Re: [PATCH v3] PCI: Mobiveil: Add Mobiveil PCIe Host Bridge IP

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Thu, Nov 23, 2017 at 03:37:46PM +0530, Subrahmanya Lingappa wrote:

[...]

> >> diff --git a/Documentation/devicetree/bindings/pci/mobiveil-pcie.txt
> >> b/Documentation/devicetree/bindings/pci/mobiveil-pcie.txt
> >> new file mode 100644
> >> index 0000000..c9e9818
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/pci/mobiveil-pcie.txt
> >> @@ -0,0 +1,68 @@
> >> +* Mobiveil AXI PCIe Root Port Bridge DT description
> >
> > Please read the DT guidelines before submitting v4:
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/submitting-patches.txt?h=v4.14
> >
> > Add a brief IP description.
> >
> >> +Required properties:
> >> +- #address-cells: Address representation for root ports, set to <3>
> >> +- #size-cells: Size representation for root ports, set to <2>
> >> +- #interrupt-cells: specifies the number of cells needed to encode an
> >> +     interrupt source. The value must be 1.
> >> +- compatible: Should contain "mbvl,axi-pcie-host-1.00"
> >
> > See documentation above.
> >
> >> +- reg: Should contain AXI PCIe registers location and length
> >> +- device_type: must be "pci"
> >> +- apio-wins : number of configured apio outbound windows
> >> +- ppio-wins : number of configured ppio inbound windows
> >> +- interrupts: Should contain AXI PCIe interrupt
> >
> > What's an AXI interrupt ?
> 
> Thats IRQ number of the AXI interconnect, shall I change into following ?
I do not understand what IRQ number of the AXI interconnect is, I know
you copied this from the Xilinx bindings but I do not understand it
regardless.

> - interrupts: Should contain PCIe interrupt number

"interrupts: PCIe controller interrupt line(s)"

that's what you mean I think.

> >> +- interrupt-map-mask,
> >> +     interrupt-map: standard PCI properties to define the mapping of the
> >> +     PCI interface to interrupt numbers.
> >> +- ranges: ranges for the PCI memory regions (I/O space region is not
> >> +     supported by hardware)
> >> +     Please refer to the standard PCI bus binding document for a more
> >> +     detailed explanation
> >> +
> >> +- bus-range: PCI bus numbers covered
> >> +
> >> +Interrupt controller child node
> >> ++++++++++++++++++++++++++++++++
> >> +Required properties:
> >> +- interrupt-controller: identifies the node as an interrupt controller
> >> +- #address-cells: specifies the number of cells needed to encode an
> >> +     address. The value must be 0.
> >> +- #interrupt-cells: specifies the number of cells needed to encode an
> >> +     interrupt source. The value must be 1.
> >> +
> >> +NOTE:
> >> +The core provides a single interrupt for both INTx/MSI messages. So,
> >> +created a interrupt controller node to support 'interrupt-map' DT
> >> +functionality.  The driver will create an IRQ domain for this map, decode
> >> +the four INTx interrupts in ISR and route them to this domain.
> >
> > DT bindings do not describe what the Linux kernel does, they describe
> > your HW, so please read the binding you wrote and make sure that's the
> > case.
> >
> 
> I followed the Xilinx example in the same folder, have used the
> similar fields and
> explanations.
> You mean I need to explain what individual reg-names actually used in driver ?

No. I mean that Xilinx bindings are wrong too. DT bindings should not
describe what a Linux kernel driver does since they are meant to
be OS agnostic and just describe HW. So remove the NOTE or reword
it in a way that does not describe what the Linux kernel does.

> I will do that if so.
> 
> >> +Example:
> >> +++++++++
> >> +     pci_express: axi-pcie@a0000000 {
> >> +             #address-cells = <3>;
> >> +             #size-cells = <2>;
> >> +             #interrupt-cells = <1>;
> >> +             compatible = "mbvl,axi-pcie-host-1.00";
> >> +             reg =   < 0xa0000000 0x00001000 >,
> >> +                     < 0xb0000000 0x00010000 >,
> >> +                     < 0xFF000000 0x00200000 >,
> >> +                     < 0xb0010000 0x00001000 >;
> >> +             reg-names =     "config_axi_slave",
> >> +                             "csr_axi_slave",
> >> +                             "gpio_slave",
> >> +                             "apb_csr";
> >> +
> >> +             device_type = "pci";
> >> +             apio-wins = <3>;
> >> +             ppio-wins = <3>;
> >> +             interrupt-parent = <&gic>;
> >> +             interrupts = < 0 89 4 >;
> >> +             interrupt-controller;
> >> +             interrupt-map-mask = <0 0 0 7>;
> >> +             interrupt-map = <0 0 0 1 &pci_express 1>,
> >> +                             <0 0 0 2 &pci_express 2>,
> >> +                             <0 0 0 3 &pci_express 3>,
> >> +                             <0 0 0 4 &pci_express 4>;
> >> +             ranges = < 0x83000000 0 0x00000000 0xa8000000 0 0x8000000>;
> >
> > Add an interrupt controller node because I want to understand how you
> > represent it.
> >
> interrupt controller node is already present here and as per
> https://elinux.org/Device_Tree_Usage#How_Interrupts_Work
> we already have all 4 required fields.
> Can you please give me an example binding in this folder to understand
> what you are looking for ?

You say in the binding that the interrupt-controller is a child node.

In your example it is not (and should probably be to make this
uniform with other PCI controller bindings).

Lorenzo

> > I will get to the code below tomorrow.
> >
> > Thanks,
> > Lorenzo
> >
> >> +     };
> >> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt
> >> b/Documentation/devicetree/bindings/vendor-prefixes.txt
> >> index f0a48ea..be61439 100644
> >> --- a/Documentation/devicetree/bindings/vendor-prefixes.txt
> >> +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
> >> @@ -179,6 +179,7 @@ msi       Micro-Star International Co. Ltd.
> >>  mti  Imagination Technologies Ltd. (formerly MIPS Technologies Inc.)
> >>  mundoreader  Mundo Reader S.L.
> >>  murata       Murata Manufacturing Co., Ltd.
> >> +mbvl Mobiveil Inc.
> >>  mxicy        Macronix International Co., Ltd.
> >>  national     National Semiconductor
> >>  nec  NEC LCD Technologies, Ltd.
