From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH 1/4] ARM: tegra: pmc: convert PMC driver to support DT only Date: Mon, 25 Feb 2013 08:43:13 -0700 Message-ID: <512B8691.5000702@wwwdotorg.org> References: <1361515491-16199-1-git-send-email-josephl@nvidia.com> <1361515491-16199-2-git-send-email-josephl@nvidia.com> <20130222130516.GW23234@tbergstrom-lnx.Nvidia.com> <1361585022.1804.11.camel@jlo-ubuntu-64.nvidia.com> <51284615.6080808@wwwdotorg.org> <20130225142841.GJ23234@tbergstrom-lnx.Nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130225142841.GJ23234-Rysk9IDjsxmJz7etNGeUX8VPkgjIgRvpAL8bYrjMMd8@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter De Schrijver Cc: Joseph Lo , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 02/25/2013 07:28 AM, Peter De Schrijver wrote: > On Sat, Feb 23, 2013 at 05:31:17AM +0100, Stephen Warren wrote: ... >> Peter, can you confirm exactly which [PMC] HW versions, if any, are 100% >> backwards-compatible? >> > > The major difference between the PMCs are the powerdomain IDs. The Tegra30 IDs > are a strict superset of the Tegra20 IDs, but the Tegra114 IDs are not. There > are differences in the CPU domains and 3D. The CPU domains aren't a problem I > think because we won't powergate those domains directly using the PMC. We > always program the flowcontroller to do the powergating on WFI. 3D is a > different story however. We do powergate 3D under software control and the > sequencing is different between Tegra30 and Tegra114. Also Tegra30 has 2 > domains for 3D while Tegra114 has only 1. Then of course Tegra114 lacks the > SATA and PCIe domains because those features are missing compared to Tegra30. > But the IDs haven't been reused. All in all I think it's best to explicitly > require the driver to support the various SoCs. That does sound like a good idea; a separate compatible value for each SoC. From mboxrd@z Thu Jan 1 00:00:00 1970 From: swarren@wwwdotorg.org (Stephen Warren) Date: Mon, 25 Feb 2013 08:43:13 -0700 Subject: [PATCH 1/4] ARM: tegra: pmc: convert PMC driver to support DT only In-Reply-To: <20130225142841.GJ23234@tbergstrom-lnx.Nvidia.com> References: <1361515491-16199-1-git-send-email-josephl@nvidia.com> <1361515491-16199-2-git-send-email-josephl@nvidia.com> <20130222130516.GW23234@tbergstrom-lnx.Nvidia.com> <1361585022.1804.11.camel@jlo-ubuntu-64.nvidia.com> <51284615.6080808@wwwdotorg.org> <20130225142841.GJ23234@tbergstrom-lnx.Nvidia.com> Message-ID: <512B8691.5000702@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 02/25/2013 07:28 AM, Peter De Schrijver wrote: > On Sat, Feb 23, 2013 at 05:31:17AM +0100, Stephen Warren wrote: ... >> Peter, can you confirm exactly which [PMC] HW versions, if any, are 100% >> backwards-compatible? >> > > The major difference between the PMCs are the powerdomain IDs. The Tegra30 IDs > are a strict superset of the Tegra20 IDs, but the Tegra114 IDs are not. There > are differences in the CPU domains and 3D. The CPU domains aren't a problem I > think because we won't powergate those domains directly using the PMC. We > always program the flowcontroller to do the powergating on WFI. 3D is a > different story however. We do powergate 3D under software control and the > sequencing is different between Tegra30 and Tegra114. Also Tegra30 has 2 > domains for 3D while Tegra114 has only 1. Then of course Tegra114 lacks the > SATA and PCIe domains because those features are missing compared to Tegra30. > But the IDs haven't been reused. All in all I think it's best to explicitly > require the driver to support the various SoCs. That does sound like a good idea; a separate compatible value for each SoC.