summaryrefslogtreecommitdiffstats
path: root/drivers/clocksource
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-03-03 12:06:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-03 12:06:09 -0800
commit8fd5e7a2d9574b3cac1c9264ad1aed3b613ed6fe (patch)
tree5696f5d31c6c75b71bfc4852fb234b773e266cfe /drivers/clocksource
parent529e5fbcd8d3cb48cf824ac8fde91cc80a9e985f (diff)
parentc60ac31542e93499b58dcfc1e3f6550ba5b5728e (diff)
downloadop-kernel-dev-8fd5e7a2d9574b3cac1c9264ad1aed3b613ed6fe.zip
op-kernel-dev-8fd5e7a2d9574b3cac1c9264ad1aed3b613ed6fe.tar.gz
Merge tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag
Pull new ImgTec Meta architecture from James Hogan: "This adds core architecture support for Imagination's Meta processor cores, followed by some later miscellaneous arch/metag cleanups and fixes which I kept separate to ease review: - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture - A few fixes all over, particularly for symbol prefixes - A few privilege protection fixes - Several cleanups (setup.c includes, split out a lot of metag_ksyms.c) - Fix some missing exports - Convert hugetlb to use vm_unmapped_area() - Copy device tree to non-init memory - Provide dma_get_sgtable()" * tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits) metag: Provide dma_get_sgtable() metag: prom.h: remove declaration of metag_dt_memblock_reserve() metag: copy devicetree to non-init memory metag: cleanup metag_ksyms.c includes metag: move mm/init.c exports out of metag_ksyms.c metag: move usercopy.c exports out of metag_ksyms.c metag: move setup.c exports out of metag_ksyms.c metag: move kick.c exports out of metag_ksyms.c metag: move traps.c exports out of metag_ksyms.c metag: move irq enable out of irqflags.h on SMP genksyms: fix metag symbol prefix on crc symbols metag: hugetlb: convert to vm_unmapped_area() metag: export clear_page and copy_page metag: export metag_code_cache_flush_all metag: protect more non-MMU memory regions metag: make TXPRIVEXT bits explicit metag: kernel/setup.c: sort includes perf: Enable building perf tools for Meta metag: add boot time LNKGET/LNKSET check metag: add __init to metag_cache_probe() ...
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/Kconfig5
-rw-r--r--drivers/clocksource/Makefile1
-rw-r--r--drivers/clocksource/metag_generic.c198
3 files changed, 204 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index e920cbe..e507ab7 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -62,3 +62,8 @@ config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
config ARM_ARCH_TIMER
bool
+
+config CLKSRC_METAG_GENERIC
+ def_bool y if METAG
+ help
+ This option enables support for the Meta per-thread timers.
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 7d671b8..4d8283a 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -21,3 +21,4 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra20_timer.o
obj-$(CONFIG_VT8500_TIMER) += vt8500_timer.o
obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o
+obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o
diff --git a/drivers/clocksource/metag_generic.c b/drivers/clocksource/metag_generic.c
new file mode 100644
index 0000000..ade7513
--- /dev/null
+++ b/drivers/clocksource/metag_generic.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (C) 2005-2013 Imagination Technologies Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * Support for Meta per-thread timers.
+ *
+ * Meta hardware threads have 2 timers. The background timer (TXTIMER) is used
+ * as a free-running time base (hz clocksource), and the interrupt timer
+ * (TXTIMERI) is used for the timer interrupt (clock event). Both counters
+ * traditionally count at approximately 1MHz.
