[PATCH v2 4/4] PCI: host: pcie-dra7xx: add support for pcie-dra7xx controller

[Kishon Vijay Abraham I]

Added support for pcie controller in dra7xx. This driver re-uses
the designware core code that is already present in kernel.

Cc: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Mohit Kumar <mohit.kumar@xxxxxx>
Cc: Jingoo Han <jg1.han@xxxxxxxxxxx>
Cc: Marek Vasut <marex@xxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
 drivers/pci/host/Kconfig      |   10 +
 drivers/pci/host/Makefile     |    1 +
 drivers/pci/host/pci-dra7xx.c |  458 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 469 insertions(+)
 create mode 100644 drivers/pci/host/pci-dra7xx.c

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 21df477..22117b0 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -1,6 +1,16 @@
 menu "PCI host controller drivers"
 	depends on PCI
 
+config PCI_DRA7XX
+	bool "TI DRA7xx PCIe controller"
+	select PCIE_DW
+	depends on OF && HAS_IOMEM && TI_PIPE3
+	help
+	 Enables support for the PCIE controller present in DRA7xx SoC. There
+	 are two instances of PCIE controller in DRA7xx. This controller can
+	 act both as EP and RC. This reuses the same Designware core as used
+	 by other SoCs.
+
 config PCI_MVEBU
 	bool "Marvell EBU PCIe controller"
 	depends on ARCH_MVEBU || ARCH_DOVE || ARCH_KIRKWOOD
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 611ba4b..c42844d 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_DRA7XX) += pci-dra7xx.o
 obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
 obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
 obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c
new file mode 100644
index 0000000..52b34fe
--- /dev/null
+++ b/drivers/pci/host/pci-dra7xx.c
@@ -0,0 +1,458 @@
+/*
+ * pcie-dra7xx - PCIe controller driver for TI DRA7xx SoCs
+ *
+ * Copyright (C) 2013-2014 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Authors: Kishon Vijay Abraham I <kishon@xxxxxx>
+ *
+ * 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/err.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+
+/* PCIe controller wrapper DRA7XX configuration registers */
+
+#define	PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN		0x0024
+#define	PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MAIN		0x0028
+#define	ERR_SYS						BIT(0)
+#define	ERR_FATAL					BIT(1)
+#define	ERR_NONFATAL					BIT(2)
+#define	ERR_COR						BIT(3)
+#define	ERR_AXI						BIT(4)
+#define	ERR_ECRC					BIT(5)
+#define	PME_TURN_OFF					BIT(8)
+#define	PME_TO_ACK					BIT(9)
+#define	PM_PME						BIT(10)
+#define	LINK_REQ_RST					BIT(11)
+#define	LINK_UP_EVT					BIT(12)
+#define	CFG_BME_EVT					BIT(13)
+#define	CFG_MSE_EVT					BIT(14)
+#define	INTERRUPTS (ERR_SYS | ERR_FATAL | ERR_NONFATAL | ERR_COR | ERR_AXI | \
+			ERR_ECRC | PME_TURN_OFF | PME_TO_ACK | PM_PME | \
+			LINK_REQ_RST | LINK_UP_EVT | CFG_BME_EVT | CFG_MSE_EVT)
+
+#define	PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI		0x0034
+#define	PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI		0x0038
+#define	INTA						BIT(0)
+#define	INTB						BIT(1)
+#define	INTC						BIT(2)
+#define	INTD						BIT(3)
+#define	MSI						BIT(4)
+#define	LEG_EP_INTERRUPTS (INTA | INTB | INTC | INTD)
+
+#define	PCIECTRL_DRA7XX_CONF_DEVICE_CMD			0x0104
+#define	LTSSM_EN					0x1
+
+#define	PCIECTRL_DRA7XX_CONF_PHY_CS			0x010C
+#define	LINK_UP						BIT(16)
+
+struct dra7xx_pcie {
+	void __iomem		*base;
+	struct phy		**phy;
+	int			phy_count;
+	struct device		*dev;
+	struct pcie_port	pp;
+};
+
+#define to_dra7xx_pcie(x)	container_of((x), struct dra7xx_pcie, pp)
+
+static inline u32 dra7xx_pcie_readl(struct dra7xx_pcie *pcie, u32 offset)
+{
+	return readl(pcie->base + offset);
+}
+
+static inline void dra7xx_pcie_writel(struct dra7xx_pcie *pcie, u32 offset,
+				      u32 value)
+{
+	writel(value, pcie->base + offset);
+}
+
+static int dra7xx_pcie_link_up(struct pcie_port *pp)
+{
+	struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pp);
+	u32 reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_PHY_CS);
+
+	return !!(reg & LINK_UP);
+}
+
+static int dra7xx_pcie_establish_link(struct pcie_port *pp)
+{
+	u32 reg;
+	unsigned int retries = 1000;
+	struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pp);
