Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.

Signed-off-by: Bharat Kumar Gogada <bhara...@xilinx.com>
Signed-off-by: Ravi Kiran Gummaluri <rgum...@xilinx.com>
---
 .../devicetree/bindings/pci/xilinx-nwl-pcie.txt    |   39 +
 drivers/pci/host/Kconfig                           |    9 +
 drivers/pci/host/Makefile                          |    1 +
 drivers/pci/host/pci-xilinx-nwl.c                  | 1038 ++++++++++++++++++++
 4 files changed, 1087 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
 create mode 100644 drivers/pci/host/pci-xilinx-nwl.c

diff --git a/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt 
b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
new file mode 100644
index 0000000..c554d6b
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
@@ -0,0 +1,39 @@
+* Xilinx NWL PCIe Root Port Bridge DT description
+
+Required properties:
+- compatible: Should contain "xlnx,nwl-pcie-2.11"
+- #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.
+- reg: Should contain Bridge, PCIe Controller registers location and length
+- device_type: must be "pci"
+- interrupts: Should contain NWL PCIe interrupt
+- 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
+
+Optional properties:
+- xlnx,msi-fifo: To enable MSI FIFO mode
+
+Example:
+++++++++
+nwl_pcie: pcie@fd0e0000 {
+       compatible = "xlnx,nwl-pcie-2.11";
+       #address-cells = <3>;
+       #size-cells = <2>;
+       #interrupt-cells = <1>;
+       device_type = "pci";
+       interrupt-parent = <&gic>;
+       interrupts = < 0 118 4
+                      0 116 4
+                      0 115 4          // MSI_1 [63...32]
+                      0 114 4 >;       // MSI_0 [31...0]
+       interrupt-names = "misc", "intx", "msi_1", "msi_0";
+       reg = <0x0 0xfd0e0000 0x1000
+              0x0 0xfd480000 0x1000
+              0x0 0xE0000000 0x1000000>;
+       reg-names = "breg", "pcireg", "cfg";
+       ranges = <0x02000000 0x00000000 0xE1000000 0x00000000 0xE1000000 0 
0x0F000000>;
+};
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index c132bdd..5ff4e7e 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -15,6 +15,15 @@ config PCI_MVEBU
        depends on ARCH_MVEBU || ARCH_DOVE
        depends on OF

+config PCI_XILINX_NWL
+       bool "NWL PCIe Core"
+       depends on ARCH_ZYNQMP && PCI_MSI
+       help
+        Say 'Y' here if you want kernel to support for Xilinx
+        NWL PCIe controller.The controller can act as Root Port
+        or End Point.The current option selection will only
+        support root port enabling.
+
 config PCIE_DW
        bool

diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 140d66f..0f3a789 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
 obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
+obj-$(CONFIG_PCI_XILINX_NWL) += pci-xilinx-nwl.o
 obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
 obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o
 obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
diff --git a/drivers/pci/host/pci-xilinx-nwl.c 
b/drivers/pci/host/pci-xilinx-nwl.c
new file mode 100644
index 0000000..6c2fa80
--- /dev/null
+++ b/drivers/pci/host/pci-xilinx-nwl.c
@@ -0,0 +1,1038 @@
+/*
+ * PCIe host controller driver for NWL PCIe Bridge
+ * Based on pci-xilinx.c, pci-tegra.c
+ *
+ * (C) Copyright 2014 - 2015, Xilinx, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+/* Bridge core config registers */
+#define BRCFG_PCIE_RX0                 0x00000000
+#define BRCFG_PCIE_RX1                 0x00000004
+#define BRCFG_AXI_MASTER               0x00000008
+#define BRCFG_PCIE_TX                  0x0000000C
+#define BRCFG_INTERRUPT                        0x00000010
+#define BRCFG_RAM_DISABLE0             0x00000014
+#define BRCFG_RAM_DISABLE1             0x00000018
+#define BRCFG_PCIE_RELAXED_ORDER       0x0000001C
+#define BRCFG_PCIE_RX_MSG_FILTER       0x00000020
+
+/* Attribute registers */
+#define NWL_ATTRIB_100                 0x00000190
+
+/* Egress - Bridge translation registers */
+#define E_BREG_CAPABILITIES            0x00000200
+#define E_BREG_STATUS                  0x00000204
+#define E_BREG_CONTROL                 0x00000208
+#define E_BREG_BASE_LO                 0x00000210
+#define E_BREG_BASE_HI                 0x00000214
+#define E_ECAM_CAPABILITIES            0x00000220
+#define E_ECAM_STATUS                  0x00000224
+#define E_ECAM_CONTROL                 0x00000228
+#define E_ECAM_BASE_LO                 0x00000230
