Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 661 insertions, 0 deletions

diff --git a/kernel/drivers/pci/host/pci-imx6.c b/kernel/drivers/pci/host/pci-imx6.c
new file mode 100644
index 000000000..fdb953677
--- /dev/null
+++ b/kernel/drivers/pci/host/pci-imx6.c
@@ -0,0 +1,661 @@
+/*
+ * PCIe host controller driver for Freescale i.MX6 SoCs
+ *
+ * Copyright (C) 2013 Kosagi
+ *		http://www.kosagi.com
+ *
+ * Author: Sean Cross <xobs@kosagi.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/resource.h>
+#include <linux/signal.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+
+#include "pcie-designware.h"
+
+#define to_imx6_pcie(x)	container_of(x, struct imx6_pcie, pp)
+
+struct imx6_pcie {
+	int			reset_gpio;
+	struct clk		*pcie_bus;
+	struct clk		*pcie_phy;
+	struct clk		*pcie;
+	struct pcie_port	pp;
+	struct regmap		*iomuxc_gpr;
+	void __iomem		*mem_base;
+};
+
+/* PCIe Root Complex registers (memory-mapped) */
+#define PCIE_RC_LCR				0x7c
+#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1	0x1
+#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2	0x2
+#define PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK	0xf
+
+/* PCIe Port Logic registers (memory-mapped) */
+#define PL_OFFSET 0x700
+#define PCIE_PL_PFLR (PL_OFFSET + 0x08)
+#define PCIE_PL_PFLR_LINK_STATE_MASK		(0x3f << 16)
+#define PCIE_PL_PFLR_FORCE_LINK			(1 << 15)
+#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
+#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
+#define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING	(1 << 29)
+#define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP		(1 << 4)
+
+#define PCIE_PHY_CTRL (PL_OFFSET + 0x114)
+#define PCIE_PHY_CTRL_DATA_LOC 0
+#define PCIE_PHY_CTRL_CAP_ADR_LOC 16
+#define PCIE_PHY_CTRL_CAP_DAT_LOC 17
+#define PCIE_PHY_CTRL_WR_LOC 18
+#define PCIE_PHY_CTRL_RD_LOC 19
+
+#define PCIE_PHY_STAT (PL_OFFSET + 0x110)
+#define PCIE_PHY_STAT_ACK_LOC 16
+
+#define PCIE_LINK_WIDTH_SPEED_CONTROL	0x80C
+#define PORT_LOGIC_SPEED_CHANGE		(0x1 << 17)
+
+/* PHY registers (not memory-mapped) */
+#define PCIE_PHY_RX_ASIC_OUT 0x100D
+
+#define PHY_RX_OVRD_IN_LO 0x1005
+#define PHY_RX_OVRD_IN_LO_RX_DATA_EN (1 << 5)
+#define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1 << 3)
+
+static int pcie_phy_poll_ack(void __iomem *dbi_base, int exp_val)
+{
+	u32 val;
+	u32 max_iterations = 10;
+	u32 wait_counter = 0;
+
+	do {
+		val = readl(dbi_base + PCIE_PHY_STAT);
+		val = (val >> PCIE_PHY_STAT_ACK_LOC) & 0x1;
+		wait_counter++;
+
+		if (val == exp_val)
+			return 0;
+
+		udelay(1);
+	} while (wait_counter < max_iterations);
+
+	return -ETIMEDOUT;
+}
+
+static int pcie_phy_wait_ack(void __iomem *dbi_base, int addr)
+{
+	u32 val;
+	int ret;
+
+	val = addr << PCIE_PHY_CTRL_DATA_LOC;
+	writel(val, dbi_base + PCIE_PHY_CTRL);
+
+	val |= (0x1 << PCIE_PHY_CTRL_CAP_ADR_LOC);
+	writel(val, dbi_base + PCIE_PHY_CTRL);
+
+	ret = pcie_phy_poll_ack(dbi_base, 1);
+	if (ret)
+		return ret;
+
+	val = addr << PCIE_PHY_CTRL_DATA_LOC;
+	writel(val, dbi_base + PCIE_PHY_CTRL);
+
+	ret = pcie_phy_poll_ack(dbi_base, 0);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/* Read from the 16-bit PCIe PHY control registers (not memory-mapped) */
+static int pcie_phy_read(void __iomem *dbi_base, int addr , int *data)
+{
+	u32 val, phy_ctl;
+	int ret;
+
+	ret = pcie_phy_wait_ack(dbi_base, addr);
+	if (ret)
+		return ret;
+
+	/* assert Read signal */
+	phy_ctl = 0x1 << PCIE_PHY_CTRL_RD_LOC;
+	writel(phy_ctl, dbi_base + PCIE_PHY_CTRL);
+
+	ret = pcie_phy_poll_ack(dbi_base, 1);
+	if (ret)
+		return ret;
+
+	val = readl(dbi_base + PCIE_PHY_STAT);
+	*data = val & 0xffff;
+
+	/* deassert Read signal */
