[2/5] PCI: iproc: Add PAXC interface support

diff --git a/drivers/pci/host/pcie-iproc-platform.c b/drivers/pci/host/pcie-iproc-platform.c
index c9550dc..716b56b 100644
--- a/drivers/pci/host/pcie-iproc-platform.c
+++ b/drivers/pci/host/pcie-iproc-platform.c
@@ -42,6 +42,13 @@  static int iproc_pcie_pltfm_probe(struct platform_device *pdev)
 	pcie->dev = &pdev->dev;
 	platform_set_drvdata(pdev, pcie);
 
+	if (of_device_is_compatible(np, "brcm,iproc-pcie"))
+		pcie->type = IPROC_PCIE_PAXB;
+	else if (of_device_is_compatible(np, "brcm,iproc-pcie-paxc"))
+		pcie->type = IPROC_PCIE_PAXC;
+	else
+		return -ENODEV;
+
 	ret = of_address_to_resource(np, 0, &reg);
 	if (ret < 0) {
 		dev_err(pcie->dev, "unable to obtain controller resources\n");
@@ -116,6 +123,7 @@  static int iproc_pcie_pltfm_remove(struct platform_device *pdev)
 
 static const struct of_device_id iproc_pcie_of_match_table[] = {
 	{ .compatible = "brcm,iproc-pcie", },
+	{ .compatible = "brcm,iproc-pcie-paxc", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, iproc_pcie_of_match_table);
diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
index eac719a..24d5b62 100644
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -30,20 +30,16 @@ 
 
 #include "pcie-iproc.h"
 
-#define CLK_CONTROL_OFFSET           0x000
 #define EP_PERST_SOURCE_SELECT_SHIFT 2
 #define EP_PERST_SOURCE_SELECT       BIT(EP_PERST_SOURCE_SELECT_SHIFT)
 #define EP_MODE_SURVIVE_PERST_SHIFT  1
 #define EP_MODE_SURVIVE_PERST        BIT(EP_MODE_SURVIVE_PERST_SHIFT)
 #define RC_PCIE_RST_OUTPUT_SHIFT     0
 #define RC_PCIE_RST_OUTPUT           BIT(RC_PCIE_RST_OUTPUT_SHIFT)
+#define PAXC_RESET_MASK              0x7f
 
-#define CFG_IND_ADDR_OFFSET          0x120
 #define CFG_IND_ADDR_MASK            0x00001ffc
 
-#define CFG_IND_DATA_OFFSET          0x124
-
-#define CFG_ADDR_OFFSET              0x1f8
 #define CFG_ADDR_BUS_NUM_SHIFT       20
 #define CFG_ADDR_BUS_NUM_MASK        0x0ff00000
 #define CFG_ADDR_DEV_NUM_SHIFT       15
@@ -55,12 +51,8 @@ 
 #define CFG_ADDR_CFG_TYPE_SHIFT      0
 #define CFG_ADDR_CFG_TYPE_MASK       0x00000003
 
-#define CFG_DATA_OFFSET              0x1fc
-
-#define SYS_RC_INTX_EN               0x330
 #define SYS_RC_INTX_MASK             0xf
 
-#define PCIE_LINK_STATUS_OFFSET      0xf0c
 #define PCIE_PHYLINKUP_SHIFT         3
 #define PCIE_PHYLINKUP               BIT(PCIE_PHYLINKUP_SHIFT)
 #define PCIE_DL_ACTIVE_SHIFT         2
@@ -71,12 +63,54 @@ 
 #define OARR_SIZE_CFG_SHIFT          1
 #define OARR_SIZE_CFG                BIT(OARR_SIZE_CFG_SHIFT)
 
