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<49da77dc-b346-68eb-9ef8-42cfb3221489@nvidia.com> Message-ID: <3f1c9325-3017-62be-1e3b-82fd28540fdf@nvidia.com> Date: Tue, 10 Dec 2019 08:53:42 -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: <49da77dc-b346-68eb-9ef8-42cfb3221489@nvidia.com> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To DRHQMAIL107.nvidia.com (10.27.9.16) 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=1575996829; bh=P6bZ47+d9lwCkq4g9cIZNuOKkvDSN8175FzlvhnDGDg=; 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=OJRjUJQbzgVX/yX7NaLjwXjWxc3o12pbk8ynv0gSzsXWShXrAMFUvUKu/SLuGMO1H QFG7ge1zXMGuEHUwph3Ic1kDxI7C1GPNtKLnkAes8BE7Wh5CSF+GKYXX7ieG1ZCLoO 4j6E13Fkk0JxiiY4QJm69xXieC6QchA3+Jhao5caitl4Z3K71TjxuYowF43fvTxVC7 pVUClt7n4o5Nb5os4upp7m5fFnwlqsPRFvDDGlqrPvNIhfwqv59QYcXV5JyWiWwGFs FWtwxYmQ8bFI1NAPMzWk2LvoQcgWO2nPi6sIy+qkVTrrCsxPEPf78EQd5PZtElpbNw Iy26venGTs6mA== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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, clk_out_3 >>>>>>>>>> with >>>>>>>>>> mux and gate for each of these clocks. >>>>>>>>>> >>>>>>>>>> Currently these PMC clocks are registered by Tegra clock driver >>>>>>>>>> using >>>>>>>>>> clk_register_mux and clk_register_gate by passing PMC base=20 >>>>>>>>>> address >>>>>>>>>> and register offsets and PMC programming for these clocks=20 >>>>>>>>>> happens >>>>>>>>>> through direct PMC access by the clock driver. >>>>>>>>>> >>>>>>>>>> With this, when PMC is in secure mode any direct PMC access=20 >>>>>>>>>> from the >>>>>>>>>> non-secure world does not go through and these clocks will=20 >>>>>>>>>> not be >>>>>>>>>> functional. >>>>>>>>>> >>>>>>>>>> This patch adds these clocks registration with PMC as a clock >>>>>>>>>> provider >>>>>>>>>> for these clocks. clk_ops callback implementations for these=20 >>>>>>>>>> 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=20 >>>>>>>> in TRM). >>>>>>>> >>>>>>>> 3. PMC doesn't gate EXTPERIPH clock but could "force-enable" 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 clk_ops >>>> for set/get parent and enable/disable. >>>> >>>> enable/disable of PMC clocks is for force-enable to force the clock to >>>> run regardless of ACCEPT_REQ or INVERT_REQ. >>>> >>>>>>> 4. clk_m_div2/4 are internal PMC OSC dividers and thus these 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=20 >>>>> 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=20 > to PMC block. > > current clock driver creates clk_m_div clocks which should actually be=20 > 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 how the >>> pinmux configuration is related to it all? >>> >>> What is internal to the Tegra chip and what are the external 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,=20 >> 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=20 >> clock source selections to choose one of the PLLA_OUT0, CLK_S,=20 >> PLLP_OUT0, CLK_M, PLLE_OUT0 >> >> So, PMC CLK1/2/4 possible parents are OSC_DIV1, OSC_DIV2, OSC_DIV4,=20 >> 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=20 >> CLKx_SRC_SEL, output clock is from driver by EXTPERIPH from CAR via=20 >> Pinmux logic or driven as per CLKx_SRC_SEL bypassing pinmux based on=20 >> 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=20 >> through the pinmux >> When CLKx_ACCEPT_REQ =3D 1, output clock is based on CLKx_SRC_SEL bits=20 >> (OSC_DIV1/2/4 and EXTPERIPH clock bypassing the pinmux) >> >> FORCE_EN bit in PMC CLock control register forces the clock to run=20 >> regardless of this. PMC clock gate is based on the state of CLKx_ACCEPT_REQ and FORCE_EN=20 like explained above. CLKx_ACCEPT_REQ is 0 default and FORCE_EN acts as gate to enable/disable=20 EXTPERIPH clock output to PMC CLK_OUT_1/2/3. So I believe we need to register as MUX and Gate rather than as a single=20 clock. Please confirm.