+	writel(0x00, dbi_base + PCIE_PHY_CTRL);
+
+	ret = pcie_phy_poll_ack(dbi_base, 0);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int pcie_phy_write(void __iomem *dbi_base, int addr, int data)
+{
+	u32 var;
+	int ret;
+
+	/* write addr */
+	/* cap addr */
+	ret = pcie_phy_wait_ack(dbi_base, addr);
+	if (ret)
+		return ret;
+
+	var = data << PCIE_PHY_CTRL_DATA_LOC;
+	writel(var, dbi_base + PCIE_PHY_CTRL);
+
+	/* capture data */
+	var |= (0x1 << PCIE_PHY_CTRL_CAP_DAT_LOC);
+	writel(var, dbi_base + PCIE_PHY_CTRL);
+
+	ret = pcie_phy_poll_ack(dbi_base, 1);
+	if (ret)
+		return ret;
+
+	/* deassert cap data */
+	var = data << PCIE_PHY_CTRL_DATA_LOC;
+	writel(var, dbi_base + PCIE_PHY_CTRL);
+
+	/* wait for ack de-assertion */
+	ret = pcie_phy_poll_ack(dbi_base, 0);
+	if (ret)
+		return ret;
+
+	/* assert wr signal */
+	var = 0x1 << PCIE_PHY_CTRL_WR_LOC;
+	writel(var, dbi_base + PCIE_PHY_CTRL);
+
+	/* wait for ack */
+	ret = pcie_phy_poll_ack(dbi_base, 1);
+	if (ret)
+		return ret;
+
+	/* deassert wr signal */
+	var = data << PCIE_PHY_CTRL_DATA_LOC;
+	writel(var, dbi_base + PCIE_PHY_CTRL);
+
+	/* wait for ack de-assertion */
+	ret = pcie_phy_poll_ack(dbi_base, 0);
+	if (ret)
+		return ret;
+
+	writel(0x0, dbi_base + PCIE_PHY_CTRL);
+
+	return 0;
+}
+
+/*  Added for PCI abort handling */
+static int imx6q_pcie_abort_handler(unsigned long addr,
+		unsigned int fsr, struct pt_regs *regs)
+{
+	return 0;
+}
+
+static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
+{
+	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
+	u32 val, gpr1, gpr12;
+
+	/*
+	 * If the bootloader already enabled the link we need some special
+	 * handling to get the core back into a state where it is safe to
+	 * touch it for configuration.  As there is no dedicated reset signal
+	 * wired up for MX6QDL, we need to manually force LTSSM into "detect"
+	 * state before completely disabling LTSSM, which is a prerequisite
+	 * for core configuration.
+	 *
+	 * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong
+	 * indication that the bootloader activated the link.
+	 */
+	regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1);
+	regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12);
+
+	if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) &&
+	    (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) {
+		val = readl(pp->dbi_base + PCIE_PL_PFLR);
+		val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
+		val |= PCIE_PL_PFLR_FORCE_LINK;
+		writel(val, pp->dbi_base + PCIE_PL_PFLR);
+
+		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
+	}
+
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+			IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+			IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
+
+	return 0;
+}
+
+static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
+{
+	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
+	int ret;
+
+	ret = clk_prepare_enable(imx6_pcie->pcie_phy);
+	if (ret) {
+		dev_err(pp->dev, "unable to enable pcie_phy clock\n");
+		goto err_pcie_phy;
+	}
+
+	ret = clk_prepare_enable(imx6_pcie->pcie_bus);
+	if (ret) {
+		dev_err(pp->dev, "unable to enable pcie_bus clock\n");
+		goto err_pcie_bus;
+	}
+
+	ret = clk_prepare_enable(imx6_pcie->pcie);
+	if (ret) {
+		dev_err(pp->dev, "unable to enable pcie clock\n");
+		goto err_pcie;
+	}
+
+	/* power up core phy and enable ref clock */
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+			IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
+	/*
+	 * the async reset input need ref clock to sync internally,
+	 * when the ref clock comes after reset, internal synced
+	 * reset time is too short, cannot meet the requirement.
