Subject: [PATCH v3 00/12] crypto: atmel - introduce shared i2c core client management and capability-based selection framework

From: Lothar Rubusch <[email-masked]>
Date: Wed, 20 May 2026 15:56:51 +0000

This patch series introduces a staged refactoring of the Atmel crypto I2C
drivers in preparation for a shared core-based architecture. The goal is to
consolidate I2C client management and selection logic into a common
atmel-i2c core driver while keeping ECC (ECDH) and SHA204A client drivers
functionally separate but interoperating through shared infrastructure.

The series moves existing ECC-specific client tracking into a shared
management structure, relocates allocation and selection logic, and
introduces capability-based filtering for hardware selection. This allows
individual crypto drivers to request hardware clients based on supported
features while still benefiting from a unified least-loaded selection
strategy.

Subsequent patches extend this base by:
- migrating client management fully into the core driver,
- introducing explicit capability advertisement by each hardware client,
- updating ECC and SHA204A drivers to participate in capability-aware allocation,
- and cleaning up probe/remove paths to ensure consistent lifecycle handling.

No functional behavioral changes are intended at this stage beyond internal
refactoring and preparation for future feature expansion. The series is
designed to preserve existing crypto functionality while gradually
centralizing shared logic in the atmel-i2c core layer, reducing duplication
and improving maintainability across all Atmel crypto drivers.

Signed-off-by: Lothar Rubusch <[email-masked]>
---
v2 -> v3:
- sashiko feedback[2]
- ecc: reorder setting ready flag in probe()
- i2c: unconditionally call flush in unregister client function, to avoid UAF for multiple devices
- i2c: fixed a sleep-in-atomic bug by moving atmel_i2c_flush_queue() outside the spin_lock section
- sha204a: reorder calls in remove() avoid UAF flagged risk
- sha204a: rephrase commit messages
[2] https://sashiko.dev/#/patchset/20260519204803.17034-1-l.rubusch%40gmail.com

v1 -> v2:
- going over Sashiko feedback[1]
- rephrasing commit messages and titles
- fix: introduce a ready/state flag to address the UAF risk
- fix: add kpp lock and refcnt to impede overwriting global driver struct
- fix: explicitely clearing rng cached buffer in return branch
- unregistering ready state by dedicated function
- reorder Atmel ECC related things and atmel I2C at beginning
- reorder Atmel SHA204a related things behind introduction of cap
- patches dropped: NULL checks in remove functions
- changed to EXPORT_SYMBOL_GPL
- additionally to alloc hw client also migrate freeing it to core driver
[1] https://sashiko.dev/#/patchset/20260517180639.9657-1-l.rubusch%40gmail.com
---
Lothar Rubusch (12):
  crypto: atmel-ecc - rename driver_data before moving it into atmel-i2c
  crypto: atmel-ecc - fix use after free situation
  crypto: atmel-ecc - fix multi-device kpp registration
  crypto: atmel - rename atmel_ecc_driver_data to atmel_i2c_client_mgmt
  crypto: atmel-i2c - move client management instance into core
  crypto: atmel-i2c - introduce shared teardown helpers and fix queue
    flush
  crypto: atmel-ecc - switch to module_i2c_driver
  crypto: atmel-i2c - move shared client allocation logic to core
  crypto: atmel-i2c - implement capability-based client selection
  crypto: atmel-sha204a - integrate into core management tracking
  crypto: atmel-sha204a - fix heap info leak on I2C transfer failure
  crypto: atmel-sha204a - switch to module_i2c_driver

 drivers/crypto/atmel-ecc.c     | 133 ++++++++++-----------------------
 drivers/crypto/atmel-i2c.c     |  76 +++++++++++++++++++
 drivers/crypto/atmel-i2c.h     |  17 ++++-
 drivers/crypto/atmel-sha204a.c |  51 ++++++++-----
 4 files changed, 166 insertions(+), 111 deletions(-)

base-commit: 6c9dddeb582fde005360f4fe02c760d45ca05fb5
-- 
2.39.5