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index 63cefa6..d7dc6c3 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -9336,6 +9336,13 @@ F:
> >> Documentation/devicetree/bindings/pci/host-generic-pci.txt
> >>  F:   drivers/pci/host/pci-host-common.c
> >>  F:   drivers/pci/host/pci-host-generic.c
> >>
> >> +PCI DRIVER FOR MOBIVEIL PCIE IP
> >> +M:   Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
> >> +L:   linux-pci@vger.kernel.org
> >> +S:   Supported
> >> +F:   Documentation/devicetree/bindings/pci/mobiveil-pcie.txt
> >> +F:   drivers/pci/host/pcie-mobiveil.c
> >> +
> >>  PCI DRIVER FOR INTEL VOLUME MANAGEMENT DEVICE (VMD)
> >>  M:   Keith Busch <keith.busch@intel.com>
> >>  L:   linux-pci@vger.kernel.org
> >> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> >> index 6f1de4f..d8fb02d 100644
> >> --- a/drivers/pci/host/Kconfig
> >> +++ b/drivers/pci/host/Kconfig
> >> @@ -37,6 +37,14 @@ config PCIE_XILINX_NWL
> >>        or End Point. The current option selection will only
> >>        support root port enabling.
> >>
> >> +config PCIE_MOBIVEIL
> >> +     bool "Mobiveil AXI PCIe host bridge support"
> >> +     depends on ARCH_ZYNQMP || COMPILE_TEST
> >> +     depends on PCI_MSI_IRQ_DOMAIN
> >> +     help
> >> +       Say 'Y' here if you want kernel to support the Mobiveil AXI PCIe
> >> +       Host Bridge driver.
> >> +
> >>  config PCIE_DW_PLAT
> >>       bool "Platform bus based DesignWare PCIe Controller"
> >>       depends on PCI_MSI_IRQ_DOMAIN
> >> @@ -103,6 +111,7 @@ config PCI_HOST_GENERIC
> >>         Say Y here if you want to support a simple generic PCI host
> >>         controller, such as the one emulated by kvmtool.
> >>
> >> +
> >>  config PCIE_SPEAR13XX
> >>       bool "STMicroelectronics SPEAr PCIe controller"
> >>       depends on ARCH_SPEAR13XX
> >> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> >> index 9b113c2..d851978 100644
> >> --- a/drivers/pci/host/Makefile
> >> +++ b/drivers/pci/host/Makefile
> >> @@ -34,3 +34,4 @@ obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
> >>  obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
> >>  obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
> >>  obj-$(CONFIG_VMD) += vmd.o
> >> +obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
> >> diff --git a/drivers/pci/host/pcie-mobiveil.c
> >> b/drivers/pci/host/pcie-mobiveil.c
> >> new file mode 100644
> >> index 0000000..abc6adf
> >> --- /dev/null
> >> +++ b/drivers/pci/host/pcie-mobiveil.c
> >> @@ -0,0 +1,899 @@
> >> +/*
> >> + * PCIe host controller driver for Mobiveil PCIe Host controller
> >> + *
> >> + * Copyright Mobiveil Corporation (C) 2013-2017. All rights reserved
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify it
> >> + * under the terms and conditions of the GNU General Public License,
> >> + * version 2, as published by the Free Software Foundation.
> >> + *
> >> + * This program is distributed in the hope it will be useful, but WITHOUT
> >> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> >> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
> >> License for
> >> + * more details.
> >> + *
> >> + * You should have received a copy of the GNU General Public
> >> License along with
> >> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#include <linux/delay.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/irqchip/chained_irq.h>
> >> +#include <linux/module.h>
> >> +#include <linux/of_address.h>
> >> +#include <linux/of_irq.h>
> >> +#include <linux/irq.h>
> >> +#include <linux/msi.h>
> >> +#include <linux/of_pci.h>
> >> +#include <linux/pci.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/irqdomain.h>
> >> +#include <linux/init.h>
> >> +#include <linux/of_platform.h>
> >> +
> >> +/* Register Offsets and Bit Positions*/
> >> +
> >> +#define WIN_NUM_0            0
> >> +#define WIN_NUM_1            1
> >> +
> >> +#define CFG_WINDOW_TYPE      0
> >> +#define IO_WINDOW_TYPE               1
> >> +#define MEM_WINDOW_TYPE      2
> >> +#define MAX_PIO_WINDOWS      8
> >> +
> >> +#define PAB_INTA_POS         5
> >> +#define OP_READ              0
> >> +#define OP_WRITE             1
> >> +
> >> +#define IB_WIN_SIZE_KB               (256*1024*1024)
> >> +
> >> +#define LTSSM_STATE_STATUS   0x0404
> >> +#define LTSSM_STATUS_CODE_MASK  0x3F
> >> +#define LTSSM_STATUS_CODE    0x2D    /* LTSSM Status Code L0 */
> >> +
> >> +#define PAB_CTRL             0x0808
> >> +#define  AMBA_PIO_ENABLE_SHIFT 0
> >> +#define  PEX_PIO_ENABLE_SHIFT        1
> >> +#define  PAGE_SEL_SHIFT      13
> >> +#define  PAGE_SEL_MASK               0x3f
> >> +#define  PAGE_SEL_OFFSET_SHIFT       10
> >> +
> >> +#define PAB_AXI_PIO_CTRL     0x0840
> >> +#define  APIO_EN_MASK                0xf
> >> +
> >> +#define PAB_PEX_PIO_CTRL     0x08C0
> >> +#define  PIO_ENABLE_SHIFT    0
> >> +#define PAB_INTP_AMBA_MISC_ENB 0x0B0C
> >> +#define PAB_INTP_AMBA_MISC_STAT 0x0B1C
> >> +#define  PAB_INTP_INTX_MASK    0x1E0 /* INTx(A-D) */
> >> +#define  PAB_INTP_MSI_MASK   0x8
> >> +
> >> +#define PAB_AXI_AMAP_CTRL(win_num)   (0x0BA0 + (0x10*win_num))
> >> +#define  WIN_ENABLE_SHIFT            0
> >> +#define  WIN_TYPE_SHIFT              1
> >> +#define  WIN_SIZE_SHIFT              10
> >> +#define PAB_EXT_AXI_AMAP_SIZE(win_num)  (0xBAF0 + (0x4*win_num))
> >> +
> >> +#define PAB_AXI_AMAP_AXI_WIN(win_num)        (0x0BA4 + (0x10*win_num))
> >> +#define  AXI_WINDOW_BASE_SHIFT    2