+	 * add one ~10us delay here.
+	 */
+	udelay(10);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
+			IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
+
+	/* allow the clocks to stabilize */
+	usleep_range(200, 500);
+
+	/* Some boards don't have PCIe reset GPIO. */
+	if (gpio_is_valid(imx6_pcie->reset_gpio)) {
+		gpio_set_value(imx6_pcie->reset_gpio, 0);
+		msleep(100);
+		gpio_set_value(imx6_pcie->reset_gpio, 1);
+	}
+	return 0;
+
+err_pcie:
+	clk_disable_unprepare(imx6_pcie->pcie_bus);
+err_pcie_bus:
+	clk_disable_unprepare(imx6_pcie->pcie_phy);
+err_pcie_phy:
+	return ret;
+
+}
+
+static void imx6_pcie_init_phy(struct pcie_port *pp)
+{
+	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
+
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+			IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
+
+	/* configure constant input signal to the pcie ctrl and phy */
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+			IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+			IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
+
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			IMX6Q_GPR8_TX_DEEMPH_GEN1, 0 << 0);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB, 0 << 6);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB, 20 << 12);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			IMX6Q_GPR8_TX_SWING_FULL, 127 << 18);
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+			IMX6Q_GPR8_TX_SWING_LOW, 127 << 25);
+}
+
+static int imx6_pcie_wait_for_link(struct pcie_port *pp)
+{
+	int count = 200;
+
+	while (!dw_pcie_link_up(pp)) {
+		usleep_range(100, 1000);
+		if (--count)
+			continue;
+
+		dev_err(pp->dev, "phy link never came up\n");
+		dev_dbg(pp->dev, "DEBUG_R0: 0x%08x, DEBUG_R1: 0x%08x\n",
+			readl(pp->dbi_base + PCIE_PHY_DEBUG_R0),
+			readl(pp->dbi_base + PCIE_PHY_DEBUG_R1));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static irqreturn_t imx6_pcie_msi_handler(int irq, void *arg)
+{
+	struct pcie_port *pp = arg;
+
+	return dw_handle_msi_irq(pp);
+}
+
+static int imx6_pcie_start_link(struct pcie_port *pp)
+{
+	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
+	uint32_t tmp;
+	int ret, count;
+
+	/*
+	 * Force Gen1 operation when starting the link.  In case the link is
+	 * started in Gen2 mode, there is a possibility the devices on the
+	 * bus will not be detected at all.  This happens with PCIe switches.
+	 */
+	tmp = readl(pp->dbi_base + PCIE_RC_LCR);
+	tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
+	tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1;
+	writel(tmp, pp->dbi_base + PCIE_RC_LCR);
+
+	/* Start LTSSM. */
+	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+			IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
+
+	ret = imx6_pcie_wait_for_link(pp);
+	if (ret)
+		return ret;
+
+	/* Allow Gen2 mode after the link is up. */
+	tmp = readl(pp->dbi_base + PCIE_RC_LCR);
+	tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
+	tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
+	writel(tmp, pp->dbi_base + PCIE_RC_LCR);
+
+	/*
+	 * Start Directed Speed Change so the best possible speed both link
+	 * partners support can be negotiated.
