Re: [edk2-platforms][PATCH 1/5] Silicon/Bcm283x: Clean up Bcm2836.h header

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

On Wed, 27 Nov 2019 at 13:56, Pete Batard <pete@akeo.ie> wrote:
>
> On 2019.11.27 12:48, Ard Biesheuvel wrote:
> > On Wed, 27 Nov 2019 at 13:37, Pete Batard <pete@akeo.ie> wrote:
> >>
> >> Add missing RNG registers, prefer reusing shorter define's
> >> instead of PCDs and clean up spacing.
> >>
> >
> > Is there a source for these register definitions?
>
> I used the most recent Linux driver I could find (but I guess I need to
> point out that it was used for reference with regards to the registers.
> Especially, no code was copied from that source).
>
> > It seems the Linux
> > driver deviates from the below (and the warmup count thing uses the
> > status register as well), so it would be helpful to quote the
> > authoritative reference here.
>
> https://github.com/raspberrypi/linux/blob/rpi-5.4.y/drivers/char/hw_random/iproc-rng200.c#L223-L224
> seems to indicate that RNG_WARMUP_COUNT (0x40000) should go into
> RNG_TOTAL_BIT_COUNT_THRESHOLD_OFFSET (them) / RNG_BIT_COUNT_THRESHOLD
> (us) and not the status register.
>
> Now, of course, since we don't have a public datasheet, it's hard to
> have absolute certainty on what's the proper register to write, but I
> guess the most recent code with a Broadcom Corporation copyright has to
> our next best thing when it comes to authoritative answer...
>

Well, there is this one too

https://github.com/raspberrypi/linux/blob/rpi-5.4.y/drivers/char/hw_random/bcm2835-rng.c

which is what I used as the basis for the existing version.





> >
> >
> >> Signed-off-by: Pete Batard <pete@akeo.ie>
> >> ---
> >>   Silicon/Broadcom/Bcm283x/Include/IndustryStandard/Bcm2836.h | 23 ++++++++++++--------
> >>   1 file changed, 14 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/Silicon/Broadcom/Bcm283x/Include/IndustryStandard/Bcm2836.h b/Silicon/Broadcom/Bcm283x/Include/IndustryStandard/Bcm2836.h
> >> index 72c8e9dc4b14..744c7ac3b9f4 100644
> >> --- a/Silicon/Broadcom/Bcm283x/Include/IndustryStandard/Bcm2836.h
> >> +++ b/Silicon/Broadcom/Bcm283x/Include/IndustryStandard/Bcm2836.h
> >> @@ -24,8 +24,7 @@
> >>
> >>   /* watchdog constants */
> >>   #define BCM2836_WDOG_OFFSET                                 0x00100000
> >> -#define BCM2836_WDOG_BASE_ADDRESS                           (FixedPcdGet64 (PcdBcm283xRegistersAddress) \
> >> -                                                            + BCM2836_WDOG_OFFSET)
> >> +#define BCM2836_WDOG_BASE_ADDRESS                           (BCM2836_SOC_REGISTERS + BCM2836_WDOG_OFFSET)
> >>   #define BCM2836_WDOG_PASSWORD                               0x5a000000
> >>   #define BCM2836_WDOG_RSTC_OFFSET                            0x0000001c
> >>   #define BCM2836_WDOG_WDOG_OFFSET                            0x00000024
> >> @@ -34,8 +33,7 @@
> >>
> >>   /* mailbox interface constants */
> >>   #define BCM2836_MBOX_OFFSET                                 0x0000b880
> >> -#define BCM2836_MBOX_BASE_ADDRESS                           (FixedPcdGet64 (PcdBcm283xRegistersAddress) \
> >> -                                                            + BCM2836_MBOX_OFFSET)
> >> +#define BCM2836_MBOX_BASE_ADDRESS                           (BCM2836_SOC_REGISTERS + BCM2836_MBOX_OFFSET)
> >>   #define BCM2836_MBOX_READ_OFFSET                            0x00000000
> >>   #define BCM2836_MBOX_STATUS_OFFSET                          0x00000018
> >>   #define BCM2836_MBOX_CONFIG_OFFSET                          0x0000001c
> >> @@ -51,12 +49,19 @@
> >>   #define BCM2836_INTC_TIMER_PENDING_OFFSET                   0x00000060
> >>
> >>   /* random number generator */
> >> -#define RNG_BASE_ADDRESS   (BCM2836_SOC_REGISTERS + 0x00104000)
> >> +#define BCM2836_RNG_OFFSET                                  0x00104000
> >> +#define RNG_BASE_ADDRESS                                    (BCM2836_SOC_REGISTERS + BCM2836_RNG_OFFSET)
> >>
> >> -#define RNG_CTRL           (RNG_BASE_ADDRESS + 0x0)
> >> -#define RNG_STATUS         (RNG_BASE_ADDRESS + 0x4)
> >> -#define RNG_DATA           (RNG_BASE_ADDRESS + 0x8)
> >> +#define RNG_CTRL                                            (RNG_BASE_ADDRESS + 0x0)
> >> +#define RNG_STATUS                                          (RNG_BASE_ADDRESS + 0x4)
> >> +#define RNG_DATA                                            (RNG_BASE_ADDRESS + 0x8)
> >> +#define RNG_BIT_COUNT                                       (RNG_BASE_ADDRESS + 0xc)
> >> +#define RNG_BIT_COUNT_THRESHOLD                             (RNG_BASE_ADDRESS + 0x10)
> >> +#define RNG_INT_STATUS                                      (RNG_BASE_ADDRESS + 0x18)
> >> +#define RNG_INT_ENABLE                                      (RNG_BASE_ADDRESS + 0x1c)
> >> +#define RNG_FIFO_DATA                                       (RNG_BASE_ADDRESS + 0x20)
> >> +#define RNG_FIFO_COUNT                                      (RNG_BASE_ADDRESS + 0x24)
> >>
> >> -#define RNG_CTRL_ENABLE    0x1
> >> +#define RNG_CTRL_ENABLE                                     0x1
> >>
> >>   #endif /*__BCM2836_H__ */
> >> --
> >> 2.21.0.windows.1
> >>
>