detected clients per driver.
The same functionality can be achieved much simpler by flagging
auto-detected clients.

Two notes regarding the usage of driver_for_each_device:
In our case it can't fail, however the function is annotated __must_check.
So a little workaround is needed to avoid a compiler warning.
Then we may remove nodes from the list over which we iterate.
This is safe, see the explanation at the beginning of lib/klist.c.

Signed-off-by: Heiner Kallweit <[email protected]>
[wsa: fixed description of the new flag]
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: core: Lock address during client device instantiation

Krzysztof reported an issue [0] which is caused by parallel attempts to
instantiate the same I2C client device. This can happen if driver
s

i2c: core: Lock address during client device instantiation

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/[email protected]/T/#m12706546e8e2414d8f1a0dc61c53393f731685cc

Fixes: caba40ec3531 ("eeprom: at24: Probe for DDR3 thermal sensor in the SPD case")
Cc: [email protected]
Tested-by: Krzysztof Piotr Oledzki <[email protected]>
Signed-off-by: Heiner Kallweit <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: Use IS_REACHABLE() for substituting empty ACPI functions

Replace IS_ENABLED() with IS_REACHABLE() to substitute empty stubs for:
i2c_acpi_get_i2c_resource()
i2c_acpi_client_count()

i2c: Use IS_REACHABLE() for substituting empty ACPI functions

Replace IS_ENABLED() with IS_REACHABLE() to substitute empty stubs for:
i2c_acpi_get_i2c_resource()
i2c_acpi_client_count()
i2c_acpi_find_bus_speed()
i2c_acpi_new_device_by_fwnode()
i2c_adapter *i2c_acpi_find_adapter_by_handle()
i2c_acpi_waive_d0_probe()

commit f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI
functions") partially fixed this conditional to depend on CONFIG_I2C,
but used IS_ENABLED(), which is wrong since CONFIG_I2C is tristate.

CONFIG_ACPI is boolean but let's also change it to use IS_REACHABLE()
to future-proof it against becoming tristate.

Somehow despite testing various combinations of CONFIG_I2C and CONFIG_ACPI
we missed the combination CONFIG_I2C=m, CONFIG_ACPI=y.

Signed-off-by: Richard Fitzgerald <[email protected]>
Fixes: f17c06c6608a ("i2c: Fix conditional for substituting empty ACPI functions")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Reviewed-by: Takashi Iwai <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: Fix conditional for substituting empty ACPI functions

Add IS_ENABLED(CONFIG_I2C) to the conditional around a bunch of ACPI
functions.

The conditional around these functions depended only on CO

i2c: Fix conditional for substituting empty ACPI functions

Add IS_ENABLED(CONFIG_I2C) to the conditional around a bunch of ACPI
functions.

The conditional around these functions depended only on CONFIG_ACPI.
But the functions are implemented in I2C core, so are only present if
CONFIG_I2C is enabled.

Signed-off-by: Richard Fitzgerald <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: header: improve kdoc for i2c_algorithm

Reword the explanation of @xfer, the old one was confusing and mixing up
terminology. Other than that, capitalize some words correctly and use
full line l

i2c: header: improve kdoc for i2c_algorithm

Reword the explanation of @xfer, the old one was confusing and mixing up
terminology. Other than that, capitalize some words correctly and use
full line length.

Signed-off-by: Wolfram Sang <[email protected]>

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i2c: header: remove unneeded stuff regarding i2c_algorithm

The forward declaration is not needed anymore. The sentence about
"following structs" became obsolete when struct i2c_algorithm became a
kd

i2c: header: remove unneeded stuff regarding i2c_algorithm

The forward declaration is not needed anymore. The sentence about
"following structs" became obsolete when struct i2c_algorithm became a
kdoc. The paragraph about return values can go because we have this
information in kdoc already.

Signed-off-by: Wolfram Sang <[email protected]>

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i2c: document new callbacks in i2c_algorithm

When updating the callbacks, adding their kernel-doc was forgotten. Add
it now.

Reported-by: Stephen Rothwell <[email protected]>
Closes: https://lor

i2c: document new callbacks in i2c_algorithm

When updating the callbacks, adding their kernel-doc was forgotten. Add
it now.

Reported-by: Stephen Rothwell <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]
Fixes: a93c2e5fe766 ("i2c: reword i2c_algorithm according to newest specification")
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: reword i2c_algorithm according to newest specification

Start changing the wording of the I2C main header wrt. the newest I2C
v7 and SMBus 3.2 specifications and replace "master/slave" with more

i2c: reword i2c_algorithm according to newest specification

Start changing the wording of the I2C main header wrt. the newest I2C
v7 and SMBus 3.2 specifications and replace "master/slave" with more
appropriate terms. The first step renames the members of struct
i2c_algorithm. Once all in-tree users are converted, the anonymous union
will go away again. All this work will also pave the way for finally
seperating the monolithic header into more fine-grained headers like
"i2c/clients.h" etc.