-#define OARR_LO(window)              (0xd20 + (window) * 8)
-#define OARR_HI(window)              (0xd24 + (window) * 8)
-#define OMAP_LO(window)              (0xd40 + (window) * 8)
-#define OMAP_HI(window)              (0xd44 + (window) * 8)
-
 #define MAX_NUM_OB_WINDOWS           2
+#define MAX_NUM_PAXC_PF              4
+
+#define IPROC_PCIE_REG_INVALID 0xffff
+
+enum iproc_pcie_reg {
+	IPROC_PCIE_CLK_CTRL = 0,
+	IPROC_PCIE_CFG_IND_ADDR,
+	IPROC_PCIE_CFG_IND_DATA,
+	IPROC_PCIE_CFG_ADDR,
+	IPROC_PCIE_CFG_DATA,
+	IPROC_PCIE_INTX_EN,
+	IPROC_PCIE_OARR_LO,
+	IPROC_PCIE_OARR_HI,
+	IPROC_PCIE_OMAP_LO,
+	IPROC_PCIE_OMAP_HI,
+	IPROC_PCIE_LINK_STATUS,
+};
+
+/* iProc PCIe PAXB registers */
+static const u16 iproc_pcie_reg_paxb[] = {
+	[IPROC_PCIE_CLK_CTRL]     = 0x000,
+	[IPROC_PCIE_CFG_IND_ADDR] = 0x120,
+	[IPROC_PCIE_CFG_IND_DATA] = 0x124,
+	[IPROC_PCIE_CFG_ADDR]     = 0x1f8,
+	[IPROC_PCIE_CFG_DATA]     = 0x1fc,
+	[IPROC_PCIE_INTX_EN]      = 0x330,
+	[IPROC_PCIE_OARR_LO]      = 0xd20,
+	[IPROC_PCIE_OARR_HI]      = 0xd24,
+	[IPROC_PCIE_OMAP_LO]      = 0xd40,
+	[IPROC_PCIE_OMAP_HI]      = 0xd44,
+	[IPROC_PCIE_LINK_STATUS]  = 0xf0c,
+};
+
+/* iProc PCIe PAXC v1 registers */
+static const u16 iproc_pcie_reg_paxc[] = {
+	[IPROC_PCIE_CLK_CTRL]     = 0x000,
+	[IPROC_PCIE_CFG_IND_ADDR] = 0x1f0,
+	[IPROC_PCIE_CFG_IND_DATA] = 0x1f4,
+	[IPROC_PCIE_CFG_ADDR]     = 0x1f8,
+	[IPROC_PCIE_CFG_DATA]     = 0x1fc,
+	[IPROC_PCIE_INTX_EN]      = IPROC_PCIE_REG_INVALID,
+	[IPROC_PCIE_OARR_LO]      = IPROC_PCIE_REG_INVALID,
+	[IPROC_PCIE_OARR_HI]      = IPROC_PCIE_REG_INVALID,
+	[IPROC_PCIE_OMAP_LO]      = IPROC_PCIE_REG_INVALID,
+	[IPROC_PCIE_OMAP_HI]      = IPROC_PCIE_REG_INVALID,
+	[IPROC_PCIE_LINK_STATUS]  = IPROC_PCIE_REG_INVALID,
+};
 
 static inline struct iproc_pcie *iproc_data(struct pci_bus *bus)
 {
@@ -91,6 +125,65 @@  static inline struct iproc_pcie *iproc_data(struct pci_bus *bus)
 	return pcie;
 }
 
+static inline bool iproc_pcie_reg_is_invalid(u16 reg_offset)
+{
+	return !!(reg_offset == IPROC_PCIE_REG_INVALID);
+}
+
+static inline u16 iproc_pcie_reg_offset(struct iproc_pcie *pcie,
+					enum iproc_pcie_reg reg)
+{
+	return pcie->reg_offsets[reg];
+}
+
+static inline u32 iproc_pcie_read_reg(struct iproc_pcie *pcie,
+				      enum iproc_pcie_reg reg)
+{
+	u16 offset = iproc_pcie_reg_offset(pcie, reg);
+
+	if (iproc_pcie_reg_is_invalid(offset))
+		return 0;
+
+	return readl(pcie->base + offset);
+}
+
+static inline void iproc_pcie_write_reg(struct iproc_pcie *pcie,
+					enum iproc_pcie_reg reg, u32 val)
+{
+	u16 offset = iproc_pcie_reg_offset(pcie, reg);
+
+	if (iproc_pcie_reg_is_invalid(offset))
+		return;
+
+	writel(val, pcie->base + offset);
+}
+
+static inline void iproc_pcie_ob_write(struct iproc_pcie *pcie,
+				       enum iproc_pcie_reg reg,
+				       unsigned window, u32 val)
+{
+	u16 offset = iproc_pcie_reg_offset(pcie, reg);
+
+	if (iproc_pcie_reg_is_invalid(offset))
+		return;
+
+	writel(val, pcie->base + offset + (window * 8));
+}
+
+static inline bool iproc_pcie_device_is_valid(struct iproc_pcie *pcie,
+					      unsigned int slot,
+					      unsigned int fn)
+{
+	if (slot > 0)
+		return false;
+
+	/* PAXC can only support limited number of functions */
+	if (pcie->type == IPROC_PCIE_PAXC && fn >= MAX_NUM_PAXC_PF)
+		return false;
+
+	return true;
+}
+
 /**
  * Note access to the configuration registers are protected at the higher layer
  * by 'pci_lock' in drivers/pci/access.c
@@ -104,28 +197,34 @@  static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
 	unsigned fn = PCI_FUNC(devfn);
 	unsigned busno = bus->number;
 	u32 val;
+	u16 offset;
+
+	if (!iproc_pcie_device_is_valid(pcie, slot, fn))
+		return NULL;
 
