pci: mvebu: Add PCIe driver for Armada-8K

This patch adds a driver for the PCIe controller integrated in the
Marvell Armada-8K SoC. This controller is based on the DesignWare
IP core.

The original version was written by Shadi and Yehuda. I ported this
driver to the latest mainline U-Boot version with DM support.

Tested on the Marvell DB-88F8040 Armada-8K eval board.

Signed-off-by: Shadi Ammouri <shadi@marvell.com>
Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Neta Zur Hershkovits <neta@marvell.com>
Cc: Kostya Porotchkin <kostap@marvell.com>
Cc: Omri Itach <omrii@marvell.com>
Cc: Igal Liberman <igall@marvell.com>
Cc: Haim Boot <hayim@marvell.com>
Cc: Hanna Hawa <hannah@marvell.com>
diff --git a/drivers/pci/pcie_dw_mvebu.c b/drivers/pci/pcie_dw_mvebu.c
new file mode 100644
index 0000000..17fa024
--- /dev/null
+++ b/drivers/pci/pcie_dw_mvebu.c
@@ -0,0 +1,535 @@
+/*
+ * Copyright (C) 2015 Marvell International Ltd.
+ *
+ * Copyright (C) 2016 Stefan Roese <sr@denx.de>
+ *
+ * Based on:
+ *   - drivers/pci/pcie_imx.c
+ *   - drivers/pci/pci_mvebu.c
+ *   - drivers/pci/pcie_xilinx.c
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <pci.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* PCI Config space registers */
+#define PCIE_CONFIG_BAR0		0x10
+#define PCIE_LINK_STATUS_REG		0x80
+#define PCIE_LINK_STATUS_SPEED_OFF	16
+#define PCIE_LINK_STATUS_SPEED_MASK	(0xf << PCIE_LINK_STATUS_SPEED_OFF)
+#define PCIE_LINK_STATUS_WIDTH_OFF	20
+#define PCIE_LINK_STATUS_WIDTH_MASK	(0xf << PCIE_LINK_STATUS_WIDTH_OFF)
+
+/* Resizable bar capability registers */
+#define RESIZABLE_BAR_CAP		0x250
+#define RESIZABLE_BAR_CTL0		0x254
+#define RESIZABLE_BAR_CTL1		0x258
+
+/* iATU registers */
+#define PCIE_ATU_VIEWPORT		0x900
+#define PCIE_ATU_REGION_INBOUND		(0x1 << 31)
+#define PCIE_ATU_REGION_OUTBOUND	(0x0 << 31)
+#define PCIE_ATU_REGION_INDEX1		(0x1 << 0)
+#define PCIE_ATU_REGION_INDEX0		(0x0 << 0)
+#define PCIE_ATU_CR1			0x904
+#define PCIE_ATU_TYPE_MEM		(0x0 << 0)
+#define PCIE_ATU_TYPE_IO		(0x2 << 0)
+#define PCIE_ATU_TYPE_CFG0		(0x4 << 0)
+#define PCIE_ATU_TYPE_CFG1		(0x5 << 0)
+#define PCIE_ATU_CR2			0x908
+#define PCIE_ATU_ENABLE			(0x1 << 31)
+#define PCIE_ATU_BAR_MODE_ENABLE	(0x1 << 30)
+#define PCIE_ATU_LOWER_BASE		0x90C
+#define PCIE_ATU_UPPER_BASE		0x910
+#define PCIE_ATU_LIMIT			0x914
+#define PCIE_ATU_LOWER_TARGET		0x918
+#define PCIE_ATU_BUS(x)			(((x) & 0xff) << 24)
+#define PCIE_ATU_DEV(x)			(((x) & 0x1f) << 19)
+#define PCIE_ATU_FUNC(x)		(((x) & 0x7) << 16)
+#define PCIE_ATU_UPPER_TARGET		0x91C
+
+#define PCIE_LINK_CAPABILITY		0x7C
+#define PCIE_LINK_CTL_2			0xA0
+#define TARGET_LINK_SPEED_MASK		0xF
+#define LINK_SPEED_GEN_1		0x1
+#define LINK_SPEED_GEN_2		0x2
+#define LINK_SPEED_GEN_3		0x3
+
+#define PCIE_GEN3_RELATED		0x890
+#define GEN3_EQU_DISABLE		(1 << 16)
+#define GEN3_ZRXDC_NON_COMP		(1 << 0)
+
+#define PCIE_GEN3_EQU_CTRL		0x8A8
+#define GEN3_EQU_EVAL_2MS_DISABLE	(1 << 5)
+
+#define PCIE_ROOT_COMPLEX_MODE_MASK	(0xF << 4)
+
+#define PCIE_LINK_UP_TIMEOUT_MS		100
+
+#define PCIE_GLOBAL_CONTROL		0x8000
+#define PCIE_APP_LTSSM_EN		(1 << 2)
+#define PCIE_DEVICE_TYPE_OFFSET		(4)
+#define PCIE_DEVICE_TYPE_MASK		(0xF)
