Re: [PATCH RESEND v4 03/15] PCI: dwc: Convert to using native IP-core versions representation

From: Bjorn Helgaas
Date: Thu Jul 28 2022 - 11:24:28 EST


On Fri, Jun 24, 2022 at 05:39:35PM +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).

These references to other drivers might be useful, but without a
function name or file name, I can't easily find them.

> 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