Commit 78bdcad0 authored by Kishon Vijay Abraham I's avatar Kishon Vijay Abraham I Committed by Bjorn Helgaas
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PCI: dra7xx: Add support to make GPIO drive PERST# line 



The PERST# line in am57x-evm is connected to a GPIO line and PERST# should
be driven high to indicate the clocks are stable (As per Figure 2-10: Power
Up of the PCIe CEM spec 3.0).

Add support to make GPIO drive PERST# line.

Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 389c7094

Documentation/devicetree/bindings/pci/ti-pci.txt

+3 −0
Original line number Diff line number Diff line
@@ -23,6 +23,9 @@ PCIe Designware Controller 
   interrupt-map-mask,

   interrupt-map : as specified in ../designware-pcie.txt



Optional Property:

 - gpios : Should be added if a gpio line is required to drive PERST# line



Example:

axi {

	compatible = "simple-bus";

drivers/pci/host/pci-dra7xx.c

+22 −2
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/irqdomain.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of_gpio.h>

#include <linux/pci.h>

#include <linux/phy/phy.h>

#include <linux/platform_device.h>
@@ -336,6 +337,9 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) 
	struct device *dev = &pdev->dev;

	struct device_node *np = dev->of_node;

	char name[10];

	int gpio_sel;

	enum of_gpio_flags flags;

	unsigned long gpio_flags;



	dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL);

	if (!dra7xx)
@@ -398,6 +402,22 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) 
		goto err_get_sync;

	}



	gpio_sel = of_get_gpio_flags(dev->of_node, 0, &flags);

	if (gpio_is_valid(gpio_sel)) {

		gpio_flags = (flags & OF_GPIO_ACTIVE_LOW) ?

				GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH;

		ret = devm_gpio_request_one(dev, gpio_sel, gpio_flags,

					    "pcie_reset");

		if (ret) {

			dev_err(&pdev->dev, "gpio%d request failed, ret %d\n",

				gpio_sel, ret);

			goto err_gpio;

		}

	} else if (gpio_sel == -EPROBE_DEFER) {

		ret = -EPROBE_DEFER;

		goto err_gpio;

	}



	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);

	reg &= ~LTSSM_EN;

	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);
@@ -406,11 +426,11 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) 


	ret = dra7xx_add_pcie_port(dra7xx, pdev);

	if (ret < 0)

		goto err_add_port;

		goto err_gpio;



	return 0;



err_add_port:

err_gpio:

	pm_runtime_put(dev);



err_get_sync:

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