u-boot/arch/riscv/cpu/ax25/Kconfig
Sean Anderson c33efafaf9 riscv: Rework riscv timer driver to only support S-mode
The riscv-timer driver currently serves as a shim for several riscv timer
drivers. This is not too desirable because it bypasses the usual timer
selection via the driver model. There is no easy way to specify an
alternate timing driver, or have the tick rate depend on the cpu's
configured frequency. The timer drivers also do not have device structs,
and so have to rely on storing parameters in gd_t. Lastly, there is no
initialization call, so driver init is done in the same function which
reads the time. This can result in confusing error messages. To a user, it
looks like the driver failed when trying to read the time, whereas it may
have failed while initializing.

This patch removes the shim functionality from the riscv-timer driver, and
has it instead implement the former rdtime.c timer driver. This is because
existing u-boot users who pass in a device tree (e.g. qemu) do not create a
timer device for S-mode u-boot. The existing behavior of creating the
riscv-timer device in the riscv cpu driver must be kept. The actual reading
of the CSRs has been redone in the style of Linux's get_cycles64.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Rick Chen <rick@andestech.com>
2020-09-30 08:54:45 +08:00

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config RISCV_NDS
bool
select ARCH_EARLY_INIT_R
imply CPU
imply CPU_RISCV
imply RISCV_TIMER if (RISCV_SMODE || SPL_RISCV_SMODE)
imply ANDES_PLIC if (RISCV_MMODE || SPL_RISCV_MMODE)
imply ANDES_PLMT if (RISCV_MMODE || SPL_RISCV_MMODE)
imply SPL_CPU_SUPPORT
imply SPL_OPENSBI
imply SPL_LOAD_FIT
help
Run U-Boot on AndeStar V5 platforms and use some specific features
which are provided by Andes Technology AndeStar V5 families.
if RISCV_NDS
config RISCV_NDS_CACHE
bool "AndeStar V5 families specific cache support"
depends on RISCV_MMODE || SPL_RISCV_MMODE
help
Provide Andes Technology AndeStar V5 families specific cache support.
endif