+
+	if (dw_pcie_link_up(pp)) {
+		dev_err(pp->dev, "link is already up\n");
+		return 0;
+	}
+
+	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
+	reg |= LTSSM_EN;
+	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);
+
+	while (retries--) {
+		reg = dra7xx_pcie_readl(dra7xx,	PCIECTRL_DRA7XX_CONF_PHY_CS);
+		if (reg & LINK_UP)
+			break;
+		usleep_range(10, 20);
+	}
+
+	if (retries == 0) {
+		dev_err(pp->dev, "link is not up\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void dra7xx_pcie_enable_interrupts(struct pcie_port *pp)
+{
+	struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pp);
+
+	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN,
+			   ~INTERRUPTS);
+	dra7xx_pcie_writel(dra7xx,
+			   PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MAIN, INTERRUPTS);
+	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI,
+			   ~LEG_EP_INTERRUPTS & ~MSI);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dra7xx_pcie_writel(dra7xx,
+				   PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI, MSI);
+	else
+		dra7xx_pcie_writel(dra7xx,
+				   PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI,
+				   LEG_EP_INTERRUPTS);
+}
+
+static void dra7xx_pcie_host_init(struct pcie_port *pp)
+{
+	dw_pcie_setup_rc(pp);
+	dra7xx_pcie_establish_link(pp);
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(pp);
+	dra7xx_pcie_enable_interrupts(pp);
+}
+
+static struct pcie_host_ops dra7xx_pcie_host_ops = {
+	.link_up = dra7xx_pcie_link_up,
+	.host_init = dra7xx_pcie_host_init,
+};
+
+static int dra7xx_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+				irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+	set_irq_flags(irq, IRQF_VALID);
+
+	return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+	.map = dra7xx_pcie_intx_map,
+};
+
+static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
+{
+	struct device *dev = pp->dev;
+	struct device_node *node = dev->of_node;
+	struct device_node *pcie_intc_node =  of_get_next_child(node, NULL);
+
+	if (!pcie_intc_node) {
+		dev_err(dev, "No PCIe Intc node found\n");
+		return PTR_ERR(pcie_intc_node);
+	}
+
+	pp->irq_domain = irq_domain_add_linear(pcie_intc_node, 4,
+					       &intx_domain_ops, pp);
+	if (!pp->irq_domain) {
+		dev_err(dev, "Failed to get a INTx IRQ domain\n");
+		return PTR_ERR(pp->irq_domain);
+	}
+
+	return 0;
+}
+
+static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
+{
+	struct pcie_port *pp = arg;
+	struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pp);
+	u32 reg;
+
+	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
+
+	switch (reg) {
+	case MSI:
+		dw_handle_msi_irq(pp);
+		break;
+	case INTA:
+	case INTB:
+	case INTC:
+	case INTD:
+		generic_handle_irq(irq_find_mapping(pp->irq_domain, ffs(reg)));
+		break;
+	}
+
+	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI, reg);
+
+	return IRQ_HANDLED;
+}
+
+
+static irqreturn_t dra7xx_pcie_irq_handler(int irq, void *arg)
+{
+	struct dra7xx_pcie *dra7xx = arg;
+	u32 reg;
+
+	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN);
+
+	if (reg & ERR_SYS)
+		dev_dbg(dra7xx->dev, "System Error\n");
+
+	if (reg & ERR_FATAL)
+		dev_dbg(dra7xx->dev, "Fatal Error\n");
+
+	if (reg & ERR_NONFATAL)
+		dev_dbg(dra7xx->dev, "Non Fatal Error\n");
+
+	if (reg & ERR_COR)
+		dev_dbg(dra7xx->dev, "Correctable Error\n");
+
+	if (reg & ERR_AXI)
+		dev_dbg(dra7xx->dev, "AXI tag lookup fatal Error\n");
+
+	if (reg & ERR_ECRC)
+		dev_dbg(dra7xx->dev, "ECRC Error\n");
+
+	if (reg & PME_TURN_OFF)
+		dev_dbg(dra7xx->dev,
+			"Power Management Event Turn-Off message received\n");
+
+	if (reg & PME_TO_ACK)
+		dev_dbg(dra7xx->dev,
+			"Power Management Turn-Off Ack message received\n");
+
+	if (reg & PM_PME)
+		dev_dbg(dra7xx->dev,
+			"PM Power Management Event message received\n");
+
+	if (reg & LINK_REQ_RST)
+		dev_dbg(dra7xx->dev, "Link Request Reset\n");
+
+	if (reg & LINK_UP_EVT)
+		dev_dbg(dra7xx->dev, "Link-up state change\n");
+
+	if (reg & CFG_BME_EVT)
+		dev_dbg(dra7xx->dev, "CFG 'Bus Master Enable' change\n");
+
+	if (reg & CFG_MSE_EVT)
+		dev_dbg(dra7xx->dev, "CFG 'Memory Space Enable' change\n");
+
+	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN, reg);
+
+	return IRQ_HANDLED;
