Commit 1c52a513 authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Bjorn Helgaas
Browse files

PCI: armada: Add driver for Marvell Armada 7K/8K PCIe controller 



The Marvell Armada 7K/8K SoCs integrate a PCIe controller from Synopsys.
Add a new driver that provides the small glue needed to use the existing
Designware driver to make it work on Marvell Armada 7K/8K SoCs.

The MSI support will be enabled at a later point.

[bhelgaas: use dev_dbg(), dw_pcie_wait_for_link()]
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 80014ad5

drivers/pci/host/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -231,4 +231,15 @@ config PCI_HOST_THUNDER_ECAM 
	help

	  Say Y here if you want ECAM support for CN88XX-Pass-1.x Cavium Thunder SoCs.



config PCIE_ARMADA_8K

	bool "Marvell Armada-8K PCIe controller"

	depends on ARCH_MVEBU

	select PCIE_DW

	select PCIEPORTBUS

	help

	  Say Y here if you want to enable PCIe controller support on

	  Armada-8K SoCs. The PCIe controller on Armada-8K is based on

	  Designware hardware and therefore the driver re-uses the

	  Designware core functions to implement the driver.



endmenu

drivers/pci/host/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -28,3 +28,4 @@ obj-$(CONFIG_PCI_HISI) += pcie-hisi.o 
obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o

obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o

obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o

obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o

drivers/pci/host/pcie-armada8k.c

0 → 100644
+262 −0
Original line number Diff line number Diff line 
/*

 * PCIe host controller driver for Marvell Armada-8K SoCs

 *

 * Armada-8K PCIe Glue Layer Source Code

 *

 * Copyright (C) 2016 Marvell Technology Group Ltd.

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */



#include <linux/clk.h>

#include <linux/delay.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/pci.h>

#include <linux/phy/phy.h>

#include <linux/platform_device.h>

#include <linux/resource.h>

#include <linux/of_pci.h>

#include <linux/of_irq.h>



#include "pcie-designware.h"



struct armada8k_pcie {

	void __iomem *base;

	struct clk *clk;

	struct pcie_port pp;

};



#define PCIE_VENDOR_REGS_OFFSET		0x8000



#define PCIE_GLOBAL_CONTROL_REG		0x0

#define PCIE_APP_LTSSM_EN		BIT(2)

#define PCIE_DEVICE_TYPE_SHIFT		4

#define PCIE_DEVICE_TYPE_MASK		0xF

#define PCIE_DEVICE_TYPE_RC		0x4 /* Root complex */



#define PCIE_GLOBAL_STATUS_REG		0x8

#define PCIE_GLB_STS_RDLH_LINK_UP	BIT(1)

#define PCIE_GLB_STS_PHY_LINK_UP	BIT(9)



#define PCIE_GLOBAL_INT_CAUSE1_REG	0x1C

#define PCIE_GLOBAL_INT_MASK1_REG	0x20

#define PCIE_INT_A_ASSERT_MASK		BIT(9)

#define PCIE_INT_B_ASSERT_MASK		BIT(10)

#define PCIE_INT_C_ASSERT_MASK		BIT(11)

#define PCIE_INT_D_ASSERT_MASK		BIT(12)



#define PCIE_ARCACHE_TRC_REG		0x50

#define PCIE_AWCACHE_TRC_REG		0x54

#define PCIE_ARUSER_REG			0x5C

#define PCIE_AWUSER_REG			0x60

/*

 * AR/AW Cache defauls: Normal memory, Write-Back, Read / Write

 * allocate

 */

#define ARCACHE_DEFAULT_VALUE		0x3511

#define AWCACHE_DEFAULT_VALUE		0x5311



#define DOMAIN_OUTER_SHAREABLE		0x2

#define AX_USER_DOMAIN_MASK		0x3

#define AX_USER_DOMAIN_SHIFT		4



#define to_armada8k_pcie(x)	container_of(x, struct armada8k_pcie, pp)



static int armada8k_pcie_link_up(struct pcie_port *pp)

{

	struct armada8k_pcie *pcie = to_armada8k_pcie(pp);

	u32 reg;

	u32 mask = PCIE_GLB_STS_RDLH_LINK_UP | PCIE_GLB_STS_PHY_LINK_UP;



	reg = readl(pcie->base + PCIE_GLOBAL_STATUS_REG);



	if ((reg & mask) == mask)

		return 1;



	dev_dbg(pp->dev, "No link detected (Global-Status: 0x%08x).\n", reg);

	return 0;

}



static void armada8k_pcie_establish_link(struct pcie_port *pp)

{

	struct armada8k_pcie *pcie = to_armada8k_pcie(pp);

	void __iomem *base = pcie->base;

	u32 reg;



	if (!dw_pcie_link_up(pp)) {

		/* Disable LTSSM state machine to enable configuration */

		reg = readl(base + PCIE_GLOBAL_CONTROL_REG);

		reg &= ~(PCIE_APP_LTSSM_EN);

		writel(reg, base + PCIE_GLOBAL_CONTROL_REG);

	}



	/* Set the device to root complex mode */

	reg = readl(base + PCIE_GLOBAL_CONTROL_REG);

	reg &= ~(PCIE_DEVICE_TYPE_MASK << PCIE_DEVICE_TYPE_SHIFT);

	reg |= PCIE_DEVICE_TYPE_RC << PCIE_DEVICE_TYPE_SHIFT;

	writel(reg, base + PCIE_GLOBAL_CONTROL_REG);



