linux-toradex.git/drivers/opp/core.c, branch v6.18

OPP: Add support to find OPP for a set of keys

2025-08-26T05:10:58+00:00

Some clients, such as PCIe, may operate at the same clock frequency
across different data rates by varying link width. In such cases,
frequency alone is not sufficient to uniquely identify an OPP.

To support these scenarios, introduce a new API
dev_pm_opp_find_key_exact() that allows OPP lookup with different
set of keys like freq, level & bandwidth.

Signed-off-by: Krishna Chaitanya Chundru 
[ Viresh: Minor cleanups ]
Signed-off-by: Viresh Kumar

OPP: switch to use kmemdup_array()

2025-05-19T10:07:53+00:00

Use kmemdup_array() to avoid multiplication and possible overflows.

Signed-off-by: Zhang Enpei 
Signed-off-by: Viresh Kumar

OPP: Use mutex locking guards

2025-05-02T05:25:52+00:00

Use mutex locking guard in the OPP core.

No intentional functional impact.

Signed-off-by: Viresh Kumar

OPP: Define and use scope-based cleanup helpers

2025-05-02T05:25:40+00:00

Define and use scope-based cleanup helpers for `struct opp` and `struct
opp_table`.

No intentional functional impact.

Signed-off-by: Viresh Kumar

OPP: Return opp_table from dev_pm_opp_get_opp_table_ref()

2025-04-24T10:35:56+00:00

For convenience of users, return back the pointer to the opp_table from
dev_pm_opp_get_opp_table_ref(), so they can do:

	opp_table = dev_pm_opp_get_opp_table_ref(tmp_table);

No intentional functional impact.

Signed-off-by: Viresh Kumar

OPP: Return opp from dev_pm_opp_get()

2025-04-24T10:35:53+00:00

For convenience of users, return back the pointer to the opp from
dev_pm_opp_get(), so they can do:

	opp = dev_pm_opp_get(tmp_opp);

No intentional functional impact.

Signed-off-by: Viresh Kumar

OPP: Remove _get_opp_table_kref()

2025-04-24T10:35:33+00:00

Use dev_pm_opp_get_opp_table_ref() directly instead.

No intentional functional impact.

Signed-off-by: Viresh Kumar

PM / OPP: Add reference counting helpers for Rust implementation

2025-01-20T03:35:51+00:00

To ensure that resources such as OPP tables or OPP nodes are not freed
while in use by the Rust implementation, it is necessary to increment
their reference count from Rust code.

This commit introduces a new helper function,
dev_pm_opp_get_opp_table_ref(), to increment the reference count of an
OPP table and declares the existing helper dev_pm_opp_get() in pm_opp.h.

Signed-off-by: Viresh Kumar

OPP: fix dev_pm_opp_find_bw_*() when bandwidth table not initialized

2024-12-23T10:57:24+00:00

If a driver calls dev_pm_opp_find_bw_ceil/floor() the retrieve bandwidth
from the OPP table but the bandwidth table was not created because the
interconnect properties were missing in the OPP consumer node, the
kernel will crash with:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
...
pc : _read_bw+0x8/0x10
lr : _opp_table_find_key+0x9c/0x174
...
Call trace:
  _read_bw+0x8/0x10 (P)
  _opp_table_find_key+0x9c/0x174 (L)
  _find_key+0x98/0x168
  dev_pm_opp_find_bw_ceil+0x50/0x88
...

In order to fix the crash, create an assert function to check
if the bandwidth table was created before trying to get a
bandwidth with _read_bw().

Fixes: add1dc094a74 ("OPP: Use generic key finding helpers for bandwidth key")
Signed-off-by: Neil Armstrong 
Signed-off-by: Viresh Kumar

OPP: add index check to assert to avoid buffer overflow in _read_freq()

2024-12-23T10:57:23+00:00

Pass the freq index to the assert function to make sure
we do not read a freq out of the opp->rates[] table when called
from the indexed variants:
dev_pm_opp_find_freq_exact_indexed() or
dev_pm_opp_find_freq_ceil/floor_indexed().

Add a secondary parameter to the assert function, unused
for assert_single_clk() then add assert_clk_index() which
will check for the clock index when called from the _indexed()
find functions.

Fixes: 142e17c1c2b4 ("OPP: Introduce dev_pm_opp_find_freq_{ceil/floor}_indexed() APIs")
Fixes: a5893928bb17 ("OPP: Add dev_pm_opp_find_freq_exact_indexed()")
Signed-off-by: Neil Armstrong 
Signed-off-by: Viresh Kumar