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authorDaniel Vetter <daniel.vetter@ffwll.ch>2012-08-17 08:57:56 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2012-08-17 09:01:08 +0200
commita22ddff8bedfe33eeb1330bbb7ef1fbe007a42c4 (patch)
tree61a2eb7fa62f5af10c2b913ca429e6b068b0eb2d /arch/arm/lib/delay.c
parent20d5a540e55a29daeef12706f9ee73baf5641c16 (diff)
parentd9875690d9b89a866022ff49e3fcea892345ad92 (diff)
Merge tag 'v3.6-rc2' into drm-intel-next
Backmerge Linux 3.6-rc2 to resolve a few funny conflicts before we put even more madness on top: - drivers/gpu/drm/i915/i915_irq.c: Just a spurious WARN removed in -fixes, that has been changed in a variable-rename in -next, too. - drivers/gpu/drm/i915/intel_ringbuffer.c: -next remove scratch_addr (since all their users have been extracted in another fucntion), -fixes added another user for a hw workaroudn. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'arch/arm/lib/delay.c')
-rw-r--r--arch/arm/lib/delay.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c
new file mode 100644
index 000000000000..d6dacc69254e
--- /dev/null
+++ b/arch/arm/lib/delay.c
@@ -0,0 +1,71 @@
+/*
+ * Delay loops based on the OpenRISC implementation.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/timex.h>
+
+/*
+ * Default to the loop-based delay implementation.
+ */
+struct arm_delay_ops arm_delay_ops = {
+ .delay = __loop_delay,
+ .const_udelay = __loop_const_udelay,
+ .udelay = __loop_udelay,
+};
+
+#ifdef ARCH_HAS_READ_CURRENT_TIMER
+static void __timer_delay(unsigned long cycles)
+{
+ cycles_t start = get_cycles();
+
+ while ((get_cycles() - start) < cycles)
+ cpu_relax();
+}
+
+static void __timer_const_udelay(unsigned long xloops)
+{
+ unsigned long long loops = xloops;
+ loops *= loops_per_jiffy;
+ __timer_delay(loops >> UDELAY_SHIFT);
+}
+
+static void __timer_udelay(unsigned long usecs)
+{
+ __timer_const_udelay(usecs * UDELAY_MULT);
+}
+
+void __init init_current_timer_delay(unsigned long freq)
+{
+ pr_info("Switching to timer-based delay loop\n");
+ lpj_fine = freq / HZ;
+ arm_delay_ops.delay = __timer_delay;
+ arm_delay_ops.const_udelay = __timer_const_udelay;
+ arm_delay_ops.udelay = __timer_udelay;
+}
+
+unsigned long __cpuinit calibrate_delay_is_known(void)
+{
+ return lpj_fine;
+}
+#endif