RE: [PATCH v10] PCI: Xilinx-NWL-PCIe: Added support for Xilinx NWL PCIe Host Controller

From: Bharat Kumar Gogada
Date: Sat Nov 28 2015 - 04:56:51 EST


> Subject: Re: [PATCH v10] PCI: Xilinx-NWL-PCIe: Added support for Xilinx NWL
> PCIe Host Controller
>
> On 27/11/15 15:02, Bharat Kumar Gogada wrote:
> > Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.
> >
> > Signed-off-by: Bharat Kumar Gogada <bharatku@xxxxxxxxxx>
> > Signed-off-by: Ravi Kiran Gummaluri <rgummal@xxxxxxxxxx>
> > Acked-by: Rob Herring <robh@xxxxxxxxxx>
> > ---
> > Changes for v10:
> > -> Changed MSI address to PCIe controller base.
> > -> Removed nwl_check_hwirq function, instead using
> > -> bitmap_find_next_zero_area
> > API to do the same.
> > ---
> > .../devicetree/bindings/pci/xilinx-nwl-pcie.txt | 68 ++
> > drivers/pci/host/Kconfig | 10 +
> > drivers/pci/host/Makefile | 1 +
> > drivers/pci/host/pcie-xilinx-nwl.c | 1068 ++++++++++++++++++++
> > 4 files changed, 1147 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
> > create mode 100644 drivers/pci/host/pcie-xilinx-nwl.c
> >
> > diff --git a/drivers/pci/host/pcie-xilinx-nwl.c
> > b/drivers/pci/host/pcie-xilinx-nwl.c
> > new file mode 100644
> > index 0000000..d070344
> > --- /dev/null
> > +++ b/drivers/pci/host/pcie-xilinx-nwl.c
>
> [...]
>
> > +#define MSI_ADDRESS 0xFD480000
> > +
>
> Really? Why do you bother having DT support then? You might as well
> hardcode everything, while you're at it.
>
> /me felling depressed now.
Agreed, I'm already having this parameter in nwl_pcie structure, will use it.
>
> > +struct nwl_msi { /* MSI information */
> > + struct irq_domain *msi_domain;
> > + unsigned long *bitmap;
> > + struct irq_domain *dev_domain;
> > + struct mutex lock; /* protect bitmap variable */
> > + int irq_msi0;
> > + int irq_msi1;
> > +};
> > +
> > +struct nwl_pcie {
> > + struct device *dev;
> > + void __iomem *breg_base;
> > + void __iomem *pcireg_base;
> > + void __iomem *ecam_base;
> > + u32 phys_breg_base; /* Physical Bridge Register Base */
> > + u32 phys_pcie_reg_base; /* Physical PCIe Controller
> Base */
> > + u32 phys_ecam_base; /* Physical Configuration Base */
>
> All these u32 should be phys_addr_t. Not all the world is 32bit, fortunately.
Agreed will address it next patch.
>
> > + u32 breg_size;
> [...]
>
>
> > +static int nwl_pcie_bridge_init(struct nwl_pcie *pcie) {
> > + struct platform_device *pdev = to_platform_device(pcie->dev);
> > + u32 breg_val, ecam_val, first_busno = 0;
> > + int err;
> > + int check_link_up = 0;
> > +
> > + /* Check for BREG present bit */
> > + breg_val = nwl_bridge_readl(pcie, E_BREG_CAPABILITIES) &
> BREG_PRESENT;
> > + if (!breg_val) {
> > + dev_err(pcie->dev, "BREG is not present\n");
> > + return breg_val;
> > + }
> > + /* Write bridge_off to breg base */
> > + nwl_bridge_writel(pcie, (u32)(pcie->phys_breg_base),
> > + E_BREG_BASE_LO);
> > +
>
> I love the casting of a u32 to a u32. You have to program E_BREG_BASE_HI as
> well, once you've fixed the data type.
> Agreed, will address this in next patch.
> > + /* Enable BREG */
> > + nwl_bridge_writel(pcie, ~BREG_ENABLE_FORCE & BREG_ENABLE,
> > + E_BREG_CONTROL);
> > + /* Check for ECAM present bit */
> > + ecam_val = nwl_bridge_readl(pcie, E_ECAM_CAPABILITIES) &
> E_ECAM_PRESENT;
> > + if (!ecam_val) {
> > + dev_err(pcie->dev, "ECAM is not present\n");
> > + return ecam_val;
> > + }
> |
> > + /* Write phy_reg_base to ecam base */
> > + nwl_bridge_writel(pcie, (u32)pcie->phys_ecam_base,
> E_ECAM_BASE_LO);
>
> Same here.
> Agreed, will address this in next patch.

Regards,
Bharat

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