 	/* root complex access */
 	if (busno == 0) {
-		if (slot >= 1)
+		iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_IND_ADDR,
+				     where & CFG_IND_ADDR_MASK);
+		offset = iproc_pcie_reg_offset(pcie, IPROC_PCIE_CFG_IND_DATA);
+		if (iproc_pcie_reg_is_invalid(offset))
 			return NULL;
-		writel(where & CFG_IND_ADDR_MASK,
-		       pcie->base + CFG_IND_ADDR_OFFSET);
-		return (pcie->base + CFG_IND_DATA_OFFSET);
+		else
+			return (pcie->base + offset);
 	}
 
-	if (fn > 1)
-		return NULL;
-
 	/* EP device access */
 	val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
 		(slot << CFG_ADDR_DEV_NUM_SHIFT) |
 		(fn << CFG_ADDR_FUNC_NUM_SHIFT) |
 		(where & CFG_ADDR_REG_NUM_MASK) |
 		(1 & CFG_ADDR_CFG_TYPE_MASK);
-	writel(val, pcie->base + CFG_ADDR_OFFSET);
-
-	return (pcie->base + CFG_DATA_OFFSET);
+	iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_ADDR, val);
+	offset = iproc_pcie_reg_offset(pcie, IPROC_PCIE_CFG_DATA);
+	if (iproc_pcie_reg_is_invalid(offset))
+		return NULL;
+	else
+		return (pcie->base + offset);
 }
 
 static struct pci_ops iproc_pcie_ops = {
@@ -138,18 +237,29 @@  static void iproc_pcie_reset(struct iproc_pcie *pcie)
 {
 	u32 val;
 
+	if (pcie->type == IPROC_PCIE_PAXC) {
+		val = iproc_pcie_read_reg(pcie, IPROC_PCIE_CLK_CTRL);
+		val &= ~PAXC_RESET_MASK;
+		iproc_pcie_write_reg(pcie, IPROC_PCIE_CLK_CTRL, val);
+		udelay(100);
+		val |= PAXC_RESET_MASK;
+		iproc_pcie_write_reg(pcie, IPROC_PCIE_CLK_CTRL, val);
+		udelay(100);
+		return;
+	}
+
 	/*
 	 * Select perst_b signal as reset source. Put the device into reset,
 	 * and then bring it out of reset
 	 */
-	val = readl(pcie->base + CLK_CONTROL_OFFSET);
+	val = iproc_pcie_read_reg(pcie, IPROC_PCIE_CLK_CTRL);
 	val &= ~EP_PERST_SOURCE_SELECT & ~EP_MODE_SURVIVE_PERST &
 		~RC_PCIE_RST_OUTPUT;
-	writel(val, pcie->base + CLK_CONTROL_OFFSET);
+	iproc_pcie_write_reg(pcie, IPROC_PCIE_CLK_CTRL, val);
 	udelay(250);
 
 	val |= RC_PCIE_RST_OUTPUT;
-	writel(val, pcie->base + CLK_CONTROL_OFFSET);
+	iproc_pcie_write_reg(pcie, IPROC_PCIE_CLK_CTRL, val);
 	msleep(100);
 }
 
@@ -160,7 +270,14 @@  static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
 	u16 pos, link_status;
 	bool link_is_active = false;
 
