[PATCH v4 3/3] PCI: imx6: Add support for i.MX6 PCIe controller

Shawn Guo shawn.guo at linaro.org
Mon Sep 16 02:06:33 EDT 2013


On Fri, Sep 13, 2013 at 09:40:22AM +0000, Sean Cross wrote:
> Add support for the PCIe port present on the i.MX6 family of controllers.
> These use the Synopsis Designware core tied to their own PHY.
> 
> Signed-off-by: Sean Cross <xobs at kosagi.com>
> ---
>  .../devicetree/bindings/pci/designware-pcie.txt    |    5 +
>  arch/arm/boot/dts/imx6qdl.dtsi                     |   16 +
>  arch/arm/mach-imx/Kconfig                          |    2 +
>  arch/arm/mach-imx/clk-imx6q.c                      |   11 +
>  drivers/pci/host/Kconfig                           |    6 +
>  drivers/pci/host/Makefile                          |    1 +
>  drivers/pci/host/pci-imx6.c                        |  482 ++++++++++++++++++++
>  7 files changed, 523 insertions(+)
>  create mode 100644 drivers/pci/host/pci-imx6.c
> 
> diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt
> index eabcb4b..41d8419 100644
> --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
> @@ -21,6 +21,11 @@ Required properties:
>  - num-lanes: number of lanes to use
>  - reset-gpio: gpio pin number of power good signal
>  
> +Optional properties for fsl,imx6-pcie
> +- power-on-gpio: gpio pin number of power-enable signal
> +- wake-up-gpio: gpio pin number of incoming wakeup signal
> +- disable-gpio: gpio pin number of outgoing rfkill/endpoint disable signal
> +
>  Example:
>  
>  SoC specific DT Entry:
> diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
> index ccd55c2..ec72271 100644
> --- a/arch/arm/boot/dts/imx6qdl.dtsi
> +++ b/arch/arm/boot/dts/imx6qdl.dtsi
> @@ -116,6 +116,22 @@
>  			arm,data-latency = <4 2 3>;
>  		};
>  
> +		pcie: pcie at 0x01000000 {
> +			compatible = "fsl,imx6-pcie", "snps,dw-pcie";

We generally use particular SoC name to specify the compatible string.
So "fsl,imx6q-pcie" will be more appropriate.

> +			reg = <0x01ffc000 0x4000>; /* DBI */
> +

Nit: please drop this blank line.

> +			#address-cells = <3>;
> +			#size-cells = <2>;
> +			device_type = "pci";
> +			ranges = <0x00000800 0 0x01f00000 0x01f00000 0 0x00080000 /* configuration space */
> +				  0x81000000 0 0          0x01f80000 0 0x00010000 /* downstream I/O */
> +				  0x82000000 0 0x01000000 0x01000000 0 0x00f00000>; /* non-prefetchable memory */
> +

Ditto

> +			num-lanes = <1>;
> +			interrupts = <0 123 0x04>;
> +			status = "disabled";
> +		};
> +
>  		pmu {
>  			compatible = "arm,cortex-a9-pmu";
>  			interrupts = <0 94 0x04>;
> diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> index 29a8af6..e6ac281 100644
> --- a/arch/arm/mach-imx/Kconfig
> +++ b/arch/arm/mach-imx/Kconfig
> @@ -801,6 +801,8 @@ config SOC_IMX6Q
>  	select HAVE_IMX_SRC
>  	select HAVE_SMP
>  	select MFD_SYSCON
> +	select MIGHT_HAVE_PCI
> +	select PCI_DOMAINS if PCI
>  	select PINCTRL
>  	select PINCTRL_IMX6Q
>  	select PL310_ERRATA_588369 if CACHE_PL310
> diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
> index 679d49a..0a2093c 100644
> --- a/arch/arm/mach-imx/clk-imx6q.c
> +++ b/arch/arm/mach-imx/clk-imx6q.c
> @@ -622,6 +622,17 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
>  	if (ret)
>  		pr_warn("failed to set up CLKO: %d\n", ret);
>  
> +	/*
> +	 * All existing boards with PCIe run them off LVDS1
> +	 */
> +	if (IS_ENABLED(CONFIG_PCI_IMX6)) {
> +		clk_set_parent(clk[lvds1_sel], clk[sata_ref]);
> +		clk_prepare_enable(clk[lvds1_gate]);
> +		clk_prepare_enable(clk[pcie_ref_125m]);
> +		clk_prepare_enable(clk[pcie_axi]);
> +        }

Use tab instead of spaces, please.

> +
> +

Drop one blank line.

