Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161374AbaDPN4r (ORCPT ); Wed, 16 Apr 2014 09:56:47 -0400 Received: from mail-ve0-f180.google.com ([209.85.128.180]:49099 "EHLO mail-ve0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161077AbaDPN4p (ORCPT ); Wed, 16 Apr 2014 09:56:45 -0400 MIME-Version: 1.0 In-Reply-To: <1392138636-29240-5-git-send-email-pawel.moll@arm.com> References: <1392138636-29240-1-git-send-email-pawel.moll@arm.com> <1392138636-29240-5-git-send-email-pawel.moll@arm.com> Date: Wed, 16 Apr 2014 08:56:45 -0500 Message-ID: Subject: Re: [PATCH 04/12] clocksource: Sched clock source for Versatile Express From: Rob Herring To: Pawel Moll Cc: "arm@kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Thomas Gleixner , Daniel Lezcano , Linus Walleij Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adding Linus W... On Tue, Feb 11, 2014 at 11:10 AM, Pawel Moll wrote: > This patch adds a trival sched clock source using free > running, 24MHz clocked counter present in the ARM Ltd. > Versatile Express platform's System Registers block. > > This code replaces the call in the VE machine code. > > Cc: Daniel Lezcano > Cc: Thomas Gleixner > Signed-off-by: Pawel Moll > --- > arch/arm/mach-vexpress/v2m.c | 2 -- > drivers/clocksource/Kconfig | 9 +++++++++ > drivers/clocksource/Makefile | 1 + > drivers/clocksource/vexpress.c | 40 ++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 50 insertions(+), 2 deletions(-) > create mode 100644 drivers/clocksource/vexpress.c > > diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c > index 90f04c9..d8a9fd7 100644 > --- a/arch/arm/mach-vexpress/v2m.c > +++ b/arch/arm/mach-vexpress/v2m.c > @@ -418,8 +418,6 @@ void __init v2m_dt_init_early(void) > pr_warning("vexpress: DT HBI (%x) is not matching " > "hardware (%x)!\n", dt_hbi, hbi); > } > - > - versatile_sched_clock_init(vexpress_get_24mhz_clock_base(), 24000000); > } > > > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig > index cd6950f..9799744 100644 > --- a/drivers/clocksource/Kconfig > +++ b/drivers/clocksource/Kconfig > @@ -140,3 +140,12 @@ config VF_PIT_TIMER > bool > help > Support for Period Interrupt Timer on Freescale Vybrid Family SoCs. > + > +config CLKSRC_VEXPRESS > + bool > + depends on MFD_VEXPRESS_SYSREG But you don't really depend on this... > + depends on GENERIC_SCHED_CLOCK I think this should be a select, not a depends. > + select CLKSRC_OF > + default y > + help > + Simple provider of sched clock on ARM Versatile Express platform. > diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile > index c7ca50a..1051a23 100644 > --- a/drivers/clocksource/Makefile > +++ b/drivers/clocksource/Makefile > @@ -37,3 +37,4 @@ obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o > obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o > obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o > obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o > +obj-$(CONFIG_CLKSRC_VEXPRESS) += vexpress.o > diff --git a/drivers/clocksource/vexpress.c b/drivers/clocksource/vexpress.c > new file mode 100644 > index 0000000..55b8ab4 > --- /dev/null > +++ b/drivers/clocksource/vexpress.c > @@ -0,0 +1,40 @@ > +/* > + * 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. > + * > + * Copyright (C) 2013 ARM Limited Did you write this last year? > + */ > + > +#include > +#include > +#include > +#include > + > +#define SYS_24MHZ 0x05c > + > +static void __iomem *vexpress_sys_24mhz; > + > +static u32 notrace vexpress_sys_24mhz_read(void) > +{ > + return readl(vexpress_sys_24mhz); > +} > + > +static void __init vexpress_sched_clock_init(struct device_node *node) > +{ > + void __iomem *base = of_iomap(node, 0); > + > + if (!base) > + return; > + > + vexpress_sys_24mhz = base + SYS_24MHZ; > + > + setup_sched_clock(vexpress_sys_24mhz_read, 32, 24000000); This frequency should come from a DT clock binding. You will have to fallback to 24MHz for backwards compatibility though. > +} Wouldn't this code work for Versatile and Realview ARM reference boards? Even the register offset is the same. > +CLOCKSOURCE_OF_DECLARE(vexpress, "arm,vexpress-sysreg", > + vexpress_sched_clock_init); > -- > 1.8.3.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/