mfd: syscon: Add check for invalid resource size

Add a consistency check to avoid assigning an invalid value to
max_register due to a possible DT misconfiguration.

Suggested-by: Mark Langsdorf <mla

mfd: syscon: Add check for invalid resource size

Add a consistency check to avoid assigning an invalid value to
max_register due to a possible DT misconfiguration.

Suggested-by: Mark Langsdorf <[email protected]>
Signed-off-by: Eder Zulian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
"syscon" compatible") broke drivers which call device_node_to_regmap

mfd: syscon: Restore device_node_to_regmap() for non-syscon nodes

Commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
"syscon" compatible") broke drivers which call device_node_to_regmap()
on nodes without a "syscon" compatible. Restore the prior behavior for
device_node_to_regmap().

This also makes using device_node_to_regmap() incompatible with
of_syscon_register_regmap() again, so add kerneldoc for
device_node_to_regmap() and syscon_node_to_regmap() to make it clear
how and when each one should be used.

Fixes: ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a "syscon" compatible")
Reported-by: Vaishnav Achath <[email protected]>
Signed-off-by: Rob Herring (Arm) <[email protected]>
Reviewed-by: Daniel Golle <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Tested-by: Chen-Yu Tsai <[email protected]>
Tested-by: Nishanth Menon <[email protected]>
Tested-by: Daniel Golle <[email protected]>
Tested-by: Frank Wunderlich <[email protected]>
Tested-by: Dhruva Gole <[email protected]>
Tested-by: Nícolas F. R. A. Prado <[email protected]>
Tested-by: AngeloGioacchino Del Regno <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Allow syscon nodes without a "syscon" compatible

of_syscon_register_regmap() was added for nodes which need a custom
regmap setup. It's not really correct for those nodes to claim they

mfd: syscon: Allow syscon nodes without a "syscon" compatible

of_syscon_register_regmap() was added for nodes which need a custom
regmap setup. It's not really correct for those nodes to claim they are
compatible with "syscon" as the default handling likely doesn't work in
those cases. If device_node_get_regmap() happens to be called first,
then of_syscon_register() will be called and an incorrect regmap will be
created (barring some other error). That may lead to unknown results in
the worst case. In the best case, of_syscon_register_regmap() will fail
with -EEXIST. This problem remains unless these cases drop "syscon" (an
ABI issue) or we exclude them using their specific compatible. ATM,
there is only one user: "google,gs101-pmu"

There are also cases of adding "syscon" compatible to existing nodes
after the fact in order to register the syscon. That presents a
potential DT ABI problem. Instead, if there's a kernel change needing a
syscon for a node, then it should be possible to allow the kernel to
register a syscon without a DT change. That's only possible by using
of_syscon_register_regmap() currently, but in the future we may want to
support a match list for cases which don't need a custom regmap.

With this change, the lookup functions will succeed for any node
registered by of_syscon_register_regmap() regardless of whether the node
compatible contains "syscon".

Signed-off-by: Rob Herring (Arm) <[email protected]>
Tested-by: Will McVicker <[email protected]>
Reviewed-by: Pankaj Dubey <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Remove the platform driver support

The platform driver is dead code. It is not used by DT platforms since
commit bdb0066df96e ("mfd: syscon: Decouple syscon interface from
platform devi

mfd: syscon: Remove the platform driver support

The platform driver is dead code. It is not used by DT platforms since
commit bdb0066df96e ("mfd: syscon: Decouple syscon interface from
platform devices") which said:

For non-DT based platforms, this patch keeps syscon platform driver
structure so that syscon can be probed and such non-DT based drivers
can use syscon_regmap_lookup_by_pdev API and access regmap handles.
Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based,
we can completely remove platform driver of syscon, and keep only helper
functions to get regmap handles.

The last user of syscon_regmap_lookup_by_pdevname() was removed in 2018.
syscon_regmap_lookup_by_pdevname() was then removed in 2019, but that
commit failed to remove the rest of the platform driver.