+#define E_ECAM_BASE_HI                 0x00000234
+
+/* Ingress - address translations */
+#define I_MSII_CAPABILITIES            0x00000300
+#define I_MSII_CONTROL                 0x00000308
+#define I_MSII_BASE_LO                 0x00000310
+#define I_MSII_BASE_HI                 0x00000314
+
+#define I_ISUB_CONTROL                 0x000003E8
+#define SET_ISUB_CONTROL               BIT(0)
+/* Rxed msg fifo  - Interrupt status registers */
+#define MSGF_MISC_STATUS               0x00000400
+#define MSGF_MISC_MASK                 0x00000404
+#define MSGF_LEG_STATUS                        0x00000420
+#define MSGF_LEG_MASK                  0x00000424
+#define MSGF_MSI_STATUS_LO             0x00000440
+#define MSGF_MSI_STATUS_HI             0x00000444
+#define MSGF_MSI_MASK_LO               0x00000448
+#define MSGF_MSI_MASK_HI               0x0000044C
+#define MSGF_RX_FIFO_POP               0x00000484
+#define MSGF_RX_FIFO_TYPE              0x00000488
+#define MSGF_RX_FIFO_ADDRLO            0x00000490
+#define MSGF_RX_FIFO_ADDRHI            0x00000494
+#define MSGF_RX_FIFO_DATA              0x00000498
+
+/* Msg filter mask bits */
+#define CFG_ENABLE_PM_MSG_FWD          BIT(1)
+#define CFG_ENABLE_INT_MSG_FWD         BIT(2)
+#define CFG_ENABLE_ERR_MSG_FWD         BIT(3)
+#define CFG_ENABLE_SLT_MSG_FWD         BIT(5)
+#define CFG_ENABLE_VEN_MSG_FWD         BIT(7)
+#define CFG_ENABLE_OTH_MSG_FWD         BIT(13)
+#define CFG_ENABLE_VEN_MSG_EN          BIT(14)
+#define CFG_ENABLE_VEN_MSG_VEN_INV     BIT(15)
+#define CFG_ENABLE_VEN_MSG_VEN_ID      GENMASK(31, 16)
+#define CFG_ENABLE_MSG_FILTER_MASK     (CFG_ENABLE_PM_MSG_FWD | \
+                                       CFG_ENABLE_INT_MSG_FWD | \
+                                       CFG_ENABLE_ERR_MSG_FWD | \
+                                       CFG_ENABLE_SLT_MSG_FWD | \
+                                       CFG_ENABLE_VEN_MSG_FWD | \
+                                       CFG_ENABLE_OTH_MSG_FWD | \
+                                       CFG_ENABLE_VEN_MSG_EN | \
+                                       CFG_ENABLE_VEN_MSG_VEN_INV | \
+                                       CFG_ENABLE_VEN_MSG_VEN_ID)
+
+/* Misc interrupt status mask bits */
+#define MSGF_MISC_SR_RXMSG_AVAIL       BIT(0)
+#define MSGF_MISC_SR_RXMSG_OVER                BIT(1)
+#define MSGF_MISC_SR_SLAVE_ERR         BIT(4)
+#define MSGF_MISC_SR_MASTER_ERR                BIT(5)
+#define MSGF_MISC_SR_I_ADDR_ERR                BIT(6)
+#define MSGF_MISC_SR_E_ADDR_ERR                BIT(7)
+
+#define MSGF_MISC_SR_PCIE_CORE         GENMASK(18, 16)
+#define MSGF_MISC_SR_PCIE_CORE_ERR     GENMASK(31, 20)
+
+#define MSGF_MISC_SR_MASKALL           (MSGF_MISC_SR_RXMSG_AVAIL | \
+                                       MSGF_MISC_SR_RXMSG_OVER | \
+                                       MSGF_MISC_SR_SLAVE_ERR | \
+                                       MSGF_MISC_SR_MASTER_ERR | \
+                                       MSGF_MISC_SR_I_ADDR_ERR | \
+                                       MSGF_MISC_SR_E_ADDR_ERR | \
+                                       MSGF_MISC_SR_PCIE_CORE | \
+                                       MSGF_MISC_SR_PCIE_CORE_ERR)
+
+/* Message rx fifo type mask bits */
+#define MSGF_RX_FIFO_TYPE_MSI  (1)
+#define MSGF_RX_FIFO_TYPE_TYPE GENMASK(1, 0)
+
+/* Legacy interrupt status mask bits */
+#define MSGF_LEG_SR_INTA               BIT(0)
+#define MSGF_LEG_SR_INTB               BIT(1)
+#define MSGF_LEG_SR_INTC               BIT(2)
+#define MSGF_LEG_SR_INTD               BIT(3)
+#define MSGF_LEG_SR_MASKALL            (MSGF_LEG_SR_INTA | MSGF_LEG_SR_INTB | \
+                                       MSGF_LEG_SR_INTC | MSGF_LEG_SR_INTD)
+
+/* MSI interrupt status mask bits */
+#define MSGF_MSI_SR_LO_MASK            BIT(0)
+#define MSGF_MSI_SR_HI_MASK            BIT(0)
+
+#define MSII_PRESENT                   BIT(0)
+#define MSII_ENABLE                    BIT(0)
+#define MSII_STATUS_ENABLE             BIT(15)
+
+/* Bridge config interrupt mask */
+#define BRCFG_INTERRUPT_MASK           BIT(0)
+#define BREG_PRESENT                   BIT(0)
+#define BREG_ENABLE                    BIT(0)
+#define BREG_ENABLE_FORCE              BIT(1)
+
+/* E_ECAM status mask bits */
+#define E_ECAM_PRESENT                 BIT(0)
+#define E_ECAM_SR_WR_PEND              BIT(16)
+#define E_ECAM_SR_RD_PEND              BIT(0)
+#define E_ECAM_SR_MASKALL              (E_ECAM_SR_WR_PEND | E_ECAM_SR_RD_PEND)
+#define E_ECAM_CR_ENABLE               BIT(0)
