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@xxxxxxxxx>
> - 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@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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