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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-06 14:09:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-06 14:09:38 -0700
commit21884a83b2192a00885d7244a1dda32debd2fbc7 (patch)
treee00267bbcac32f0114b3d21a20c61107d2314c40 /drivers/clocksource/zevio-timer.c
parent8b70a90cabafb6a6e1a0d3f838b38355fe48337e (diff)
parent73b0cd674ccc64c921e25bd7154f26d342116539 (diff)
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core updates from Thomas Gleixner: "The timer changes contain: - posix timer code consolidation and fixes for odd corner cases - sched_clock implementation moved from ARM to core code to avoid duplication by other architectures - alarm timer updates - clocksource and clockevents unregistration facilities - clocksource/events support for new hardware - precise nanoseconds RTC readout (Xen feature) - generic support for Xen suspend/resume oddities - the usual lot of fixes and cleanups all over the place The parts which touch other areas (ARM/XEN) have been coordinated with the relevant maintainers. Though this results in an handful of trivial to solve merge conflicts, which we preferred over nasty cross tree merge dependencies. The patches which have been committed in the last few days are bug fixes plus the posix timer lot. The latter was in akpms queue and next for quite some time; they just got forgotten and Frederic collected them last minute." * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits) hrtimer: Remove unused variable hrtimers: Move SMP function call to thread context clocksource: Reselect clocksource when watchdog validated high-res capability posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting posix_timers: fix racy timer delta caching on task exit posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule() selftests: add basic posix timers selftests posix_cpu_timers: consolidate expired timers check posix_cpu_timers: consolidate timer list cleanups posix_cpu_timer: consolidate expiry time type tick: Sanitize broadcast control logic tick: Prevent uncontrolled switch to oneshot mode tick: Make oneshot broadcast robust vs. CPU offlining x86: xen: Sync the CMOS RTC as well as the Xen wallclock x86: xen: Sync the wallclock when the system time is set timekeeping: Indicate that clock was set in the pvclock gtod notifier timekeeping: Pass flags instead of multiple bools to timekeeping_update() xen: Remove clock_was_set() call in the resume path hrtimers: Support resuming with two or more CPUs online (but stopped) timer: Fix jiffies wrap behavior of round_jiffies_common() ...
Diffstat (limited to 'drivers/clocksource/zevio-timer.c')
-rw-r--r--drivers/clocksource/zevio-timer.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/clocksource/zevio-timer.c b/drivers/clocksource/zevio-timer.c
new file mode 100644
index 00000000000..ca81809d159
--- /dev/null
+++ b/drivers/clocksource/zevio-timer.c
@@ -0,0 +1,215 @@
+/*
+ * linux/drivers/clocksource/zevio-timer.c
+ *
+ * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#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;
+ struct irqaction clkevt_irq;
+
+ 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 void zevio_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev)
+{
+ struct zevio_timer *timer = container_of(dev, struct zevio_timer,
+ clkevt);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_RESUME:
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* Enable timer interrupts */
+ writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_MSK);
+ writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK);
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ /* 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);
+ break;
+ case CLOCK_EVT_MODE_PERIODIC:
+ default:
+ /* Unsupported */
+ break;
+ }
+}
+
+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(sizeof(*timer), GFP_KERNEL);
+ 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.%s_clocksource",
+ (unsigned long long)res.start, node->name);
+
+ scnprintf(timer->clockevent_name, sizeof(timer->clockevent_name),
+ "%llx.%s_clockevent",
+ (unsigned long long)res.start, node->name);
+
+ if (timer->interrupt_regs && irqnr) {
+ timer->clkevt.name = timer->clockevent_name;
+ timer->clkevt.set_next_event = zevio_timer_set_event;
+ timer->clkevt.set_mode = zevio_timer_set_mode;
+ timer->clkevt.rating = 200;
+ timer->clkevt.cpumask = cpu_all_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));
+
+ timer->clkevt_irq.name = timer->clockevent_name;
+ timer->clkevt_irq.handler = zevio_timer_interrupt;
+ timer->clkevt_irq.dev_id = timer;
+ timer->clkevt_irq.flags = IRQF_TIMER | IRQF_IRQPOLL;
+
+ setup_irq(irqnr, &timer->clkevt_irq);
+
+ 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;
+}
+
+CLOCKSOURCE_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_add);