Signed-off-by: Rob Herring (Arm) <[email protected]>
Tested-by: Krzysztof Kozlowski <[email protected]>
Tested-by: Will McVicker <[email protected]>
Acked-by: Liviu Dudau <[email protected]>
Reviewed-by: Pankaj Dubey <[email protected]>
Tested-by: Pankaj Dubey <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Fix race in device_node_get_regmap()

It is possible for multiple, simultaneous callers calling
device_node_get_regmap() with the same node to fail to find an entry in
the syscon_list. T

mfd: syscon: Fix race in device_node_get_regmap()

It is possible for multiple, simultaneous callers calling
device_node_get_regmap() with the same node to fail to find an entry in
the syscon_list. There is a period of time while the first caller is
calling of_syscon_register() that subsequent callers also fail to find
an entry in the syscon_list and then call of_syscon_register() a second
time.

Fix this by keeping the lock held until after of_syscon_register()
completes and adds the node to syscon_list. Convert the spinlock to a
mutex as many of the functions called in of_syscon_register() such as
kzalloc() and of_clk_get() may sleep.

Fixes: bdb0066df96e ("mfd: syscon: Decouple syscon interface from platform devices")
Signed-off-by: Rob Herring (Arm) <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Tested-by: Krzysztof Kozlowski <[email protected]>
Tested-by: Will McVicker <[email protected]>
Tested-by: Pankaj Dubey <[email protected]>
Reviewed-by: Pankaj Dubey <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Use regmap max_register_is_0 as needed

syscon has always set the optional max_register configuration of
regmap to ensure the correct checks are in place. However, a recent
commit 0ec74a

mfd: syscon: Use regmap max_register_is_0 as needed

syscon has always set the optional max_register configuration of
regmap to ensure the correct checks are in place. However, a recent
commit 0ec74ad3c157 ("regmap: rework ->max_register handling")
introduced explicit configuration in regmap framework for register
maps that is exactly 1 register, when max_register is pointing to a
valid register 0. This commit solved a previous limitation of regmap
framework.

Update syscon driver to consistent in regmap configuration for
all sizes of syscons by using this new capability by setting
max_register_is_0, when the max_register is valid and 0.

Signed-off-by: Nishanth Menon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Use scoped variables with memory allocators to simplify error paths

Allocate the memory with scoped/cleanup.h to reduce error handling and
make the code a bit simpler.

Signed-off-by: K

mfd: syscon: Use scoped variables with memory allocators to simplify error paths

Allocate the memory with scoped/cleanup.h to reduce error handling and
make the code a bit simpler.

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Add of_syscon_register_regmap() API

The of_syscon_register_regmap() API allows an externally created regmap
to be registered with syscon. This regmap can then be returned to client
driv

mfd: syscon: Add of_syscon_register_regmap() API

The of_syscon_register_regmap() API allows an externally created regmap
to be registered with syscon. This regmap can then be returned to client
drivers using the syscon_regmap_lookup_by_phandle() APIs.

The API is used by platforms where mmio access to the syscon registers is
not possible, and a underlying soc driver like exynos-pmu provides a SoC
specific regmap that can issue a SMC or hypervisor call to write the
register.

This approach keeps the SoC complexities out of syscon, but allows common
drivers such as syscon-poweroff, syscon-reboot and friends that are used
by many SoCs already to be re-used.

Signed-off-by: Peter Griffin <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Reviewed-by: Sam Protsenko <[email protected]>
Tested-by: Will McVicker <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Call of_node_put() only when of_parse_phandle() takes a ref

of_parse_phandle() returns a device_node with refcount incremented, which
the callee needs to call of_node_put() on when done

mfd: syscon: Call of_node_put() only when of_parse_phandle() takes a ref

of_parse_phandle() returns a device_node with refcount incremented, which
the callee needs to call of_node_put() on when done. We should only call
of_node_put() when the property argument is provided though as otherwise
nothing has taken a reference on the node.

Fixes: 45330bb43421 ("mfd: syscon: Allow property as NULL in syscon_regmap_lookup_by_phandle")
Signed-off-by: Peter Griffin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Fix null pointer dereference in of_syscon_register()

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: e15d7f2b81d2 ("mfd: syscon: Us

mfd: syscon: Fix null pointer dereference in of_syscon_register()

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
Signed-off-by: Kunwu Chan <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Allow reset control for syscon devices

Simple syscon devices may require deassertion of a reset signal in order
to access their register set. Rather than requiring a custom driver to
im

mfd: syscon: Allow reset control for syscon devices

Simple syscon devices may require deassertion of a reset signal in order
to access their register set. Rather than requiring a custom driver to
implement this, we can use the generic "resets" specifiers to link a
reset line to the syscon.