+#define E_ECAM_SIZE_LOC                        GENMASK(20, 16)
+#define E_ECAM_SIZE_SHIFT              16
+#define ECAM_BUS_LOC_SHIFT             20
+#define ECAM_DEV_LOC_SHIFT             12
+#define NWL_ECAM_VALUE_DEFAULT         12
+#define NWL_ECAM_SIZE_MIN              4096
+
+#define ATTR_UPSTREAM_FACING           BIT(6)
+#define CFG_DMA_REG_BAR                        GENMASK(2, 0)
+
+/* msgf_rx_fifo_pop bits */
+#define MSGF_RX_FIFO_POP_POP   BIT(0)
+
+#define INT_PCI_MSI_NR                 (2 * 32)
+
+/* Readin the PS_LINKUP */
+#define PS_LINKUP_OFFSET                       0x00000238
+#define PCIE_PHY_LINKUP_BIT                    BIT(0)
+#define PHY_RDY_LINKUP_BIT                     BIT(1)
+#define PCIE_USER_LINKUP                       0
+#define PHY_RDY_LINKUP                         1
+#define LINKUP_ITER_CHECK                      5
+
+/* PCIE Message Request */
+#define TX_PCIE_MSG                            0x00000620
+#define TX_PCIE_MSG_CNTL                       0x00000004
+#define TX_PCIE_MSG_SPEC_LO                    0x00000008
+#define TX_PCIE_MSG_SPEC_HI                    0x0000000C
+#define TX_PCIE_MSG_DATA                       0x00000010
+
+#define MSG_BUSY_BIT                           BIT(8)
+#define MSG_EXECUTE_BIT                                BIT(0)
+#define MSG_DONE_BIT                           BIT(16)
+#define MSG_DONE_STATUS_BIT                    (BIT(25) | BIT(24))
+#define RANDOM_DIGIT                           0x11223344
+#define PATTRN_SSLP_TLP                                0x01005074
+
+/**
+ * struct nwl_msi - MSI information
+ *
+ * @chip: MSI controller
+ * @used: Declare Bitmap for MSI
+ * @domain: IRQ domain pointer
+ * @pages: MSI pages
+ * @lock: mutex lock
+ * @irq_msi0: msi0 interrupt number
+ * @irq_msi1: msi1 interrupt number
+ */
+struct nwl_msi {
+       struct msi_controller chip;
+       DECLARE_BITMAP(used, INT_PCI_MSI_NR);
+       struct irq_domain *domain;
+       unsigned long pages;
+       struct mutex lock;
+       int irq_msi0;
+       int irq_msi1;
+};
+
+/**
+ * struct nwl_pcie - PCIe port information
+ *
+ * @dev: Device pointer
+ * @breg_base: IO Mapped Bridge Register Base
+ * @pcireg_base: IO Mapped PCIe controller attributes
+ * @ecam_base: IO Mapped configuration space
+ * @phys_breg_base: Physical Bridge Register Base
+ * @phys_pcie_reg_base: Physical PCIe Controller Attributes
+ * @phys_ecam_base: Physical Configuration Base
+ * @breg_size: Bridge Register space
+ * @pcie_reg_size: PCIe controller attributes space
+ * @ecam_size: PCIe Configuration space
+ * @irq_intx: Legacy interrupt number
+ * @irq_misc: Misc interrupt number
+ * @ecam_value: ECAM value
+ * @last_busno: Last Bus number configured
+ * @link_up: Link status flag
+ * @enable_msi_fifo: Enable MSI FIFO mode
+ * @bus: PCI bus
+ * @msi: MSI interrupt info
+ */
+struct nwl_pcie {
+       struct device *dev;
+       void __iomem *breg_base;
+       void __iomem *pcireg_base;
+       void __iomem *ecam_base;
+       u32 phys_breg_base;
+       u32 phys_pcie_reg_base;
+       u32 phys_ecam_base;
+       u32 breg_size;
+       u32 pcie_reg_size;
+       u32 ecam_size;
+       int irq_intx;
+       int irq_misc;
+       u32 ecam_value;
+       u8 last_busno;
+       u8 link_up;
+       bool enable_msi_fifo;
+       struct pci_bus *bus;
+       struct nwl_msi msi;
+};
+
+static inline struct nwl_msi *to_nwl_msi(struct msi_controller *chip)
+{
+       return container_of(chip, struct nwl_msi, chip);
+}
+
+static inline u32 nwl_bridge_readl(struct nwl_pcie *pcie, u32 off)
+{
+       return readl(pcie->breg_base + off);
+}
+
+static inline void nwl_bridge_writel(struct nwl_pcie *pcie, u32 val, u32 off)
+{
+       writel(val, pcie->breg_base + off);
+}
+
+static inline bool nwl_pcie_is_link_up(struct nwl_pcie *pcie, u32 check_bit)
+{
+       unsigned int status = -EINVAL;
+
+       if (check_bit == PCIE_USER_LINKUP)
+               status = (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) &
+                         PCIE_PHY_LINKUP_BIT) ? 1 : 0;
+       else if (check_bit == PHY_RDY_LINKUP)
+               status = (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) &
+                         PHY_RDY_LINKUP_BIT) ? 1 : 0;
+       return status;
+}
+
+/**
+ * nwl_pcie_get_config_base - Get configuration base
+ *
+ * @bus: Bus structure of current bus
+ * @devfn: Device/function
+ * @where: Offset from base
+ *
+ * Return: Base address of the configuration space needed to be
+ *        accessed.
