From mboxrd@z Thu Jan 1 00:00:00 1970 From: Addy Subject: Re: [PATCH] ARM: dts: Switch i2c0 to 400kHz on rk3288-evb-rk808 Date: Thu, 11 Sep 2014 17:17:58 +0800 Message-ID: <541168C6.2090603@rock-chips.com> References: <1410409815-22200-1-git-send-email-dianders@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1410409815-22200-1-git-send-email-dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Doug Anderson , Heiko Stuebner Cc: Chris Zhong , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 11 Sep 2014 12:30, Doug Anderson writes: > We should be able to talk to the PMIC at 400kHz. No need to talk at > the slow 100kHz. > > As measured by ftrace (with a bunch of extra patches, since cpufreq > for rk808 hasn't landed yet): > before this change: cpu0_set_target() => ~500us > after this change: cpu0_set_target() => ~300us > > Signed-off-by: Doug Anderson > --- > arch/arm/boot/dts/rk3288-evb-rk808.dts | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/boot/dts/rk3288-evb-rk808.dts b/arch/arm/boot/dts/rk3288-evb-rk808.dts > index 36db177..ff522f8 100644 > --- a/arch/arm/boot/dts/rk3288-evb-rk808.dts > +++ b/arch/arm/boot/dts/rk3288-evb-rk808.dts > @@ -18,6 +18,7 @@ > }; > > &i2c0 { > + clock-frequency = <400000>; > status = "okay"; > > rk808: pmic@1b { I have tested on rk3288-pinky board, it work well. so Reviewed-by Addy Ke Tested-by Addy Ke -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html