> >> +
> >> +#define PAB_AXI_AMAP_PEX_WIN_L(win_num)     (0x0BA8 + (0x10*win_num))
> >> +#define  PAB_BUS_SHIFT               24
> >> +#define  PAB_DEVICE_SHIFT    19
> >> +#define  PAB_FUNCTION_SHIFT  16
> >> +
> >> +#define PAB_AXI_AMAP_PEX_WIN_H(win_num) (0x0BAC + (0x10*win_num))
> >> +#define PAB_INTP_AXI_PIO_CLASS       0x474
> >> +
> >> +#define PAB_PEX_AMAP_CTRL(win_num)   (0x4BA0 + (0x10*win_num))
> >> +#define AMAP_CTRL_EN_SHIFT           0
> >> +#define AMAP_CTRL_TYPE_SHIFT         1       /* 0: interrupt, 2: memory */
> >> +
> >> +#define PAB_EXT_PEX_AMAP_SIZEN(win_num) (0xBEF0 + (0x4*win_num))
> >> +#define PAB_PEX_AMAP_AXI_WIN(win_num)   (0x4BA4 + (0x10*win_num))
> >> +#define PAB_PEX_AMAP_PEX_WIN_L(win_num) (0x4BA8 + (0x10*win_num))
> >> +#define PAB_PEX_AMAP_PEX_WIN_H(win_num) (0x4BAC + (0x10*win_num))
> >> +
> >> +#define PCI_NUM_INTX         4
> >> +#define PCI_NUM_MSI          16
> >> +
> >> +#define MSI_BASE_LO_OFFSET   0x04
> >> +#define MSI_BASE_HI_OFFSET   0x08
> >> +#define MSI_SIZE_OFFSET      0x0c
> >> +#define MSI_ENABLE_OFFSET    0x14
> >> +#define MSI_ENABLE_SHIFT     0
> >> +#define MSI_STATUS_OFFSET    0x18
> >> +#define MSI_STATUS_SHIFT     0
> >> +#define MSI_OCCUPANCY_OFFSET    0x1c
> >> +#define MSI_DATA_OFFSET      0x20
> >> +#define MSI_ADDR_L_OFFSET    0x24
> >> +#define MSI_ADDR_H_OFFSET    0x28
> >> +#define ilog2_u32(num) (__ffs(num)-1)
> >> +
> >> +/*
> >> + * PCIe port information
> >> + */
> >> +struct mobiveil_pcie {
> >> +     struct platform_device *pdev;
> >> +     void __iomem *config_axi_slave_base;    /* endpoint config base */
> >> +     void __iomem *csr_axi_slave_base;       /* root port config base */
> >> +     void __iomem *gpio_slave_base;  /* GPIO register base */
> >> +     void __iomem *apb_csr_base;     /* MSI register base */
> >> +     struct irq_domain *irq_domain;
> >> +     struct resource bus_range;
> >> +     struct list_head resources;
> >> +     int *msi_pages;
> >> +     int *msi_pages_phys;
> >> +     char root_bus_nr;
> >> +     int irq;
> >> +     int apio_wins;
> >> +     int ppio_wins;
> >> +     int ob_wins_configured; /*  configured outbound windows */
> >> +     int ib_wins_configured; /*  configured inbound windows */
> >> +     struct resource *ob_io_res;
> >> +     struct resource *ob_mem_res[3];
> >> +};
> >> +
> >> +static DECLARE_BITMAP(msi_irq_in_use, PCI_NUM_MSI);
> >> +
> >> +static inline void csr_writel(struct mobiveil_pcie *pcie,
> >> +                     const unsigned int value, const unsigned int reg)
> >> +{
> >> +     writel_relaxed(value, pcie->csr_axi_slave_base + reg);
> >> +}
> >> +
> >> +static inline unsigned int csr_readl(struct mobiveil_pcie *pcie,
> >> +                     const unsigned int reg)
> >> +{
> >> +     return readl_relaxed(pcie->csr_axi_slave_base + reg);
> >> +}
> >> +
> >> +static inline int gpio_read(struct mobiveil_pcie *pcie, int addr)
> >> +{
> >> +     return ioread32(pcie->gpio_slave_base + addr);
> >> +}
> >> +
> >> +static inline void gpio_write(struct mobiveil_pcie *pcie, int val,
> >> int addr)
> >> +{
> >> +     iowrite32(val, pcie->gpio_slave_base + addr);
> >> +     if (val != gpio_read(pcie, addr)) {
> >> +             dev_info(&pcie->pdev->dev,
> >> +                      "WARNING:gpio_write: expected : %x at: %x, found: %x\n ",
> >> +                      val, addr, gpio_read(pcie, addr));
> >> +     }
> >> +}
> >> +
> >> +static bool mobiveil_pcie_link_is_up(struct mobiveil_pcie *pcie)
> >> +{
> >> +     return (csr_readl(pcie, LTSSM_STATE_STATUS) &
> >> +             LTSSM_STATUS_CODE_MASK) == LTSSM_STATUS_CODE;
> >> +}
> >> +
> >> +static bool mobiveil_pcie_valid_device(struct pci_bus *bus,
> >> unsigned int devfn)
> >> +{
> >> +     struct mobiveil_pcie *pcie = bus->sysdata;
> >> +
> >> +     /* Check if link is up when trying to access downstream ports */
> >> +     if (bus->number != pcie->root_bus_nr)
> >> +             if (!mobiveil_pcie_link_is_up(pcie))
> >> +                     return false;
> >> +
> >> +     /* Only one device down on each root port */
> >> +     if ((bus->number == pcie->root_bus_nr) && (devfn > 0))
> >> +             return false;
> >> +
> >> +     /*
> >> +      * Do not read more than one device on the bus directly
> >> +      * attached to RC
> >> +      */
> >> +     if ((bus->primary == pcie->root_bus_nr) && (devfn > 0))
> >> +             return false;
> >> +
> >> +     return true;
> >> +}
> >> +
> >> +/*
> >> + * mobiveil_pcie_map_bus - routine to get the configuration base of either
> >> + * root port or endpoint
> >> + *
> >> + * Relies on pci_lock serialization
> >> + */
> >> +static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
> >> +                                        unsigned int devfn, int where)
> >> +{
> >> +     struct mobiveil_pcie *pcie = bus->sysdata;
> >> +     unsigned int value;
> >> +
> >> +     if (!mobiveil_pcie_valid_device(bus, devfn))
> >> +             return NULL;
> >> +
> >> +     if (bus->number == pcie->root_bus_nr) {
> >> +             /* RC config access (in CSR space) */
> >> +             return pcie->csr_axi_slave_base + where;
> >> +     } else {
> >> +             /*
> >> +              * EP config access (in Config/APIO space)
> >> +              * Program PEX Address base (31..16 bits) with appropriate value
> >> +              * (BDF) in PAB_AXI_AMAP_PEX_WIN_L0 Register.