>  	/* Set initial power mode */
>  	imx6q_set_lpm(WAIT_CLOCKED);
>  
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index 3d95048..efa24d9 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -15,6 +15,12 @@ config PCI_EXYNOS
>  	select PCIEPORTBUS
>  	select PCIE_DW
>  
> +config PCI_IMX6
> +	bool "Freescale i.MX6 PCIe controller"
> +	depends on SOC_IMX6Q
> +	select PCIEPORTBUS
> +	select PCIE_DW
> +
>  config PCI_TEGRA
>  	bool "NVIDIA Tegra PCIe controller"
>  	depends on ARCH_TEGRA
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index c9a997b..287d6a0 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -1,4 +1,5 @@
>  obj-$(CONFIG_PCIE_DW) += pcie-designware.o
>  obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
> +obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
>  obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
>  obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> new file mode 100644
> index 0000000..a3f9053
> --- /dev/null
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -0,0 +1,482 @@
> +/*
> + * PCIe host controller driver for Freescale i.MX6 SoCs
> + *
> + * Copyright (C) 2013 Kosagi
> + *		http://www.kosagi.com
> + *
> + * Author: Sean Cross <xobs at 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/delay.h>
> +#include <linux/gpio.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_gpio.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/resource.h>
> +#include <linux/signal.h>
> +#include <linux/types.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
> +
> +#include "pcie-designware.h"
> +
> +#define to_imx6_pcie(x)	container_of(x, struct imx6_pcie, pp)
> +
> +struct imx6_pcie {
> +	int			reset_gpio;
> +	int			power_on_gpio;
> +	int			wake_up_gpio;
> +	int			disable_gpio;
> +	struct pcie_port	pp;
> +	struct regmap		*iomuxc_gpr;
> +	void __iomem		*mem_base;
> +};
> +
> +/* PCIe Port Logic registers (memory-mapped) */
> +#define PL_OFFSET 0x700
> +#define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
> +#define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
> +
> +#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_DATA_LOC 0
> +#define PCIE_PHY_STAT_ACK_LOC 16
> +
> +/* 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)

(1 << 5), please.

> +#define PHY_RX_OVRD_IN_LO_RX_PLL_EN (1<<3)

Ditto

> +
> +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++;
> +		udelay(1);
> +	} while ((wait_counter < max_iterations) && (val != exp_val));
> +
> +	if (val != exp_val)
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
> +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 << PCIE_PHY_STAT_DATA_LOC));

One unnecessary parentheses.

> +
> +	/* 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-assetion */
> +	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-assetion */
> +	ret = pcie_phy_poll_ack(dbi_base, 0);
> +	if (ret)
> +		return ret;
> +
> +	writel(0x0, dbi_base + PCIE_PHY_CTRL);
> +
> +	return 0;
> +}
> +
> +static int imx6_pcie_assert_core_reset(struct pcie_port *pp)
> +{
> +	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);

Nit: have a blank line here.

> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +			IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18);
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +			IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +			IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
> +
> +	gpio_set_value(imx6_pcie->reset_gpio, 0);
> +	msleep(100);
> +	gpio_set_value(imx6_pcie->reset_gpio, 1);
> +
> +	return 0;
> +}
> +
> +static int imx6_pcie_deassert_core_reset(struct pcie_port *pp)
> +{
> +	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
> +
> +	if (gpio_is_valid(imx6_pcie->power_on_gpio))
> +		gpio_set_value(imx6_pcie->power_on_gpio, 1);
> +
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +			IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18);
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
> +			IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
> +
> +	/* allow the clocks to stabilize */
> +	usleep_range(100, 200);
> +
> +	return 0;
> +}
> +
> +static void imx6_pcie_init_phy(struct pcie_port *pp)
> +{
> +	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
> +
> +	/* FIXME the field name should be aligned to RM */

Why cannot this be fixed right now?

> +	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 void imx6_pcie_host_init(struct pcie_port *pp)
> +{
> +	int count = 0;
> +	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
> +
> +	imx6_pcie_assert_core_reset(pp);
> +
> +	imx6_pcie_init_phy(pp);
> +
> +	imx6_pcie_deassert_core_reset(pp);
> +
> +	dw_pcie_setup_rc(pp);
> +
> +	regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> +			IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
> +
> +	while (!dw_pcie_link_up(pp)) {
> +		usleep_range(100, 1000);
> +		count++;
> +		if (count >= 10) {
> +			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));
> +			break;
> +		}
> +	}
> +
> +	return;
> +}
> +
> +static int imx6_pcie_link_up(struct pcie_port *pp)
> +{
> +	u32 rc, ltssm, rx_valid, temp;
> +
> +	/* link is debug bit 36, debug register 1 starts at bit 32 */
> +	rc = readl(pp->dbi_base + PCIE_PHY_DEBUG_R1) & (0x1 << (36 - 32));
> +	if (rc)
> +		return -EAGAIN;
> +
> +	/* 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
> +	 */

	/*
	 * Multiple lines comment
	 * ...
	 */

> +	pcie_phy_read(pp->dbi_base, PCIE_PHY_RX_ASIC_OUT, &rx_valid);
> +	ltssm = readl(pp->dbi_base + PCIE_PHY_DEBUG_R0) & 0x3F;
> +
> +	if (rx_valid & 0x01)
> +		return 0;
> +
> +	if (ltssm != 0x0d)
> +		return 0;
> +
> +	dev_err(pp->dev,
> +		"transition to gen2 is stuck, reset PHY!\n");
> +
> +	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);
> +
> +	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 add_pcie_port(struct pcie_port *pp, struct platform_device *pdev)

imx6_pcie_add_port to have the proper namespace?