+ */
+static void __iomem *nwl_pcie_get_config_base(struct pci_bus *bus,
+                                                unsigned int devfn,
+                                                int where)
+{
+       struct nwl_pcie *pcie = bus->sysdata;
+       int relbus;
+
+       relbus = (bus->number << ECAM_BUS_LOC_SHIFT) |
+                       (devfn << ECAM_DEV_LOC_SHIFT);
+
+       return pcie->ecam_base + relbus + where;
+}
+
+/**
+ * nwl_setup_sspl - Set Slot Power limit
+ *
+ * @pcie: PCIe port information
+ */
+static int nwl_setup_sspl(struct nwl_pcie *pcie)
+{
+       unsigned int status;
+       int check = 0;
+
+       do {
+               status = nwl_bridge_readl(pcie, TX_PCIE_MSG) & MSG_BUSY_BIT;
+               if (!status) {
+                       /*
+                        * Generate the TLP message for a single EP
+                        * [TODO] Add a multi-endpoint code
+                        */
+                       nwl_bridge_writel(pcie, 0x0,
+                                         TX_PCIE_MSG + TX_PCIE_MSG_CNTL);
+                       nwl_bridge_writel(pcie, 0x0,
+                                         TX_PCIE_MSG + TX_PCIE_MSG_SPEC_LO);
+                       nwl_bridge_writel(pcie, 0x0,
+                                         TX_PCIE_MSG + TX_PCIE_MSG_SPEC_HI);
+                       nwl_bridge_writel(pcie, 0x0,
+                                         TX_PCIE_MSG + TX_PCIE_MSG_DATA);
+                       /* Pattern to generate SSLP TLP */
+                       nwl_bridge_writel(pcie, PATTRN_SSLP_TLP,
+                                         TX_PCIE_MSG + TX_PCIE_MSG_CNTL);
+                       nwl_bridge_writel(pcie, RANDOM_DIGIT,
+                                         TX_PCIE_MSG + TX_PCIE_MSG_DATA);
+                       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie,
+                                         TX_PCIE_MSG) | 0x1, TX_PCIE_MSG);
+                       status = 0;
+                       do {
+                               status = nwl_bridge_readl(pcie, TX_PCIE_MSG) &
+                                                         MSG_DONE_BIT;
+                               if (!status && (check < 1)) {
+                                       mdelay(1);
+                                       check++;
+                               } else {
+                                       return false;
+                               }
+
+                       } while (!status);
+                       status = nwl_bridge_readl(pcie, TX_PCIE_MSG)
+                                                 & MSG_DONE_STATUS_BIT;
+               }
+       } while (status);
+
+       return true;
+}
+
+/**
+ * nwl_nwl_readl_config - Read configuration space
+ *
+ * @bus: Bus structure of current bus
+ * @devfn: Device/function
+ * @where: Offset from base
+ * @size: Byte/word/dword
+ * @val: Value to be read
+ *
+ * Return: PCIBIOS_SUCCESSFUL on success
+ *        PCIBIOS_DEVICE_NOT_FOUND on failure.
+ */
+static int nwl_nwl_readl_config(struct pci_bus *bus,
+                               unsigned int devfn,
+                               int where,
+                               int size,
+                               u32 *val)
+{
+       void __iomem *addr;
+
+       if (!bus->number && devfn > 0) {
+               *val = 0xFFFFFFFF;
+               return PCIBIOS_DEVICE_NOT_FOUND;
+       }
+
+       addr = nwl_pcie_get_config_base(bus, devfn, where);
+
+       switch (size) {
+       case 1:
+               *val = readb(addr);
+               break;
+       case 2:
+               *val = readw(addr);
+               break;
+       default:
+               *val = readl(addr);
+               break;
+       }
+       return PCIBIOS_SUCCESSFUL;
+}
+
+/**
+ * nwl_nwl_writel_config - Write configuration space
+ *
+ * @bus: Bus structure of current bus
+ * @devfn: Device/function
+ * @where: Offset from base
+ * @size: Byte/word/dword
+ * @val: Value to be written to device
+ *
+ * Return: PCIBIOS_SUCCESSFUL on success,
+ *        PCIBIOS_DEVICE_NOT_FOUND on failure.