+	 */
+	tmp = readl(pp->dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL);
+	tmp |= PORT_LOGIC_SPEED_CHANGE;
+	writel(tmp, pp->dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL);
+
+	count = 200;
+	while (count--) {
+		tmp = readl(pp->dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL);
+		/* Test if the speed change finished. */
+		if (!(tmp & PORT_LOGIC_SPEED_CHANGE))
+			break;
+		usleep_range(100, 1000);
+	}
+
+	/* Make sure link training is finished as well! */
+	if (count)
+		ret = imx6_pcie_wait_for_link(pp);
+	else
+		ret = -EINVAL;
+
+	if (ret) {
+		dev_err(pp->dev, "Failed to bring link up!\n");
+	} else {
+		tmp = readl(pp->dbi_base + 0x80);
+		dev_dbg(pp->dev, "Link up, Gen=%i\n", (tmp >> 16) & 0xf);
+	}
+
+	return ret;
+}
+
+static void imx6_pcie_host_init(struct pcie_port *pp)
+{
+	imx6_pcie_assert_core_reset(pp);
+
+	imx6_pcie_init_phy(pp);
+
+	imx6_pcie_deassert_core_reset(pp);
+
+	dw_pcie_setup_rc(pp);
+
+	imx6_pcie_start_link(pp);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(pp);
+}
+
+static void imx6_pcie_reset_phy(struct pcie_port *pp)
+{
+	uint32_t temp;
+
+	pcie_phy_read(pp->dbi_base, PHY_RX_OVRD_IN_LO, &temp);
+	temp |= (PHY_RX_OVRD_IN_LO_RX_DATA_EN |
+		 PHY_RX_OVRD_IN_LO_RX_PLL_EN);
+	pcie_phy_write(pp->dbi_base, PHY_RX_OVRD_IN_LO, temp);
+
+	usleep_range(2000, 3000);
+
+	pcie_phy_read(pp->dbi_base, PHY_RX_OVRD_IN_LO, &temp);
+	temp &= ~(PHY_RX_OVRD_IN_LO_RX_DATA_EN |
+		  PHY_RX_OVRD_IN_LO_RX_PLL_EN);
+	pcie_phy_write(pp->dbi_base, PHY_RX_OVRD_IN_LO, temp);
+}
+
+static int imx6_pcie_link_up(struct pcie_port *pp)
+{
+	u32 rc, debug_r0, rx_valid;
+	int count = 5;
+
+	/*
+	 * Test if the PHY reports that the link is up and also that the LTSSM
+	 * training finished. There are three possible states of the link when
+	 * this code is called:
+	 * 1) The link is DOWN (unlikely)
+	 *     The link didn't come up yet for some reason. This usually means
+	 *     we have a real problem somewhere. Reset the PHY and exit. This
+	 *     state calls for inspection of the DEBUG registers.
+	 * 2) The link is UP, but still in LTSSM training
+	 *     Wait for the training to finish, which should take a very short
+	 *     time. If the training does not finish, we have a problem and we
+	 *     need to inspect the DEBUG registers. If the training does finish,
+	 *     the link is up and operating correctly.
+	 * 3) The link is UP and no longer in LTSSM training
+	 *     The link is up and operating correctly.
+	 */
+	while (1) {
+		rc = readl(pp->dbi_base + PCIE_PHY_DEBUG_R1);
+		if (!(rc & PCIE_PHY_DEBUG_R1_XMLH_LINK_UP))
+			break;
+		if (!(rc & PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING))
+			return 1;
+		if (!count--)
+			break;
+		dev_dbg(pp->dev, "Link is up, but still in training\n");
+		/*
+		 * Wait a little bit, then re-check if the link finished
+		 * the training.
+		 */
+		usleep_range(1000, 2000);
+	}
+	/*
+	 * From L0, initiate MAC entry to gen2 if EP/RC supports gen2.
+	 * Wait 2ms (LTSSM timeout is 24ms, PHY lock is ~5us in gen2).