> +{
> +	int ret;
> +
> +	pp->irq = platform_get_irq(pdev, 0);
> +	if (!pp->irq) {
> +		dev_err(&pdev->dev, "failed to get irq\n");
> +		return -ENODEV;
> +	}
> +
> +	pp->root_bus_nr = -1;
> +	pp->ops = &imx6_pcie_host_ops;
> +
> +	spin_lock_init(&pp->conf_lock);
> +	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;
> +
> +	dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!dbi_base) {
> +		dev_err(&pdev->dev, "dbi_base memory resource not found\n");
> +		return -ENODEV;
> +	}
> +
> +	pp->dbi_base = devm_request_and_ioremap(&pdev->dev, dbi_base);
> +	if (IS_ERR(pp->dbi_base)) {
> +		dev_err(&pdev->dev, "unable to remap dbi_base\n");
> +		ret = PTR_ERR(pp->dbi_base);
> +		goto err;
> +	}

See kerneldoc of devm_request_and_ioremap().  I believe that the help
already takes care of printing error messages.

> +
> +	/* 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");
> +			goto err;
> +		}
> +	}

The reset-gpio is not optional but required.  So if we do not have a
valid reset-gpio, the probe should fail.  And that's why we can access
reset_gpio in imx6_pcie_assert_core_reset() without checking if it's
valid.

> +
> +	imx6_pcie->power_on_gpio = of_get_named_gpio(np, "power-on-gpio", 0);
> +	if (gpio_is_valid(imx6_pcie->power_on_gpio)) {
> +		ret = devm_gpio_request_one(&pdev->dev,
> +					imx6_pcie->power_on_gpio,
> +					GPIOF_OUT_INIT_LOW,
> +					"PCIe power enable");
> +		if (ret) {
> +			dev_err(&pdev->dev, "unable to get power-on gpio\n");
> +			goto err;
> +		}
> +	}
> +
> +	imx6_pcie->wake_up_gpio = of_get_named_gpio(np, "wake-up-gpio", 0);
> +	if (gpio_is_valid(imx6_pcie->wake_up_gpio)) {
> +		ret = devm_gpio_request_one(&pdev->dev,
> +					imx6_pcie->wake_up_gpio,
> +					GPIOF_IN,
> +					"PCIe wake up");
> +		if (ret) {
> +			dev_err(&pdev->dev, "unable to get wake-up gpio\n");
> +			goto err;
> +		}
> +	}
> +
> +	imx6_pcie->disable_gpio = of_get_named_gpio(np, "disable-gpio", 0);
> +	if (gpio_is_valid(imx6_pcie->disable_gpio)) {
> +		ret = devm_gpio_request_one(&pdev->dev,
> +					imx6_pcie->disable_gpio,
> +					GPIOF_OUT_INIT_HIGH,
> +					"PCIe disable endpoint");
> +		if (ret) {
> +			dev_err(&pdev->dev, "unable to get disable-ep gpio\n");
> +			goto err;
> +		}
> +	}
> +
> +	/* 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");
> +		ret = PTR_ERR(imx6_pcie->iomuxc_gpr);
> +		goto err;
> +	}
> +
> +	ret = add_pcie_port(pp, pdev);
> +	if (ret < 0)
> +		goto err;
> +
> +	platform_set_drvdata(pdev, imx6_pcie);
> +	return 0;
> +
> +err:
> +	return ret;
> +}
> +
> +static const struct of_device_id imx6_pcie_of_match[] = {
> +	{ .compatible = "fsl,imx6-pcie", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, imx6_pcie_of_match);
> +
> +static struct platform_driver imx6_pcie_driver = {
> +	.driver = {
> +		.name	= "imx6-pcie",
> +		.owner	= THIS_MODULE,
> +		.of_match_table = of_match_ptr(imx6_pcie_of_match),
> +	},
> +};
> +
> +/* Freescale PCIe driver does not allow module unload */
> +
> +static int __init pcie_init(void)
> +{
> +	return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe);
> +}
> +subsys_initcall(pcie_init);

Any reason why it cannot be module_init()?

Shawn

> +
> +MODULE_AUTHOR("Sean Cross <xobs at kosagi.com>");
> +MODULE_DESCRIPTION("Freescale i.MX6 PCIe host controller driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.7.9.5
> 




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