> >> +              */
> >> +
> >> +             /* Relies on pci_lock serialization */
> >> +             value = csr_readl(pcie, PAB_AXI_AMAP_PEX_WIN_L(0));
> >> +             csr_writel(pcie,
> >> +                     bus->number << PAB_BUS_SHIFT |
> >> +                     (devfn >> 3) << PAB_DEVICE_SHIFT |
> >> +                     (devfn & 7) << PAB_FUNCTION_SHIFT,
> >> +                     PAB_AXI_AMAP_PEX_WIN_L(0));
> >> +             return pcie->config_axi_slave_base + where;
> >> +     }
> >> +}
> >> +
> >> +static struct pci_ops mobiveil_pcie_ops = {
> >> +     .map_bus = mobiveil_pcie_map_bus,
> >> +     .read = pci_generic_config_read,
> >> +     .write = pci_generic_config_write,
> >> +};
> >> +
> >> +static irqreturn_t mobiveil_pcie_isr(int irq, void *data)
> >> +{
> >> +     struct mobiveil_pcie *pcie = (struct mobiveil_pcie *)data;
> >> +     unsigned int fifo_occ;
> >> +     unsigned int msi_addr_l, msi_addr_h, msi_data;
> >> +     unsigned int status, status2;
> >> +     unsigned long shifted_status;
> >> +     unsigned int bit1 = 0, virq;
> >> +     unsigned int val, mask;
> >> +
> >> +     /*
> >> +      * The core provides a single interrupt for both INTx/MSI messages.
> >> +      * So we'll read both INTx and MSI statuses
> >> +      */
> >> +
> >> +     /* read INTx status */
> >> +     val = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT);
> >> +     mask = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> >> +     status = val & mask;
> >> +
> >> +     /* Handle INTx */
> >> +     if (status & PAB_INTP_INTX_MASK) {
> >> +             while ((shifted_status =
> >> +                     (csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT) >>
> >> +                      PAB_INTA_POS)) != 0) {
> >> +                     for_each_set_bit(bit1, &shifted_status, PCI_NUM_INTX) {
> >> +                             /* clear interrupts */
> >> +                             csr_writel(pcie, shifted_status << PAB_INTA_POS,
> >> +                                        PAB_INTP_AMBA_MISC_STAT);
> >> +
> >> +                             virq =
> >> +                                 irq_find_mapping(pcie->irq_domain,
> >> +                                                  bit1 + 1);
> >> +                             if (virq)
> >> +                                     generic_handle_irq(virq);
> >> +                             else
> >> +                                     dev_err(&pcie->pdev->dev,
> >> +                                             "unexpected IRQ, INT%d\n",
> >> +                                             bit1);
> >> +
> >> +                     }
> >> +                     shifted_status = 0;
> >> +             }
> >> +     }
> >> +
> >> +     /* read MSI status */
> >> +     status2 = readl(pcie->apb_csr_base + MSI_STATUS_OFFSET);
> >> +
> >> +     /* handle MSI interrupts */
> >> +     if ((status & PAB_INTP_MSI_MASK)
> >> +         || (status2 & (1 << MSI_STATUS_SHIFT))) {
> >> +             do {
> >> +                     fifo_occ = readl(pcie->apb_csr_base
> >> +                                      + MSI_OCCUPANCY_OFFSET);
> >> +                     msi_data = readl(pcie->apb_csr_base + MSI_DATA_OFFSET);
> >> +                     msi_addr_l = readl(pcie->apb_csr_base
> >> +                                        + MSI_ADDR_L_OFFSET);
> >> +                     msi_addr_h = readl(pcie->apb_csr_base
> >> +                                        + MSI_ADDR_H_OFFSET);
> >> +                     /* Handle MSI */
> >> +                     if (msi_data)
> >> +                             generic_handle_irq(msi_data);
> >> +                     else
> >> +                             dev_err(&pcie->pdev->dev, "MSI data null\n");
> >> +
> >> +                     status2 = readl(pcie->apb_csr_base + MSI_STATUS_OFFSET);
> >> +             } while ((status2 & (1 << MSI_STATUS_SHIFT)));
> >> +     }
> >> +
> >> +     csr_writel(pcie, status, PAB_INTP_AMBA_MISC_STAT);
> >> +     return IRQ_HANDLED;
> >> +}
> >> +
> >> +/* routine to parse device tree */
> >> +static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
> >> +{
> >> +     struct device *dev = &pcie->pdev->dev;
> >> +     struct platform_device *pdev = pcie->pdev;
> >> +     struct device_node *node = dev->of_node;
> >> +     resource_size_t iobase;
> >> +     struct resource *res;
> >> +     const char *type;
> >> +     int err;
> >> +
> >> +     type = of_get_property(node, "device_type", NULL);
> >> +     if (!type || strcmp(type, "pci")) {
> >> +             dev_err(dev, "invalid \"device_type\" %s\n", type);
> >> +             return -EINVAL;
> >> +     }
> >> +
> >> +     /* map config resource */
> >> +     res =
> >> +         platform_get_resource_byname(pdev, IORESOURCE_MEM,
> >> +                                      "config_axi_slave");
> >> +     pcie->config_axi_slave_base = devm_ioremap_resource(dev, res);
> >> +     if (IS_ERR(pcie->config_axi_slave_base))
> >> +             return PTR_ERR(pcie->config_axi_slave_base);
> >> +     pcie->ob_io_res = res;
> >> +
> >> +     /* map csr resource */
> >> +     res =
> >> +         platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr_axi_slave");
> >> +     pcie->csr_axi_slave_base = devm_ioremap_resource(dev, res);
