From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Y1CaB-0001b0-17 for barebox@lists.infradead.org; Wed, 17 Dec 2014 11:15:55 +0000 Date: Wed, 17 Dec 2014 12:15:32 +0100 From: Sascha Hauer Message-ID: <20141217111532.GU14482@pengutronix.de> References: <1417478608-11670-1-git-send-email-antonynpavlov@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1417478608-11670-1-git-send-email-antonynpavlov@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [RFC] clock: incorporate dummy clocksource into core clock code To: Antony Pavlov Cc: barebox@lists.infradead.org On Tue, Dec 02, 2014 at 03:03:28AM +0300, Antony Pavlov wrote: > Signed-off-by: Antony Pavlov > --- > common/clock.c | 20 ++++++++++++++-- > drivers/clocksource/Kconfig | 27 ++++++++-------------- > drivers/clocksource/Makefile | 1 - > drivers/clocksource/dummy.c | 55 -------------------------------------------- > 4 files changed, 28 insertions(+), 75 deletions(-) Applied, thanks Sascha > > 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 > +#include > #include > #include > #include > @@ -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 > - * > - * 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 > -#include > -#include > - > -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); > -- > 2.1.3 > > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox