Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753534Ab1BVIAd (ORCPT ); Tue, 22 Feb 2011 03:00:33 -0500 Received: from smtp-out.google.com ([74.125.121.67]:37217 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751944Ab1BVIAb convert rfc822-to-8bit (ORCPT ); Tue, 22 Feb 2011 03:00:31 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=kgqpyKV79Ifz2F5u7jkxniVLKw2zBZ37bya0A2oxljjZluRMMPZLNSHs0UXGuQo/Ue dQI4lGEG+FcLpWG6JMXA== MIME-Version: 1.0 In-Reply-To: References: <1298342392-21236-1-git-send-email-ccross@android.com> <1298342392-21236-6-git-send-email-ccross@android.com> Date: Tue, 22 Feb 2011 00:00:25 -0800 X-Google-Sender-Auth: hMis9uTpOgBa8b6vqrOG3zdSdBY Message-ID: Subject: Re: [PATCH 5/7] ARM: tegra: timer: Enable timer and rtc clocks From: Colin Cross To: Olof Johansson Cc: linux-tegra@vger.kernel.org, konkers@android.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mike@compulab.co.il, Russell King Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2004 Lines: 57 On Mon, Feb 21, 2011 at 9:32 PM, Olof Johansson wrote: > Hi, > > > On Mon, Feb 21, 2011 at 6:39 PM, Colin Cross wrote: >> Enable the timer and rtc clocks to prevent them being >> turned off by the bootloader clock disabling code. >> >> Signed-off-by: Colin Cross >> --- >> ?arch/arm/mach-tegra/timer.c | ? 14 ++++++++++++-- >> ?1 files changed, 12 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c >> index ffa6a68..31b4f56 100644 >> --- a/arch/arm/mach-tegra/timer.c >> +++ b/arch/arm/mach-tegra/timer.c >> @@ -18,6 +18,7 @@ >> ?*/ >> >> ?#include >> +#include >> ?#include >> ?#include >> ?#include >> @@ -193,9 +194,20 @@ static struct irqaction tegra_timer_irq = { >> >> ?static void __init tegra_init_timer(void) >> ?{ >> + ? ? ? struct clk *clk; >> ? ? ? ?unsigned long rate = clk_measure_input_freq(); >> ? ? ? ?int ret; >> >> + ? ? ? clk = clk_get_sys("timer", NULL); >> + ? ? ? BUG_ON(IS_ERR(clk)); >> + ? ? ? clk_enable(clk); >> + ? ? ? clk_put(clk); >> + >> + ? ? ? clk = clk_get_sys("rtc-tegra", NULL); >> + ? ? ? BUG_ON(IS_ERR(clk)); >> + ? ? ? clk_enable(clk); >> + ? ? ? clk_put(clk); > > Why initialize the rtc clock here? Not all boards use it and instead > use the rtc on the pmic. Seems wasteful to clock it unless the driver > for it is probed and configured. timekeeping_suspend uses read_persistent_clock and not the RTC driver to track time in suspend. The Tegra implementation of read_persistent_clock reads from the internal RTC registers. Its a 32 kHz clock, so it's power usage is negligible, and it is required on all Tegra boards. -- 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/