+ */
+
+#include <clocksource/metag_generic.h>
+#include <linux/cpu.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+
+#include <asm/clock.h>
+#include <asm/hwthread.h>
+#include <asm/core_reg.h>
+#include <asm/metag_mem.h>
+#include <asm/tbx.h>
+
+#define HARDWARE_FREQ 1000000 /* 1MHz */
+#define HARDWARE_DIV 1 /* divide by 1 = 1MHz clock */
+#define HARDWARE_TO_NS_SHIFT 10 /* convert ticks to ns */
+
+static unsigned int hwtimer_freq = HARDWARE_FREQ;
+static DEFINE_PER_CPU(struct clock_event_device, local_clockevent);
+static DEFINE_PER_CPU(char [11], local_clockevent_name);
+
+static int metag_timer_set_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ __core_reg_set(TXTIMERI, -delta);
+ return 0;
+}
+
+static void metag_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ /* We should disable the IRQ here */
+ break;
+
+ case CLOCK_EVT_MODE_PERIODIC:
+ case CLOCK_EVT_MODE_UNUSED:
+ WARN_ON(1);
+ break;
+ };
+}
+
+static cycle_t metag_clocksource_read(struct clocksource *cs)
+{
+ return __core_reg_get(TXTIMER);
+}
+
+static struct clocksource clocksource_metag = {
+ .name = "META",
+ .rating = 200,
+ .mask = CLOCKSOURCE_MASK(32),
+ .read = metag_clocksource_read,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static irqreturn_t metag_timer_interrupt(int irq, void *dummy)
+{
+ struct clock_event_device *evt = &__get_cpu_var(local_clockevent);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction metag_timer_irq = {
+ .name = "META core timer",
+ .handler = metag_timer_interrupt,
+ .flags = IRQF_TIMER | IRQF_IRQPOLL | IRQF_PERCPU,
+};
+
+unsigned long long sched_clock(void)
+{
+ unsigned long long ticks = __core_reg_get(TXTIMER);
+ return ticks << HARDWARE_TO_NS_SHIFT;
+}
+
+static void __cpuinit arch_timer_setup(unsigned int cpu)
+{
+ unsigned int txdivtime;
+ struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
+ char *name = per_cpu(local_clockevent_name, cpu);
+
+ txdivtime = __core_reg_get(TXDIVTIME);
+
+ txdivtime &= ~TXDIVTIME_DIV_BITS;
+ txdivtime |= (HARDWARE_DIV & TXDIVTIME_DIV_BITS);
+
+ __core_reg_set(TXDIVTIME, txdivtime);
+
+ sprintf(name, "META %d", cpu);
+ clk->name = name;
+ clk->features = CLOCK_EVT_FEAT_ONESHOT,
+
+ clk->rating = 200,
+ clk->shift = 12,
+ clk->irq = tbisig_map(TBID_SIGNUM_TRT),
+ clk->set_mode = metag_timer_set_mode,
+ clk->set_next_event = metag_timer_set_next_event,
+
+ clk->mult = div_sc(hwtimer_freq, NSEC_PER_SEC, clk->shift);
+ clk->max_delta_ns = clockevent_delta2ns(0x7fffffff, clk);
+ clk->min_delta_ns = clockevent_delta2ns(0xf, clk);
+ clk->cpumask = cpumask_of(cpu);
+
+ clockevents_register_device(clk);
+
+ /*
+ * For all non-boot CPUs we need to synchronize our free
+ * running clock (TXTIMER) with the boot CPU's clock.
+ *
+ * While this won't be accurate, it should be close enough.
+ */
+ if (cpu) {
+ unsigned int thread0 = cpu_2_hwthread_id[0];
+ unsigned long val;
+
+ val = core_reg_read(TXUCT_ID, TXTIMER_REGNUM, thread0);
+ __core_reg_set(TXTIMER, val);
+ }
+}
+
+static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (long)hcpu;
+
+ switch (action) {
+ case CPU_STARTING:
+ case CPU_STARTING_FROZEN:
+ arch_timer_setup(cpu);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata arch_timer_cpu_nb = {
+ .notifier_call = arch_timer_cpu_notify,
+};
+
+int __init metag_generic_timer_init(void)
+{
+ /*
+ * On Meta 2 SoCs, the actual frequency of the timer is based on the
+ * Meta core clock speed divided by an integer, so it is only
+ * approximately 1MHz. Calculating the real frequency here drastically
+ * reduces clock skew on these SoCs.
+ */
+#ifdef CONFIG_METAG_META21
+ hwtimer_freq = get_coreclock() / (metag_in32(EXPAND_TIMER_DIV) + 1);
+#endif
+ clocksource_register_hz(&clocksource_metag, hwtimer_freq);
+
+ setup_irq(tbisig_map(TBID_SIGNUM_TRT), &metag_timer_irq);
+
+ /* Configure timer on boot CPU */
+ arch_timer_setup(smp_processor_id());
+
+ /* Hook cpu boot to configure other CPU's timers */
+ register_cpu_notifier(&arch_timer_cpu_nb);
+
+ return 0;
+}
OpenPOWER on IntegriCloud