+#define PCIE_DEVICE_TYPE_EP		(0x0) /* Endpoint */
+#define PCIE_DEVICE_TYPE_LEP		(0x1) /* Legacy endpoint */
+#define PCIE_DEVICE_TYPE_RC		(0x4) /* Root complex */
+
+#define PCIE_GLOBAL_STATUS		0x8008
+#define PCIE_GLB_STS_RDLH_LINK_UP	(1 << 1)
+#define PCIE_GLB_STS_PHY_LINK_UP	(1 << 9)
+
+#define PCIE_ARCACHE_TRC		0x8050
+#define PCIE_AWCACHE_TRC		0x8054
+#define ARCACHE_SHAREABLE_CACHEABLE	0x3511
+#define AWCACHE_SHAREABLE_CACHEABLE	0x5311
+
+#define LINK_SPEED_GEN_1                0x1
+#define LINK_SPEED_GEN_2                0x2
+#define LINK_SPEED_GEN_3                0x3
+
+/**
+ * struct pcie_dw_mvebu - MVEBU DW PCIe controller state
+ *
+ * @ctrl_base: The base address of the register space
+ * @cfg_base: The base address of the configuration space
+ * @cfg_size: The size of the configuration space which is needed
+ *            as it gets written into the PCIE_ATU_LIMIT register
+ * @first_busno: This driver supports multiple PCIe controllers.
+ *               first_busno stores the bus number of the PCIe root-port
+ *               number which may vary depending on the PCIe setup
+ *               (PEX switches etc).
+ */
+struct pcie_dw_mvebu {
+	void *ctrl_base;
+	void *cfg_base;
+	fdt_size_t cfg_size;
+	int first_busno;
+};
+
+static int pcie_dw_get_link_speed(const void *regs_base)
+{
+	return (readl(regs_base + PCIE_LINK_STATUS_REG) &
+		PCIE_LINK_STATUS_SPEED_MASK) >> PCIE_LINK_STATUS_SPEED_OFF;
+}
+
+static int pcie_dw_get_link_width(const void *regs_base)
+{
+	return (readl(regs_base + PCIE_LINK_STATUS_REG) &
+		PCIE_LINK_STATUS_WIDTH_MASK) >> PCIE_LINK_STATUS_WIDTH_OFF;
+}
+
+/**
+ * set_cfg_address() - Configure the PCIe controller config space access
+ *
+ * @pcie: Pointer to the PCI controller state
+ * @d: PCI device to access
+ * @where: Offset in the configuration space
+ *
+ * Configures the PCIe controller to access the configuration space of
+ * a specific PCIe device and returns the address to use for this
+ * access.
+ *
+ * Return: Address that can be used to access the configation space
+ *         of the requested device / offset
+ */
+static uintptr_t set_cfg_address(struct pcie_dw_mvebu *pcie,
+				 pci_dev_t d, uint where)
+{
+	uintptr_t va_address;
+
+	/*
+	 * Region #0 is used for Outbound CFG space access.
+	 * Direction = Outbound
+	 * Region Index = 0
+	 */
+	writel(0, pcie->ctrl_base + PCIE_ATU_VIEWPORT);
+
+	if (PCI_BUS(d) == (pcie->first_busno + 1))
+		/* For local bus, change TLP Type field to 4. */
+		writel(PCIE_ATU_TYPE_CFG0, pcie->ctrl_base + PCIE_ATU_CR1);
+	else
+		/* Otherwise, change TLP Type field to 5. */
+		writel(PCIE_ATU_TYPE_CFG1, pcie->ctrl_base + PCIE_ATU_CR1);
+
+	if (PCI_BUS(d) == pcie->first_busno) {
+		/* Accessing root port configuration space. */
+		va_address = (uintptr_t)pcie->ctrl_base;
+	} else {
+		writel(d << 8, pcie->ctrl_base + PCIE_ATU_LOWER_TARGET);
+		va_address = (uintptr_t)pcie->cfg_base;
+	}
+
+	va_address += where & ~0x3;
+
+	return va_address;
+}
+
+/**
+ * pcie_dw_addr_valid() - Check for valid bus address
+ *
+ * @d: The PCI device to access
+ * @first_busno: Bus number of the PCIe controller root complex
+ *
+ * Return 1 (true) if the PCI device can be accessed by this controller.