> >> +     if (IS_ERR(pcie->csr_axi_slave_base))
> >> +             return PTR_ERR(pcie->csr_axi_slave_base);
> >> +
> >> +     /* map gpio resource */
> >> +     res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "gpio_slave");
> >> +     pcie->gpio_slave_base =
> >> +         devm_ioremap_nocache(dev, res->start, resource_size(res));
> >> +     if (IS_ERR(pcie->gpio_slave_base))
> >> +             return PTR_ERR(pcie->gpio_slave_base);
> >> +
> >> +     /* map gpio resource */
> >> +     res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "apb_csr");
> >> +     pcie->apb_csr_base =
> >> +         devm_ioremap_nocache(dev, res->start, resource_size(res));
> >> +     if (IS_ERR(pcie->apb_csr_base))
> >> +             return PTR_ERR(pcie->apb_csr_base);
> >> +
> >> +     /* read the number of windows requested */
> >> +     if (!pcie->apio_wins &&
> >> +             of_property_read_u32(node, "apio-wins", &pcie->apio_wins)) {
> >> +             pcie->apio_wins = MAX_PIO_WINDOWS;
> >> +     }
> >> +
> >> +     if (!pcie->ppio_wins &&
> >> +             of_property_read_u32(node, "ppio-wins", &pcie->ppio_wins)) {
> >> +             pcie->ppio_wins = MAX_PIO_WINDOWS;
> >> +     }
> >> +
> >> +     /* map IRQ resource */
> >> +     pcie->irq = irq_of_parse_and_map(node, 0);
> >> +     err = devm_request_irq(&pdev->dev, pcie->irq, mobiveil_pcie_isr,
> >> +                             IRQF_SHARED | IRQF_NO_THREAD,
> >> +                             "mobiveil-pcie", pcie);
> >> +     if (err) {
> >> +             dev_err(&pdev->dev, "unable to request IRQ %d\n", pcie->irq);
> >> +             return err;
> >> +     }
> >> +
> >> +     INIT_LIST_HEAD(&pcie->resources);
> >> +     /* parse the host bridge base addresses from the device tree file */
> >> +     err = of_pci_get_host_bridge_resources(node,
> >> +                     0, 0xff, &pcie->resources, &iobase);
> >> +     if (err) {
> >> +             dev_err(dev, "Getting bridge resources failed\n");
> >> +             return -ENOMEM;
> >> +     }
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +/*
> >> + * access_paged_register - routine to access paged register of root complex
> >> + *
> >> + * registers of RC are paged, with pg_sel field of the PAB_CTRL
> >> + * register needs to be updated with page of the register, before
> >> + * accessing least significant 10 bits offset
> >> + *
> >> + * This routine does the PAB_CTRL updation and split access of the
> >> + * offset
> >> + *
> >> + */
> >> +static unsigned int access_paged_register(struct mobiveil_pcie *pcie,
> >> +                                     unsigned int write,
> >> +                                     unsigned int val,
> >> +                                     unsigned int offset)
> >> +{
> >> +     int pab_ctrl_dw, pg_sel;
> >> +     unsigned int off = (offset & 0x3FF) + 0xC00;
> >> +
> >> +     pab_ctrl_dw = csr_readl(pcie, PAB_CTRL);
> >> +     pg_sel = (offset >> PAGE_SEL_OFFSET_SHIFT) & PAGE_SEL_MASK;
> >> +
> >> +     /* clear pg_sel field */
> >> +     pab_ctrl_dw = (pab_ctrl_dw & ~(PAGE_SEL_MASK << PAGE_SEL_SHIFT));
> >> +
> >> +     /* set pg_sel field */
> >> +     pab_ctrl_dw |= ((pg_sel << PAGE_SEL_SHIFT));
> >> +     csr_writel(pcie, pab_ctrl_dw, PAB_CTRL);
> >> +
> >> +     if (write == OP_WRITE)
> >> +             csr_writel(pcie, val, off);
> >> +     else
> >> +             return csr_readl(pcie, off);
> >> +     return 0;
> >> +
> >> +}
> >> +
> >> +/*
> >> + * routine to program the inbound windows
> >> + */
> >> +static void program_ib_windows(struct mobiveil_pcie *pcie,
> >> +                             int win_num,
> >> +                             int pci_addr,
> >> +                             int type,
> >> +                             int size_kb)
> >> +{
> >> +     int pio_ctrl_val;
> >> +     int amap_ctrl_dw;
> >> +     u64 size64 = (-1 << (WIN_SIZE_SHIFT + ilog2_u32(size_kb)));
> >> +
> >> +     if ((pcie->ib_wins_configured + 1) > pcie->ppio_wins) {
> >> +             dev_err(&pcie->pdev->dev,
> >> +                     "ERROR: trying for more than max inbound windows in device tree !\n");
> >> +             return;
> >> +     }
> >> +
> >> +     pio_ctrl_val = csr_readl(pcie, PAB_PEX_PIO_CTRL);
> >> +     csr_writel(pcie,
> >> +             pio_ctrl_val | (1 << PIO_ENABLE_SHIFT), PAB_PEX_PIO_CTRL);
> >> +     amap_ctrl_dw =  access_paged_register(pcie,
> >> +                             OP_READ, 0, PAB_PEX_AMAP_CTRL(win_num));
> >> +     amap_ctrl_dw = (amap_ctrl_dw | (type << AMAP_CTRL_TYPE_SHIFT));
> >> +     amap_ctrl_dw = (amap_ctrl_dw | (1 << AMAP_CTRL_EN_SHIFT));
> >> +
> >> +     access_paged_register(pcie, OP_WRITE,
> >> +                             amap_ctrl_dw | (size64 & 0xFFFFFFFF),
> >> +                             PAB_PEX_AMAP_CTRL(win_num));
> >> +
> >> +     access_paged_register(pcie, OP_WRITE, upper_32_bits(size64),
> >> +                             PAB_EXT_PEX_AMAP_SIZEN(win_num));
> >> +
> >> +     access_paged_register(pcie, OP_WRITE, pci_addr,
> >> +                             PAB_PEX_AMAP_AXI_WIN(win_num));
> >> +
> >> +     access_paged_register(pcie, OP_WRITE, pci_addr,
> >> +                             PAB_PEX_AMAP_PEX_WIN_L(win_num));
> >> +
> >> +     access_paged_register(pcie, OP_WRITE, 0,