	/* Set the PCIe master AxCache attributes */

	writel(ARCACHE_DEFAULT_VALUE, base + PCIE_ARCACHE_TRC_REG);

	writel(AWCACHE_DEFAULT_VALUE, base + PCIE_AWCACHE_TRC_REG);



	/* Set the PCIe master AxDomain attributes */

	reg = readl(base + PCIE_ARUSER_REG);

	reg &= ~(AX_USER_DOMAIN_MASK << AX_USER_DOMAIN_SHIFT);

	reg |= DOMAIN_OUTER_SHAREABLE << AX_USER_DOMAIN_SHIFT;

	writel(reg, base + PCIE_ARUSER_REG);



	reg = readl(base + PCIE_AWUSER_REG);

	reg &= ~(AX_USER_DOMAIN_MASK << AX_USER_DOMAIN_SHIFT);

	reg |= DOMAIN_OUTER_SHAREABLE << AX_USER_DOMAIN_SHIFT;

	writel(reg, base + PCIE_AWUSER_REG);



	/* Enable INT A-D interrupts */

	reg = readl(base + PCIE_GLOBAL_INT_MASK1_REG);

	reg |= PCIE_INT_A_ASSERT_MASK | PCIE_INT_B_ASSERT_MASK |

	       PCIE_INT_C_ASSERT_MASK | PCIE_INT_D_ASSERT_MASK;

	writel(reg, base + PCIE_GLOBAL_INT_MASK1_REG);



	if (!dw_pcie_link_up(pp)) {

		/* Configuration done. Start LTSSM */

		reg = readl(base + PCIE_GLOBAL_CONTROL_REG);

		reg |= PCIE_APP_LTSSM_EN;

		writel(reg, base + PCIE_GLOBAL_CONTROL_REG);

	}



	/* Wait until the link becomes active again */

	if (dw_pcie_wait_for_link(pp))

		dev_err(pp->dev, "Link not up after reconfiguration\n");

}



static void armada8k_pcie_host_init(struct pcie_port *pp)

{

	dw_pcie_setup_rc(pp);

	armada8k_pcie_establish_link(pp);

}



static irqreturn_t armada8k_pcie_irq_handler(int irq, void *arg)

{

	struct pcie_port *pp = arg;

	struct armada8k_pcie *pcie = to_armada8k_pcie(pp);

	void __iomem *base = pcie->base;

	u32 val;



	/*

	 * Interrupts are directly handled by the device driver of the

	 * PCI device. However, they are also latched into the PCIe

	 * controller, so we simply discard them.

	 */

	val = readl(base + PCIE_GLOBAL_INT_CAUSE1_REG);

	writel(val, base + PCIE_GLOBAL_INT_CAUSE1_REG);



	return IRQ_HANDLED;

}



static struct pcie_host_ops armada8k_pcie_host_ops = {

	.link_up = armada8k_pcie_link_up,

	.host_init = armada8k_pcie_host_init,

};



static int armada8k_add_pcie_port(struct pcie_port *pp,

				  struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	int ret;



	pp->root_bus_nr = -1;

	pp->ops = &armada8k_pcie_host_ops;



	pp->irq = platform_get_irq(pdev, 0);

	if (!pp->irq) {

		dev_err(dev, "failed to get irq for port\n");

		return -ENODEV;

	}



	ret = devm_request_irq(dev, pp->irq, armada8k_pcie_irq_handler,

			       IRQF_SHARED, "armada8k-pcie", pp);

	if (ret) {

		dev_err(dev, "failed to request irq %d\n", pp->irq);

		return ret;

	}



	ret = dw_pcie_host_init(pp);

	if (ret) {

		dev_err(dev, "failed to initialize host: %d\n", ret);

		return ret;

	}



	return 0;

}



static int armada8k_pcie_probe(struct platform_device *pdev)

{

	struct armada8k_pcie *pcie;

	struct pcie_port *pp;

	struct device *dev = &pdev->dev;

	struct resource *base;

	int ret;



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

	if (!pcie)

		return -ENOMEM;



	pcie->clk = devm_clk_get(dev, NULL);

	if (IS_ERR(pcie->clk))

		return PTR_ERR(pcie->clk);



	clk_prepare_enable(pcie->clk);



	pp = &pcie->pp;

	pp->dev = dev;

	platform_set_drvdata(pdev, pcie);



	/* Get the dw-pcie unit configuration/control registers base. */

	base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");

	pp->dbi_base = devm_ioremap_resource(dev, base);

	if (IS_ERR(pp->dbi_base)) {

		dev_err(dev, "couldn't remap regs base %p\n", base);

		ret = PTR_ERR(pp->dbi_base);

		goto fail;

	}



	pcie->base = pp->dbi_base + PCIE_VENDOR_REGS_OFFSET;



	ret = armada8k_add_pcie_port(pp, pdev);

	if (ret)

		goto fail;



	return 0;



fail:

	if (!IS_ERR(pcie->clk))

		clk_disable_unprepare(pcie->clk);



	return ret;

}



static const struct of_device_id armada8k_pcie_of_match[] = {

	{ .compatible = "marvell,armada8k-pcie", },

	{},

};

MODULE_DEVICE_TABLE(of, armada8k_pcie_of_match);



static struct platform_driver armada8k_pcie_driver = {

	.probe		= armada8k_pcie_probe,

	.driver = {

		.name	= "armada8k-pcie",

		.of_match_table = of_match_ptr(armada8k_pcie_of_match),

	},

};



module_platform_driver(armada8k_pcie_driver);



MODULE_DESCRIPTION("Armada 8k PCIe host controller driver");

MODULE_AUTHOR("Yehuda Yitshak <yehuday@marvell.com>");

MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");

MODULE_LICENSE("GPL v2");

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