Signed-off-by: Wolfram Sang <[email protected]>
Reviewed-by: Andi Shyti <[email protected]>
Signed-off-by: Andi Shyti <[email protected]>

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

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *. This

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

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 <[email protected]>
Reviewed-by: Alex Elder <[email protected]>
Acked-by: Sumit Garg <[email protected]>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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i2c: Add nop fwnode operations

Add nop variants of i2c_find_device_by_fwnode(),
i2c_find_adapter_by_fwnode() and i2c_get_adapter_by_fwnode() for use
without CONFIG_I2C.

Signed-off-by: Sakari Ailus

i2c: Add nop fwnode operations

Add nop variants of i2c_find_device_by_fwnode(),
i2c_find_adapter_by_fwnode() and i2c_get_adapter_by_fwnode() for use
without CONFIG_I2C.

Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: Remove I2C_CLASS_SPD

Remove this class after all users have been gone.

Signed-off-by: Heiner Kallweit <[email protected]>
Signed-off-by: Andi Shyti <[email protected]>

i2c: remove redundant condition

I2C_M_RD is defined as and guaranteed to be 1 and 'flag & I2C_M_RD' is
one or zero. No need for an additional condition to obtain the value.

Signed-off-by: Hsin-Yu.C

i2c: remove redundant condition

I2C_M_RD is defined as and guaranteed to be 1 and 'flag & I2C_M_RD' is
one or zero. No need for an additional condition to obtain the value.

Signed-off-by: Hsin-Yu.Chen <[email protected]>
Reviewed-by: Andi Shyti <[email protected]>
[wsa: slightly updated commit message]
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
i2c_adapter_type a

i2c: constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
i2c_adapter_type and i2c_client_type variables to be constant structures as
well, placing it into read-only memory which can not be modified at
runtime.

Signed-off-by: Ricardo B. Marliere <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: make i2c_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the i2c_bus_type variable to be a constant structure as well, placing
it into read-only memor

i2c: make i2c_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the i2c_bus_type variable to be a constant structure as well, placing
it into read-only memory which can not be modified at runtime.

Note, the sound/soc/rockchip/rk3399_gru_sound.c also needed tweaking as
it decided to save off a pointer to a bus type for internal stuff, and
it was using the i2c_bus_type as well.

Signed-off-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Mark Brown <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: create debugfs entry per adapter

Two drivers already implement custom debugfs handling for their
i2c_adapter and more will come. So, let the core create a debugfs
directory per adapter and pass

i2c: create debugfs entry per adapter

Two drivers already implement custom debugfs handling for their
i2c_adapter and more will come. So, let the core create a debugfs
directory per adapter and pass that to drivers for their debugfs files.

Signed-off-by: Wolfram Sang <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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include/linux/i2c.h: remove I2C_CLASS_DDC support

After removal of the legacy EEPROM driver and I2C_CLASS_DDC support in
olpc_dcon there's no i2c client driver left supporting I2C_CLASS_DDC.
Class-b

include/linux/i2c.h: remove I2C_CLASS_DDC support

After removal of the legacy EEPROM driver and I2C_CLASS_DDC support in
olpc_dcon there's no i2c client driver left supporting I2C_CLASS_DDC.
Class-based device auto-detection is a legacy mechanism and shouldn't
be used in new code. So we can remove this class completely now.

Signed-off-by: Heiner Kallweit <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: Drop legacy callback .probe_new()

Now that all drivers are converted to the (new) .probe() callback, the
temporary .probe_new() can go away. \o/

Link: https://lore.kernel.org/linux-i2c/2023062

i2c: Drop legacy callback .probe_new()

Now that all drivers are converted to the (new) .probe() callback, the
temporary .probe_new() can go away. \o/

Link: https://lore.kernel.org/linux-i2c/[email protected]
Reviewed-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Jean Delvare <[email protected]>
Signed-off-by: Uwe Kleine-König <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

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i2c: Add i2c_get_match_data()

Add i2c_get_match_data() to get match data for I2C, ACPI and
DT-based matching, so that we can optimize the driver code.

Suggested-by: Geert Uytterhoeven <geert+renesa

i2c: Add i2c_get_match_data()

Add i2c_get_match_data() to get match data for I2C, ACPI and
DT-based matching, so that we can optimize the driver code.

Suggested-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Biju Das <[email protected]>
[wsa: simplified var initialization]
Signed-off-by: Wolfram Sang <[email protected]>

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