> >> +                             PAB_PEX_AMAP_PEX_WIN_H(win_num));
> >> +}
> >> +
> >> +/*
> >> + * routine to program the outbound windows
> >> + */
> >> +static void program_ob_windows(struct mobiveil_pcie *pcie,
> >> +                             int win_num,
> >> +                             u64 cpu_addr,
> >> +                             u64 pci_addr,
> >> +                             int config_io_bit,
> >> +                             int size_kb)
> >> +{
> >> +
> >> +     unsigned int value, type;
> >> +     u64 size64 = (-1 << (WIN_SIZE_SHIFT + ilog2_u32(size_kb)));
> >> +
> >> +     if ((pcie->ob_wins_configured + 1) > pcie->apio_wins) {
> >> +             dev_err(&pcie->pdev->dev,
> >> +                     "ERROR: trying for more than max outbound windows in device tree !\n");
> >> +             return;
> >> +     }
> >> +
> >> +
> >> +     /*
> >> +      * program Enable Bit to 1, Type Bit to (00) base 2, AXI Window Size Bit
> >> +      * to 4 KB in PAB_AXI_AMAP_CTRL register
> >> +      */
> >> +     type = config_io_bit;
> >> +     value = csr_readl(pcie, PAB_AXI_AMAP_CTRL(win_num));
> >> +     csr_writel(pcie,
> >> +                     1 << WIN_ENABLE_SHIFT  |
> >> +                     type << WIN_TYPE_SHIFT |
> >> +                     lower_32_bits(size64),
> >> +                     PAB_AXI_AMAP_CTRL(win_num));
> >> +
> >> +     access_paged_register(pcie, OP_WRITE, upper_32_bits(size64),
> >> +                             PAB_EXT_AXI_AMAP_SIZE(win_num));
> >> +
> >> +     /*
> >> +      * program AXI window base with appropriate value in
> >> +      * PAB_AXI_AMAP_AXI_WIN0 register
> >> +      */
> >> +     value = csr_readl(pcie, PAB_AXI_AMAP_AXI_WIN(win_num));
> >> +     csr_writel(pcie,
> >> +                     cpu_addr >> AXI_WINDOW_BASE_SHIFT <<
> >> +                     AXI_WINDOW_BASE_SHIFT, PAB_AXI_AMAP_AXI_WIN(win_num));
> >> +
> >> +     value = csr_readl(pcie, PAB_AXI_AMAP_PEX_WIN_H(win_num));
> >> +
> >> +     csr_writel(pcie, lower_32_bits(pci_addr),
> >> +                     PAB_AXI_AMAP_PEX_WIN_L(win_num));
> >> +     csr_writel(pcie, upper_32_bits(pci_addr),
> >> +                     PAB_AXI_AMAP_PEX_WIN_H(win_num));
> >> +
> >> +     pcie->ob_wins_configured++;
> >> +}
> >> +
> >> +/*
> >> + * routine to prepare the PCIe slot for power up
> >> + */
> >> +static void mobiveil_pcie_establish_link(struct mobiveil_pcie *pcie)
> >> +{
> >> +
> >> +     int secs = 4;
> >> +
> >> +     /* send PRESET to the slot */
> >> +     gpio_write(pcie, 0x80000000, 0xa0344);
> >> +     gpio_write(pcie, 0x80000000, 0xa0348);
> >> +     gpio_write(pcie, 0x00000000, 0xa0054);
> >> +     gpio_write(pcie, 0x80000000, 0xa0054);
> >> +     dev_info(&pcie->pdev->dev,
> >> +              "mobiveil_pcie_establish_link: waiting for %d seconds\n",
> >> +              secs);
> >> +     mdelay(secs * 1000);
> >> +}
> >> +
> >> +static void mobiveil_bringup_link(struct mobiveil_pcie *pcie)
> >> +{
> >> +     int reset_cnt = 0;
> >> +     struct device *dev = &pcie->pdev->dev;
> >> +
> >> +     if (!mobiveil_pcie_link_is_up(pcie)) {
> >> +             /*
> >> +              * if FSBL is not patched, link won't be up so let's bring it
> >> +              * up by writing DIRM and OEN registers EMIO 6:0 programming
> >> +              * sequence [3:0] = Link Width; [6:4] = Link Speed. Current
> >> +              * setting width=4, speed = 1
> >> +              */
> >> +             gpio_write(pcie, 0x7f, 0xa02c4);
> >> +             gpio_write(pcie, 0x7f, 0xa02c8);
> >> +             gpio_write(pcie, 0x14, 0xa004c);
> >> +
> >> +             gpio_write(pcie, 0x0200, 0xa0244);
> >> +             gpio_write(pcie, 0x0200, 0xa0248);
> >> +             gpio_write(pcie, 0x37f7, 0x180208);
> >> +             gpio_write(pcie, 0xfdff, 0xa0044);
> >> +
> >> +             mdelay(2 * 1000);
> >> +
> >> +             while (!mobiveil_pcie_link_is_up(pcie)) {
> >> +                     dev_info(dev,
> >> +                              "%s: PRESET retry, reset_cnt : %d\n",
> >> +                              __func__, reset_cnt++);
> >> +                     mobiveil_pcie_establish_link(pcie);
> >> +             }
> >> +
> >> +     }
> >> +     dev_info(dev, "link up\n");
> >> +}
> >> +
> >> +static void mobiveil_setup_config_access(struct mobiveil_pcie *pcie)
> >> +{
> >> +     unsigned int value;
> >> +     int type = 0;
> >> +     int pab_ctrl;
> >> +     struct resource_entry *win, *tmp;
> >> +
> >> +     /*
> >> +      * program Bus Master Enable Bit in Command Register in PAB Config
> >> +      * Space
> >> +      */
> >> +     value = csr_readl(pcie, PCI_COMMAND);
> >> +     csr_writel(pcie,
> >> +             value |
> >> +             PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
> >> +             PCI_COMMAND);
> >> +
> >> +     /*
> >> +      * program PIO Enable Bit to 1 (and PEX PIO Enable to 1) in PAB_CTRL
> >> +      * register
> >> +      */
> >> +     pab_ctrl = csr_readl(pcie, PAB_CTRL);
> >> +     csr_writel(pcie, pab_ctrl | (1 << AMBA_PIO_ENABLE_SHIFT) |
> >> +             (1 << PEX_PIO_ENABLE_SHIFT),
> >> +             PAB_CTRL);
> >> +
> >> +     csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
> >> +             PAB_INTP_AMBA_MISC_ENB);
> >> +
