From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24FC0C2D0C6 for ; Wed, 11 Dec 2019 18:50:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1F88222C4 for ; Wed, 11 Dec 2019 18:50:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="rbi6f2Ld" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726717AbfLKSuW (ORCPT ); Wed, 11 Dec 2019 13:50:22 -0500 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:18004 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726242AbfLKSuW (ORCPT ); Wed, 11 Dec 2019 13:50:22 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 11 Dec 2019 10:50:13 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Wed, 11 Dec 2019 10:50:19 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Wed, 11 Dec 2019 10:50:19 -0800 Received: from [10.2.169.141] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 11 Dec 2019 18:50:12 +0000 Subject: Re: [PATCH v3 03/15] soc: tegra: Add Tegra PMC clock registrations into PMC driver From: Sowjanya Komatineni To: Dmitry Osipenko , , , , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , References: <1575600535-26877-1-git-send-email-skomatineni@nvidia.com> <1575600535-26877-4-git-send-email-skomatineni@nvidia.com> <7cf4ff77-2f33-4ee5-0e09-5aa6aef3e8be@gmail.com>

<288a1701-def6-d628-26bc-a305f817bdb1@gmail.com> <78644d45-2ae3-121f-99fc-0a46f205907d@nvidia.com>

<49da77dc-b346-68eb-9ef8-42cfb3221489@nvidia.com> <3f1c9325-3017-62be-1e3b-82fd28540fdf@nvidia.com> <6fcbff3d-8695-7cd0-60de-6eb523b6964c@gmail.com> <8eb792ad-cded-05cc-93fc-763be7ee66aa@nvidia.com> Message-ID: Date: Wed, 11 Dec 2019 10:50:11 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <8eb792ad-cded-05cc-93fc-763be7ee66aa@nvidia.com> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: quoted-printable Content-Language: en-US DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1576090213; bh=VyqMDGmm+JI2LIt/qKWwHVNdqu5k+ibwjmxWczdvl2M=; h=X-PGP-Universal:Subject:From:To:CC:References:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Transfer-Encoding: Content-Language; b=rbi6f2LdMWVuWgEhsuE+o+qRQkNfWp676UQI1FOhAW84IoX0Fin2HcdhwJAsnx3f9 Dzge0ELIjJGM8/2jL8C4kbAtd+AkR1Gx8Q4kH8q+zGr4gxc/qncaNpvCa9H17DPGV6 3oTCMzp7QXTSzD7YxTnsssQo/Qox2KhwR87SawDsk6Xvn6mDAyFiyvTIopHBMhjC7w NXZnmoKoUYL3t2nBsi9fqkTh8geAFYPquZVTedqnwXrI4Y8qytgsduwEBoYZ3q8OdF q1ogM5cwrW7pZZ2/owRVhbPe21fUCba8MVBb07nr1ivNsH4qPnCDU1oesVmKXXvFFM +3q6/vKb3OvHg== Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 12/10/19 5:06 PM, Sowjanya Komatineni wrote: > > On 12/10/19 9:41 AM, Dmitry Osipenko wrote: >> 10.12.2019 19:53, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>> On 12/9/19 3:03 PM, Sowjanya Komatineni wrote: >>>> On 12/9/19 12:46 PM, Sowjanya Komatineni wrote: >>>>> On 12/9/19 12:12 PM, Dmitry Osipenko wrote: >>>>>> 08.12.2019 00:36, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82= : >>>>>>> On 12/7/19 11:59 AM, Sowjanya Komatineni wrote: >>>>>>>> On 12/7/19 8:00 AM, Dmitry Osipenko wrote: >>>>>>>>> 07.12.2019 18:53, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >>>>>>>>>> 07.12.2019 18:47, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1=82= : >>>>>>>>>>> 07.12.2019 17:28, Dmitry Osipenko =D0=BF=D0=B8=D1=88=D0=B5=D1= =82: >>>>>>>>>>>> 06.12.2019 05:48, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5= =D1=82: >>>>>>>>>>>>> Tegra210 and prior Tegra PMC has clk_out_1, clk_out_2,=20 >>>>>>>>>>>>> clk_out_3 >>>>>>>>>>>>> with >>>>>>>>>>>>> mux and gate for each of these clocks. >>>>>>>>>>>>> >>>>>>>>>>>>> Currently these PMC clocks are registered by Tegra clock=20 >>>>>>>>>>>>> driver >>>>>>>>>>>>> using >>>>>>>>>>>>> clk_register_mux and clk_register_gate by passing PMC base >>>>>>>>>>>>> address >>>>>>>>>>>>> and register offsets and PMC programming for these clocks >>>>>>>>>>>>> happens >>>>>>>>>>>>> through direct PMC access by the clock driver. >>>>>>>>>>>>> >>>>>>>>>>>>> With this, when PMC is in secure mode any direct PMC access >>>>>>>>>>>>> from the >>>>>>>>>>>>> non-secure world does not go through and these clocks will >>>>>>>>>>>>> not be >>>>>>>>>>>>> functional. >>>>>>>>>>>>> >>>>>>>>>>>>> This patch adds these clocks registration with PMC as a clock >>>>>>>>>>>>> provider >>>>>>>>>>>>> for these clocks. clk_ops callback implementations for these >>>>>>>>>>>>> clocks >>>>>>>>>>>>> uses tegra_pmc_readl and tegra_pmc_writel which supports PMC >>>>>>>>>>>>> programming >>>>>>>>>>>>> in secure mode and non-secure mode. >>>>>>>>>>>>> >>>>>>>>>>>>> Signed-off-by: Sowjanya Komatineni >>>>>>>>>>>>> --- >>>>>>>>>>> [snip] >>>>>>>>>>> >>>>>>>>>>>>> + >>>>>>>>>>>>> +static const struct clk_ops pmc_clk_gate_ops =3D { >>>>>>>>>>>>> +=C2=A0=C2=A0=C2=A0 .is_enabled =3D pmc_clk_is_enabled, >>>>>>>>>>>>> +=C2=A0=C2=A0=C2=A0 .enable =3D pmc_clk_enable, >>>>>>>>>>>>> +=C2=A0=C2=A0=C2=A0 .disable =3D pmc_clk_disable, >>>>>>>>>>>>> +}; >>>>>>>>>>>> What's the benefit of separating GATE from the MUX? >>>>>>>>>>>> >>>>>>>>>>>> I think it could be a single clock. >>>>>>>>>>> According to TRM: >>>>>>>>>>> >>>>>>>>>>> 1. GATE and MUX are separate entities. >>>>>>>>>>> >>>>>>>>>>> 2. GATE is the parent of MUX (see PMC's CLK_OUT paths diagram >>>>>>>>>>> in TRM). >>>>>>>>>>> >>>>>>>>>>> 3. PMC doesn't gate EXTPERIPH clock but could "force-enable"=20 >>>>>>>>>>> it, >>>>>>>>>>> correct? >>>>>>> Was following existing clk-tegra-pmc as I am not sure of reason for >>>>>>> having these clocks registered as separate mux and gate clocks. >>>>>>> >>>>>>> Yes, PMC clocks can be registered as single clock and can use=20 >>>>>>> clk_ops >>>>>>> for set/get parent and enable/disable. >>>>>>> >>>>>>> enable/disable of PMC clocks is for force-enable to force the=20 >>>>>>> clock to >>>>>>> run regardless of ACCEPT_REQ or INVERT_REQ. >>>>>>> >>>>>>>>>> 4. clk_m_div2/4 are internal PMC OSC dividers and thus these=20 >>>>>>>>>> clocks >>>>>>>>>> should belong to PMC. >>>>>>>>> Also, it should be "osc" and not "clk_m". >>>>>>>> I followed the same parents as it were in existing clk-tegra-pmc >>>>>>>> driver. >>>>>>>> >>>>>>>> Yeah they are wrong and they should be from osc and not clk_m. >>>>>>>> >>>>>>>> Will fix in next version. >>>>>>>> >>>> Reg clk_m_div2/3, they are dividers at OSC pad and not really internal >>>> to PMC block. >>>> >>>> current clock driver creates clk_m_div clocks which should actually be >>>> osc_div2/osc_div4 clocks with osc as parent. >>>> >>>> There are no clk_m_div2 and clk_m_div4 from clk_m >>>> >>>> Will fix this in next version. >>>> >>>>>> Could you please describe the full EXTPERIPH clock topology and=20 >>>>>> how the >>>>>> pinmux configuration is related to it all? >>>>>> >>>>>> What is internal to the Tegra chip and what are the external=20 >>>>>> outputs? >>>>>> >>>>>> Is it possible to bypass PMC on T30+ for the EXTPERIPH clocks? >>>>> PMC CLK1/2/3 possible sources are OSC_DIV1, OSC_DIV2, OSC_DIV4, >>>>> EXTPERIPH from CAR. >>>>> >>>>> OSC_DIV1/2/4 are with internal dividers at the OSC Pads >>>>> >>>>> EXTPERIPH is from CAR and it has reset and enable controls along with >>>>> clock source selections to choose one of the PLLA_OUT0, CLK_S, >>>>> PLLP_OUT0, CLK_M, PLLE_OUT0 >>>>> >>>>> So, PMC CLK1/2/4 possible parents are OSC_DIV1, OSC_DIV2, OSC_DIV4, >>>>> EXTERN. >>>>> >>>>> >>>>> CLK1/2/3 also has Pinmux to route EXTPERIPH output on to these pins. >>>>> >>>>> >>>>> When EXTERN output clock is selected for these PMC clocks thru >>>>> CLKx_SRC_SEL, output clock is from driver by EXTPERIPH from CAR via >>>>> Pinmux logic or driven as per CLKx_SRC_SEL bypassing pinmux based on >>>>> CLKx_ACCEPT_REQ bit. >>>>> >>>>> >>>>> PMC Clock control register has bit CLKx_ACCEPT_REQ >>>>> When CLKx_ACCEPT_REQ =3D 0, output clock driver is from by EXTPERIPH >>>>> through the pinmux >>>>> When CLKx_ACCEPT_REQ =3D 1, output clock is based on CLKx_SRC_SEL bit= s >>>>> (OSC_DIV1/2/4 and EXTPERIPH clock bypassing the pinmux) >>>>> >>>>> FORCE_EN bit in PMC CLock control register forces the clock to run >>>>> regardless of this. >>> PMC clock gate is based on the state of CLKx_ACCEPT_REQ and FORCE_EN >>> like explained above. >>> >>> CLKx_ACCEPT_REQ is 0 default and FORCE_EN acts as gate to=20 >>> enable/disable >>> EXTPERIPH clock output to PMC CLK_OUT_1/2/3. >> [and to enable OSC as well] >> >>> So I believe we need to register as MUX and Gate rather than as a=20 >>> single >>> clock. Please confirm. >> 1. The force-enabling is applied to both OSC and EXTERN sources of >> PMC_CLK_OUT_x by PMC at once. >> >> 2. Both of PMC's force-enabling and OSC/EXTERN selection is internal=20 >> to PMC. >> >> Should be better to define it as a single "pmc_clk_out_x". I don't see >> any good reasons for differentiating PMC's Gate from the MUX, it's a >> single hardware unit from a point of view of the rest of the system. >> >> Peter, do you have any objections? > > We added fallback option for audio mclk and also added check for=20 > assigned-clock-parents dt property in audio driver and if its not then=20 > we do parent init configuration in audio driver. > > Current clock driver creates 2 separate clocks clk_out_1_mux and=20 > clk_out_1 for each pmc clock in clock driver and uses extern1 as=20 > parent to clk_out_1_mux and clk_out_1_mux is parent to clk_out_1. > > With change of registering each pmc clock as a single clock, when we=20 > do parent init assignment in audio driver when=20 > assigned-clock-properties are not used in DT (as we removed parent=20 > inits for extern and clk_outs from clock driver), we should still try=20 > to get clock based on clk_out_1_mux as parent assignment of extern1 is=20 > for clk_out_1_mux as per existing clock tree. > > clk_out_1_mux clock retrieve will fail with this change of single=20 > clock when any new platform device tree doesn't specify=20 > assigned-clock-parents properties and tegra_asoc_utils_init fails. > > With single clock, extern1 is the parent for clk_out_1 and with=20 > separate clocks for mux and gate, extern1 is the parent for=20 > clk_out_1_mux. If we move to single clock now, it need one more additional fallback=20 implementation in audio driver during parent configuration as=20 clk_out_1_mux will not be there with single clock change and old/current=20 kernel has it as it uses separate clocks for pmc mux and gate. Also, with single clock for both PMC mux and gate now, new DT should use=20 extern1 as parent to CLK_OUT_1 as CLK_OUT_1_MUX will not be there old=20 PMC dt-bindings has separate clocks for MUX (CLK_OUT_1_MUX) and gate=20 (CLK_OUT_1) DT bindings will not be compatible b/w old and new changes if we move to=20 Single PMC clock now. Should we go with same separate clocks to have it compatible to avoid=20 all this?