-	val = readl(pcie->base + PCIE_LINK_STATUS_OFFSET);
+	/*
+	 * PAXC connects to emulated endpoint devices directly and does not
+	 * have a Serdes. Therefore skip the link detection logic here
+	 */
+	if (pcie->type == IPROC_PCIE_PAXC)
+		return 0;
+
+	val = iproc_pcie_read_reg(pcie, IPROC_PCIE_LINK_STATUS);
 	if (!(val & PCIE_PHYLINKUP) || !(val & PCIE_DL_ACTIVE)) {
 		dev_err(pcie->dev, "PHY or data link is INACTIVE!\n");
 		return -ENODEV;
@@ -221,7 +338,7 @@  static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
 
 static void iproc_pcie_enable(struct iproc_pcie *pcie)
 {
-	writel(SYS_RC_INTX_MASK, pcie->base + SYS_RC_INTX_EN);
+	iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, SYS_RC_INTX_MASK);
 }
 
 /**
@@ -272,11 +389,15 @@  static int iproc_pcie_setup_ob(struct iproc_pcie *pcie, u64 axi_addr,
 	axi_addr -= ob->axi_offset;
 
 	for (i = 0; i < MAX_NUM_OB_WINDOWS; i++) {
-		writel(lower_32_bits(axi_addr) | OARR_VALID |
-		       (ob->set_oarr_size ? 1 : 0), pcie->base + OARR_LO(i));
-		writel(upper_32_bits(axi_addr), pcie->base + OARR_HI(i));
-		writel(lower_32_bits(pci_addr), pcie->base + OMAP_LO(i));
-		writel(upper_32_bits(pci_addr), pcie->base + OMAP_HI(i));
+		iproc_pcie_ob_write(pcie, IPROC_PCIE_OARR_LO, i,
+				    lower_32_bits(axi_addr) | OARR_VALID |
+				    (ob->set_oarr_size ? 1 : 0));
+		iproc_pcie_ob_write(pcie, IPROC_PCIE_OARR_HI, i,
+				    upper_32_bits(axi_addr));
+		iproc_pcie_ob_write(pcie, IPROC_PCIE_OMAP_LO, i,
+				    lower_32_bits(pci_addr));
+		iproc_pcie_ob_write(pcie, IPROC_PCIE_OMAP_HI, i,
+				    upper_32_bits(pci_addr));
 
 		size -= ob->window_size;
 		if (size == 0)
@@ -340,6 +461,19 @@  int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
 		goto err_exit_phy;
 	}
 
+	switch (pcie->type) {
+	case IPROC_PCIE_PAXB:
+		pcie->reg_offsets = iproc_pcie_reg_paxb;
+		break;
+	case IPROC_PCIE_PAXC:
+		pcie->reg_offsets = iproc_pcie_reg_paxc;
+		break;
+	default:
+		dev_err(pcie->dev, "incompatible iProc PCIe interface\n");
+		ret = -EINVAL;
+		goto err_power_off_phy;
+	}
+
 	iproc_pcie_reset(pcie);
 
 	if (pcie->need_ob_cfg) {
diff --git a/drivers/pci/host/pcie-iproc.h b/drivers/pci/host/pcie-iproc.h
index d3dc940..051b651 100644
--- a/drivers/pci/host/pcie-iproc.h
+++ b/drivers/pci/host/pcie-iproc.h
@@ -15,6 +15,20 @@ 
 #define _PCIE_IPROC_H
 
 /**
+ * iProc PCIe interface type
+ *
+ * PAXB is the wrapper used in root complex that can be connected to an
+ * external endpoint device
+ *
+ * PAXC is the wrapper used in root complex dedicated for internal emulated
+ * endpoint devices
+ */
+enum iproc_pcie_type {
+	IPROC_PCIE_PAXB = 0,
+	IPROC_PCIE_PAXC,
+};
+
+/**
  * iProc PCIe outbound mapping
  * @set_oarr_size: indicates the OARR size bit needs to be set
  * @axi_offset: offset from the AXI address to the internal address used by
@@ -29,7 +43,10 @@  struct iproc_pcie_ob {
 
 /**
  * iProc PCIe device
+ *
  * @dev: pointer to device data structure
+ * @type: iProc PCIe interface type
+ * @reg_offsets: register offsets
  * @base: PCIe host controller I/O register base
  * @sysdata: Per PCI controller data (ARM-specific)
  * @root_bus: pointer to root bus
@@ -41,6 +58,8 @@  struct iproc_pcie_ob {
  */
 struct iproc_pcie {
 	struct device *dev;
+	enum iproc_pcie_type type;
+	const u16 *reg_offsets;
 	void __iomem *base;
 #ifdef CONFIG_ARM
 	struct pci_sys_data sysdata;