The Andes PLMT driver directly accesses the mtime MMIO region, indicating its intended use in the M-mode boot stage. However, since U-Boot proper (S-mode) also uses the PLMT driver, we need to specifically mark the region as readable through PMPCFGx (or S/U-mode read-only shared data region for Smepmp) in OpenSBI.
Granting permission for this case doesn't make sense. Instead, we should use the generic RISC-V timer driver to read the mtime through the TIME CSR. Therefore, we add the SPL_ANDES_PLMT_TIMER config, which ensures that the PLMT driver is linked exclusively against M-mode U-Boot or U-Boot SPL binaries.
Signed-off-by: Yu Chien Peter Lin peterlin@andestech.com Reviewed-by: Samuel Holland samuel@sholland.org --- Changes v1 -> v2: - Drop imply conditions for *ANDES_PLMT_TIMER - Add Samuel's RB-tag --- arch/riscv/cpu/andesv5/Kconfig | 3 ++- drivers/timer/Kconfig | 9 ++++++++- drivers/timer/Makefile | 2 +- 3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/cpu/andesv5/Kconfig b/arch/riscv/cpu/andesv5/Kconfig index 82bb5a2a53..57177b7b64 100644 --- a/arch/riscv/cpu/andesv5/Kconfig +++ b/arch/riscv/cpu/andesv5/Kconfig @@ -4,8 +4,9 @@ config RISCV_NDS imply CPU imply CPU_RISCV imply RISCV_TIMER if (RISCV_SMODE || SPL_RISCV_SMODE) + imply ANDES_PLMT_TIMER + imply SPL_ANDES_PLMT_TIMER imply ANDES_PLICSW if (RISCV_MMODE || SPL_RISCV_MMODE) - imply ANDES_PLMT_TIMER if (RISCV_MMODE || SPL_RISCV_MMODE) imply V5L2_CACHE imply SPL_CPU imply SPL_OPENSBI diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig index 915b2af160..157298a941 100644 --- a/drivers/timer/Kconfig +++ b/drivers/timer/Kconfig @@ -59,7 +59,14 @@ config ALTERA_TIMER
config ANDES_PLMT_TIMER bool - depends on RISCV_MMODE || SPL_RISCV_MMODE + depends on RISCV_MMODE + help + The Andes PLMT block holds memory-mapped mtime register + associated with timer tick. + +config SPL_ANDES_PLMT_TIMER + bool + depends on SPL_RISCV_MMODE help The Andes PLMT block holds memory-mapped mtime register associated with timer tick. diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile index 1ca74805fd..1f5c16fdf3 100644 --- a/drivers/timer/Makefile +++ b/drivers/timer/Makefile @@ -4,7 +4,7 @@
obj-y += timer-uclass.o obj-$(CONFIG_ALTERA_TIMER) += altera_timer.o -obj-$(CONFIG_ANDES_PLMT_TIMER) += andes_plmt_timer.o +obj-$(CONFIG_$(SPL_)ANDES_PLMT_TIMER) += andes_plmt_timer.o obj-$(CONFIG_ARC_TIMER) += arc_timer.o obj-$(CONFIG_ARM_TWD_TIMER) += arm_twd_timer.o obj-$(CONFIG_AST_TIMER) += ast_timer.o