From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olliver Schinagl Subject: Re: [PATCH] i2c: mv64xxx: The n clockdiv factor is 0 based on sunxi SoCs Date: Thu, 01 Oct 2015 20:51:59 +0200 Message-ID: <560D80CF.6050500@schinagl.nl> References: <1443365828-8956-1-git-send-email-hdegoede@redhat.com> <560813CF.4000807@schinagl.nl> <20150929120943.GP7104@lukather> Reply-To: oliver+list-dxLnbx3+1qmEVqv0pETR8A@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Return-path: In-Reply-To: <20150929120943.GP7104@lukather> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Maxime Ripard Cc: hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Wolfram Sang , Thomas Petazzoni , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org List-Id: linux-i2c@vger.kernel.org Hey Maxime, On 29-09-15 14:09, Maxime Ripard wrote: > On Sun, Sep 27, 2015 at 06:05:35PM +0200, Olliver Schinagl wrote: >> Hey Hans, >> >> On 27-09-15 16:57, Hans de Goede wrote: >>> According to the datasheets to n factor for dividing the tclk is >>> 2 to the power n on Allwinner SoCs, not 2 to the power n + 1 as it is >>> on other mv64xxx implementations. >> Ah! >>> I've contacted Allwinner about this and they have confirmed that the >>> datasheet is correct. >>> >>> This commit fixes the clk-divider calculations for Allwinner SoCs >>> accordingly. >> So this explains why all my i2c frequenties are double of what I setup. >> Thanks for taking the time of figuring it out! I'll give it a test hopefully >> soon. > It would have been great to let us know... If your talking about past tence, I actually did ;) [0][1] and I actually had a tree made ready just 3 weeks ago with 3.15 to start my bisection with. It seemed logical to see if it worked there as that was the first iteration (based on the sunxi/allwinner based tree before the mv migration. Anyway, I even built tried to build the kernel! but my gcc failed to build it so i put it on the back-burner for a while. WIth Hans having figured it out and fixing it, I'll absolutly will take a nother look and check with a scope if it all works out now. Olliver [0] http://irclog.whitequark.org/linux-sunxi/2015-01-16#11522114; [1] http://s24.postimg.org/yiykh6kkl/DS1_Z_Quick_Print2.png > Maxime > From mboxrd@z Thu Jan 1 00:00:00 1970 From: oliver+list@schinagl.nl (Olliver Schinagl) Date: Thu, 01 Oct 2015 20:51:59 +0200 Subject: [linux-sunxi] [PATCH] i2c: mv64xxx: The n clockdiv factor is 0 based on sunxi SoCs In-Reply-To: <20150929120943.GP7104@lukather> References: <1443365828-8956-1-git-send-email-hdegoede@redhat.com> <560813CF.4000807@schinagl.nl> <20150929120943.GP7104@lukather> Message-ID: <560D80CF.6050500@schinagl.nl> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hey Maxime, On 29-09-15 14:09, Maxime Ripard wrote: > On Sun, Sep 27, 2015 at 06:05:35PM +0200, Olliver Schinagl wrote: >> Hey Hans, >> >> On 27-09-15 16:57, Hans de Goede wrote: >>> According to the datasheets to n factor for dividing the tclk is >>> 2 to the power n on Allwinner SoCs, not 2 to the power n + 1 as it is >>> on other mv64xxx implementations. >> Ah! >>> I've contacted Allwinner about this and they have confirmed that the >>> datasheet is correct. >>> >>> This commit fixes the clk-divider calculations for Allwinner SoCs >>> accordingly. >> So this explains why all my i2c frequenties are double of what I setup. >> Thanks for taking the time of figuring it out! I'll give it a test hopefully >> soon. > It would have been great to let us know... If your talking about past tence, I actually did ;) [0][1] and I actually had a tree made ready just 3 weeks ago with 3.15 to start my bisection with. It seemed logical to see if it worked there as that was the first iteration (based on the sunxi/allwinner based tree before the mv migration. Anyway, I even built tried to build the kernel! but my gcc failed to build it so i put it on the back-burner for a while. WIth Hans having figured it out and fixing it, I'll absolutly will take a nother look and check with a scope if it all works out now. Olliver [0] http://irclog.whitequark.org/linux-sunxi/2015-01-16#11522114; [1] http://s24.postimg.org/yiykh6kkl/DS1_Z_Quick_Print2.png > Maxime >