[PATCH v9 0/3] hwrng: add hwrng support for Rockchip RK3568

[Herbert Xu]

On Tue, Jul 30, 2024 at 05:08:04PM +0100, Daniel Golle wrote:
> Rockchip SoCs used to have a random number generator as part of their
> crypto device.
> 
> However newer Rockchip SoCs like the RK3568 have an independent True
> Random Number Generator device. This patchset adds a driver for it and
> enables it in the device tree for RK3568.
> 
> It turns out the HW RNG returns very low quality on RK3566, so while
> it is theoretically also present on that SoC, only enable it on RK3568
> for now on which the quality expectations are met.
> 
> Tested on FriendlyARM NanoPi R5C.
> 
> v8 -> v9:
>  * Patch 1: revert to v7
> 
>  * Patch 2: revert to v7, use 922 as quality
> 
>  * Patch 3: drop new properties, but enable only in rk3568.dtsi
> 
> v7 -> v8:
>  * Patch 1: document new properties
>    - introduce 'rockchip,sample-count'
>    - require to specify 'quality' (0~1024)
> 
>  * Patch 2:
>    - read sample-count and quality from DT
> 
>  * Patch 3:
>    - disable hwrng in rk356x.dtsi, enable only in rk3568.dtsi
>    - set sample-count 1000 and quality 900 (87.9%) as before
> 
> v6 -> v7:
>  * Patch 1: unchanged
> 
>  * Patch 2: bring back rk_rng_write_ctl()
>    - bring back rk_rng_write_ctl() with improved comment to describe
>      the hardware.
> 
>  * Patch 3: unchaned
> 
> v5 -> v6:
>  * Patch 1: unchanged
> 
>  * Patch 2: get rid of #ifdef
>    - use if (IS_ENABLED(...)) { ... }instead of #ifdef inside functions
>    - use __maybe_unused for functions previously enclosed by #ifdef'ery
> 
>  * Patch 3: unchanged
> 
> v4 -> v5:
>  * Patch 1: always use RK3568 name
>    - use full RK3568 name in patch description
>    - add RK3568 to title in binding
> 
>  * Patch 2: full name and cosmetics
>    - also always mention RK3568 as there may be other RNG in other
>      (future) Rockchip SoCs
>    - remove debug output on successful probe
>    - use MODULE_AUTHOR several times instead of single comma-separated
> 
>  * Patch 3: unchanged
> 
> v3 -> v4:
>  * Patch 1: minor corrections
>    - fix Rokchip -> Rockchip typo
>    - change commit title as requested
> 
>  * Patch 2: improved error handling and resource management
>    - Always use writel() instead of writel_relaxed()
>    - Use pm_runtime_resume_and_get
>    - Correctly return error code in rk_rng_read()
>    - Make use of devm_reset_control_array_get_exclusive
>    - Use devm_pm_runtime_enable and there by get rid of rk_rng_remove()
> 
>  * Patch 3:
>    - Move node to conform with ordering by address
> 
> v2 -> v3: patch adopted by Daniel Golle
>  * Patch 1: address comments of Krzysztof Kozlowski, add MAINTAINERS
>    - improved description
>    - meaningful clock-names
>    - add entry in MAINTAINERS files
> 
>  * Patch 2: numerous code-style improvements
>    - drop misleading rk_rng_write_ctl(), simplify I/O writes
>    - drop unused TRNG_RNG_DOUT_[1-7] macros
>    - handle error handling for pm_runtime_get_sync()
>    - use memcpy_fromio() instead of open coding for-loop
>    - some minor white-spaces fixes
> 
>  * Patch 3:
>    - use clock-names as defined in dt-bindings
> 
> v1 -> v2:
>  * Patch 1: fix issues reported by Rob Herring and Krzysztof Kozlowski:
>    - Rename rockchip-rng.yaml into rockchip,rk3568-rng.yaml
>    - Fix binding title and description
>    - Fix compatible property
>    - Rename clocks and add the corresponding descriptions
>    - Drop reset-names
>    - Add a bus definition with #address-cells and #size-cells to the
>      example.
> 
>  * Patch 2: fix issue reported by kernel test robot <lkp at intel.com>
>    - Do not read the random registers as big endian, looking at the
>      RK3568 TRM this is actually not needed. This fixes a sparse
>      warning.
> 
>  * Patch 3: unchanged
> 
> 
> Aurelien Jarno (3):
>   dt-bindings: rng: Add Rockchip RK3568 TRNG
>   hwrng: add hwrng driver for Rockchip RK3568 SoC
>   arm64: dts: rockchip: add DT entry for RNG to RK356x
> 
>  .../bindings/rng/rockchip,rk3568-rng.yaml     |  61 +++++
>  MAINTAINERS                                   |   7 +
>  arch/arm64/boot/dts/rockchip/rk3568.dtsi      |   4 +
>  arch/arm64/boot/dts/rockchip/rk356x.dtsi      |  10 +
>  drivers/char/hw_random/Kconfig                |  14 ++
>  drivers/char/hw_random/Makefile               |   1 +
>  drivers/char/hw_random/rockchip-rng.c         | 227 ++++++++++++++++++
>  7 files changed, 324 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml
>  create mode 100644 drivers/char/hw_random/rockchip-rng.c
> 
> -- 
> 2.45.2

Patches 1-2 applied.  Thanks.
-- 
Email: Herbert Xu <herbert at gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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