[PATCH v2 2/3] pci/designware: Add base driver for Designware PCIe

[Minghuan.Lian at freescale.com]

Hi Arnd,

I do not directly add arm64 support to pcie-designware.c, the
main reason is that it is hard to port other 5 platform PCIe
driver based on pcie-designware to the new implementation.
However, not changing those PCIe driver means the code for
arm32 must be remained.

I add a new file pcie-designware-base.c. Compared with
pcie-designware.c, there are main 3 differences.
1. It is a new implementation followed the latest PCIe
architecture-independent API without any code for specific
architecture.
2. There is no MSI chip code, which will be implemented in a 
separated file.
3. Improve ATU use - support more than 2 ATUs and use an exclusive
ATU to translate MEM transaction.

After other platform PCIe owner port the driver to pcie-designware-base.c,
The pcie-designware.c can be removed.

Thanks,
Minghuan

> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd at arndb.de]
> Sent: Wednesday, April 15, 2015 6:37 PM
> To: linux-arm-kernel at lists.infradead.org
> Cc: Lian Minghuan-B31939; linux-pci at vger.kernel.org; Jingoo Han; Hu
> Mingkai-B21284; Zang Roy-R61911; Yoder Stuart-B08248; Bjorn Helgaas;
> Wood Scott-B07421
> Subject: Re: [PATCH v2 2/3] pci/designware: Add base driver for Designware
> PCIe
> 
> On Wednesday 15 April 2015 17:48:34 Minghuan Lian wrote:
> > The Synopsys Designware IP is shared with couples of platforms under
> > multiple architectures. The patch is to provide basic
> > architecture-independent Designware PCIe host driver including ATU
> > initialization and PCI OPS. Currently, which supports arm and arm64
> > simultaneously.
> >
> > Signed-off-by: Minghuan Lian <Minghuan.Lian at freescale.com>
> > ---
> > change log:
> > v1-v2:
> > 1. Get MSI chip according to dts property 'msi-parent'
> > 2. Simplify platform_get_resource_byname() failure checking
> >
> >  drivers/pci/host/Kconfig                |   3 +
> >  drivers/pci/host/Makefile               |   1 +
> >  drivers/pci/host/pcie-designware-base.c | 293
> > ++++++++++++++++++++++++++++++++
> > drivers/pci/host/pcie-designware-base.h |  63 +++++++
> >
> 
> I don't understand this patch at all. What is the relation between this driver
> and the existing pcie-designware.c? From the description above, they would
> be the same.
> 
> 	Arnd