+ */
+static int nwl_nwl_writel_config(struct pci_bus *bus,
+                               unsigned int devfn,
+                               int where,
+                               int size,
+                               u32 val)
+{
+       void __iomem *addr;
+       int err = 0;
+       struct nwl_pcie *pcie = bus->sysdata;
+
+       if (!bus->number && devfn > 0)
+               return PCIBIOS_DEVICE_NOT_FOUND;
+
+       addr = nwl_pcie_get_config_base(bus, devfn, where);
+
+       switch (size) {
+       case 1:
+               writeb(val, addr);
+               break;
+       case 2:
+               writew(val, addr);
+               break;
+       default:
+               writel(val, addr);
+               break;
+       }
+       if (addr == (pcie->ecam_base + PCI_EXP_SLTCAP)) {
+               err = nwl_setup_sspl(pcie);
+               if (!err)
+                       return PCIBIOS_SET_FAILED;
+       }
+
+       return PCIBIOS_SUCCESSFUL;
+}
+
+/* PCIe operations */
+static struct pci_ops nwl_pcie_ops = {
+       .read  = nwl_nwl_readl_config,
+       .write = nwl_nwl_writel_config,
+};
+
+static irqreturn_t nwl_pcie_misc_handler(int irq, void *data)
+{
+       struct nwl_pcie *pcie = (struct nwl_pcie *)data;
+       u32 misc_stat;
+
+       /* Checking for misc interrupts */
+       misc_stat = nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
+                                    MSGF_MISC_SR_MASKALL;
+       if (!misc_stat)
+               return IRQ_NONE;
+
+       if (misc_stat & MSGF_MISC_SR_RXMSG_OVER)
+               dev_err(pcie->dev, "Received Message FIFO Overflow\n");
+
+       if (misc_stat & MSGF_MISC_SR_SLAVE_ERR)
+               dev_err(pcie->dev, "Slave error\n");
+
+       if (misc_stat & MSGF_MISC_SR_MASTER_ERR)
+               dev_err(pcie->dev, "Master error\n");
+
+       if (misc_stat & MSGF_MISC_SR_I_ADDR_ERR)
+               dev_err(pcie->dev,
+                       "In Misc Ingress address translation error\n");
+
+       if (misc_stat & MSGF_MISC_SR_E_ADDR_ERR)
+               dev_err(pcie->dev,
+                       "In Misc Egress address translation error\n");
+
+       if (misc_stat & MSGF_MISC_SR_PCIE_CORE_ERR)
+               dev_err(pcie->dev, "PCIe Core error\n");
+
+       if (pcie->enable_msi_fifo) {
+               if (misc_stat & MSGF_MISC_SR_RXMSG_AVAIL) {
+                       u32 msg_type = nwl_bridge_readl(pcie,
+                                                       MSGF_RX_FIFO_TYPE) &
+                                                       MSGF_RX_FIFO_TYPE_TYPE;
+
+                       if (msg_type == MSGF_RX_FIFO_TYPE_MSI) {
+                               u32 irq_msi;
+                               struct nwl_msi *msi = &pcie->msi;
+                               u32 msi_data = nwl_bridge_readl(pcie,
+                                                       MSGF_RX_FIFO_DATA);
+                               /* Let all ready be completed before write */
+                               rmb();
+                               /* POP the FIFO */
+                               nwl_bridge_writel(pcie, MSGF_RX_FIFO_POP_POP,
+                                                 MSGF_RX_FIFO_POP);
+
+                               /* Handle the msi virtual interrupt */
+                               irq_msi = irq_find_mapping(msi->domain,
+                                                          msi_data);
+
+                               if (irq_msi) {
+                                       if (test_bit(msi_data, msi->used))
+                                               generic_handle_irq(irq_msi);
+                                       else
+                                               dev_info(pcie->dev,
+                                                        "unhandled MSI %d\n",
+                                                        irq_msi);
+                               } else {
+                                       dev_info(pcie->dev, "unexpected MSI\n");
+                               }
+                       }
+               }
+       }
+       /* Clear misc interrupt status */
+       nwl_bridge_writel(pcie, misc_stat, MSGF_MISC_STATUS);
+
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t nwl_pcie_leg_handler(int irq, void *data)
+{
+       struct nwl_pcie *pcie = (struct nwl_pcie *)data;
+       u32 leg_stat;
+
+       /* Checking for legacy interrupts */
+       leg_stat = nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
+                               MSGF_LEG_SR_MASKALL;
+       if (!leg_stat)
+               return IRQ_NONE;
+
+       if (leg_stat & MSGF_LEG_SR_INTA)
+               dev_dbg(pcie->dev, "legacy interruptA\n");
+
+       if (leg_stat & MSGF_LEG_SR_INTB)
+               dev_dbg(pcie->dev, "legacy interruptB\n");
+
+       if (leg_stat & MSGF_LEG_SR_INTC)
+               dev_dbg(pcie->dev, "legacy interruptC\n");
+
+       if (leg_stat & MSGF_LEG_SR_INTD)
+               dev_dbg(pcie->dev, "legacy interruptD\n");
+
+       return IRQ_HANDLED;
+}
+
+static void __nwl_pcie_msi_handler(struct nwl_pcie *pcie,
+                                       unsigned long reg, u32 val)
+{
+       struct nwl_msi *msi = &pcie->msi;
+       unsigned int offset, index;
+       int irq_msi;
+
+       offset = find_first_bit(&reg, 32);
+       index = offset;
+
+       /* Clear the interrupt */
+       nwl_bridge_writel(pcie, 1 << offset, val);
+
+       /* Handle the msi virtual interrupt */
+       irq_msi = irq_find_mapping(msi->domain, index);
+       if (irq_msi) {
+               if (test_bit(index, msi->used))
+                       generic_handle_irq(irq_msi);
+               else
+                       dev_info(pcie->dev, "unhandled MSI\n");
+       } else {
+               /* that's weird who triggered this? just clear it */
+               dev_info(pcie->dev, "unexpected MSI\n");
+       }
+}
+
+static irqreturn_t nwl_pcie_msi_handler(int irq, void *data)
+{
+       struct nwl_pcie *pcie = data;
+       unsigned long reg;
+       int processed = 0;
+
+       reg = nwl_bridge_readl(pcie, MSGF_MSI_STATUS_LO);
+       if (reg) {
+               __nwl_pcie_msi_handler(pcie, reg, MSGF_MSI_STATUS_LO);
+               processed++;
+       }
+
+       reg = nwl_bridge_readl(pcie, MSGF_MSI_STATUS_HI);
+       if (reg) {
+               __nwl_pcie_msi_handler(pcie, reg, MSGF_MSI_STATUS_HI);
+               processed++;
+       }
+
+       return processed > 0 ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int nwl_msi_alloc(struct nwl_msi *chip)
+{
+       int msi;
+
+       mutex_lock(&chip->lock);
+
+       msi = find_first_zero_bit(chip->used, INT_PCI_MSI_NR);
+       if (msi < INT_PCI_MSI_NR)
+               set_bit(msi, chip->used);
+       else
+               msi = -ENOSPC;
+
+       mutex_unlock(&chip->lock);
+
+       return msi;
+}
+
+static void nwl_msi_free(struct nwl_msi *chip, unsigned long irq)
+{
+       struct device *dev = chip->chip.dev;
+
+       mutex_lock(&chip->lock);
+
+       if (!test_bit(irq, chip->used))
+               dev_err(dev, "trying to free unused MSI#%lu\n", irq);
+       else
+               clear_bit(irq, chip->used);
+
+       mutex_unlock(&chip->lock);
+}
+
+static int nwl_msi_setup_irq(struct msi_controller *chip, struct pci_dev *pdev,
+                              struct msi_desc *desc)
+{
+       struct nwl_msi *msi = to_nwl_msi(chip);
+       struct msi_msg msg;
+       unsigned int irq;
+       int hwirq;
+
+       if (desc->msi_attrib.is_msix) {
+               /* currently we are not supporting MSIx */
+               return -ENOSPC;
+       }
+
+       hwirq = nwl_msi_alloc(msi);
+       if (hwirq < 0)
+               return hwirq;
+
+       irq = irq_create_mapping(msi->domain, hwirq);
+       if (!irq)
+               return -EINVAL;
+
+       irq_set_msi_desc(irq, desc);
+
+       msg.address_lo = virt_to_phys((void *)msi->pages);
+       /* 32 bit address only */
+       msg.address_hi = 0;
+       msg.data = hwirq;
+
+       write_msi_msg(irq, &msg);
+
+       return 0;
+}
+
+static void nwl_msi_teardown_irq(struct msi_controller *chip, unsigned int irq)
+{
+       struct nwl_msi *msi = to_nwl_msi(chip);
+       struct irq_data *d = irq_get_irq_data(irq);
+
+       nwl_msi_free(msi, d->hwirq);
+}
+
+static struct irq_chip nwl_msi_irq_chip = {
+       .name = "nwl_pcie:msi",
+       .irq_enable = unmask_msi_irq,
+       .irq_disable = mask_msi_irq,
+       .irq_mask = mask_msi_irq,
+       .irq_unmask = unmask_msi_irq,
+};
+
+static int nwl_msi_map(struct irq_domain *domain, unsigned int irq,
+                        irq_hw_number_t hwirq)
+{
+       irq_set_chip_and_handler(irq, &nwl_msi_irq_chip, handle_simple_irq);
+       irq_set_chip_data(irq, domain->host_data);
+       set_irq_flags(irq, IRQF_VALID);
+
+       return 0;
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+       .map = nwl_msi_map,
+};
+
+static int nwl_pcie_enable_msi(struct nwl_pcie *pcie, struct pci_bus *bus)
+{
+       struct platform_device *pdev = to_platform_device(pcie->dev);
+       struct nwl_msi *msi = &pcie->msi;
+       unsigned long base;
+       int ret;
+
+       mutex_init(&msi->lock);
+
+       /* Assign msi chip hooks */
+       msi->chip.dev = pcie->dev;
+       msi->chip.setup_irq = nwl_msi_setup_irq;
+       msi->chip.teardown_irq = nwl_msi_teardown_irq;
+
+       bus->msi = &msi->chip;
+       /* Allocate linear irq domain */
+       msi->domain = irq_domain_add_linear(pcie->dev->of_node, INT_PCI_MSI_NR,
+                                           &msi_domain_ops, &msi->chip);
+       if (!msi->domain) {
+               dev_err(&pdev->dev, "failed to create IRQ domain\n");
+               return -ENOMEM;
+       }
+
+       /* Check for msii_present bit */
+       ret = nwl_bridge_readl(pcie, I_MSII_CAPABILITIES) & MSII_PRESENT;
+       if (!ret) {
+               dev_err(pcie->dev, "MSI not present\n");
+               ret = -EIO;
+               goto err;
+       }
+
+       /* Enable MSII */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
+                         MSII_ENABLE, I_MSII_CONTROL);
+       if (!pcie->enable_msi_fifo)
+               /* Enable MSII status */
+               nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
+                                 MSII_STATUS_ENABLE, I_MSII_CONTROL);
+
+       /* setup AFI/FPCI range */
+       msi->pages = __get_free_pages(GFP_KERNEL, 0);
+       base = virt_to_phys((void *)msi->pages);
+       /* Write base to MSII_BASE_LO */
+       nwl_bridge_writel(pcie, base, I_MSII_BASE_LO);
+
+       /* Write 0x0 to MSII_BASE_HI */
+       nwl_bridge_writel(pcie, 0x0, I_MSII_BASE_HI);
+
+       /* Disable high range msi interrupts */
