#ifndef __ASM_ARM_DELAY_H
#define __ASM_ARM_DELAY_H
+#include <asm/memory.h>
#include <asm/param.h> /* HZ */
-extern void __delay(int loops);
+#define MAX_UDELAY_MS 2
+#define UDELAY_MULT ((UL(2199023) * HZ) >> 11)
+#define UDELAY_SHIFT 30
+
+#ifndef __ASSEMBLY__
+
+extern struct arm_delay_ops {
+ void (*delay)(unsigned long);
+ void (*const_udelay)(unsigned long);
+ void (*udelay)(unsigned long);
+} arm_delay_ops;
+
+#define __delay(n) arm_delay_ops.delay(n)
/*
* This function intentionally does not exist; if you see references to
* division by multiplication: you don't have to worry about
* loss of precision.
*
- * Use only for very small delays ( < 1 msec). Should probably use a
+ * Use only for very small delays ( < 2 msec). Should probably use a
* lookup table, really, as the multiplications take much too long with
* short delays. This is a "reasonable" implementation, though (and the
* first constant multiplications gets optimized away if the delay is
* a constant)
*/
-extern void __udelay(unsigned long usecs);
-extern void __const_udelay(unsigned long);
-
-#define MAX_UDELAY_MS 2
+#define __udelay(n) arm_delay_ops.udelay(n)
+#define __const_udelay(n) arm_delay_ops.const_udelay(n)
#define udelay(n) \
(__builtin_constant_p(n) ? \
((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \
- __const_udelay((n) * ((2199023U*HZ)>>11))) : \
+ __const_udelay((n) * UDELAY_MULT)) : \
__udelay(n))
+/* Loop-based definitions for assembly code. */
+extern void __loop_delay(unsigned long loops);
+extern void __loop_udelay(unsigned long usecs);
+extern void __loop_const_udelay(unsigned long);
+
+#endif /* __ASSEMBLY__ */
+
#endif /* defined(_ARM_DELAY_H) */
static struct clock_event_device __percpu **arch_timer_evt;
+extern void init_current_timer_delay(unsigned long freq);
+
/*
* Architected system timer support.
*/
if (err)
goto out_free_irq;
+ init_current_timer_delay(arch_timer_rate);
return 0;
out_free_irq:
extern void fpundefinstr(void);
/* platform dependent support */
-EXPORT_SYMBOL(__udelay);
-EXPORT_SYMBOL(__const_udelay);
+EXPORT_SYMBOL(arm_delay_ops);
/* networking */
EXPORT_SYMBOL(csum_partial);
lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \
csumpartialcopy.o csumpartialcopyuser.o clearbit.o \
- delay.o findbit.o memchr.o memcpy.o \
+ delay.o delay-loop.o findbit.o memchr.o memcpy.o \
memmove.o memset.o memzero.o setbit.o \
strncpy_from_user.o strnlen_user.o \
strchr.o strrchr.o \
--- /dev/null
+/*
+ * linux/arch/arm/lib/delay.S
+ *
+ * Copyright (C) 1995, 1996 Russell King
+ *
+ * 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/linkage.h>
+#include <asm/assembler.h>
+#include <asm/delay.h>
+ .text
+
+.LC0: .word loops_per_jiffy
+.LC1: .word UDELAY_MULT
+
+/*
+ * r0 <= 2000
+ * lpj <= 0x01ffffff (max. 3355 bogomips)
+ * HZ <= 1000
+ */
+
+ENTRY(__loop_udelay)
+ ldr r2, .LC1
+ mul r0, r2, r0
+ENTRY(__loop_const_udelay) @ 0 <= r0 <= 0x7fffff06
+ mov r1, #-1
+ ldr r2, .LC0
+ ldr r2, [r2] @ max = 0x01ffffff
+ add r0, r0, r1, lsr #32-14
+ mov r0, r0, lsr #14 @ max = 0x0001ffff
+ add r2, r2, r1, lsr #32-10
+ mov r2, r2, lsr #10 @ max = 0x00007fff
+ mul r0, r2, r0 @ max = 2^32-1
+ add r0, r0, r1, lsr #32-6
+ movs r0, r0, lsr #6
+ moveq pc, lr
+
+/*
+ * loops = r0 * HZ * loops_per_jiffy / 1000000
+ */
+
+@ Delay routine
+ENTRY(__loop_delay)
+ subs r0, r0, #1
+#if 0
+ movls pc, lr
+ subs r0, r0, #1
+ movls pc, lr
+ subs r0, r0, #1
+ movls pc, lr
+ subs r0, r0, #1
+ movls pc, lr
+ subs r0, r0, #1
+ movls pc, lr
+ subs r0, r0, #1
+ movls pc, lr
+ subs r0, r0, #1
+ movls pc, lr
+ subs r0, r0, #1
+#endif
+ bhi __loop_delay
+ mov pc, lr
+ENDPROC(__loop_udelay)
+ENDPROC(__loop_const_udelay)
+ENDPROC(__loop_delay)
+++ /dev/null
-/*
- * linux/arch/arm/lib/delay.S
- *
- * Copyright (C) 1995, 1996 Russell King
- *
- * 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/linkage.h>
-#include <asm/assembler.h>
-#include <asm/param.h>
- .text
-
-.LC0: .word loops_per_jiffy
-.LC1: .word (2199023*HZ)>>11
-
-/*
- * r0 <= 2000
- * lpj <= 0x01ffffff (max. 3355 bogomips)
- * HZ <= 1000
- */
-
-ENTRY(__udelay)
- ldr r2, .LC1
- mul r0, r2, r0
-ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
- mov r1, #-1
- ldr r2, .LC0
- ldr r2, [r2] @ max = 0x01ffffff
- add r0, r0, r1, lsr #32-14
- mov r0, r0, lsr #14 @ max = 0x0001ffff
- add r2, r2, r1, lsr #32-10
- mov r2, r2, lsr #10 @ max = 0x00007fff
- mul r0, r2, r0 @ max = 2^32-1
- add r0, r0, r1, lsr #32-6
- movs r0, r0, lsr #6
- moveq pc, lr
-
-/*
- * loops = r0 * HZ * loops_per_jiffy / 1000000
- *
- * Oh, if only we had a cycle counter...
- */
-
-@ Delay routine
-ENTRY(__delay)
- subs r0, r0, #1
-#if 0
- movls pc, lr
- subs r0, r0, #1
- movls pc, lr
- subs r0, r0, #1
- movls pc, lr
- subs r0, r0, #1
- movls pc, lr
- subs r0, r0, #1
- movls pc, lr
- subs r0, r0, #1
- movls pc, lr
- subs r0, r0, #1
- movls pc, lr
- subs r0, r0, #1
-#endif
- bhi __delay
- mov pc, lr
-ENDPROC(__udelay)
-ENDPROC(__const_udelay)
-ENDPROC(__delay)
--- /dev/null
+/*
+ * 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
orr r4, r4, #MDREFR_K1DB2
ldr r5, =PPCR
- @ Pre-load __udelay into the I-cache
+ @ Pre-load __loop_udelay into the I-cache
mov r0, #1
- bl __udelay
+ bl __loop_udelay
mov r0, r0
@ The following must all exist in a single cache line to
@ delay 90us and set CPU PLL to lowest speed
@ fixes resume problem on high speed SA1110
mov r0, #90
- bl __udelay
+ bl __loop_udelay
mov r1, #0
str r1, [r5]
mov r0, #90
- bl __udelay
+ bl __loop_udelay
/*
* SA1110 SDRAM controller workaround. register values:
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff