hte: Use kasprintf() instead of fixed buffer formatting

Improve readability and maintainability by replacing a hardcoded string
allocation and formatting by the use of the kasprintf() helper.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dipen Patel <dipenp@nvidia.com>
Signed-off-by: Dipen Patel <dipenp@nvidia.com>

hte: Annotate struct hte_device with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct hte_device.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Dipen Patel <dipenp@nvidia.com>
Cc: timestamp@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Dipen Patel <dipenp@nvidia.com>

hte: 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 was 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.

Acked-by: Dipen Patel <dipenp@nvidia.com>
Link: https://lore.kernel.org/r/20230714174600.4057041-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

hte: Use device_match_of_node()

Replace the open-code with device_match_of_node().

Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Signed-off-by: Dipen Patel <dipenp@nvidia.com>

hte: Use of_property_present() for testing DT property presence

It is preferred to use typed property access functions (i.e.
of_property_read_<type> functions) rather than low-level
of_get_property/of_find_property functions for reading properties. As
part of this, convert of_get_property/of_find_property calls to the
recently added of_property_present() helper when we just want to test
for presence of a property and nothing more.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Signed-off-by: Dipen Patel <dipenp@nvidia.com>

hte: Use of_property_present() for testing DT property presence

It is preferred to use typed property access functions (i.e.
of_property_read_<type> functions) rather than low-level
of_get_property/of_find_property functions for reading properties. As
part of this, convert of_get_property/of_find_property calls to the
recently added of_property_present() helper when we just want to test
for presence of a property and nothing more.

Acked-by: Dipen Patel <dipenp@nvidia.com>
Link: https://lore.kernel.org/r/20230310144706.1542365-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

hte: Uninitialized variable in hte_ts_get()

The "free_name" variable is sometimes used without being initialized.

Fixes: 31ab09b42188 ("drivers: Add hardware timestamp engine (HTE) subsystem")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

hte: Fix off by one in hte_push_ts_ns()

The &chip->gdev->ei[] array has chip->nlines elements so this >
comparison needs to be >= to prevent an out of bounds access. The
gdev->ei[] array is allocated in hte_register_chip().

Fixes: 31ab09b42188 ("drivers: Add hardware timestamp engine (HTE) subsystem")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dipen Patel <dipenp@nvidia.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers: Add hardware timestamp engine (HTE) subsystem

Some devices can timestamp system lines/signals/Buses in real-time
using the hardware counter or other hardware means which can give
finer granularity and help avoid jitter introduced by software
timestamping. To utilize such functionality, this patchset creates
HTE subsystem where devices can register themselves as providers so
that the consumers devices can request specific line from the
providers. The patch also adds compilation support in Makefile and
menu options in Kconfig.

The provider does following:
- Registers chip with the framework.
- Provides translation hook to convert logical line id.
- Provides enable/disable, request/release callbacks.
- Pushes timestamp data to HTE subsystem.

The consumer does following:
- Initializes line attribute.
- Gets HTE timestamp descriptor.
- Requests timestamp functionality.
- Puts HTE timestamp descriptor.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>