+       nwl_bridge_writel(pcie, (u32)~MSGF_MSI_SR_HI_MASK, MSGF_MSI_MASK_HI);
+
+       /* Clear pending high range msi interrupts */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie,  MSGF_MSI_STATUS_HI) &
+                         MSGF_MSI_SR_HI_MASK, MSGF_MSI_STATUS_HI);
+       /* Get msi_1 IRQ number */
+       msi->irq_msi1 = platform_get_irq_byname(pdev, "msi_1");
+       if (msi->irq_msi1 < 0) {
+               dev_err(&pdev->dev, "failed to get IRQ#%d\n", msi->irq_msi1);
+               goto err;
+       }
+       /* Register msi handler */
+       ret = devm_request_irq(pcie->dev, msi->irq_msi1, nwl_pcie_msi_handler,
+                              0, nwl_msi_irq_chip.name, pcie);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "failed to request IRQ#%d\n",
+                                       msi->irq_msi1);
+               goto err;
+       }
+
+       /* Enable all high range msi interrupts */
+       nwl_bridge_writel(pcie, MSGF_MSI_SR_HI_MASK, MSGF_MSI_MASK_HI);
+
+       /* Disable low range msi interrupts */
+       nwl_bridge_writel(pcie, (u32)~MSGF_MSI_SR_LO_MASK, MSGF_MSI_MASK_LO);
+
+       /* Clear pending low range msi interrupts */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MSI_STATUS_LO) &
+                         MSGF_MSI_SR_LO_MASK, MSGF_MSI_STATUS_LO);
+       /* Get msi_0 IRQ number */
+       msi->irq_msi0 = platform_get_irq_byname(pdev, "msi_0");
+       if (msi->irq_msi0 < 0) {
+               dev_err(&pdev->dev, "failed to get IRQ#%d\n", msi->irq_msi0);
+               goto err;
+       }
+       /* Register msi handler */
+       ret = devm_request_irq(pcie->dev, msi->irq_msi0, nwl_pcie_msi_handler,
+                              0, nwl_msi_irq_chip.name, pcie);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "failed to request IRQ#%d\n",
+                                       msi->irq_msi0);
+               goto err;
+       }
+       /* Enable all low range msi interrupts */
+       nwl_bridge_writel(pcie, MSGF_MSI_SR_LO_MASK, MSGF_MSI_MASK_LO);
+
+       return 0;
+err:
+       irq_domain_remove(msi->domain);
+       return ret;
+}
+
+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);
+
+       /* Enable BREG */
+       nwl_bridge_writel(pcie, ~BREG_ENABLE_FORCE & BREG_ENABLE,
+                         E_BREG_CONTROL);
+
+       /* Disable DMA channel registers */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_PCIE_RX0) |
+                         CFG_DMA_REG_BAR, BRCFG_PCIE_RX0);
+
+       /* Enable the bridge config interrupt */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_INTERRUPT) |
+                         BRCFG_INTERRUPT_MASK, BRCFG_INTERRUPT);
+       /* Enable Ingress subtractive decode translation */
+       nwl_bridge_writel(pcie, SET_ISUB_CONTROL, I_ISUB_CONTROL);
+
+       /* Enable msg filtering details */
+       nwl_bridge_writel(pcie, CFG_ENABLE_MSG_FILTER_MASK,
+                         BRCFG_PCIE_RX_MSG_FILTER);
+       do {
+               err = nwl_pcie_is_link_up(pcie, PHY_RDY_LINKUP);
+               if (err != 1) {
+                       check_link_up++;
+                       if (check_link_up > LINKUP_ITER_CHECK)
+                               return -ENODEV;
+               }
+       } while (!err);
+
+       /* 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;
+       }
+
+       /* Enable ECAM */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
+                         E_ECAM_CR_ENABLE, E_ECAM_CONTROL);
+       /* Write ecam_value on ecam_control */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
+                         (pcie->ecam_value << E_ECAM_SIZE_SHIFT),
+                         E_ECAM_CONTROL);
+       /* Write phy_reg_base to ecam base */
+       nwl_bridge_writel(pcie, (u32)pcie->phys_ecam_base, E_ECAM_BASE_LO);
+
+       /* Get bus range */
+       ecam_val = nwl_bridge_readl(pcie, E_ECAM_CONTROL);
+       pcie->last_busno = (ecam_val & E_ECAM_SIZE_LOC) >> E_ECAM_SIZE_SHIFT;
+       /* Write primary, secondary and subordinate bus numbers */
+       ecam_val = first_busno;
+       ecam_val |= (first_busno + 1) << 8;
+       ecam_val |= (pcie->last_busno << E_ECAM_SIZE_SHIFT);
+       writel(ecam_val, (pcie->ecam_base + PCI_PRIMARY_BUS));
+
+       /* Check if PCIe link is up? */
+       pcie->link_up = nwl_pcie_is_link_up(pcie, PCIE_USER_LINKUP);
+       if (!pcie->link_up)
+               dev_info(pcie->dev, "Link is DOWN\n");
+       else
+               dev_info(pcie->dev, "Link is UP\n");
+
+       /* Disable all misc interrupts */
+       nwl_bridge_writel(pcie, (u32)~MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);
+
+       /* Clear pending misc interrupts */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
+                         MSGF_MISC_SR_MASKALL, MSGF_MISC_STATUS);
+
+       /* Get misc IRQ number */
+       pcie->irq_misc = platform_get_irq_byname(pdev, "misc");
+       if (pcie->irq_misc < 0) {
+               dev_err(&pdev->dev, "failed to get misc IRQ#%d\n",
+                       pcie->irq_misc);
+               return pcie->irq_misc;
+       }
+       /* Register misc handler */
+       err = devm_request_irq(pcie->dev, pcie->irq_misc,
+                              nwl_pcie_misc_handler, IRQF_SHARED,
+                              "nwl_pcie:misc", pcie);
+       if (err) {
