Re: [PATCH v2 05/17] PCI: dwc: Convert to using native IP-core versions representation

From: Rob Herring <robh@kernel.org>
To: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: "Jingoo Han" <jingoohan1@gmail.com>,
	"Gustavo Pimentel" <gustavo.pimentel@synopsys.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Rahul Tanwar" <rtanwar@maxlinear.com>,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Jonathan Hunter" <jonathanh@nvidia.com>,
	"Serge Semin" <fancer.lancer@gmail.com>,
	"Alexey Malahov" <Alexey.Malahov@baikalelectronics.ru>,
	"Pavel Parkhomenko" <Pavel.Parkhomenko@baikalelectronics.ru>,
	"Frank Li" <Frank.Li@nxp.com>,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	linux-pci@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org
Subject: Re: [PATCH v2 05/17] PCI: dwc: Convert to using native IP-core versions representation
Date: Mon, 16 May 2022 15:31:22 -0500	[thread overview]
Message-ID: <20220516203122.GC3209795-robh@kernel.org> (raw)
In-Reply-To: <20220503214638.1895-6-Sergey.Semin@baikalelectronics.ru>

On Wed, May 04, 2022 at 12:46:26AM +0300, Serge Semin wrote:
> Since DWC PCIe v4.70a the controller version can be read from the
> PORT_LOGIC.PCIE_VERSION_OFF register. Version is represented in the FourCC
> format [1]. It's standard versioning approach for the Synopsys DWC
> IP-cores. Moreover some of the DWC kernel drivers already make use of it
> to fixup version-dependent functionality (See DWC USB3, Stmicro STMMAC or
> recent DW SPI driver). In order to preserve the standard version
> representation and prevent the data conversion back and forth, we suggest
> to preserve the native version representation in the DWC PCIe driver too
> in the same way as it has already been done in the rest of the DWC
> drivers. IP-core version reading from the CSR will be introduced in the
> next commit together with a simple macro-based API to use it.
> 
> [1] https://en.wikipedia.org/wiki/FourCC
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> ---
>  drivers/pci/controller/dwc/pci-keystone.c    | 12 ++++++------
>  drivers/pci/controller/dwc/pcie-designware.c |  8 ++++----
>  drivers/pci/controller/dwc/pcie-designware.h | 10 +++++++++-
>  drivers/pci/controller/dwc/pcie-intel-gw.c   |  4 ++--
>  drivers/pci/controller/dwc/pcie-tegra194.c   |  2 +-
>  5 files changed, 22 insertions(+), 14 deletions(-)

Reviewed-by: Rob Herring <robh@kernel.org>