From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH V2 1/3] ARM: dts: tegra: add clock source for PMC Date: Wed, 20 Mar 2013 09:54:16 -0600 Message-ID: <5149DBA8.4030308@wwwdotorg.org> References: <1363594199-10974-1-git-send-email-josephl@nvidia.com> <1363594199-10974-2-git-send-email-josephl@nvidia.com> <51489586.9090605@wwwdotorg.org> <1363774325.5697.19.camel@jlo-ubuntu-64.nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1363774325.5697.19.camel-yx3yKKdKkHfc7b1ADBJPm0n48jw8i0AO@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Joseph Lo Cc: "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 03/20/2013 04:12 AM, Joseph Lo wrote: > On Wed, 2013-03-20 at 00:42 +0800, Stephen Warren wrote: >> On 03/18/2013 02:09 AM, Joseph Lo wrote: >>> The clock source of PMC is PCLK. Adding it into DTS for Tegra20 and Tegra30. >> >>> diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi >> >>> pmc { >>> compatible = "nvidia,tegra20-pmc"; >>> reg = <0x7000e400 0x400>; >>> + clocks = <&tegra_car 110>; >>> }; >> >> The DT binding documentation needs to list the set of clocks that must >> be present. >> >> Doesn't the PMC also receive a "clk32k_in" from the PMIC, or is that >> routed into the CAR, and then into the PMC? Either way, the PMC module >> receives that clock somehow. Since there are multiple clocks, that also >> means that a clock-names property is required. > > Do you mean the DTS below and add it into binding document? > > / SoC dts including file > pmc { > compatible = "nvidia,tegra20-pmc"; > reg = <0x7000e400 0x400>; > clocks = <&tegra_car 110>, <&clk32k_in>; > clock-names= "pclk", "clk32k_in"; > }; Yes, that's what should technically be present. > / Tegra board dts file > > pmic { > ... > clocks { > compatible = "simple-bus"; > #address-cells = <1>; > #size-cells = <0>; > > clk32k_in: clock@0 { > compatible = "fixed-clock"; > reg=<0>; > #clock-cells = <0>; > clock-frequency = <32768>; > }; > }; > }; That won't work; the PMIC drivers don't enumerate sub-nodes as busss, so that clocks node won't ever be processed. Also, the PMIC drivers aren't clock providers in most cases. It's not quite a correct representation of the HW, but I would suggest simply creating a top-level "clock" node for that fixed clock. If we ever have more top-level clocks, we can move them into a top-level "clocks" node at that time. Note: If there aren't already any other top-level clock nodes (which I think is the case), the node can be named just "clock" rather than "clock@0", since there are no naming conflicts. From mboxrd@z Thu Jan 1 00:00:00 1970 From: swarren@wwwdotorg.org (Stephen Warren) Date: Wed, 20 Mar 2013 09:54:16 -0600 Subject: [PATCH V2 1/3] ARM: dts: tegra: add clock source for PMC In-Reply-To: <1363774325.5697.19.camel@jlo-ubuntu-64.nvidia.com> References: <1363594199-10974-1-git-send-email-josephl@nvidia.com> <1363594199-10974-2-git-send-email-josephl@nvidia.com> <51489586.9090605@wwwdotorg.org> <1363774325.5697.19.camel@jlo-ubuntu-64.nvidia.com> Message-ID: <5149DBA8.4030308@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/20/2013 04:12 AM, Joseph Lo wrote: > On Wed, 2013-03-20 at 00:42 +0800, Stephen Warren wrote: >> On 03/18/2013 02:09 AM, Joseph Lo wrote: >>> The clock source of PMC is PCLK. Adding it into DTS for Tegra20 and Tegra30. >> >>> diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi >> >>> pmc { >>> compatible = "nvidia,tegra20-pmc"; >>> reg = <0x7000e400 0x400>; >>> + clocks = <&tegra_car 110>; >>> }; >> >> The DT binding documentation needs to list the set of clocks that must >> be present. >> >> Doesn't the PMC also receive a "clk32k_in" from the PMIC, or is that >> routed into the CAR, and then into the PMC? Either way, the PMC module >> receives that clock somehow. Since there are multiple clocks, that also >> means that a clock-names property is required. > > Do you mean the DTS below and add it into binding document? > > / SoC dts including file > pmc { > compatible = "nvidia,tegra20-pmc"; > reg = <0x7000e400 0x400>; > clocks = <&tegra_car 110>, <&clk32k_in>; > clock-names= "pclk", "clk32k_in"; > }; Yes, that's what should technically be present. > / Tegra board dts file > > pmic { > ... > clocks { > compatible = "simple-bus"; > #address-cells = <1>; > #size-cells = <0>; > > clk32k_in: clock at 0 { > compatible = "fixed-clock"; > reg=<0>; > #clock-cells = <0>; > clock-frequency = <32768>; > }; > }; > }; That won't work; the PMIC drivers don't enumerate sub-nodes as busss, so that clocks node won't ever be processed. Also, the PMIC drivers aren't clock providers in most cases. It's not quite a correct representation of the HW, but I would suggest simply creating a top-level "clock" node for that fixed clock. If we ever have more top-level clocks, we can move them into a top-level "clocks" node at that time. Note: If there aren't already any other top-level clock nodes (which I think is the case), the node can be named just "clock" rather than "clock at 0", since there are no naming conflicts.