Hi Chen-Yu,
thank you for reviewing and testing.
On Sat, Jul 13, 2024 at 02:48:39PM +0800, Chen-Yu Tsai wrote:
> Hi,
>
> On Sat, Jul 13, 2024 at 8:38 AM Daniel Golle <daniel@xxxxxxxxxxxxxx> 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.
> >
>
> Have you tested any of the later iterations? For me it stopped working
> at v3. After v3 (including v3), all it spits out is zeros.
I've not examined the actual values it returns, I will do so in future
iterations.
Alsom, I misread the original rk_rng_write_ctl() function, I will bring
it back and also improve the comment describing it.
>
> > 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
>
> This is probably the culprit. The RNG and RST control registers have
> enable bits in their top 16 bits. Without those set together with the
> actual bit values, the writes to the registers have no effect.
>
> Please check all your writel calls against the TRM and add appropriate
> bitmasks for the upper 16 bits.
The upper 16 bits are apparently used as hardware mask when writing the
lower 16 bits...
I will send v7 after testing.
>
>
> ChenYu
>
> > - 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/rk356x.dtsi | 9 +
> > drivers/char/hw_random/Kconfig | 14 ++
> > drivers/char/hw_random/Makefile | 1 +
> > drivers/char/hw_random/rockchip-rng.c | 220 ++++++++++++++++++
> > 6 files changed, 312 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
> >
