From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751591AbbLJCBV (ORCPT ); Wed, 9 Dec 2015 21:01:21 -0500 Received: from mailout3.samsung.com ([203.254.224.33]:46101 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750715AbbLJCBT (ORCPT ); Wed, 9 Dec 2015 21:01:19 -0500 MIME-version: 1.0 Content-type: text/plain; charset=utf-8 X-AuditID: cbfee691-f79766d0000012b6-71-5668dcdbc459 Content-transfer-encoding: 8BIT Message-id: <5668DCDB.8020609@samsung.com> Date: Thu, 10 Dec 2015 11:00:59 +0900 From: Chanwoo Choi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 To: Krzysztof Kozlowski , myungjoo.ham@samsung.com, kgene@kernel.org Cc: kyungmin.park@samsung.com, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, linux@arm.linux.org.uk, tjakobi@math.uni-bielefeld.de, linux.amoon@gmail.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v2 03/19] ARM: dts: Add DMC bus node for Exynos3250 References: <1449634091-1842-1-git-send-email-cw00.choi@samsung.com> <1449634091-1842-4-git-send-email-cw00.choi@samsung.com> <5668CADE.8090706@samsung.com> <5668D0B6.1030902@samsung.com> <5668D34B.1010602@samsung.com> In-reply-to: <5668D34B.1010602@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrPIsWRmVeSWpSXmKPExsWyRsSkWPf2nYwwgxsnNC3mHznHatH/ZiGr xblXKxktXr8wtOh//JrZ4mzTG3aLy7vmsFl87j3CaDHj/D4mi3Ubb7Fb3L7Ma7H0+kUmi9uN K9gsJkxfy2LRuvcIu0Xb6g+sDgIea+atYfRoae5h87jc18vksXPWXXaPlcu/sHlsWtXJ5vHv GLtH35ZVjB6fN8kFcEZx2aSk5mSWpRbp2yVwZaxeu5SlYKVUxZ8Xb5gbGD+KdDFyckgImEic u7SZCcIWk7hwbz1bFyMXh5DACkaJxZsWsMIUHVywmh0isZRR4vnv48wgCV4BQYkfk++xdDFy cDALyEscuZQNYapLTJmSC1H+gFFi+729LBDlWhL3Xs8EW8YioCpx89t1sDgbUHz/ixtsIL2i AhES3ScqQcIiAvESm15cBbuHWeAuk8TF90/YQBLCAu4Sx34dZ4JbcO72VkaQBKeAtsSu2TsY QRISAis5JJq372SE2CYg8W3yIbBDJQRkJTYdYIZ4TFLi4IobLBMYxWYheWcWwjuzEN5ZwMi8 ilE0tSC5oDgpvchUrzgxt7g0L10vOT93EyMw3k//ezZxB+P9A9aHGAU4GJV4eC+4pIcJsSaW FVfmHmI0BbphIrOUaHI+MKnklcQbGpsZWZiamBobmVuaKYnz6kj/DBYSSE8sSc1OTS1ILYov Ks1JLT7EyMTBKdXAWD7NqeFPVb3owtQj8v3Gx55LNzNNefifOY6h4aq679UViddZOS6fi+Mt PRzWEfnqez23yCyxVWkvDF6WLyzU1efewRxyIGL79/fPohgWB7Aez1Pd+z9b4mt/1nrn9X82 aJy1/aNnfCdt4tqol/HrXDc8dJhR97UvQyL7Vm4xc3HJ2QYv51wxJZbijERDLeai4kQAljny NPICAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrDKsWRmVeSWpSXmKPExsVy+t9jAd3bdzLCDN7MULKYf+Qcq0X/m4Ws FuderWS0eP3C0KL/8Wtmi7NNb9gtLu+aw2bxufcIo8WM8/uYLNZtvMVucfsyr8XS6xeZLG43 rmCzmDB9LYtF694j7BZtqz+wOgh4rJm3htGjpbmHzeNyXy+Tx85Zd9k9Vi7/wuaxaVUnm8e/ Y+wefVtWMXp83iQXwBnVwGiTkZqYklqkkJqXnJ+SmZduq+QdHO8cb2pmYKhraGlhrqSQl5ib aqvk4hOg65aZA/SFkkJZYk4pUCggsbhYSd8O04TQEDddC5jGCF3fkCC4HiMDNJCwhjFj9dql LAUrpSr+vHjD3MD4UaSLkZNDQsBE4uCC1ewQtpjEhXvr2boYuTiEBJYySjz/fZwZJMErICjx Y/I9li5GDg5mAXmJI5eyIUx1iSlTciHKHzBKbL+3lwWiXEvi3uuZTCA2i4CqxM1v18HibEDx /S9usIH0igpESHSfqAQJiwjES2x6cRVsLbPAXSaJi++fsIEkhAXcJY79Os4Et+Dc7a2MIAlO AW2JXbN3ME5gFJiF5LxZCOfNQjhvASPzKkaJ1ILkguKk9FzDvNRyveLE3OLSvHS95PzcTYzg lPJMagfjwV3uhxgFOBiVeHgvuKSHCbEmlhVX5h5ilOBgVhLh7bqVESbEm5JYWZValB9fVJqT WnyI0RTov4nMUqLJ+cB0l1cSb2hsYmZkaWRuaGFkbK4kzlt7KTJMSCA9sSQ1OzW1ILUIpo+J g1OqgbGnQr8xbZa+RFTe3i1hL67XiXbM9bxX8JO7xobfITE5+3dj4Ka5S11/pUYm/tZOc5So S/o/vXrf3y8eSsVTOzbbls9umfVOlqHu4pTzktbWPGH87N+3Vn9PfXySy5Up4rhY8bcJvWJH 