> >> +     /* program PIO Enable Bit to 1 and Config Window Enable Bit to 1 in
> >> +      * PAB_AXI_PIO_CTRL Register
> >> +      */
> >> +     value = csr_readl(pcie, PAB_AXI_PIO_CTRL);
> >> +     csr_writel(pcie, value | APIO_EN_MASK, PAB_AXI_PIO_CTRL);
> >> +
> >> +     /*
> >> +      * we'll program one outbound window for config reads and
> >> +      * another default inbound window for all the upstream traffic
> >> +      * rest of the outbound windows will be configured according to
> >> +      * the "ranges" field defined in device tree
> >> +      */
> >> +
> >> +     /* config outbound translation window */
> >> +     program_ob_windows(pcie,
> >> +                     pcie->ob_wins_configured, pcie->ob_io_res->start,
> >> +                     0,
> >> +                     CFG_WINDOW_TYPE,
> >> +                     resource_size(pcie->ob_io_res)/1024);
> >> +
> >> +     /* memory inbound  translation window */
> >> +     program_ib_windows(pcie, WIN_NUM_1, 0, MEM_WINDOW_TYPE, IB_WIN_SIZE_KB);
> >> +
> >> +     /* Get the I/O and memory ranges from DT */
> >> +     resource_list_for_each_entry_safe(win, tmp, &pcie->resources) {
> >> +             type = 0;
> >> +             if (resource_type(win->res) == IORESOURCE_MEM)
> >> +                     type = MEM_WINDOW_TYPE;
> >> +             if (resource_type(win->res) == IORESOURCE_IO)
> >> +                     type = IO_WINDOW_TYPE;
> >> +             if (type) {
> >> +                     /* configure outbound translation window */
> >> +                     pcie->ob_mem_res[pcie->ob_wins_configured] =  win->res;
> >> +                     program_ob_windows(pcie,
> >> +                             pcie->ob_wins_configured,
> >> +                             win->res->start,
> >> +                             0,
> >> +                             type,
> >> +                             resource_size(win->res)/1024);
> >> +             }
> >> +     }
> >> +
> >> +
> >> +
> >> +}
> >> +
> >> +/* routine to setup the INTx related data */
> >> +static int mobiveil_pcie_intx_map(struct irq_domain *domain,
> >> unsigned int irq,
> >> +                               irq_hw_number_t hwirq)
> >> +{
> >> +     irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
> >> +     irq_set_chip_data(irq, domain->host_data);
> >> +     return 0;
> >> +}
> >> +
> >> +/* INTx domain opeartions structure */
> >> +static const struct irq_domain_ops intx_domain_ops = {
> >> +     .map = mobiveil_pcie_intx_map,
> >> +};
> >> +
> >> +static void mobiveil_pcie_destroy_msi(unsigned int irq)
> >> +{
> >> +     struct msi_desc *msi;
> >> +     struct mobiveil_pcie *pcie;
> >> +
> >> +     if (!test_bit(irq, msi_irq_in_use)) {
> >> +             msi = irq_get_msi_desc(irq);
> >> +             pcie = msi_desc_to_pci_sysdata(msi);
> >> +             dev_info(&pcie->pdev->dev,
> >> +                      "Trying to free unused MSI#%d\n", irq);
> >> +     } else {
> >> +             clear_bit(irq, msi_irq_in_use);
> >> +     }
> >> +}
> >> +
> >> +static int mobiveil_pcie_assign_msi(struct mobiveil_pcie *pcie)
> >> +{
> >> +     int pos;
> >> +
> >> +     pos = find_first_zero_bit(msi_irq_in_use, PCI_NUM_MSI);
> >> +     if (pos < PCI_NUM_MSI)
> >> +             set_bit(pos, msi_irq_in_use);
> >> +     else
> >> +             return -ENOSPC;
> >> +
> >> +     return pos;
> >> +}
> >> +
> >> +static void mobiveil_msi_teardown_irq(struct msi_controller *chip,
> >> +                             unsigned int irq)
> >> +{
> >> +     mobiveil_pcie_destroy_msi(irq);
> >> +     irq_dispose_mapping(irq);
> >> +}
> >> +
> >> +static int mobiveil_pcie_msi_setup_irq(struct msi_controller *chip,
> >> +                             struct pci_dev *pdev,
> >> +                             struct msi_desc *desc)
> >> +{
> >> +     int hwirq;
> >> +     unsigned int irq;
> >> +     struct msi_msg msg;
> >> +     phys_addr_t msg_addr;
> >> +     struct mobiveil_pcie *pcie = pdev->bus->sysdata;
> >> +
> >> +     hwirq = mobiveil_pcie_assign_msi(pcie);
> >> +     if (hwirq < 0)
> >> +             return -EINVAL;
> >> +
> >> +     irq = irq_create_mapping(pcie->irq_domain, hwirq);
> >> +     if (!irq)
> >> +             return -EINVAL;
> >> +
> >> +     irq_set_msi_desc(irq, desc);
> >> +
> >> +     msg_addr =
> >> +             virt_to_phys((void *)pcie->msi_pages + (hwirq * sizeof(int)));
> >> +
> >> +     msg.address_hi = upper_32_bits(msg_addr);
> >> +     msg.address_lo = lower_32_bits(msg_addr);
> >> +     msg.data = irq;
> >> +
> >> +     pci_write_msi_msg(irq, &msg);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static struct msi_controller mobiveil_pcie_msi_chip = {
> >> +     .setup_irq = mobiveil_pcie_msi_setup_irq,
> >> +     .teardown_irq = mobiveil_msi_teardown_irq,
> >> +};
> >> +
> >> +static struct irq_chip mobiveil_msi_irq_chip = {
> >> +     .name = "Mobiveil PCIe MSI",
> >> +     .irq_enable = pci_msi_unmask_irq,
> >> +     .irq_disable = pci_msi_mask_irq,
> >> +     .irq_mask = pci_msi_mask_irq,
> >> +     .irq_unmask = pci_msi_unmask_irq,
> >> +};
> >> +
> >> +static int mobiveil_pcie_msi_map(struct irq_domain *domain,
> >> unsigned int irq,
> >> +                              irq_hw_number_t hwirq)
> >> +{
> >> +     irq_set_chip_and_handler(irq, &mobiveil_msi_irq_chip,
