summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-nomadik/timer.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-14 17:48:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-14 17:48:14 -0700
commit2ca7d674d7ab2220707b2ada0b690c0e7c95e7ac (patch)
tree9c0927ed1d540e5fd704c1f82689870786514655 /arch/arm/mach-nomadik/timer.c
parent2195d2818c37bdf263865f1e9effccdd9fc5f9d4 (diff)
parent87d721ad7a37b7650dd710c88dd5c6a5bf9fe996 (diff)
downloadop-kernel-dev-2ca7d674d7ab2220707b2ada0b690c0e7c95e7ac.zip
op-kernel-dev-2ca7d674d7ab2220707b2ada0b690c0e7c95e7ac.tar.gz
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (257 commits) [ARM] Update mach-types ARM: 5636/1: Move vendor enum to AMBA include ARM: Fix pfn_valid() for sparse memory [ARM] orion5x: Add LaCie NAS 2Big Network support [ARM] pxa/sharpsl_pm: zaurus c3000 aka spitz: fix resume ARM: 5686/1: at91: Correct AC97 reset line in at91sam9263ek board ARM: 5640/1: This patch modifies the support of AC97 on the at91sam9263 ek board ARM: 5689/1: Update default config of HP Jornada 700-series machines ARM: 5691/1: fix cache aliasing issues between kmap() and kmap_atomic() with highmem ARM: 5688/1: ks8695_serial: disable_irq() lockup ARM: 5687/1: fix an oops with highmem ARM: 5684/1: Add nuc960 platform to w90x900 ARM: 5683/1: Add nuc950 platform to w90x900 ARM: 5682/1: Add cpu.c and dev.c and modify some files of w90p910 platform ARM: 5626/1: add suspend/resume functions to amba-pl011 serial driver ARM: 5625/1: fix hard coded 4K resource size in amba bus detection MMC: MMCI: convert realview MMC to use gpiolib ARM: 5685/1: Make MMCI driver compile without gpiolib ARM: implement highpte ARM: Show FIQ in /proc/interrupts on CONFIG_FIQ ... Fix up trivial conflict in arch/arm/kernel/signal.c. It was due to the TIF_NOTIFY_RESUME addition in commit d0420c83f ("KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures") and follow-ups.
Diffstat (limited to 'arch/arm/mach-nomadik/timer.c')
-rw-r--r--arch/arm/mach-nomadik/timer.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/arch/arm/mach-nomadik/timer.c b/arch/arm/mach-nomadik/timer.c
new file mode 100644
index 0000000..d1738e7
--- /dev/null
+++ b/arch/arm/mach-nomadik/timer.c
@@ -0,0 +1,164 @@
+/*
+ * linux/arch/arm/mach-nomadik/timer.c
+ *
+ * Copyright (C) 2008 STMicroelectronics
+ * Copyright (C) 2009 Alessandro Rubini, somewhat based on at91sam926x
+ *
+ * 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/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/clockchips.h>
+#include <linux/jiffies.h>
+#include <asm/mach/time.h>
+#include <mach/mtu.h>
+
+#define TIMER_CTRL 0x80 /* No divisor */
+#define TIMER_PERIODIC 0x40
+#define TIMER_SZ32BIT 0x02
+
+/* Initial value for SRC control register: all timers use MXTAL/8 source */
+#define SRC_CR_INIT_MASK 0x00007fff
+#define SRC_CR_INIT_VAL 0x2aaa8000
+
+static u32 nmdk_count; /* accumulated count */
+static u32 nmdk_cycle; /* write-once */
+static __iomem void *mtu_base;
+
+/*
+ * clocksource: the MTU device is a decrementing counters, so we negate
+ * the value being read.
