Re: PCIe: Xilinx: sdhci-pci: probe() issue

[Bjorn Helgaas <bhelgaas@google.com>]

Hi Naveen,

On Mon, Jul 20, 2015 at 5:55 AM, Naveen Kumar Parna
<pnaveenkos@gmail.com> wrote:
> Hi ,
>
> I have a Verilog image & hardware which provides a PCIe interface with
> two BAR’s(BAR0 & BAR1) to host.
>
> BAR0 is having customized UART, GPIO and 1-wire prom modules. These
> modules are accessed via customized PCIe interface driver.
>
> BAR1 is having SD Host controller as per SD Specifications. Here
> requirement is such that we should use Linux kernel stack drivers
> (sdhci.ko & sdhci-pci.ko).
>
>
> Here the issue is only one driver’s probe() function gets executed
> i.e. either customized PCIe driver or sdhci-pci.ko.

The PCI infrastructure is designed such that a bus/device/function
address identifies a single device.  To that device, we can attach a
single driver, which manages all BARs on that device.  There is no
provision for attaching one driver to BAR0 and a different driver to
BAR1.

To manage the device you describe, you'd have to have a driver that
claims the entire PCI device, including both BARs.  That driver would
internally deal with the UART, GPIO, 1-wire prom, and SD host
controller modules.

Bjorn