+	 * If (MAC/LTSSM.state == Recovery.RcvrLock)
+	 * && (PHY/rx_valid==0) then pulse PHY/rx_reset. Transition
+	 * to gen2 is stuck
+	 */
+	pcie_phy_read(pp->dbi_base, PCIE_PHY_RX_ASIC_OUT, &rx_valid);
+	debug_r0 = readl(pp->dbi_base + PCIE_PHY_DEBUG_R0);
+
+	if (rx_valid & 0x01)
+		return 0;
+
+	if ((debug_r0 & 0x3f) != 0x0d)
+		return 0;
+
+	dev_err(pp->dev, "transition to gen2 is stuck, reset PHY!\n");
+	dev_dbg(pp->dev, "debug_r0=%08x debug_r1=%08x\n", debug_r0, rc);
+
+	imx6_pcie_reset_phy(pp);
+
+	return 0;
+}
+
+static struct pcie_host_ops imx6_pcie_host_ops = {
+	.link_up = imx6_pcie_link_up,
+	.host_init = imx6_pcie_host_init,
+};
+
+static int __init imx6_add_pcie_port(struct pcie_port *pp,
+			struct platform_device *pdev)
+{
+	int ret;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+		if (pp->msi_irq <= 0) {
+			dev_err(&pdev->dev, "failed to get MSI irq\n");
+			return -ENODEV;
+		}
+
+		ret = devm_request_irq(&pdev->dev, pp->msi_irq,
+				       imx6_pcie_msi_handler,
+				       IRQF_SHARED, "mx6-pcie-msi", pp);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to request MSI irq\n");
+			return -ENODEV;
+		}
+	}
+
+	pp->root_bus_nr = -1;
+	pp->ops = &imx6_pcie_host_ops;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __init imx6_pcie_probe(struct platform_device *pdev)
+{
+	struct imx6_pcie *imx6_pcie;
+	struct pcie_port *pp;
+	struct device_node *np = pdev->dev.of_node;
+	struct resource *dbi_base;
+	int ret;
+
+	imx6_pcie = devm_kzalloc(&pdev->dev, sizeof(*imx6_pcie), GFP_KERNEL);
+	if (!imx6_pcie)
+		return -ENOMEM;
+
+	pp = &imx6_pcie->pp;
+	pp->dev = &pdev->dev;
+
+	/* Added for PCI abort handling */
+	hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
+		"imprecise external abort");
+
+	dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pp->dbi_base = devm_ioremap_resource(&pdev->dev, dbi_base);
+	if (IS_ERR(pp->dbi_base))
+		return PTR_ERR(pp->dbi_base);
+
+	/* Fetch GPIOs */
+	imx6_pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
+	if (gpio_is_valid(imx6_pcie->reset_gpio)) {
+		ret = devm_gpio_request_one(&pdev->dev, imx6_pcie->reset_gpio,
+					    GPIOF_OUT_INIT_LOW, "PCIe reset");
+		if (ret) {
+			dev_err(&pdev->dev, "unable to get reset gpio\n");
+			return ret;
+		}
+	}
+
+	/* Fetch clocks */
+	imx6_pcie->pcie_phy = devm_clk_get(&pdev->dev, "pcie_phy");
+	if (IS_ERR(imx6_pcie->pcie_phy)) {
+		dev_err(&pdev->dev,
+			"pcie_phy clock source missing or invalid\n");
+		return PTR_ERR(imx6_pcie->pcie_phy);
+	}
+
+	imx6_pcie->pcie_bus = devm_clk_get(&pdev->dev, "pcie_bus");
+	if (IS_ERR(imx6_pcie->pcie_bus)) {
+		dev_err(&pdev->dev,
+			"pcie_bus clock source missing or invalid\n");
+		return PTR_ERR(imx6_pcie->pcie_bus);
+	}
+
+	imx6_pcie->pcie = devm_clk_get(&pdev->dev, "pcie");
+	if (IS_ERR(imx6_pcie->pcie)) {
+		dev_err(&pdev->dev,
+			"pcie clock source missing or invalid\n");
+		return PTR_ERR(imx6_pcie->pcie);
+	}
+
+	/* Grab GPR config register range */
+	imx6_pcie->iomuxc_gpr =
+		 syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
+	if (IS_ERR(imx6_pcie->iomuxc_gpr)) {
+		dev_err(&pdev->dev, "unable to find iomuxc registers\n");
+		return PTR_ERR(imx6_pcie->iomuxc_gpr);
+	}
+
+	ret = imx6_add_pcie_port(pp, pdev);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, imx6_pcie);
+	return 0;
+}
+
+static void imx6_pcie_shutdown(struct platform_device *pdev)
+{
+	struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev);
+
+	/* bring down link, so bootloader gets clean state in case of reboot */
+	imx6_pcie_assert_core_reset(&imx6_pcie->pp);
+}
+
+static const struct of_device_id imx6_pcie_of_match[] = {
+	{ .compatible = "fsl,imx6q-pcie", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, imx6_pcie_of_match);
+
+static struct platform_driver imx6_pcie_driver = {
+	.driver = {
+		.name	= "imx6q-pcie",
+		.of_match_table = imx6_pcie_of_match,
+	},
+	.shutdown = imx6_pcie_shutdown,
+};
+
+/* Freescale PCIe driver does not allow module unload */
+
+static int __init imx6_pcie_init(void)
+{
+	return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe);
+}
+module_init(imx6_pcie_init);
+
+MODULE_AUTHOR("Sean Cross <xobs@kosagi.com>");
+MODULE_DESCRIPTION("Freescale i.MX6 PCIe host controller driver");
+MODULE_LICENSE("GPL v2");