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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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6.2 kB · 253 lines
C
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#include <linux/clocksource.h>#include <linux/clockchips.h>#include <linux/cpu.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/irq.h>#include <linux/io.h>#include <linux/of.h>#include <linux/of_address.h>#include <linux/of_irq.h>#include <linux/sched_clock.h>
#include <asm/delay.h>
#define TIMER_MATCH_VAL 0x0000#define TIMER_COUNT_VAL 0x0004#define TIMER_ENABLE 0x0008#define TIMER_ENABLE_CLR_ON_MATCH_EN BIT(1)#define TIMER_ENABLE_EN BIT(0)#define TIMER_CLEAR 0x000C#define DGT_CLK_CTL 0x10#define DGT_CLK_CTL_DIV_4 0x3#define TIMER_STS_GPT0_CLR_PEND BIT(10)
#define GPT_HZ 32768
static void __iomem *event_base;static void __iomem *sts_base;
static irqreturn_t msm_timer_interrupt(int irq, void *dev_id){ struct clock_event_device *evt = dev_id; /* Stop the timer tick */ if (clockevent_state_oneshot(evt)) { u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE); ctrl &= ~TIMER_ENABLE_EN; writel_relaxed(ctrl, event_base + TIMER_ENABLE); } evt->event_handler(evt); return IRQ_HANDLED;}
static int msm_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt){ u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
ctrl &= ~TIMER_ENABLE_EN; writel_relaxed(ctrl, event_base + TIMER_ENABLE);
writel_relaxed(ctrl, event_base + TIMER_CLEAR); writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
if (sts_base) while (readl_relaxed(sts_base) & TIMER_STS_GPT0_CLR_PEND) cpu_relax();
writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE); return 0;}
static int msm_timer_shutdown(struct clock_event_device *evt){ u32 ctrl;
ctrl = readl_relaxed(event_base + TIMER_ENABLE); ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN); writel_relaxed(ctrl, event_base + TIMER_ENABLE); return 0;}
static struct clock_event_device __percpu *msm_evt;
static void __iomem *source_base;
static notrace u64 msm_read_timer_count(struct clocksource *cs){ return readl_relaxed(source_base + TIMER_COUNT_VAL);}
static struct clocksource msm_clocksource = { .name = "dg_timer", .rating = 300, .read = msm_read_timer_count, .mask = CLOCKSOURCE_MASK(32), .flags = CLOCK_SOURCE_IS_CONTINUOUS,};
static int msm_timer_irq;static int msm_timer_has_ppi;
static int msm_local_timer_starting_cpu(unsigned int cpu){ struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu); int err;
evt->irq = msm_timer_irq; evt->name = "msm_timer"; evt->features = CLOCK_EVT_FEAT_ONESHOT; evt->rating = 200; evt->set_state_shutdown = msm_timer_shutdown; evt->set_state_oneshot = msm_timer_shutdown; evt->tick_resume = msm_timer_shutdown; evt->set_next_event = msm_timer_set_next_event; evt->cpumask = cpumask_of(cpu);
clockevents_config_and_register(evt, GPT_HZ, 4, 0xffffffff);
if (msm_timer_has_ppi) { enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING); } else { err = request_irq(evt->irq, msm_timer_interrupt, IRQF_TIMER | IRQF_NOBALANCING | IRQF_TRIGGER_RISING, "gp_timer", evt); if (err) pr_err("request_irq failed\n"); }
return 0;}
static int msm_local_timer_dying_cpu(unsigned int cpu){ struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu);
disable_percpu_irq(evt->irq); return 0;}
static u64 notrace msm_sched_clock_read(void){ return msm_clocksource.read(&msm_clocksource);}
static unsigned long msm_read_current_timer(void){ return msm_clocksource.read(&msm_clocksource);}
static struct delay_timer msm_delay_timer = { .read_current_timer = msm_read_current_timer,};
static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq, bool percpu){ struct clocksource *cs = &msm_clocksource; int res = 0;
msm_timer_irq = irq; msm_timer_has_ppi = percpu;
msm_evt = alloc_percpu(struct clock_event_device); if (!msm_evt) { pr_err("memory allocation failed for clockevents\n"); goto err; }
if (percpu) res = request_percpu_irq(irq, msm_timer_interrupt, "gp_timer", msm_evt);
if (res) { pr_err("request_percpu_irq failed\n"); } else { /* Install and invoke hotplug callbacks */ res = cpuhp_setup_state(CPUHP_AP_QCOM_TIMER_STARTING, "clockevents/qcom/timer:starting", msm_local_timer_starting_cpu, msm_local_timer_dying_cpu); if (res) { free_percpu_irq(irq, msm_evt); goto err; } }
err: writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE); res = clocksource_register_hz(cs, dgt_hz); if (res) pr_err("clocksource_register failed\n"); sched_clock_register(msm_sched_clock_read, sched_bits, dgt_hz); msm_delay_timer.freq = dgt_hz; register_current_timer_delay(&msm_delay_timer);
return res;}
static int __init msm_dt_timer_init(struct device_node *np){ u32 freq; int irq, ret; struct resource res; u32 percpu_offset; void __iomem *base; void __iomem *cpu0_base;
base = of_iomap(np, 0); if (!base) { pr_err("Failed to map event base\n"); return -ENXIO; }
/* We use GPT0 for the clockevent */ irq = irq_of_parse_and_map(np, 1); if (irq <= 0) { pr_err("Can't get irq\n"); return -EINVAL; }
/* We use CPU0's DGT for the clocksource */ if (of_property_read_u32(np, "cpu-offset", &percpu_offset)) percpu_offset = 0;
ret = of_address_to_resource(np, 0, &res); if (ret) { pr_err("Failed to parse DGT resource\n"); return ret; }
cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res)); if (!cpu0_base) { pr_err("Failed to map source base\n"); return -EINVAL; }
if (of_property_read_u32(np, "clock-frequency", &freq)) { iounmap(cpu0_base); pr_err("Unknown frequency\n"); return -EINVAL; }
event_base = base + 0x4; sts_base = base + 0x88; source_base = cpu0_base + 0x24; freq /= 4; writel_relaxed(DGT_CLK_CTL_DIV_4, source_base + DGT_CLK_CTL);
ret = msm_timer_init(freq, 32, irq, !!percpu_offset); if (ret) iounmap(cpu0_base);
return ret;}TIMER_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init);TIMER_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init);