[U-Boot,RFC] ARM: at91: Print CPU serial number in cpuinfo

The SAMA5D2 and SAMA5D4 series SoCs have a 64-bit Serial Number (unique
ID) burned in, which is displayed with 'print_cpuinfo()' now (in the
same format the SAM-BA applet prints it).

Example output:

CPU: SAMA5D27 1G bits DDR2 SDRAM
Serial number 0: 0x4630394b
              1: 0x190d2750
Crystal frequency:       24 MHz
CPU clock        :      492 MHz
Master clock     :      164 MHz

Signed-off-by: Alexander Dahl <ada@thorsis.com>
---

I looked over lots of other 'print_cpuinfo()' implementations for
different SoCs and found none printing a unique ID at all. Is there
another place for this? Is it just few SoCs have such a serial number
at all? Or is it not desired to print those along with the other CPU
info?

Greets
Alex

---
 arch/arm/mach-at91/armv7/cpu.c | 8 ++++++++
 1 file changed, 8 insertions(+)

On 27.11.2019 14:44, Alexander Dahl wrote:

> The SAMA5D2 and SAMA5D4 series SoCs have a 64-bit Serial Number (unique
> ID) burned in, which is displayed with 'print_cpuinfo()' now (in the
> same format the SAM-BA applet prints it).
> 
> Example output:
> 
> CPU: SAMA5D27 1G bits DDR2 SDRAM
> Serial number 0: 0x4630394b
>                1: 0x190d2750
> Crystal frequency:       24 MHz
> CPU clock        :      492 MHz
> Master clock     :      164 MHz
> 
> Signed-off-by: Alexander Dahl <ada@thorsis.com>
> ---
> 
> I looked over lots of other 'print_cpuinfo()' implementations for
> different SoCs and found none printing a unique ID at all. Is there
> another place for this? Is it just few SoCs have such a serial number
> at all? Or is it not desired to print those along with the other CPU
> info?
> 

Hi Alex,

I do not have anything against it.
Nor do I have a strong opinion about which way to go. Is it better to 
just have a CMD that prints out this serial or print it at boot ? Maybe 
some other people have a different idea ?

Eugen

> Greets
> Alex
> 
> ---
>   arch/arm/mach-at91/armv7/cpu.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/arch/arm/mach-at91/armv7/cpu.c b/arch/arm/mach-at91/armv7/cpu.c
> index 5da067cda1..6d50e1aea4 100644
> --- a/arch/arm/mach-at91/armv7/cpu.c
> +++ b/arch/arm/mach-at91/armv7/cpu.c
> @@ -13,6 +13,7 @@
>   #include <asm/arch/hardware.h>
>   #include <asm/arch/at91_pit.h>
>   #include <asm/arch/at91_gpbr.h>
> +#include <asm/arch/at91_sfr.h>
>   #include <asm/arch/clk.h>
> 
>   #ifndef CONFIG_SYS_AT91_MAIN_CLOCK
> @@ -42,9 +43,16 @@ void arch_preboot_os(void)
>   #if defined(CONFIG_DISPLAY_CPUINFO)
>   int print_cpuinfo(void)
>   {
> +       struct atmel_sfr *sfr = (struct atmel_sfr *)ATMEL_BASE_SFR;
>          char buf[32];
> 
>          printf("CPU: %s\n", get_cpu_name());
> +
> +#if defined(CONFIG_SAMA5D2) || defined(CONFIG_SAMA5D4)
> +       printf("Serial number 0: 0x%08x\n", sfr->sn0);
> +       printf("              1: 0x%08x\n", sfr->sn1);
> +#endif
> +
>          printf("Crystal frequency: %8s MHz\n",
>                 strmhz(buf, get_main_clk_rate()));
>          printf("CPU clock        : %8s MHz\n",
> --
> 2.20.1
> 
>