On Wed, Jul 29, 2020 at 5:56 PM Sean Anderson <sean...@gmail.com> wrote: > > 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 <sean...@gmail.com> > --- > > Changes in v2: > - Remove RISCV_RDTIME KConfig option > > arch/riscv/Kconfig | 8 -------- > arch/riscv/lib/Makefile | 1 - > arch/riscv/lib/rdtime.c | 38 ------------------------------------ > drivers/timer/Kconfig | 6 +++--- > drivers/timer/riscv_timer.c | 39 +++++++++++++++++++------------------ > 5 files changed, 23 insertions(+), 69 deletions(-) > delete mode 100644 arch/riscv/lib/rdtime.c >
Reviewed-by: Bin Meng <bin.m...@windriver.com>