This change adds an optional reset line to the syscon device
description, and deasserts the reset if detected.

Signed-off-by: Jeremy Kerr <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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Revert "mfd: syscon: Remove repetition of the regmap_get_val_endian()"

This reverts commit 72a95859728a7866522e6633818bebc1c2519b17.

It broke reboots on big-endian MIPS and MIPS64 malta QEMU instan

Revert "mfd: syscon: Remove repetition of the regmap_get_val_endian()"

This reverts commit 72a95859728a7866522e6633818bebc1c2519b17.

It broke reboots on big-endian MIPS and MIPS64 malta QEMU instances,
which use the syscon driver. Little-endian is not effected, which means
likely it's important to handle regmap_get_val_endian() in this function
after all.

Fixes: 72a95859728a ("mfd: syscon: Remove repetition of the regmap_get_val_endian()")
Reviewed-by: Andy Shevchenko <[email protected]>
Cc: Lee Jones <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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mfd: syscon: Remove repetition of the regmap_get_val_endian()

Since the commit 0dbdb76c0ca8 ("regmap: mmio: Parse endianness
definitions from DT") regmap MMIO parses DT itsef, no need to
repeat this

mfd: syscon: Remove repetition of the regmap_get_val_endian()

Since the commit 0dbdb76c0ca8 ("regmap: mmio: Parse endianness
definitions from DT") regmap MMIO parses DT itsef, no need to
repeat this in the caller(s).

Signed-off-by: Andy Shevchenko <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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syscon: Use %pa to format the variable of resource_size_t type

Instead of explicit casting, use %pa specifier to format
the variable of resource_size_t type.

Signed-off-by: Andy Shevchenko <andriy.

syscon: Use %pa to format the variable of resource_size_t type

Instead of explicit casting, use %pa specifier to format
the variable of resource_size_t type.

Signed-off-by: Andy Shevchenko <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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mfd: syscon: Use of_iomap() instead of ioremap()

This automatically selects between ioremap() and ioremap_np() on
platforms that require it, such as Apple SoCs.

Signed-off-by: Hector Martin <marcan

mfd: syscon: Use of_iomap() instead of ioremap()

This automatically selects between ioremap() and ioremap_np() on
platforms that require it, such as Apple SoCs.

Signed-off-by: Hector Martin <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Free the allocated name field of struct regmap_config

The commit 529a1101212a("mfd: syscon: Don't free allocated name
for regmap_config") doesn't free the allocated name field of struct

mfd: syscon: Free the allocated name field of struct regmap_config

The commit 529a1101212a("mfd: syscon: Don't free allocated name
for regmap_config") doesn't free the allocated name field of struct
regmap_config, but introduce a memory leak. There is another
commit 94cc89eb8fa5("regmap: debugfs: Fix handling of name string
for debugfs init delays") fixing this debugfs init issue from root
cause. With this fixing, the name field in struct regmap_debugfs_node
is removed. When initialize debugfs for syscon driver, the name
field of struct regmap_config is not used anymore. So, the allocated
name field of struct regmap_config is need to be freed directly after
regmap initialization to avoid memory leak.

Cc: [email protected]
Fixes: 529a1101212a("mfd: syscon: Don't free allocated name for regmap_config")
Signed-off-by: Meng Li <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Add syscon_regmap_lookup_by_phandle_optional() function.

This adds syscon_regmap_lookup_by_phandle_optional() function to get an
optional regmap.

It behaves the same as syscon_regmap_l

mfd: syscon: Add syscon_regmap_lookup_by_phandle_optional() function.

This adds syscon_regmap_lookup_by_phandle_optional() function to get an
optional regmap.

It behaves the same as syscon_regmap_lookup_by_phandle() except where
there is no regmap phandle. In this case, instead of returning -ENODEV,
the function returns NULL. This makes error checking simpler when the
regmap phandle is optional.

Suggested-by: Nicolas Boichat <[email protected]>
Signed-off-by: Enric Balletbo i Serra <[email protected]>
Reviewed-by: Matthias Brugger <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Don't free allocated name for regmap_config

The name allocated for the regmap_config structure is freed
pretty early, right after the registration of the MMIO region.

