From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-la0-x234.google.com ([2a00:1450:4010:c03::234]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XyG6z-000858-Ct for barebox@lists.infradead.org; Tue, 09 Dec 2014 08:25:39 +0000 Received: by mail-la0-f52.google.com with SMTP id hs14so76575lab.25 for ; Tue, 09 Dec 2014 00:25:13 -0800 (PST) Date: Tue, 9 Dec 2014 12:26:52 +0400 From: Antony Pavlov Message-Id: <20141209122652.3774fea9bd46bf5c6e13dbfc@gmail.com> In-Reply-To: <1417478608-11670-1-git-send-email-antonynpavlov@gmail.com> References: <1417478608-11670-1-git-send-email-antonynpavlov@gmail.com> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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: Sascha Hauer Cc: barebox@lists.infradead.org On Tue, 2 Dec 2014 03:03:28 +0300 Antony Pavlov wrote: ping > 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(-) > = > 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 +=3D CONFIG_CLOCKSOURCE_DUMMY_RATE; > + > + return dummy_counter; > + } > = > /* read clocksource: */ > cycle_now =3D 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 initializ= ed. > + WARNING!!! Built-in software-only clocksource doesn't provide cor= rect timing. > + The option CONFIG_CLOCKSOURCE_DUMMY_RATE is used to adjust this clock= source. > 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-$(CONFIG_ARM_SMP_TWD) +=3D arm_smp_twd.o > obj-$(CONFIG_CLOCKSOURCE_BCM2835) +=3D bcm2835.o > obj-$(CONFIG_CLOCKSOURCE_CLPS711X) +=3D clps711x.o > obj-$(CONFIG_CLOCKSOURCE_DIGIC) +=3D digic.o > -obj-$(CONFIG_CLOCKSOURCE_DUMMY) +=3D dummy.o > obj-$(CONFIG_CLOCKSOURCE_MVEBU) +=3D mvebu.o > obj-$(CONFIG_CLOCKSOURCE_NOMADIK) +=3D nomadik.o > obj-$(CONFIG_CLOCKSOURCE_ORION) +=3D 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 =3D 1; > - } > - > - dummy_counter +=3D CONFIG_CLOCKSOURCE_DUMMY_RATE; > - > - return dummy_counter; > -} > - > -static struct clocksource dummy_cs =3D { > - .read =3D dummy_cs_read, > - .mask =3D CLOCKSOURCE_MASK(32), > -}; > - > -static int clocksource_init(void) > -{ > - dummy_counter =3D 0; > - > - clocks_calc_mult_shift(&dummy_cs.mult, &dummy_cs.shift, > - 100000000, NSEC_PER_SEC, 10); > - > - pr_debug("clocksource_init: mult=3D%08x, shift=3D%08x\n", > - dummy_cs.mult, dummy_cs.shift); > - > - return init_clock(&dummy_cs); > -} > -pure_initcall(clocksource_init); > -- = > 2.1.3 > = -- = --=A0 Best regards, =A0 Antony Pavlov _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox