Dear Daniel, Csky subsystem is pulled into linux-4.20, ref: [1] So could you help merge the C-SKY timer drivers' patches into linux-4.20? (2 timer drivers and 2 dt-binding-docs) [1] https://lore.kernel.org/lkml/CAHk-=whq5ebFd2CKE0bybLOY7ttMPxGiXF3WkzFXtkYhAbJqSg@xxxxxxxxxxxxxx/ Best Regards Guo Ren On Mon, Oct 15, 2018 at 01:07:41PM +0800, Guo Ren wrote: > The driver is for C-SKY SMP timer. It only support oneshot event > and 32bit overflow for clocksource. Per cpu core has one timer and > all timers share one clock-counter-input the same clocksource. > > This use mfcr&mtcr instructions to access the regs. > > Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx> > Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> > --- > Changelog: > - Add COMPILE_TEST > - Fixup smp boot error, cpuhp_setup_state must after timer_of_init() > - Add rollback for timer_of_cleanup. > - Use request_percpu_irq separate from time_of. > - Remove #define CPUHP_AP_CSKY_TIMER_STARTING. > - Add CPUHP_AP_CSKY_TIMER_STARTING in cpuhotplug.h. > - Support csky mp timer alpha version. > - Just use low-counter with 32bit width as clocksource. > - Coding convention with upstream feed-back. > --- > --- > drivers/clocksource/Kconfig | 10 +++ > drivers/clocksource/Makefile | 1 + > drivers/clocksource/timer-mp-csky.c | 173 ++++++++++++++++++++++++++++++++++++ > include/linux/cpuhotplug.h | 1 + > 4 files changed, 185 insertions(+) > create mode 100644 drivers/clocksource/timer-mp-csky.c > > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig > index a11f4ba..591c9a8 100644 > --- a/drivers/clocksource/Kconfig > +++ b/drivers/clocksource/Kconfig > @@ -620,4 +620,14 @@ config RISCV_TIMER > is accessed via both the SBI and the rdcycle instruction. This is > required for all RISC-V systems. > > +config CSKY_MP_TIMER > + bool "SMP Timer for the C-SKY platform" if COMPILE_TEST > + depends on CSKY > + select TIMER_OF > + help > + Say yes here to enable C-SKY SMP timer driver used for C-SKY SMP > + system. > + csky,mptimer is not only used in SMP system, it also could be used > + single core system. It's not a mmio reg and it use mtcr/mfcr instruction. > + > endmenu > diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile > index db51b24..5ce82d3 100644 > --- a/drivers/clocksource/Makefile > +++ b/drivers/clocksource/Makefile > @@ -79,3 +79,4 @@ obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o > obj-$(CONFIG_X86_NUMACHIP) += numachip.o > obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o > obj-$(CONFIG_RISCV_TIMER) += riscv_timer.o > +obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o > diff --git a/drivers/clocksource/timer-mp-csky.c b/drivers/clocksource/timer-mp-csky.c > new file mode 100644 > index 0000000..a8acc43 > --- /dev/null > +++ b/drivers/clocksource/timer-mp-csky.c > @@ -0,0 +1,173 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. > + > +#include <linux/init.h> > +#include <linux/interrupt.h> > +#include <linux/sched_clock.h> > +#include <linux/cpu.h> > +#include <linux/of_irq.h> > +#include <asm/reg_ops.h> > + > +#include "timer-of.h" > + > +#define PTIM_CCVR "cr<3, 14>" > +#define PTIM_CTLR "cr<0, 14>" > +#define PTIM_LVR "cr<6, 14>" > +#define PTIM_TSR "cr<1, 14>" > + > +static int csky_mptimer_irq; > + > +static int csky_mptimer_set_next_event(unsigned long delta, > + struct clock_event_device *ce) > +{ > + mtcr(PTIM_LVR, delta); > + > + return 0; > +} > + > +static int csky_mptimer_shutdown(struct clock_event_device *ce) > +{ > + mtcr(PTIM_CTLR, 0); > + > + return 0; > +} > + > +static int csky_mptimer_oneshot(struct clock_event_device *ce) > +{ > + mtcr(PTIM_CTLR, 1); > + > + return 0; > +} > + > +static int csky_mptimer_oneshot_stopped(struct