On 2/22/20 11:05 AM, Ang, Chee Hong wrote:
From: Chee Hong Ang chee.hong.ang@intel.com
Allow reading external oscillator and FPGA clock's frequency from System Manager's Boot Scratch Register 1 and Boot Scratch Register 2 in non-secure mode (EL2) on SoC 64bits platform.
Signed-off-by: Chee Hong Ang chee.hong.ang@intel.com
arch/arm/mach-socfpga/wrap_pll_config_s10.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-socfpga/wrap_pll_config_s10.c b/arch/arm/mach- socfpga/wrap_pll_config_s10.c index 3da8579..7bd92d0 100644 --- a/arch/arm/mach-socfpga/wrap_pll_config_s10.c +++ b/arch/arm/mach-socfpga/wrap_pll_config_s10.c @@ -9,6 +9,7 @@ #include <asm/io.h> #include <asm/arch/handoff_s10.h> #include <asm/arch/system_manager.h> +#include <asm/arch/secure_reg_helper.h>
const struct cm_config * const cm_get_default_config(void) { @@ -39,8 +40,8 @@ const unsigned int cm_get_osc_clk_hz(void) writel(clock, socfpga_get_sysmgr_addr() + SYSMGR_SOC64_BOOT_SCRATCH_COLD1); #endif
- return readl(socfpga_get_sysmgr_addr() +
SYSMGR_SOC64_BOOT_SCRATCH_COLD1);
- return socfpga_secure_reg_read32(socfpga_get_sysmgr_addr() +
SYSMGR_SOC64_BOOT_SCRATCH_COLD1); }
const unsigned int cm_get_intosc_clk_hz(void) @@ -56,6 +57,6 @@ const unsigned int cm_get_fpga_clk_hz(void) writel(clock, socfpga_get_sysmgr_addr() + SYSMGR_SOC64_BOOT_SCRATCH_COLD2); #endif
- return readl(socfpga_get_sysmgr_addr() +
SYSMGR_SOC64_BOOT_SCRATCH_COLD2);
- return socfpga_secure_reg_read32(socfpga_get_sysmgr_addr() +
SYSMGR_SOC64_BOOT_SCRATCH_COLD2); } -- 2.7.4
This clock info could be directly read from the handoff table (OCRAM) instead of the System Manager's boot scratch register (secure zone). Please refer to my full explanation in my previous email reply: [PATCH v2 11/21] arm: socfpga: Secure register access for clock manager (SoC 64bits)
Simon raised a good security concern on this approach. I will drop this approach. Will go for high-level APIs in ATF for clock queries: INTEL_SIP_SMC_CLK_GET_OSC INTEL_SIP_SMC_CLK_GET_FPGA
Can't you have a clock driver read out the clock tree once and then have all the drivers in U-Boot just get clock settings from the clock driver?