+ *
+ * Return: 1 on valid, 0 on invalid
+ */
+static int pcie_dw_addr_valid(pci_dev_t d, int first_busno)
+{
+	if ((PCI_BUS(d) == first_busno) && (PCI_DEV(d) > 0))
+		return 0;
+	if ((PCI_BUS(d) == first_busno + 1) && (PCI_DEV(d) > 0))
+		return 0;
+
+	return 1;
+}
+
+/**
+ * pcie_dw_mvebu_read_config() - Read from configuration space
+ *
+ * @bus: Pointer to the PCI bus
+ * @bdf: Identifies the PCIe device to access
+ * @offset: The offset into the device's configuration space
+ * @valuep: A pointer at which to store the read value
+ * @size: Indicates the size of access to perform
+ *
+ * Read a value of size @size from offset @offset within the configuration
+ * space of the device identified by the bus, device & function numbers in @bdf
+ * on the PCI bus @bus.
+ *
+ * Return: 0 on success
+ */
+static int pcie_dw_mvebu_read_config(struct udevice *bus, pci_dev_t bdf,
+				     uint offset, ulong *valuep,
+				     enum pci_size_t size)
+{
+	struct pcie_dw_mvebu *pcie = dev_get_priv(bus);
+	uintptr_t va_address;
+	ulong value;
+
+	debug("PCIE CFG read:  (b,d,f)=(%2d,%2d,%2d) ",
+	      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
+
+	if (!pcie_dw_addr_valid(bdf, pcie->first_busno)) {
+		debug("- out of range\n");
+		*valuep = pci_get_ff(size);
+		return 0;
+	}
+
+	va_address = set_cfg_address(pcie, bdf, offset);
+
+	value = readl(va_address);
+
+	debug("(addr,val)=(0x%04x, 0x%08lx)\n", offset, value);
+	*valuep = pci_conv_32_to_size(value, offset, size);
+
+	return 0;
+}
+
+/**
+ * pcie_dw_mvebu_write_config() - Write to configuration space
+ *
+ * @bus: Pointer to the PCI bus
+ * @bdf: Identifies the PCIe device to access
+ * @offset: The offset into the device's configuration space
+ * @value: The value to write
+ * @size: Indicates the size of access to perform
+ *
+ * Write the value @value of size @size from offset @offset within the
+ * configuration space of the device identified by the bus, device & function
+ * numbers in @bdf on the PCI bus @bus.
+ *
+ * Return: 0 on success
+ */
+static int pcie_dw_mvebu_write_config(struct udevice *bus, pci_dev_t bdf,
+				      uint offset, ulong value,
+				      enum pci_size_t size)
+{
+	struct pcie_dw_mvebu *pcie = dev_get_priv(bus);
+	uintptr_t va_address;
+	ulong old;
+
+	debug("PCIE CFG write: (b,d,f)=(%2d,%2d,%2d) ",
+	      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
+	debug("(addr,val)=(0x%04x, 0x%08lx)\n", offset, value);
+
+	if (!pcie_dw_addr_valid(bdf, pcie->first_busno)) {
+		debug("- out of range\n");
+		return 0;
+	}
+
+	va_address = set_cfg_address(pcie, bdf, offset);
+
+	old = readl(va_address);
+	value = pci_conv_size_to_32(old, value, offset, size);
+	writel(value, va_address);
+
+	return 0;
+}
+
+/**
+ * pcie_dw_configure() - Configure link capabilities and speed
+ *
+ * @regs_base: A pointer to the PCIe controller registers
+ * @cap_speed: The capabilities and speed to configure
+ *
+ * Configure the link capabilities and speed in the PCIe root complex.