> >> +                              handle_simple_irq);
> >> +     irq_set_chip_data(irq, domain->host_data);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static const struct irq_domain_ops msi_domain_ops = {
> >> +     .map = mobiveil_pcie_msi_map,
> >> +};
> >> +
> >> +static void mobiveil_pcie_enable_msi(struct mobiveil_pcie *pcie)
> >> +{
> >> +     phys_addr_t msg_addr;
> >> +
> >> +     pcie->msi_pages = (void *)__get_free_pages(GFP_DMA, 0);
> >> +     msg_addr = virt_to_phys((void *)pcie->msi_pages);
> >> +     pcie->msi_pages_phys = (void *)msg_addr;
> >> +
> >> +     writel_relaxed(lower_32_bits(msg_addr),
> >> +             pcie->apb_csr_base + MSI_BASE_LO_OFFSET);
> >> +     writel_relaxed(upper_32_bits(msg_addr),
> >> +             pcie->apb_csr_base + MSI_BASE_HI_OFFSET);
> >> +     writel_relaxed(4096, pcie->apb_csr_base + MSI_SIZE_OFFSET);
> >> +     writel_relaxed(1 << MSI_ENABLE_SHIFT,
> >> +             pcie->apb_csr_base + MSI_ENABLE_OFFSET);
> >> +}
> >> +
> >> +static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
> >> +{
> >> +     struct device *dev = &pcie->pdev->dev;
> >> +     struct device_node *node = dev->of_node;
> >> +
> >> +     /* Setup INTx */
> >> +     pcie->irq_domain =
> >> +             irq_domain_add_linear(node, PCI_NUM_INTX + 1, &intx_domain_ops,
> >> +                               pcie);
> >> +
> >> +     if (!pcie->irq_domain) {
> >> +             dev_err(dev, "Failed to get a INTx IRQ domain\n");
> >> +             return -ENOMEM;
> >> +     }
> >> +     /* Setup MSI */
> >> +     if (IS_ENABLED(CONFIG_PCI_MSI)) {
> >> +             pcie->irq_domain =
> >> +                     irq_domain_add_linear(node,
> >> +                                             PCI_NUM_MSI,
> >> +                                             &msi_domain_ops,
> >> +                                             &mobiveil_pcie_msi_chip);
> >> +             if (!pcie->irq_domain) {
> >> +                     dev_err(dev, "Failed to get a MSI IRQ domain\n");
> >> +                     return PTR_ERR(pcie->irq_domain);
> >> +             }
> >> +
> >> +             mobiveil_pcie_enable_msi(pcie);
> >> +     }
> >> +     return 0;
> >> +}
> >> +
> >> +static int mobiveil_pcie_probe(struct platform_device *pdev)
> >> +{
> >> +     struct mobiveil_pcie *pcie;
> >> +     struct pci_bus *bus;
> >> +     struct pci_bus *child;
> >> +     int ret;
> >> +
> >> +     /* allocate the PCIe port */
> >> +     pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
> >> +     if (!pcie)
> >> +             return -ENOMEM;
> >> +
> >> +     pcie->pdev = pdev;
> >> +
> >> +     /* parse the device tree */
> >> +     ret = mobiveil_pcie_parse_dt(pcie);
> >> +     if (ret) {
> >> +             dev_err(&pdev->dev, "Parsing DT failed, ret: %x\n", ret);
> >> +             return ret;
> >> +     }
> >> +
> >> +     /* setup the PCIe slot link power*/
> >> +     mobiveil_bringup_link(pcie);
> >> +
> >> +     /*
> >> +      * configure all inbound and outbound windows and prepare the RC for
> >> +      * config access
> >> +      */
> >> +     mobiveil_setup_config_access(pcie);
> >> +
> >> +     /* fixup for PCIe class register */
> >> +     csr_writel(pcie, 0x060402AB, PAB_INTP_AXI_PIO_CLASS);
> >> +
> >> +     /* initialize the IRQ domains */
> >> +     ret = mobiveil_pcie_init_irq_domain(pcie);
> >> +     if (ret) {
> >> +             dev_err(&pdev->dev, "Failed creating IRQ Domain\n");
> >> +             return ret;
> >> +     }
> >> +
> >> +     /* create the PCIe root bus */
> >> +     bus =
> >> +     pci_create_root_bus(&pdev->dev, 0,
> >> +                     &mobiveil_pcie_ops, pcie, &pcie->resources);
> >> +     if (!bus)
> >> +             return -ENOMEM;
> >> +
> >> +     /* setup MSI, if enabled */
> >> +     if (IS_ENABLED(CONFIG_PCI_MSI)) {
> >> +             mobiveil_pcie_msi_chip.dev = &pcie->pdev->dev;
> >> +             bus->msi = &mobiveil_pcie_msi_chip;
> >> +     }
> >> +
> >> +     /* setup the kernel resources for the newly added PCIe root bus */
> >> +     pci_scan_child_bus(bus);
> >> +     pci_assign_unassigned_bus_resources(bus);
> >> +
> >> +     list_for_each_entry(child, &bus->children, node)
> >> +             pcie_bus_configure_settings(child);
> >> +
> >> +     pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
> >> +     pci_bus_add_devices(bus);
> >> +     platform_set_drvdata(pdev, pcie);
> >> +
> >> +     return ret;
> >> +}
> >> +
> >> +static const struct of_device_id mobiveil_pcie_of_match[] = {
> >> +     {.compatible = "mbvl,axi-pcie-host-1.00",},
> >> +     {},
> >> +};
> >> +
> >> +MODULE_DEVICE_TABLE(of, mobiveil_pcie_of_match);
> >> +
> >> +static struct platform_driver mobiveil_pcie_driver = {
> >> +     .probe = mobiveil_pcie_probe,
> >> +     .driver = {
> >> +                     .name = "mobiveil-pcie",
> >> +                     .of_match_table = mobiveil_pcie_of_match,
> >> +                     .suppress_bind_attrs = true,
> >> +             },
> >> +};
> >> +
> >> +builtin_platform_driver(mobiveil_pcie_driver);
> >> +
> >> +MODULE_LICENSE("GPL v2");
> >> +MODULE_DESCRIPTION("Mobiveil PCIe host controller driver");
> >> +MODULE_AUTHOR("Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>");
> >> --
> >> 1.8.3.1
> 
> Thanks.