diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/mips/sgi-ip27/ip27-timer.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c new file mode 100644 index 000000000..9d5524753 --- /dev/null +++ b/arch/mips/sgi-ip27/ip27-timer.c @@ -0,0 +1,238 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org) + * Copytight (C) 1999, 2000 Silicon Graphics, Inc. + */ +#include <linux/bcd.h> +#include <linux/clockchips.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/sched_clock.h> +#include <linux/interrupt.h> +#include <linux/kernel_stat.h> +#include <linux/param.h> +#include <linux/smp.h> +#include <linux/time.h> +#include <linux/timex.h> +#include <linux/mm.h> +#include <linux/platform_device.h> + +#include <asm/time.h> +#include <asm/pgtable.h> +#include <asm/sgialib.h> +#include <asm/sn/ioc3.h> +#include <asm/sn/klconfig.h> +#include <asm/sn/arch.h> +#include <asm/sn/addrs.h> +#include <asm/sn/sn_private.h> +#include <asm/sn/sn0/ip27.h> +#include <asm/sn/sn0/hub.h> + +#define TICK_SIZE (tick_nsec / 1000) + +/* Includes for ioc3_init(). */ +#include <asm/sn/types.h> +#include <asm/sn/sn0/addrs.h> +#include <asm/sn/sn0/hubni.h> +#include <asm/sn/sn0/hubio.h> +#include <asm/pci/bridge.h> + +static void enable_rt_irq(struct irq_data *d) +{ +} + +static void disable_rt_irq(struct irq_data *d) +{ +} + +static struct irq_chip rt_irq_type = { + .name = "SN HUB RT timer", + .irq_mask = disable_rt_irq, + .irq_unmask = enable_rt_irq, +}; + +static int rt_next_event(unsigned long delta, struct clock_event_device *evt) +{ + unsigned int cpu = smp_processor_id(); + int slice = cputoslice(cpu); + unsigned long cnt; + + cnt = LOCAL_HUB_L(PI_RT_COUNT); + cnt += delta; + LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt); + + return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; +} + +unsigned int rt_timer_irq; + +static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent); +static DEFINE_PER_CPU(char [11], hub_rt_name); + +static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id) +{ + unsigned int cpu = smp_processor_id(); + struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); + int slice = cputoslice(cpu); + + /* + * Ack + */ + LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0); + cd->event_handler(cd); + + return IRQ_HANDLED; +} + +struct irqaction hub_rt_irqaction = { + .handler = hub_rt_counter_handler, + .flags = IRQF_PERCPU | IRQF_TIMER, + .name = "hub-rt", +}; + +/* + * This is a hack; we really need to figure these values out dynamically + * + * Since 800 ns works very well with various HUB frequencies, such as + * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. + * + * Ralf: which clock rate is used to feed the counter? + */ +#define NSEC_PER_CYCLE 800 +#define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) + +void hub_rt_clock_event_init(void) +{ + unsigned int cpu = smp_processor_id(); + struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu); + unsigned char *name = per_cpu(hub_rt_name, cpu); + int irq = rt_timer_irq; + + sprintf(name, "hub-rt %d", cpu); + cd->name = name; + cd->features = CLOCK_EVT_FEAT_ONESHOT; + clockevent_set_clock(cd, CYCLES_PER_SEC); + cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd); + cd->max_delta_ticks = 0xfffffffffffff; + cd->min_delta_ns = clockevent_delta2ns(0x300, cd); + cd->min_delta_ticks = 0x300; + cd->rating = 200; + cd->irq = irq; + cd->cpumask = cpumask_of(cpu); + cd->set_next_event = rt_next_event; + clockevents_register_device(cd); +} + +static void __init hub_rt_clock_event_global_init(void) +{ + int irq; + + do { + smp_wmb(); + irq = rt_timer_irq; + if (irq) + break; + + irq = allocate_irqno(); + if (irq < 0) + panic("Allocation of irq number for timer failed"); + } while (xchg(&rt_timer_irq, irq)); + + irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq); + setup_irq(irq, &hub_rt_irqaction); +} + +static u64 hub_rt_read(struct clocksource *cs) +{ + return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); +} + +struct clocksource hub_rt_clocksource = { + .name = "HUB-RT", + .rating = 200, + .read = hub_rt_read, + .mask = CLOCKSOURCE_MASK(52), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static u64 notrace hub_rt_read_sched_clock(void) +{ + return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT); +} + +static void __init hub_rt_clocksource_init(void) +{ + struct clocksource *cs = &hub_rt_clocksource; + + clocksource_register_hz(cs, CYCLES_PER_SEC); + + sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC); +} + +void __init plat_time_init(void) +{ + hub_rt_clocksource_init(); + hub_rt_clock_event_global_init(); + hub_rt_clock_event_init(); +} + +void cpu_time_init(void) +{ + lboard_t *board; + klcpu_t *cpu; + int cpuid; + + /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */ + board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27); + if (!board) + panic("Can't find board info for myself."); + + cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX; + cpu = (klcpu_t *) KLCF_COMP(board, cpuid); + if (!cpu) + panic("No information about myself?"); + + printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed); + + set_c0_status(SRB_TIMOCLK); +} + +void hub_rtc_init(cnodeid_t cnode) +{ + + /* + * We only need to initialize the current node. + * If this is not the current node then it is a cpuless + * node and timeouts will not happen there. + */ + if (get_compact_nodeid() == cnode) { + LOCAL_HUB_S(PI_RT_EN_A, 1); + LOCAL_HUB_S(PI_RT_EN_B, 1); + LOCAL_HUB_S(PI_PROF_EN_A, 0); + LOCAL_HUB_S(PI_PROF_EN_B, 0); + LOCAL_HUB_S(PI_RT_COUNT, 0); + LOCAL_HUB_S(PI_RT_PEND_A, 0); + LOCAL_HUB_S(PI_RT_PEND_B, 0); + } +} + +static int __init sgi_ip27_rtc_devinit(void) +{ + struct resource res; + + memset(&res, 0, sizeof(res)); + res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + + IOC3_BYTEBUS_DEV0); + res.end = res.start + 32767; + res.flags = IORESOURCE_MEM; + + return IS_ERR(platform_device_register_simple("rtc-m48t35", -1, + &res, 1)); +} + +/* + * kludge make this a device_initcall after ioc3 resource conflicts + * are resolved + */ +late_initcall(sgi_ip27_rtc_devinit); |