+ */
+static void pcie_dw_configure(const void *regs_base, u32 cap_speed)
+{
+	/*
+	 * TODO (shadi@marvell.com, sr@denx.de):
+	 * Need to read the serdes speed from the dts and according to it
+	 * configure the PCIe gen
+	 */
+
+	/* Set link to GEN 3 */
+	clrsetbits_le32(regs_base + PCIE_LINK_CTL_2,
+			TARGET_LINK_SPEED_MASK, cap_speed);
+	clrsetbits_le32(regs_base + PCIE_LINK_CAPABILITY,
+			TARGET_LINK_SPEED_MASK, cap_speed);
+	setbits_le32(regs_base + PCIE_GEN3_EQU_CTRL, GEN3_EQU_EVAL_2MS_DISABLE);
+}
+
+/**
+ * is_link_up() - Return the link state
+ *
+ * @regs_base: A pointer to the PCIe controller registers
+ *
+ * Return: 1 (true) for active line and 0 (false) for no link
+ */
+static int is_link_up(const void *regs_base)
+{
+	u32 mask = PCIE_GLB_STS_RDLH_LINK_UP | PCIE_GLB_STS_PHY_LINK_UP;
+	u32 reg;
+
+	reg = readl(regs_base + PCIE_GLOBAL_STATUS);
+	if ((reg & mask) == mask)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * wait_link_up() - Wait for the link to come up
+ *
+ * @regs_base: A pointer to the PCIe controller registers
+ *
+ * Return: 1 (true) for active line and 0 (false) for no link (timeout)
+ */
+static int wait_link_up(const void *regs_base)
+{
+	unsigned long timeout;
+
+	timeout = get_timer(0) + PCIE_LINK_UP_TIMEOUT_MS;
+	while (!is_link_up(regs_base)) {
+		if (get_timer(0) > timeout)
+			return 0;
+	};
+
+	return 1;
+}
+
+/**
+ * pcie_dw_mvebu_pcie_link_up() - Configure the PCIe root port
+ *
+ * @regs_base: A pointer to the PCIe controller registers
+ * @cap_speed: The capabilities and speed to configure
+ *
+ * Configure the PCIe controller root complex depending on the
+ * requested link capabilities and speed.
+ *
+ * Return: 1 (true) for active line and 0 (false) for no link
+ */
+static int pcie_dw_mvebu_pcie_link_up(const void *regs_base, u32 cap_speed)
+{
+	if (!is_link_up(regs_base)) {
+		/* Disable LTSSM state machine to enable configuration */
+		clrbits_le32(regs_base + PCIE_GLOBAL_CONTROL,
+			     PCIE_APP_LTSSM_EN);
+	}
+
+	clrsetbits_le32(regs_base + PCIE_GLOBAL_CONTROL,
+			PCIE_DEVICE_TYPE_MASK << PCIE_DEVICE_TYPE_OFFSET,
+			PCIE_DEVICE_TYPE_RC << PCIE_DEVICE_TYPE_OFFSET);
+
+	/* Set the PCIe master AXI attributes */
+	writel(ARCACHE_SHAREABLE_CACHEABLE, regs_base + PCIE_ARCACHE_TRC);
+	writel(AWCACHE_SHAREABLE_CACHEABLE, regs_base + PCIE_AWCACHE_TRC);
+
+	/* DW pre link configurations */
+	pcie_dw_configure(regs_base, cap_speed);
+
+	if (!is_link_up(regs_base)) {
+		/* Configuration done. Start LTSSM */
+		setbits_le32(regs_base + PCIE_GLOBAL_CONTROL,
+			     PCIE_APP_LTSSM_EN);
+	}
+
+	/* Check that link was established */
+	if (!wait_link_up(regs_base))
+		return 0;
+
+	/*
+	 * Link can be established in Gen 1. still need to wait
+	 * till MAC nagaotiation is completed
+	 */
+	udelay(100);
+
+	return 1;
+}
+
+/**
+ * pcie_dw_regions_setup() - iATU region setup
+ *
+ * @pcie: Pointer to the PCI controller state
+ *
+ * Configure the iATU regions in the PCIe controller for outbound access.
+ */
+static void pcie_dw_regions_setup(struct pcie_dw_mvebu *pcie)
+{
+	/*
+	 * Region #0 is used for Outbound CFG space access.
+	 * Direction = Outbound
+	 * Region Index = 0
+	 */
+	writel(0, pcie->ctrl_base + PCIE_ATU_VIEWPORT);
+
+	writel((u32)(uintptr_t)pcie->cfg_base, pcie->ctrl_base
+	       + PCIE_ATU_LOWER_BASE);
+	writel(0, pcie->ctrl_base + PCIE_ATU_UPPER_BASE);
+	writel((u32)(uintptr_t)pcie->cfg_base + pcie->cfg_size,
+	       pcie->ctrl_base + PCIE_ATU_LIMIT);
+
+	writel(0, pcie->ctrl_base + PCIE_ATU_LOWER_TARGET);
+	writel(0, pcie->ctrl_base + PCIE_ATU_UPPER_TARGET);
+	writel(PCIE_ATU_TYPE_CFG0, pcie->ctrl_base + PCIE_ATU_CR1);
+	writel(PCIE_ATU_ENABLE, pcie->ctrl_base + PCIE_ATU_CR2);
+}
+
+/**
+ * pcie_dw_set_host_bars() - Configure the host BARs
+ *
+ * @regs_base: A pointer to the PCIe controller registers
+ *
+ * Configure the host BARs of the PCIe controller root port so that
+ * PCI(e) devices may access the system memory.
