diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/clocksource/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/timer-mp-csky.c | 173 |
3 files changed, 184 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index a11f4ba98b05c..591c9a8649a5e 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 db51b2427e8a6..5ce82d39cda7d 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 0000000000000..a8acc431a774c --- /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); |