On Tue, Feb 26, 2019 at 3:14 AM Fabrice Gasnier <fabrice.gasnier@xxxxxx> wrote: > > On 2/25/19 5:53 PM, Rob Herring wrote: > > On Wed, Jan 30, 2019 at 05:38:53PM +0100, Fabrice Gasnier wrote: > >> Add documentation for STMicroelectronics STM32 Factory-programmed > >> read only memory area. > >> > >> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> > >> --- > >> .../devicetree/bindings/nvmem/st,stm32-romem.txt | 31 ++++++++++++++++++++++ > >> 1 file changed, 31 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt > >> > >> diff --git a/Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt b/Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt > >> new file mode 100644 > >> index 0000000..fbff52e > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt > >> @@ -0,0 +1,31 @@ > >> +STMicroelectronics STM32 Factory-programmed data device tree bindings > >> + > >> +This represents STM32 Factory-programmed read only non-volatile area: locked > >> +flash, OTP, read-only HW regs... This contains various information such as: > > > > Several distinct types here. Does s/w need to know the difference > > rather than just one generic-ish compatible? Access size restrictions > > maybe? Ability to unlock and program? > > Hi Rob, > > The reading part is represented here as "st,stm32-romem" compatible, to > simply handle read only access. I agree this could be a generic-ish. > > BUT the specifics are regarding the ability to unlock/lock and program. > Access size can vary from one part to another (e.g. on stm32f4, > reference manual sates: OTP area is divided into 16 OTP data blocks of > 32 bytes. on stm32f7, OTP area is divided into 16 OTP data blocks of 64 > bytes.) > > In STM32MP15, both the read & write access through the BSEC are > specific, represented by dedicated compatible. > > Do you wish I update the compatible to something like: > "st,stm32f4-otp" > "st,stm32mp15-bsec" > ? Yes, I think given the above that makes sense. We can always map specific bindings to generic drivers, but not the reverse. Rob