+ */
+static cycle_t nmdk_read_timer(struct clocksource *cs)
+{
+ u32 count = readl(mtu_base + MTU_VAL(0));
+ return nmdk_count + nmdk_cycle - count;
+
+}
+
+static struct clocksource nmdk_clksrc = {
+ .name = "mtu_0",
+ .rating = 120,
+ .read = nmdk_read_timer,
+ .shift = 20,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
+ * Clockevent device: currently only periodic mode is supported
+ */
+static void nmdk_clkevt_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev)
+{
+ unsigned long flags;
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ /* enable interrupts -- and count current value? */
+ raw_local_irq_save(flags);
+ writel(readl(mtu_base + MTU_IMSC) | 1, mtu_base + MTU_IMSC);
+ raw_local_irq_restore(flags);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ BUG(); /* Not supported, yet */
+ /* FALLTHROUGH */
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ /* disable irq */
+ raw_local_irq_save(flags);
+ writel(readl(mtu_base + MTU_IMSC) & ~1, mtu_base + MTU_IMSC);
+ raw_local_irq_restore(flags);
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+}
+
+static struct clock_event_device nmdk_clkevt = {
+ .name = "mtu_0",
+ .features = CLOCK_EVT_FEAT_PERIODIC,
+ .shift = 32,
+ .rating = 100,
+ .set_mode = nmdk_clkevt_mode,
+};
+
+/*
+ * IRQ Handler for the timer 0 of the MTU block. The irq is not shared
+ * as we are the only users of mtu0 by now.
+ */
+static irqreturn_t nmdk_timer_interrupt(int irq, void *dev_id)
+{
+ /* ack: "interrupt clear register" */
+ writel( 1 << 0, mtu_base + MTU_ICR);
+
+ /* we can't count lost ticks, unfortunately */
+ nmdk_count += nmdk_cycle;
+ nmdk_clkevt.event_handler(&nmdk_clkevt);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Set up timer interrupt, and return the current time in seconds.
+ */
+static struct irqaction nmdk_timer_irq = {
+ .name = "Nomadik Timer Tick",
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .handler = nmdk_timer_interrupt,
+};
+
+static void nmdk_timer_reset(void)
+{
+ u32 cr;
+
+ writel(0, mtu_base + MTU_CR(0)); /* off */
+
+ /* configure load and background-load, and fire it up */
+ writel(nmdk_cycle, mtu_base + MTU_LR(0));
+ writel(nmdk_cycle, mtu_base + MTU_BGLR(0));
+ cr = MTU_CRn_PERIODIC | MTU_CRn_PRESCALE_1 | MTU_CRn_32BITS;
+ writel(cr, mtu_base + MTU_CR(0));
+ writel(cr | MTU_CRn_ENA, mtu_base + MTU_CR(0));
+}
+
+static void __init nmdk_timer_init(void)
+{
+ u32 src_cr;
+ unsigned long rate;
+ int bits;
+
+ rate = CLOCK_TICK_RATE; /* 2.4MHz */
+ nmdk_cycle = (rate + HZ/2) / HZ;
+
+ /* Configure timer sources in "system reset controller" ctrl reg */
+ src_cr = readl(io_p2v(NOMADIK_SRC_BASE));
+ src_cr &= SRC_CR_INIT_MASK;
+ src_cr |= SRC_CR_INIT_VAL;
+ writel(src_cr, io_p2v(NOMADIK_SRC_BASE));
+
+ /* Save global pointer to mtu, used by functions above */
+ mtu_base = io_p2v(NOMADIK_MTU0_BASE);
+
+ /* Init the timer and register clocksource */
+ nmdk_timer_reset();
+
+ nmdk_clksrc.mult = clocksource_hz2mult(rate, nmdk_clksrc.shift);
+ bits = 8*sizeof(nmdk_count);
+ nmdk_clksrc.mask = CLOCKSOURCE_MASK(bits);
+
+ clocksource_register(&nmdk_clksrc);
+
+ /* Register irq and clockevents */
+ setup_irq(IRQ_MTU0, &nmdk_timer_irq);
+ nmdk_clkevt.mult = div_sc(rate, NSEC_PER_SEC, nmdk_clkevt.shift);
+ nmdk_clkevt.cpumask = cpumask_of(0);
+ clockevents_register_device(&nmdk_clkevt);
+}
+
+struct sys_timer nomadik_timer = {
+ .init = nmdk_timer_init,
+};
OpenPOWER on IntegriCloud