Unfortunately, th

mfd: syscon: Don't free allocated name for regmap_config

The name allocated for the regmap_config structure is freed
pretty early, right after the registration of the MMIO region.

Unfortunately, that doesn't follow the life cycle that debugfs
expects, as it can access the name field long after the free
has occurred.

Move the free on the error path, and keep it forever otherwise.

Fixes: e15d7f2b81d2 ("mfd: syscon: Use a unique name with regmap_config")
Signed-off-by: Marc Zyngier <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through mar

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[email protected]>

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mfd: syscon: Use a unique name with regmap_config

The DT node full name is currently being used in regmap_config
which in turn is used to create the regmap debugfs directories.
This name however is

mfd: syscon: Use a unique name with regmap_config

The DT node full name is currently being used in regmap_config
which in turn is used to create the regmap debugfs directories.
This name however is not guaranteed to be unique and the regmap
debugfs registration can fail in the cases where the syscon nodes
have the same unit-address but are present in different DT node
hierarchies. Replace this logic using the syscon reg resource
address instead (inspired from logic used while creating platform
devices) to ensure a unique name is given for each syscon.

Signed-off-by: Suman Anna <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Add arguments support for syscon reference

There are a lot of similar global registers being used across multiple SoCs
from Unisoc. But most of these registers are assigned with differe

mfd: syscon: Add arguments support for syscon reference

There are a lot of similar global registers being used across multiple SoCs
from Unisoc. But most of these registers are assigned with different offset
for different SoCs. It is hard to handle all of them in an all-in-one
kernel image.

Add a helper function to get regmap with arguments where we could put some
extra information such as the offset value.

Signed-off-by: Orson Zhai <[email protected]>
Tested-by: Baolin Wang <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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mfd: syscon: Re-use resource_size() to count max_register

Instead of open coded variant use resource_size() and replace
weird '- 3' to more understandable '- 4'.

Signed-off-by: Andy Shevchenko <and

mfd: syscon: Re-use resource_size() to count max_register

Instead of open coded variant use resource_size() and replace
weird '- 3' to more understandable '- 4'.

Signed-off-by: Andy Shevchenko <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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Revert "mfd: syscon: Set name of regmap_config"

This reverts commit 500f9ff518cf55930c670b0e2b8901caf70a7548.

The original commit is a duplication of the exactly previously added
commit 408d1d570a6

Revert "mfd: syscon: Set name of regmap_config"

This reverts commit 500f9ff518cf55930c670b0e2b8901caf70a7548.

The original commit is a duplication of the exactly previously added
commit 408d1d570a63 ("mfd: syscon: Set regmap name to DT node name").
Revert the unnecessary later one.

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

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mfd/syscon: Add device_node_to_regmap()

device_node_to_regmap() is exactly like syscon_node_to_regmap(), but it
does not check that the node is compatible with "syscon", and won't
attach the first c

mfd/syscon: Add device_node_to_regmap()

device_node_to_regmap() is exactly like syscon_node_to_regmap(), but it
does not check that the node is compatible with "syscon", and won't
attach the first clock it finds to the regmap.

The rationale behind this, is that one device node with a standard
compatible string "foo,bar" can be covered by multiple drivers sharing a
regmap, or by a single driver doing all the job without a regmap, but
these are implementation details which shouldn't reflect on the
devicetree.

Signed-off-by: Paul Cercueil <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Paul Burton <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Lee Jones <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Michael Turquette <[email protected]>
Cc: Stephen Boyd <[email protected]>
Cc: Jason Cooper <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Mathieu Malaterre <[email protected]>

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mfd: Remove unused helper syscon_regmap_lookup_by_pdevname

Nobody uses the exported helper syscon_regmap_lookup_by_pdevname,
to lookup a device by name. Let us remove it.

Suggested-by: Arnd Bergman

mfd: Remove unused helper syscon_regmap_lookup_by_pdevname

Nobody uses the exported helper syscon_regmap_lookup_by_pdevname,
to lookup a device by name. Let us remove it.

Suggested-by: Arnd Bergman <[email protected]>
Cc: Arnd Bergman <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Signed-off-by: Suzuki K Poulose <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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