How can we access the Intel® Stratix® 10 SoC SP Timer registers in UBOOT or Linux user space (EL0: non-privileged execution)?

Description

By default, the SP timers didn’t out of reset in UBOOT. We will fail to access the S10 SoC SP Timer registers in UBOOT or Linux user space(EL0:non-privileged
execution).

Resolution

UBOOT changes made:

/u-boot/arch/arm/mach-socfpga/spl_s10.c (added codes after line 70)
socfpga_per_reset(SOCFPGA_RESET(SPTIMER0), 0);
socfpga_per_reset(SOCFPGA_RESET(SPTIMER1), 0);
 
/u-boot/arch/arm/mach-socfpga/include/mach/reset_manager_s10.h (added codes after line 105)
#define RSTMGR_SPTIMER0        RSTMGR_DEFINE(2, 6)
#define RSTMGR_SPTIMER1         RSTMGR_DEFINE(2, 7)

Then we can read/write the SP timers.

SOCFPGA_STRATIX10 # mw ffd24800 ffffffff; mw ffd21160 01010101; mw ffd21164 01010101; mw ffd21064 01010101; mw ffd21068 01010101
SOCFPGA_STRATIX10 #

stratix10swvp login: root
Last login: Sat Jun 24 05:27:20 UTC 2017 on ttyS0

root@stratix10swvp:~# devmem2 0xffc03000 w 0xa5a5a5a5

root@stratix10swvp:~# devmem2 0xffc03000
Value at address 0xFFC03000 (0xffff8021c000): 0xA5A5A5A5