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authorAntony Pavlov <antonynpavlov@gmail.com>2014-12-02 03:03:28 +0300
committerSascha Hauer <s.hauer@pengutronix.de>2014-12-17 12:15:11 +0100
commitfbb3be384548b1ded9ebcc4a4b45ff57bd2f38a1 (patch)
tree16a452bed34cb2adaac0fca3efda7bb3b13a2be6
parent704f59fe652bfca0d649390956530cb3ae43db24 (diff)
downloadbarebox-fbb3be384548b1ded9ebcc4a4b45ff57bd2f38a1.tar.gz
clock: incorporate dummy clocksource into core clock code
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
-rw-r--r--common/clock.c20
-rw-r--r--drivers/clocksource/Kconfig27
-rw-r--r--drivers/clocksource/Makefile1
-rw-r--r--drivers/clocksource/dummy.c55
4 files changed, 28 insertions, 75 deletions
diff --git a/common/clock.c b/common/clock.c
index 2ee81da..35c9e6c 100644
--- a/common/clock.c
+++ b/common/clock.c
@@ -22,6 +22,7 @@
*/
#include <common.h>
+#include <init.h>
#include <asm-generic/div64.h>
#include <clock.h>
#include <poller.h>
@@ -35,6 +36,16 @@ static uint64_t time_ns;
*/
uint64_t time_beginning;
+static int dummy_csrc_warn(void)
+{
+ if (!current_clock) {
+ pr_warn("Warning: Using dummy clocksource\n");
+ }
+
+ return 0;
+}
+late_initcall(dummy_csrc_warn);
+
/**
* get_time_ns - get current timestamp in nanoseconds
*/
@@ -44,8 +55,13 @@ uint64_t get_time_ns(void)
uint64_t cycle_now, cycle_delta;
uint64_t ns_offset;
- if (!cs)
- return 0;
+ if (!cs) {
+ static uint64_t dummy_counter;
+
+ dummy_counter += CONFIG_CLOCKSOURCE_DUMMY_RATE;
+
+ return dummy_counter;
+ }
/* read clocksource: */
cycle_now = cs->read() & cs->mask;
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index fc5a389..598edc9 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -18,28 +18,21 @@ config CLOCKSOURCE_DIGIC
bool
depends on ARCH_DIGIC
-config CLOCKSOURCE_DUMMY
- bool "Enable dummy software-only clocksource"
+config CLOCKSOURCE_DUMMY_RATE
+ int
+ prompt "dummy clocksource rate"
+ default 1000
help
When porting barebox to a new SoC there might be a case
of broken or absent clocksource. This causes barebox serial
console to be non functional.
- To solve the problem this software-only clocksource driver is used.
- WARNING!!! This clocksource doesn't provide correct timing.
- To adjust this clocksource please use CONFIG_CLOCKSOURCE_DUMMY_RATE.
+ To solve the problem barebox has built-in software-only clocksource.
+ The software-only clocksource is used only if no hardware clocksource
+ is registered. This can help if initialization order is wrong so that
+ the time functions are used before the real clocksource was initialized.
+ WARNING!!! Built-in software-only clocksource doesn't provide correct timing.
+ The option CONFIG_CLOCKSOURCE_DUMMY_RATE is used to adjust this clocksource.
The bigger rate valuest makes clocksource "faster".
- It's possible to add this clocksource unconditionally.
- This clocksource starts very early (pure_initcall) so
- real clocksource will take over.
- This can help if initialization order is wrong so that
- the time functions are used before the real clocksource
- was initialized.
-
-config CLOCKSOURCE_DUMMY_RATE
- int
- prompt "dummy clocksource rate"
- depends on CLOCKSOURCE_DUMMY
- default 1000
config CLOCKSOURCE_MVEBU
bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index b80df6b..f5f5141 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -3,7 +3,6 @@ obj-$(CONFIG_ARM_SMP_TWD) += arm_smp_twd.o
obj-$(CONFIG_CLOCKSOURCE_BCM2835) += bcm2835.o
obj-$(CONFIG_CLOCKSOURCE_CLPS711X) += clps711x.o
obj-$(CONFIG_CLOCKSOURCE_DIGIC) += digic.o
-obj-$(CONFIG_CLOCKSOURCE_DUMMY) += dummy.o
obj-$(CONFIG_CLOCKSOURCE_MVEBU) += mvebu.o
obj-$(CONFIG_CLOCKSOURCE_NOMADIK) += nomadik.o
obj-$(CONFIG_CLOCKSOURCE_ORION) += orion.o
diff --git a/drivers/clocksource/dummy.c b/drivers/clocksource/dummy.c
deleted file mode 100644
index 96f9b6e..0000000
--- a/drivers/clocksource/dummy.c
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright (C) 2013 Antony Pavlov <antonynpavlov@gmail.com>
- *
- * This file is part of barebox.
- * See file CREDITS for list of people who contributed to this project.
- *
- * 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.
- *
- */
-
-#include <common.h>
-#include <init.h>
-#include <clock.h>
-
-static uint64_t dummy_counter;
-
-static uint64_t dummy_cs_read(void)
-{
- static int first;
-
- if (!first) {
- pr_warn("Warning: Using dummy clocksource\n");
- first = 1;
- }
-
- dummy_counter += CONFIG_CLOCKSOURCE_DUMMY_RATE;
-
- return dummy_counter;
-}
-
-static struct clocksource dummy_cs = {
- .read = dummy_cs_read,
- .mask = CLOCKSOURCE_MASK(32),
-};
-
-static int clocksource_init(void)
-{
- dummy_counter = 0;
-
- clocks_calc_mult_shift(&dummy_cs.mult, &dummy_cs.shift,
- 100000000, NSEC_PER_SEC, 10);
-
- pr_debug("clocksource_init: mult=%08x, shift=%08x\n",
- dummy_cs.mult, dummy_cs.shift);
-
- return init_clock(&dummy_cs);
-}
-pure_initcall(clocksource_init);