Messages in this thread | | | Date | Wed, 9 Nov 2022 18:35:06 +0100 | Subject | Re: [PATCH 3/3] nvmem: stm32: add OP-TEE support for STM32MP13x | From | Patrick DELAUNAY <> |
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Hi,
On 11/8/22 11:03, Srinivas Kandagatla wrote: > > > On 02/11/2022 10:59, Patrick DELAUNAY wrote: >> Hi, >> >> On 11/1/22 08:26, Srinivas Kandagatla wrote: >>> >>> >>> On 28/10/2022 15:52, Patrick Delaunay wrote: >>>> For boot with OP-TEE on STM32MP13, the communication with the secure >>>> world no more use STMicroelectronics SMC but communication with the >>>> BSEC TA, for data access (read/write) or lock operation: >>>> - all the request are sent to OP-TEE trusted application, >>>> - for upper OTP with ECC protection and with word programming only >>>> each OTP are permanently locked when programmed to avoid ECC error >>>> on the second write operation >>>> >>>> Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com> >>>> --- >>> >>> For some reason I pushed this patch without a full review, This is >>> now reverted from nvmem-next. >> >> >> Ok >> >> >>> >>> Why not add TEE client based new driver instead of ifdefing around >>> this driver? Also I see there is not much common across both drivers >>> anyway. >> >> >> I hesitate between the 2 solutions. I choose this update to handle >> the STM32MP15 support with OP-TEE. > > How are you to handing this? > >> >> For backward compatibility reason the same driver STM32 ROMEM >> associated to compatible "st,stm32mp15-bsec" should be kept. >> >> - the lower OTP can directly accessible by Linux (the IP is not >> secured) => boot with SPL > > Can we determine this at runtime?
Not directly with IP register, but we detect the OP-TEE support at runtime.
> >> >> - the upper OTP and the write operation are requested by >> STMicroelectronics SMCs >> >> => boot with TF-A SPMIN and old OP-TEE (before migration to STM32 >> BSEC PTA) >> >> >> But in the future OP-TEE the access to OTP should be also done with >> STM32 BSEC PTA... > > Given that we have only one compatible for these two type of > combinations how are you planning to deal with both the cases and > still be backward compatible?
yes, as it is the SOC dtsi, I don't want change the IP compatible
but I will handle in this driver probe to be backward compatible: detection of OP-TEE presence and SMC/PTA support.
only the STM32MP13 SoC only use the PTA, as we have no backward compatibility issue.
I will include this STM32MP15 patch in the serie for V2, it should be mode clear for the review.
> > --srini >> >> >> I can manage this compatibility by detection in STM32 romem driver if >> the booth access are managed in the same driver. > > > >> >> This patch can be added in the serie to understood the detection >> mechanism. >>
Regards
Patrick
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