2015-08-16 20:18 GMT+09:00 Heiner Kallweit <hkallweit1@xxxxxxxxx>: > Am 15.08.2015 um 13:19 schrieb Heiner Kallweit: >> I'm having issues making the hardware RNG work on a Samsung Exynos 5422 (Odroid XU4) with kernel 4.2rc6. >> No random number generation is started if I write the appropriate value (0x18) to the hash control register. >> >> What I did so far: >> Splitted the sss DT node in exynos5420.dtsi into one for the s5p-sss driver and one for the exynos-rng driver. >> (s5p-sss doesn't seem to need the hash registers from offset 0x400) >> >> sss: sss@10830000 { >> icompatible = "samsung,exynos4210-secss"; >> reg = <0x10830000 0x400>; >> interrupts = <0 112 0>; >> clocks = <&clock CLK_SSS>; >> clock-names = "secss"; >> }; >> >> rng: rng@10830400 { >> compatible = "samsung,exynosrng-secss"; >> reg = <0x10830400 0x300>; >> clocks = <&clock CLK_SSS>; >> clock-names = "secss"; >> }; >> >> The DT binding is just for testing and after adding some DT glue logic (of_device_id table) to the exynos-rng driver >> it binds to the rng platform device. >> The clock also seems to be ok with a rate of 266 MHz. >> As is the driver hangs in a loop because the PRNG_DONE in the status register bit never gets set. >> >> I traced it back to the hash control register not accepting value 0x8 (or 0x18 incl. the start bit) for the PRNG. >> Writing a value and reading it back works for values from 0 to 5 only. >> As I have no SSS datasheet my only other reference is drivers/crypto/ace_sha.h in the uboot source code >> which also uses the HW RNG. >> >> Any hint would be appreciated. >> > After some more testing it seems like SSS in general has problems on Exynos 5422. > Also the AES implementation in s5p-sss doesn't work. dmesg output: > > [ 7.116739] alg: skcipher: encryption failed on chunk test 1 for ecb-aes-s5p: ret=22 > [ 7.123673] s5p-sss driver registered Have you tried or looked at vendor code for Samsung mobile devices? The code can be downloaded from opensource.samsung.com. I think the model with Exynos5422 is SM-G900H. I don't have any other hints... Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html