This series adds support for the MCF54418 hardware random number generator
(RNGB).

The MCF54418 contains an RNGB hardware block compatible with the imx-rngc
driver. This series enables its use by:
- Adding platform device registration for the RNG hardware
- Enabling the clock at platform initialization
- Making the imx-rngc driver compatible with Coldfire's always-on clock
model using devm_clk_get_optional()

Testing on DLC Next board shows:
- Hardware RNG throughput: 26 MB/s
- FIPS 140-2 quality: 0.2% failure rate (rng-tools)
- Boot time improvement: CRNG initialization 7 seconds faster

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>
---
Changes in v4:
- Postpone const qualifiers for now
- Link to v3: https://lore.kernel.org/r/20251124-b4-m5441x-add-rng-support-v3-0-f447251dad27@yoseli.org

Changes in v3:
- Depend on COLDFIRE is enough
- Split the clock change in a dedicated commit
- Link to v2: https://lore.kernel.org/r/20251107-b4-m5441x-add-rng-support-v2-0-f91d685832b9@yoseli.org

Changes in v2:
- Split const qualifier changes into a separate patch as suggested by
Frank Li
- Mark all resource arrays (including RNG) as const in device.c
- No functional changes to RNG implementation

---
Jean-Michel Hautbois (2):
      hwrng: imx-rngc: Use optional clock
      m68k: coldfire: Add RNG support for MCF54418

 arch/m68k/coldfire/device.c       | 28 ++++++++++++++++++++++++++++
 arch/m68k/coldfire/m5441x.c       |  2 +-
 arch/m68k/include/asm/m5441xsim.h |  9 +++++++++
 drivers/char/hw_random/Kconfig    |  3 ++-
 drivers/char/hw_random/imx-rngc.c |  9 ++++++++-
 5 files changed, 48 insertions(+), 3 deletions(-)
---
base-commit: ac3fd01e4c1efce8f2c054cdeb2ddd2fc0fb150d
change-id: 20251107-b4-m5441x-add-rng-support-0fdb8d40210a

Best regards,
--  
Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org>