+               dev_err(pcie->dev, "fail to register misc IRQ#%d\n",
+                       pcie->irq_misc);
+               return err;
+       }
+       /* Enable all misc interrupts */
+       nwl_bridge_writel(pcie, MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);
+
+       /* Disable all legacy interrupts */
+       nwl_bridge_writel(pcie, (u32)~MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);
+
+       /* Clear pending legacy interrupts */
+       nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
+                         MSGF_LEG_SR_MASKALL, MSGF_LEG_STATUS);
+       /* Get intx IRQ number */
+       pcie->irq_intx = platform_get_irq_byname(pdev, "intx");
+       if (pcie->irq_intx < 0) {
+               dev_err(&pdev->dev, "failed to get intx IRQ#%d\n",
+                       pcie->irq_intx);
+               return pcie->irq_intx;
+       }
+
+       /* Register intx handler */
+       err = devm_request_irq(pcie->dev, pcie->irq_intx,
+                              nwl_pcie_leg_handler, IRQF_SHARED,
+                              "nwl_pcie:intx", pcie);
+       if (err) {
+               dev_err(pcie->dev, "fail to register intx IRQ#%d\n",
+                       pcie->irq_intx);
+               return err;
+       }
+       /* Enable all legacy interrupts */
+       nwl_bridge_writel(pcie, MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);
+
+       return 0;
+}
+
+static int nwl_pcie_parse_dt(struct nwl_pcie *pcie,
+                                       struct platform_device *pdev)
+{
+       struct device_node *node = pcie->dev->of_node;
+       struct resource *res;
+       const char *type;
+
+       /* Check for device type */
+       type = of_get_property(node, "device_type", NULL);
+       if (!type || strcmp(type, "pci")) {
+               dev_err(pcie->dev, "invalid \"device_type\" %s\n", type);
+               return -EINVAL;
+       }
+
+       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "breg");
+       pcie->breg_base = devm_ioremap_resource(pcie->dev, res);
+       if (IS_ERR(pcie->breg_base))
+               return PTR_ERR(pcie->breg_base);
+       pcie->phys_breg_base = res->start;
+
+       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcireg");
+       pcie->pcireg_base = devm_ioremap_resource(pcie->dev, res);
+       if (IS_ERR(pcie->pcireg_base))
+               return PTR_ERR(pcie->pcireg_base);
+       pcie->phys_pcie_reg_base = res->start;
+
+       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+       pcie->ecam_base = devm_ioremap_resource(pcie->dev, res);
+       if (IS_ERR(pcie->ecam_base))
+               return PTR_ERR(pcie->ecam_base);
+       pcie->phys_ecam_base = res->start;
+
+       pcie->enable_msi_fifo = of_property_read_bool(node, "xlnx,msi-fifo");
+
+       return 0;
+}
+
+static const struct of_device_id nwl_pcie_of_match[] = {
+       { .compatible = "xlnx,nwl-pcie-2.11", },
+       {}
+};
+
+static int nwl_pcie_probe(struct platform_device *pdev)
+{
+       struct device_node *node = pdev->dev.of_node;
+       struct nwl_pcie *pcie;
+       struct pci_bus *bus;
+       int err;
+
+       resource_size_t iobase = 0;
+       LIST_HEAD(res);
+
+       /* Allocate private nwl_pcie struct */
+       pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+       if (!pcie)
+               return -ENOMEM;
+
+       /* Set ecam value */
+       pcie->ecam_value = NWL_ECAM_VALUE_DEFAULT;
+
+       pcie->dev = &pdev->dev;
+
+       /* Parse the device tree */
+       err = nwl_pcie_parse_dt(pcie, pdev);
+       if (err) {
+               dev_err(pcie->dev, "Parsing DT failed\n");
+               return err;
+       }
+       /* Bridge initialization */
+       err = nwl_pcie_bridge_init(pcie);
+       if (err) {
+               dev_err(pcie->dev, "HW Initalization failed\n");
+               return err;
+       }
+
+       err = of_pci_get_host_bridge_resources(node, 0, 0xff, &res, &iobase);
+       if (err) {
+               pr_err("Getting bridge resources failed\n");
+               return err;
+       }
+       bus = pci_create_root_bus(&pdev->dev, 0,
+                                 &nwl_pcie_ops, pcie, &res);
+       if (!bus)
+               return -ENOMEM;
+
+       /* Enable MSI */
+       if (IS_ENABLED(CONFIG_PCI_MSI)) {
+               err = nwl_pcie_enable_msi(pcie, bus);
+               if (err < 0) {
+                       dev_err(&pdev->dev,
+                               "failed to enable MSI support: %d\n",
+                               err);
+                       return err;
+               }
+       }
+       pci_scan_child_bus(bus);
+       pci_assign_unassigned_bus_resources(bus);
+       pci_bus_add_devices(bus);
+       platform_set_drvdata(pdev, pcie);
+
+       return 0;
+}
+
+static int nwl_pcie_remove(struct platform_device *pdev)
+{
+       platform_set_drvdata(pdev, NULL);
+
+       return 0;
+}
+
+static struct platform_driver nwl_pcie_driver = {
+       .driver = {
+               .name = "nwl-pcie",
+               .of_match_table = nwl_pcie_of_match,
+       },
+       .probe = nwl_pcie_probe,
+       .remove = nwl_pcie_remove,
+};
+module_platform_driver(nwl_pcie_driver);
+
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_DESCRIPTION("NWL PCIe driver");
+MODULE_LICENSE("GPL");
--
1.7.4
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