Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
Something went wrong. Try again.
5.6 kB · 213 lines
C
at master
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214// SPDX-License-Identifier: GPL-2.0-only/* * linux/drivers/clocksource/zevio-timer.c * * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au> */
#include <linux/io.h>#include <linux/irq.h>#include <linux/of.h>#include <linux/of_address.h>#include <linux/of_irq.h>#include <linux/clk.h>#include <linux/clockchips.h>#include <linux/cpumask.h>#include <linux/interrupt.h>#include <linux/slab.h>
#define IO_CURRENT_VAL 0x00#define IO_DIVIDER 0x04#define IO_CONTROL 0x08
#define IO_TIMER1 0x00#define IO_TIMER2 0x0C
#define IO_MATCH_BEGIN 0x18#define IO_MATCH(x) (IO_MATCH_BEGIN + ((x) << 2))
#define IO_INTR_STS 0x00#define IO_INTR_ACK 0x00#define IO_INTR_MSK 0x04
#define CNTL_STOP_TIMER (1 << 4)#define CNTL_RUN_TIMER (0 << 4)
#define CNTL_INC (1 << 3)#define CNTL_DEC (0 << 3)
#define CNTL_TOZERO 0#define CNTL_MATCH(x) ((x) + 1)#define CNTL_FOREVER 7
/* There are 6 match registers but we only use one. */#define TIMER_MATCH 0
#define TIMER_INTR_MSK (1 << (TIMER_MATCH))#define TIMER_INTR_ALL 0x3F
struct zevio_timer { void __iomem *base; void __iomem *timer1, *timer2; void __iomem *interrupt_regs;
struct clk *clk; struct clock_event_device clkevt;
char clocksource_name[64]; char clockevent_name[64];};
static int zevio_timer_set_event(unsigned long delta, struct clock_event_device *dev){ struct zevio_timer *timer = container_of(dev, struct zevio_timer, clkevt);
writel(delta, timer->timer1 + IO_CURRENT_VAL); writel(CNTL_RUN_TIMER | CNTL_DEC | CNTL_MATCH(TIMER_MATCH), timer->timer1 + IO_CONTROL);
return 0;}
static int zevio_timer_shutdown(struct clock_event_device *dev){ struct zevio_timer *timer = container_of(dev, struct zevio_timer, clkevt);
/* Disable timer interrupts */ writel(0, timer->interrupt_regs + IO_INTR_MSK); writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); /* Stop timer */ writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); return 0;}
static int zevio_timer_set_oneshot(struct clock_event_device *dev){ struct zevio_timer *timer = container_of(dev, struct zevio_timer, clkevt);
/* Enable timer interrupts */ writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_MSK); writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); return 0;}
static irqreturn_t zevio_timer_interrupt(int irq, void *dev_id){ struct zevio_timer *timer = dev_id; u32 intr;
intr = readl(timer->interrupt_regs + IO_INTR_ACK); if (!(intr & TIMER_INTR_MSK)) return IRQ_NONE;
writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_ACK); writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL);
if (timer->clkevt.event_handler) timer->clkevt.event_handler(&timer->clkevt);
return IRQ_HANDLED;}
static int __init zevio_timer_add(struct device_node *node){ struct zevio_timer *timer; struct resource res; int irqnr, ret;
timer = kzalloc_obj(*timer); if (!timer) return -ENOMEM;
timer->base = of_iomap(node, 0); if (!timer->base) { ret = -EINVAL; goto error_free; } timer->timer1 = timer->base + IO_TIMER1; timer->timer2 = timer->base + IO_TIMER2;
timer->clk = of_clk_get(node, 0); if (IS_ERR(timer->clk)) { ret = PTR_ERR(timer->clk); pr_err("Timer clock not found! (error %d)\n", ret); goto error_unmap; }
timer->interrupt_regs = of_iomap(node, 1); irqnr = irq_of_parse_and_map(node, 0);
of_address_to_resource(node, 0, &res); scnprintf(timer->clocksource_name, sizeof(timer->clocksource_name), "%llx.%pOFn_clocksource", (unsigned long long)res.start, node);
scnprintf(timer->clockevent_name, sizeof(timer->clockevent_name), "%llx.%pOFn_clockevent", (unsigned long long)res.start, node);
if (timer->interrupt_regs && irqnr) { timer->clkevt.name = timer->clockevent_name; timer->clkevt.set_next_event = zevio_timer_set_event; timer->clkevt.set_state_shutdown = zevio_timer_shutdown; timer->clkevt.set_state_oneshot = zevio_timer_set_oneshot; timer->clkevt.tick_resume = zevio_timer_set_oneshot; timer->clkevt.rating = 200; timer->clkevt.cpumask = cpu_possible_mask; timer->clkevt.features = CLOCK_EVT_FEAT_ONESHOT; timer->clkevt.irq = irqnr;
writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); writel(0, timer->timer1 + IO_DIVIDER);
/* Start with timer interrupts disabled */ writel(0, timer->interrupt_regs + IO_INTR_MSK); writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK);
/* Interrupt to occur when timer value matches 0 */ writel(0, timer->base + IO_MATCH(TIMER_MATCH));
if (request_irq(irqnr, zevio_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL, timer->clockevent_name, timer)) { pr_err("%s: request_irq() failed\n", timer->clockevent_name); }
clockevents_config_and_register(&timer->clkevt, clk_get_rate(timer->clk), 0x0001, 0xffff); pr_info("Added %s as clockevent\n", timer->clockevent_name); }
writel(CNTL_STOP_TIMER, timer->timer2 + IO_CONTROL); writel(0, timer->timer2 + IO_CURRENT_VAL); writel(0, timer->timer2 + IO_DIVIDER); writel(CNTL_RUN_TIMER | CNTL_FOREVER | CNTL_INC, timer->timer2 + IO_CONTROL);
clocksource_mmio_init(timer->timer2 + IO_CURRENT_VAL, timer->clocksource_name, clk_get_rate(timer->clk), 200, 16, clocksource_mmio_readw_up);
pr_info("Added %s as clocksource\n", timer->clocksource_name);
return 0;error_unmap: iounmap(timer->base);error_free: kfree(timer); return ret;}
static int __init zevio_timer_init(struct device_node *node){ return zevio_timer_add(node);}
TIMER_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_init);