3ezeHQtblWuZuqfoUefqhHV97L3ejCWh3YtryrNFlFiKMxINtZiLihMBpdBq/z8DAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015년 12월 10일 10:20, Krzysztof Kozlowski wrote: > On 10.12.2015 10:09, Chanwoo Choi wrote: >> On 2015년 12월 10일 09:44, Krzysztof Kozlowski wrote: >>> On 09.12.2015 13:07, Chanwoo Choi wrote: >>>> This patch adds the DMC (Dynamic Memory Controller) bus node for Exynos3250 SoC. >>>> The DMC is an AMBA AXI-compliant slave to interface external JEDEC standard >>>> SDRAM devices. The bus includes the OPP tables and the source clock for DMC >>>> block. >>>> >>>> Following list specifies the detailed relation between the clock and DMC block: >>>> - The source clock of DMC block : div_dmc >>>> >>>> Signed-off-by: Chanwoo Choi >>>> --- >>>> arch/arm/boot/dts/exynos3250.dtsi | 34 ++++++++++++++++++++++++++++++++++ >>>> 1 file changed, 34 insertions(+) >>>> >>>> diff --git a/arch/arm/boot/dts/exynos3250.dtsi b/arch/arm/boot/dts/exynos3250.dtsi >>>> index 2f30d632f1cc..7214c5e42150 100644 >>>> --- a/arch/arm/boot/dts/exynos3250.dtsi >>>> +++ b/arch/arm/boot/dts/exynos3250.dtsi >>>> @@ -687,6 +687,40 @@ >>>> clock-names = "ppmu"; >>>> status = "disabled"; >>>> }; >>>> + >>>> + bus_dmc: bus_dmc { >>>> + compatible = "samsung,exynos-bus"; >>>> + clocks = <&cmu_dmc CLK_DIV_DMC>; >>>> + clock-names = "bus"; >>>> + operating-points-v2 = <&bus_dmc_opp_table>; >>>> + status = "disabled"; >>>> + }; >>>> + >>>> + bus_dmc_opp_table: opp_table1 { >>> >>> This is the firsy opp_table, right? So: >>> s/opp_table1/opp_table0/ >> >> Right. It is first opp_table in exynos3250.dtsi. >> But, I'm considering the OPP table of CPU freqeuncy as opp_table0. >> So, I have the plan that support the operation-points-v2 for Exynos3250 CPU. > > Ok > >> >>> >>>> + compatible = "operating-points-v2"; >>>> + opp-shared; >>>> + >>>> + opp00 { >>>> + opp-hz = /bits/ 64 <50000000>; >>>> + opp-microvolt = <800000>; >>>> + }; >>>> + opp01 { >>>> + opp-hz = /bits/ 64 <100000000>; >>>> + opp-microvolt = <800000>; >>>> + }; >>>> + opp02 { >>>> + opp-hz = /bits/ 64 <134000000>; >>>> + opp-microvolt = <800000>; >>> >>> Why 134, not 133 MHz? >> >> When I used the 133000000, the source clock is changed to 100Mhz instead of 133MHz. >> I add following test result on exynos3250-rinato board. >> >> Case1. >> When I use the 134 MHz, the source clock is changed to 133MHz >> : exynos-bus soc:bus_dmc: old_freq(200000000) -> new_freq (134000000) (real: 133333334) >> >> Case2. >> When I use the 133 MHz, the source clock is changed to 100MHz >> : exynos-bus soc:bus_dmc: old_freq(200000000) -> new_freq (133000000) (real: 100000000) > > Now I remember that issue. You could use here directly 133333334 but > that also would look a little bit weird... so 134 is ok for me. Could > just add a comment that desired frequency is actually "133 MHz"? Do you prefer among following example? Example1. opp02 { /* The desired frequency is 133MHz because * clock change has the dependency on clock driver. * When set rate as 134MHz, the clock driver would * change the 133MHz actually instead of 134MHz. */ opp-hz = /bits/ 64 <134000000>; opp-microvolt = <800000>; }; Example2. opp02 { opp-hz = /bits/ 64 <133333334>; opp-microvolt = <800000>; }; Best Regards, Chanwoo Choi