+ */
+static void pcie_dw_set_host_bars(const void *regs_base)
+{
+	u32 size = gd->ram_size;
+	u64 max_size;
+	u32 reg;
+	u32 bar0;
+
+	/* Verify the maximal BAR size */
+	reg = readl(regs_base + RESIZABLE_BAR_CAP);
+	max_size = 1ULL << (5 + (reg + (1 << 4)));
+
+	if (size > max_size) {
+		size = max_size;
+		printf("Warning: PCIe BARs can't map all DRAM space\n");
+	}
+
+	/* Set the BAR base and size towards DDR */
+	bar0 = CONFIG_SYS_SDRAM_BASE & ~0xf;
+	bar0 |= PCI_BASE_ADDRESS_MEM_TYPE_32;
+	writel(CONFIG_SYS_SDRAM_BASE, regs_base + PCIE_CONFIG_BAR0);
+
+	reg = ((size >> 20) - 1) << 12;
+	writel(size, regs_base + RESIZABLE_BAR_CTL0);
+}
+
+/**
+ * pcie_dw_mvebu_probe() - Probe the PCIe bus for active link
+ *
+ * @dev: A pointer to the device being operated on
+ *
+ * Probe for an active link on the PCIe bus and configure the controller
+ * to enable this port.
+ *
+ * Return: 0 on success, else -ENODEV
+ */
+static int pcie_dw_mvebu_probe(struct udevice *dev)
+{
+	struct pcie_dw_mvebu *pcie = dev_get_priv(dev);
+	struct udevice *ctlr = pci_get_controller(dev);
+	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
+
+	pcie->first_busno = dev->seq;
+
+	/* Don't register host if link is down */
+	if (!pcie_dw_mvebu_pcie_link_up(pcie->ctrl_base, LINK_SPEED_GEN_3)) {
+		printf("PCIE-%d: Link down\n", dev->seq);
+		return -ENODEV;
+	}
+
+	printf("PCIE-%d: Link up (Gen%d-x%d, Bus%d)\n", dev->seq,
+	       pcie_dw_get_link_speed(pcie->ctrl_base),
+	       pcie_dw_get_link_width(pcie->ctrl_base), hose->first_busno);
+
+	pcie_dw_regions_setup(pcie);
+
+	/* Set the CLASS_REV of RC CFG header to PCI_CLASS_BRIDGE_PCI */
+	clrsetbits_le32(pcie->ctrl_base + PCI_CLASS_REVISION,
+			0xffff << 16, PCI_CLASS_BRIDGE_PCI << 16);
+
+	pcie_dw_set_host_bars(pcie->ctrl_base);
+
+	return 0;
+}
+
+/**
+ * pcie_dw_mvebu_ofdata_to_platdata() - Translate from DT to device state
+ *
+ * @dev: A pointer to the device being operated on
+ *
+ * Translate relevant data from the device tree pertaining to device @dev into
+ * state that the driver will later make use of. This state is stored in the
+ * device's private data structure.
+ *
+ * Return: 0 on success, else -EINVAL
+ */
+static int pcie_dw_mvebu_ofdata_to_platdata(struct udevice *dev)
+{
+	struct pcie_dw_mvebu *pcie = dev_get_priv(dev);
+
+	/* Get the controller base address */
+	pcie->ctrl_base = (void *)dev_get_addr_index(dev, 0);
+	if ((fdt_addr_t)pcie->ctrl_base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	/* Get the config space base address and size */
+	pcie->cfg_base = (void *)dev_get_addr_size_index(dev, 1,
+							 &pcie->cfg_size);
+	if ((fdt_addr_t)pcie->cfg_base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct dm_pci_ops pcie_dw_mvebu_ops = {
+	.read_config	= pcie_dw_mvebu_read_config,
+	.write_config	= pcie_dw_mvebu_write_config,
+};
+
+static const struct udevice_id pcie_dw_mvebu_ids[] = {
+	{ .compatible = "marvell,armada8k-pcie" },
+	{ }
+};
+
+U_BOOT_DRIVER(pcie_dw_mvebu) = {
+	.name			= "pcie_dw_mvebu",
+	.id			= UCLASS_PCI,
+	.of_match		= pcie_dw_mvebu_ids,
+	.ops			= &pcie_dw_mvebu_ops,
+	.ofdata_to_platdata	= pcie_dw_mvebu_ofdata_to_platdata,
+	.probe			= pcie_dw_mvebu_probe,
+	.priv_auto_alloc_size	= sizeof(struct pcie_dw_mvebu),
+};