clock_event_device *ce) > +{ > + mtcr(PTIM_CTLR, 0); > + > + return 0; > +} > + > +static DEFINE_PER_CPU(struct timer_of, csky_to) = { > + .flags = TIMER_OF_CLOCK, > + .clkevt = { > + .rating = 300, > + .features = CLOCK_EVT_FEAT_PERCPU | > + CLOCK_EVT_FEAT_ONESHOT, > + .set_state_shutdown = csky_mptimer_shutdown, > + .set_state_oneshot = csky_mptimer_oneshot, > + .set_state_oneshot_stopped = csky_mptimer_oneshot_stopped, > + .set_next_event = csky_mptimer_set_next_event, > + }, > +}; > + > +static irqreturn_t csky_timer_interrupt(int irq, void *dev) > +{ > + struct timer_of *to = this_cpu_ptr(&csky_to); > + > + mtcr(PTIM_TSR, 0); > + > + to->clkevt.event_handler(&to->clkevt); > + > + return IRQ_HANDLED; > +} > + > +/* > + * clock event for percpu > + */ > +static int csky_mptimer_starting_cpu(unsigned int cpu) > +{ > + struct timer_of *to = per_cpu_ptr(&csky_to, cpu); > + > + to->clkevt.cpumask = cpumask_of(cpu); > + > + clockevents_config_and_register(&to->clkevt, timer_of_rate(to), > + 2, ULONG_MAX); > + > + enable_percpu_irq(csky_mptimer_irq, 0); > + > + return 0; > +} > + > +static int csky_mptimer_dying_cpu(unsigned int cpu) > +{ > + disable_percpu_irq(csky_mptimer_irq); > + > + return 0; > +} > + > +/* > + * clock source > + */ > +static u64 sched_clock_read(void) > +{ > + return (u64)mfcr(PTIM_CCVR); > +} > + > +static u64 clksrc_read(struct clocksource *c) > +{ > + return (u64)mfcr(PTIM_CCVR); > +} > + > +struct clocksource csky_clocksource = { > + .name = "csky", > + .rating = 400, > + .mask = CLOCKSOURCE_MASK(32), > + .flags = CLOCK_SOURCE_IS_CONTINUOUS, > + .read = clksrc_read, > +}; > + > +static int __init csky_mptimer_init(struct device_node *np) > +{ > + int ret, cpu, cpu_rollback; > + struct timer_of *to = NULL; > + > + /* > + * Csky_mptimer is designed for C-SKY SMP multi-processors and > + * every core has it's own private irq and regs for clkevt and > + * clksrc. > + * > + * The regs is accessed by cpu instruction: mfcr/mtcr instead of > + * mmio map style. So we needn't mmio-address in dts, but we still > + * need to give clk and irq number. > + * > + * We use private irq for the mptimer and irq number is the same > + * for every core. So we use request_percpu_irq() in timer_of_init. > + */ > + csky_mptimer_irq = irq_of_parse_and_map(np, 0); > + if (csky_mptimer_irq <= 0) > + return -EINVAL; > + > + ret = request_percpu_irq(csky_mptimer_irq, csky_timer_interrupt, > + "csky_mp_timer", &csky_to); > + if (ret) > + return -EINVAL; > + > + for_each_possible_cpu(cpu) { > + to = per_cpu_ptr(&csky_to, cpu); > + ret = timer_of_init(np, to); > + if (ret) > + goto rollback; > + } > + > + clocksource_register_hz(&csky_clocksource, timer_of_rate(to)); > + sched_clock_register(sched_clock_read, 32, timer_of_rate(to)); > + > + ret = cpuhp_setup_state(CPUHP_AP_CSKY_TIMER_STARTING, > + "clockevents/csky/timer:starting", > + csky_mptimer_starting_cpu, > + csky_mptimer_dying_cpu); > + if (ret) > + return -EINVAL; > + > + return 0; > + > +rollback: > + for_each_possible_cpu(cpu_rollback) { > + if (cpu_rollback == cpu) > + break; > + > + to = per_cpu_ptr(&csky_to, cpu_rollback); > + timer_of_cleanup(to); > + } > + return -EINVAL; > +} > +TIMER_OF_DECLARE(csky_mptimer, "csky,mptimer", csky_mptimer_init); > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > index caf40ad..e0cd2ba 100644 > --- a/include/linux/cpuhotplug.h > +++ b/include/linux/cpuhotplug.h > @@ -126,6 +126,7 @@ enum cpuhp_state { > CPUHP_AP_MIPS_GIC_TIMER_STARTING, > CPUHP_AP_ARC_TIMER_STARTING, > CPUHP_AP_RISCV_TIMER_STARTING, > + CPUHP_AP_CSKY_TIMER_STARTING, > CPUHP_AP_KVM_STARTING, > CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING, > CPUHP_AP_KVM_ARM_VGIC_STARTING, > -- > 2.7.4
