The current RISC-V timer driver is convoluted and implements two
distinct timers:
1. S-mode timer: This is for Linux RISC-V S-mode with MMU. The
clocksource is implemented using TIME CSR and clockevent device
is implemented using SBI Timer calls.
2. M-mode timer: This is for Linux RISC-V M-mode without MMU. The
clocksource is implemented using CLINT MMIO time register and
clockevent device is implemented using CLINT MMIO timecmp registers.
This patchset removes clint related code from RISC-V timer driver and
arch/riscv directory. Instead, the series adds a dedicated MMIO based
CLINT driver under drivers/clocksource directory which can be used by
Linux RISC-V M-mode (i.e NoMMU Linux RISC-V).
The patchset is based up Linux-5.7-rc6 and can be found at riscv_clint_v1
branch of: https://github.com/avpatel/linux.git
These patches require "New RISC-V Local Interrupt Controller Driver"
which can be found at at riscv_intc_v5 branch of:
https://github.com/avpatel/linux.git
This series is tested on:
1. QEMU RV64 virt machine using Linux RISC-V S-mode
2. QEMU RV32 virt machine using Linux RISC-V S-mode
3. QEMU RV64 virt machine using Linux RISC-V M-mode (i.e. NoMMU)
Anup Patel (5):
RISC-V: Add mechanism to provide custom IPI operations
RISC-V: Remove CLINT related code
clocksource/drivers/timer-riscv: Remove MMIO related stuff
clocksource/drivers: Add CLINT timer driver
dt-bindings: timer: Add CLINT bindings
.../bindings/timer/sifive,clint.txt | 33 +++
arch/riscv/Kconfig | 2 +-
arch/riscv/include/asm/clint.h | 39 ---
arch/riscv/include/asm/smp.h | 11 +
arch/riscv/include/asm/timex.h | 28 +--
arch/riscv/kernel/Makefile | 2 +-
arch/riscv/kernel/clint.c | 44 ----
arch/riscv/kernel/setup.c | 2 -
arch/riscv/kernel/smp.c | 53 ++--
arch/riscv/kernel/smpboot.c | 4 +-
drivers/clocksource/Kconfig | 12 +-
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-clint.c | 226 ++++++++++++++++++
drivers/clocksource/timer-riscv.c | 17 +-
include/linux/cpuhotplug.h | 1 +
15 files changed, 330 insertions(+), 145 deletions(-)
create mode 100644 Documentation/devicetree/bindings/timer/sifive,clint.txt
delete mode 100644 arch/riscv/include/asm/clint.h
delete mode 100644 arch/riscv/kernel/clint.c
create mode 100644 drivers/clocksource/timer-clint.c
--
2.25.1