+}
+
+static int add_pcie_port(struct dra7xx_pcie *dra7xx,
+			  struct platform_device *pdev)
+{
+	int ret;
+	struct pcie_port *pp;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+
+	pp = &dra7xx->pp;
+	pp->dev = dev;
+	pp->ops = &dra7xx_pcie_host_ops;
+
+	pp->irq = platform_get_irq(pdev, 1);
+	if (pp->irq < 0) {
+		dev_err(dev, "missing IRQ resource\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_irq(&pdev->dev, pp->irq,
+			       dra7xx_pcie_msi_irq_handler, IRQF_SHARED,
+			       "dra7-pcie-msi",	pp);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request irq\n");
+		return ret;
+	}
+
+	if (!IS_ENABLED(CONFIG_PCI_MSI)) {
+		ret = dra7xx_pcie_init_irq_domain(pp);
+		if (ret < 0)
+			return ret;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rc_dbics");
+	pp->dbi_base = devm_ioremap(dev, res->start, resource_size(res));
+	if (!pp->dbi_base)
+		return -ENOMEM;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dra7xx->dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __init dra7xx_pcie_probe(struct platform_device *pdev)
+{
+	u32 reg;
+	int ret;
+	int irq;
+	int i;
+	int phy_count;
+	struct phy **phy;
+	void __iomem *base;
+	struct resource *res;
+	struct dra7xx_pcie *dra7xx;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	char name[10];
+
+	dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL);
+	if (!dra7xx)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "missing IRQ resource\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_irq(dev, irq, dra7xx_pcie_irq_handler,
+			       IRQF_SHARED, "dra7xx-pcie-main", dra7xx);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		return ret;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ti_conf");
+	base = devm_ioremap_nocache(dev, res->start, resource_size(res));
+	if (!base)
+		return -ENOMEM;
+
+	phy_count = of_property_count_strings(np, "phy-names");
+	if (phy_count < 0) {
+		dev_err(dev, "unable to find the strings\n");
+		return phy_count;
+	}
+
+	phy = devm_kzalloc(dev, sizeof(*phy) * phy_count, GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	for (i = 0; i < phy_count; i++) {
+		snprintf(name, sizeof(name), "pcie-phy%d", i);
+		phy[i] = devm_phy_get(dev, name);
+		if (IS_ERR(phy[i]))
+			return PTR_ERR(phy[i]);
+
+		ret = phy_init(phy[i]);
+		if (ret < 0)
+			goto err_phy;
+
+		ret = phy_power_on(phy[i]);
+		if (ret < 0) {
+			phy_exit(phy[i]);
+			goto err_phy;
+		}
+	}
+
+	dra7xx->base = base;
+	dra7xx->phy = phy;
+	dra7xx->dev = dev;
+	dra7xx->phy_count = phy_count;
+
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (IS_ERR_VALUE(ret)) {
+		dev_err(dev, "pm_runtime_get_sync failed\n");
+		goto err_phy;
+	}
+
+	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
+	reg &= ~LTSSM_EN;
+	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);
+
+	platform_set_drvdata(pdev, dra7xx);
+
+	ret = add_pcie_port(dra7xx, pdev);
+	if (ret < 0)
+		goto err_add_port;
+
+	return 0;
+
+err_add_port:
+	pm_runtime_put(dev);
+	pm_runtime_disable(dev);
+
+err_phy:
+	while (--i >= 0) {
+		phy_power_off(phy[i]);
+		phy_exit(phy[i]);
+	}
+
+	return ret;
+}
+
+static int __exit dra7xx_pcie_remove(struct platform_device *pdev)
+{
+	struct dra7xx_pcie *dra7xx = platform_get_drvdata(pdev);
+	struct pcie_port *pp = &dra7xx->pp;
+	struct device *dev = &pdev->dev;
+	int count = dra7xx->phy_count;
+
+	if (pp->irq_domain)
+		irq_domain_remove(pp->irq_domain);
+	pm_runtime_put(dev);
+	pm_runtime_disable(dev);
+	while (count--) {
+		phy_power_off(dra7xx->phy[count]);
+		phy_exit(dra7xx->phy[count]);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_dra7xx_pcie_match[] = {
+	{ .compatible = "ti,dra7-pcie", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_dra7xx_pcie_match);
+
+static struct platform_driver dra7xx_pcie_driver = {
+	.remove		= __exit_p(dra7xx_pcie_remove),
+	.driver = {
+		.name	= "dra7-pcie",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_dra7xx_pcie_match,
+	},
+};
+
+module_platform_driver_probe(dra7xx_pcie_driver, dra7xx_pcie_probe);
+
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@xxxxxx>");
+MODULE_DESCRIPTION("TI PCIe controller driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.9.5

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