Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932710AbcDLIUL (ORCPT ); Tue, 12 Apr 2016 04:20:11 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:44449 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932581AbcDLIT6 convert rfc822-to-8bit (ORCPT ); Tue, 12 Apr 2016 04:19:58 -0400 X-AuditID: cbfee68d-f79e86d0000012da-1c-570cafa94b7d MIME-version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 8BIT Message-id: <570CAFA9.2060607@samsung.com> Date: Tue, 12 Apr 2016 17:19:53 +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, kyungmin.park@samsung.com, kgene@kernel.org, s.nawrocki@samsung.com, tomasz.figa@gmail.com Cc: rjw@rjwysocki.net, 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, linux.amoon@gmail.com, m.reichl@fivetechno.de, tjakobi@math.uni-bielefeld.de, inki.dae@samsung.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org Subject: Re: [PATCH v9 07/20] PM / devfreq: exynos: Update documentation for bus devices using passive governor References: <1460347078-15175-1-git-send-email-cw00.choi@samsung.com> <1460347078-15175-8-git-send-email-cw00.choi@samsung.com> <570CA50A.3010505@samsung.com> In-reply-to: <570CA50A.3010505@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrKKsWRmVeSWpSXmKPExsWyRsSkWHflep5wg+PPlC3mHznHatH/ZiGr xblXKxktJt2fwGLx+oWhRf/j18wWZ5vesFtsenyN1eLyrjlsFp97jzBazDi/j8li3cZb7Ba3 L/NavDzyg9Fi6fWLTBa3G1ewWUyYvpbF4szpS6wWrXuPsFscftPOatG2+gOrxapdfxgdxDzW zFvD6NHS3MPmcbmvl8nj1p16j52z7rJ7rFz+hc1j06pONo/NS+o9/h1j99hytZ3Fo2/LKkaP z5vkAniiuGxSUnMyy1KL9O0SuDJOff7JXvBLtuLD82esDYwbJboYOTkkBEwkLh15zgRhi0lc uLeerYuRi0NIYAWjxJ7FZ9lhii7enAiVmMUo0XSnEyzBKyAo8WPyPRYQm1lAXWLSvEXMELaI xNQNPxghbG2JZQtfM0M0P2CUaP/RAbSOA6hZS+LXrnCQGhYBVYn7M5+zgthsQOH9L26wgZSI CkRIdJ+oBAmLCKxmlLh/LBJkDLPAWmaJV+2NYPXCAoUSH4/dYIKYv4hRYt2XVrCDOIEWH++c A3a1hMAXDomNcyewQmwTkPg2+RALyAYJAVmJTQeYIb6UlDi44gbLBEbxWUh+m4Xkt1lIfpuF 5LcFjCyrGEVTC5ILipPSiwz1ihNzi0vz0vWS83M3MQJTz+l/z3p3MN4+YH2IUYCDUYmH94Ez T7gQa2JZcWXuIUZToIsmMkuJJucDE1xeSbyhsZmRhamJqbGRuaWZkjivotTPYCGB9MSS1OzU 1ILUovii0pzU4kOMTBycUg2MJydM1dI8P9chtPu3Twrv2dPzxPaVZD3Y5Z92ROzbtnXTHkQ/ /1fK0nJWxmOLMdO/934z3vEFxq30fFT91DzgZsTG9aeExRtf7su7ZMHyc9MJmX0Mbw8otz5x f1pz5EBA7Om988o65t1vnyG7as6pjrSD5ax/HfjT0hq8LafIrbY6WGJ+UPrnQiWW4oxEQy3m ouJEAMgcwVg4AwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrBKsWRmVeSWpSXmKPExsVy+t9jQd2V63nCDQ7/k7aYf+Qcq0X/m4Ws FuderWS0mHR/AovF6xeGFv2PXzNbnG16w26x6fE1VovLu+awWXzuPcJoMeP8PiaLdRtvsVvc vsxr8fLID0aLpdcvMlncblzBZjFh+loWizOnL7FatO49wm5x+E07q0Xb6g+sFqt2/WF0EPNY M28No0dLcw+bx+W+XiaPW3fqPXbOusvusXL5FzaPTas62Tw2L6n3+HeM3WPL1XYWj74tqxg9 Pm+SC+CJamC0yUhNTEktUkjNS85PycxLt1XyDo53jjc1MzDUNbS0MFdSyEvMTbVVcvEJ0HXL zAF6WEmhLDGnFCgUkFhcrKRvh2lCaIibrgVMY4Sub0gQXI+RARpIWMOYcXjjUbaCF7IVD792 MTYwzpfoYuTkkBAwkbh4cyIbhC0mceHeeiCbi0NIYBajRNOdTnaQBK+AoMSPyfdYuhg5OJgF 5CWOXMoGCTMLqEtMmreIGaL+AaNE+48OJpAaXgEtiV+7wkFqWARUJe7PfM4KYrMBhfe/uMEG UiIqECHRfaISJCwisJpR4v6xSJAxzAJrmSVetTeC1QsLFEp8PHaDCWL+IkaJdV9aWUASnALa Esc757BNYAS6EuG8WQjnzUJy3gJG5lWMEqkFyQXFSem5Rnmp5XrFibnFpXnpesn5uZsYwanq mfQOxsO73A8xCnAwKvHwPnDmCRdiTSwrrsw9xCjBwawkwvtxLVCINyWxsiq1KD++qDQntfgQ oynQgxOZpUST84FpNK8k3tDYxMzI0sjc0MLI2FxJnPfx/3VhQgLpiSWp2ampBalFMH1MHJxS DYwusuKPTS/8OFjU+2r7j+/Kjd83qoXp5QhqL2tYd2aH34qFuRV/33ufP/Q4oUL4a5OLR+/L Wu98yzqzrosKS5XETB+7u2jvKpaddjy2oPS9jGzHtu/eRs8FmAUEl+8U3rXH7B7v0Q2XJ9y+ /byjNaOpXdIy5OBdIdGzR1a7C4hMmrEriNlx+XwlluKMREMt5qLiRABOsJn8awMAAA== 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 Content-Length: 3728 Lines: 86 On 2016년 04월 12일 16:34, Krzysztof Kozlowski wrote: > On 04/11/2016 05:57 AM, Chanwoo Choi wrote: >> This patch updates the documentation for passive bus devices and adds the >> detailed example of Exynos3250. >> >> Signed-off-by: Chanwoo Choi >> Acked-by: MyungJoo Ham >> --- >> .../devicetree/bindings/devfreq/exynos-bus.txt | 250 ++++++++++++++++++++- >> 1 file changed, 247 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/devfreq/exynos-bus.txt b/Documentation/devicetree/bindings/devfreq/exynos-bus.txt >> index 78171b918e3f..03f13d38f1a1 100644 >> --- a/Documentation/devicetree/bindings/devfreq/exynos-bus.txt >> +++ b/Documentation/devicetree/bindings/devfreq/exynos-bus.txt >> @@ -8,22 +8,46 @@ of the bus in runtime. To monitor the usage of each bus in runtime, >> the driver uses the PPMU (Platform Performance Monitoring Unit), which >> is able to measure the current load of sub-blocks. >> >> +The Exynos SoC includes the various sub-blocks which have the each AXI bus. >> +The each AXI bus has the owned source clock but, has not the only owned >> +power line. The power line might be shared among one more sub-blocks. >> +So, we can divide into two type of device as the role of each sub-block. >> +There are two type of bus devices as following: >> +- parent bus device >> +- passive bus device >> + >> +Basically, parent and passive bus device share the same power line. >> +The parent bus device can only change the voltage of shared power line >> +and the rest bus devices (passive bus device) depend on the decision of >> +the parent bus device. If there are three blocks which share the VDD_xxx >> +power line, Only one block should be parent device and then the rest blocks >> +should depend on the parent device as passive device. >> + >> + VDD_xxx |--- A block (parent) >> + |--- B block (passive) >> + |--- C block (passive) >> + >> There are a little different composition among Exynos SoC because each Exynos >> SoC has different sub-blocks. Therefore, shch difference should be specified > > s/shch/such/ I'll fix it on patch2 because this typo happen on patch2. > >> in devicetree file instead of each device driver. In result, this driver >> is able to support the bus frequency for all Exynos SoCs. >> >> -Required properties for bus device: >> +Required properties for all bus devices: >> - compatible: Should be "samsung,exynos-bus". >> - clock-names : the name of clock used by the bus, "bus". >> - clocks : phandles for clock specified in "clock-names" property. >> - operating-points-v2: the OPP table including frequency/voltage information >> to support DVFS (Dynamic Voltage/Frequency Scaling) feature. >> + >> +Required properties only for parent bus device: >> - vdd-supply: the regulator to provide the buses with the voltage. >> - devfreq-events: the devfreq-event device to monitor the current utilization >> of buses. >> >> -Optional properties for bus device: >> +Required properties only for passive bus device: >> +- devfreq: the parent bus device. >> + >> +Optional properties only for parent bus device: >> - exynos,saturation-ratio: the percentage value which is used to calibrate >> the performance count against total cycle count. >> - exynos,voltage-tolerance: the percentage value for bus voltage tolerance >> @@ -34,7 +58,20 @@ Example1: >> power line (regulator). The MIF (Memory Interface) AXI bus is used to >> transfer data between DRAM and CPU and uses the VDD_MIF regualtor. > > s/regualtor/regulator/ ditto. > > > Acked-by: Krzysztof Kozlowski Thanks for your review. Best Regards, Chanwoo Choi