PCI: layerscape: Add Freescale Layerscape PCIe driver

Add support for Freescale Layerscape PCIe controller.  This driver re-uses
the Synopsis DesignWare core code.

[bhelgaas: add Kconfig dependency on CONFIG_ARM]
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

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

+Freescale Layerscape PCIe controller
+
+This PCIe host controller is based on the Synopsis Designware PCIe IP
+and thus inherits all the common properties defined in designware-pcie.txt.
+
+Required properties:
+- compatible: should contain the platform identifier such as "fsl,ls1021a-pcie"
+- reg: base addresses and lengths of the PCIe controller
+- interrupts: A list of interrupt outputs of the controller. Must contain an
+  entry for each entry in the interrupt-names property.
+- interrupt-names: Must include the following entries:
+  "intr": The interrupt that is asserted for controller interrupts
+- fsl,pcie-scfg: Must include two entries.
+  The first entry must be a link to the SCFG device node
+  The second entry must be '0' or '1' based on physical PCIe controller index.
+  This is used to get SCFG PEXN registers
+
+Example:
+
+	pcie@3400000 {
+		compatible = "fsl,ls1021a-pcie", "snps,dw-pcie";
+		reg = <0x00 0x03400000 0x0 0x00010000   /* controller registers */
+		       0x40 0x00000000 0x0 0x00002000>; /* configuration space */
+		reg-names = "regs", "config";
+		interrupts = <GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH>; /* controller interrupt */
+		interrupt-names = "intr";
+		fsl,pcie-scfg = <&scfg 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		device_type = "pci";
+		num-lanes = <4>;
+		bus-range = <0x0 0xff>;
+		ranges = <0x81000000 0x0 0x00000000 0x40 0x00010000 0x0 0x00010000   /* downstream I/O */
+			  0xc2000000 0x0 0x20000000 0x40 0x20000000 0x0 0x20000000   /* prefetchable memory */
+			  0x82000000 0x0 0x40000000 0x40 0x40000000 0x0 0x40000000>; /* non-prefetchable memory */
+		#interrupt-cells = <1>;
+		interrupt-map-mask = <0 0 0 7>;
+		interrupt-map = <0000 0 0 1 &gic GIC_SPI 91  IRQ_TYPE_LEVEL_HIGH>,
+				<0000 0 0 2 &gic GIC_SPI 188 IRQ_TYPE_LEVEL_HIGH>,
+				<0000 0 0 3 &gic GIC_SPI 190 IRQ_TYPE_LEVEL_HIGH>,
+				<0000 0 0 4 &gic GIC_SPI 192 IRQ_TYPE_LEVEL_HIGH>;
+	};

MAINTAINERS

@@ -6983,6 +6983,16 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/pci/xgene-pci.txt
 F:	drivers/pci/host/pci-xgene.c
 
+PCI DRIVER FOR FREESCALE LAYERSCAPE
+M:	Minghuan Lian <minghuan.Lian@freescale.com>
+M:	Mingkai Hu <mingkai.hu@freescale.com>
+M:	Roy Zang <tie-fei.zang@freescale.com>
+L:	linuxppc-dev@lists.ozlabs.org
+L:	linux-pci@vger.kernel.org
+L:	linux-arm-kernel@lists.infradead.org
+S:	Maintained
+F:	drivers/pci/host/*layerscape*
+
 PCI DRIVER FOR IMX6
 M:	Richard Zhu <r65037@freescale.com>
 M:	Lucas Stach <l.stach@pengutronix.de>

drivers/pci/host/Kconfig

@@ -91,4 +91,12 @@ config PCI_XGENE
 	  There are 5 internal PCIe ports available. Each port is GEN3 capable
 	  and have varied lanes from x1 to x8.
 
+config PCI_LAYERSCAPE
+	bool "Freescale Layerscape PCIe controller"
+	depends on OF && ARM
+	select PCIE_DW
+	select MFD_SYSCON
+	help
+	  Say Y here if you want PCIe controller support on Layerscape SoCs.
+
 endmenu

drivers/pci/host/Makefile

@@ -11,3 +11,4 @@ obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
 obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
 obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
+obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o

drivers/pci/host/pci-layerscape.c

+/*
+ * PCIe host controller driver for Freescale Layerscape SoCs
+ *
+ * Copyright (C) 2014 Freescale Semiconductor.
+ *
+  * Author: Minghuan Lian <Minghuan.Lian@freescale.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/kernel.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/resource.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pcie-designware.h"
+
+/* PEX1/2 Misc Ports Status Register */
+#define SCFG_PEXMSCPORTSR(pex_idx)	(0x94 + (pex_idx) * 4)
+#define LTSSM_STATE_SHIFT	20
+#define LTSSM_STATE_MASK	0x3f
+#define LTSSM_PCIE_L0		0x11 /* L0 state */
+
+/* Symbol Timer Register and Filter Mask Register 1 */
+#define PCIE_STRFMR1 0x71c
+
+struct ls_pcie {
+	struct list_head node;
+	struct device *dev;
+	struct pci_bus *bus;
+	void __iomem *dbi;
+	struct regmap *scfg;
+	struct pcie_port pp;
+	int index;
+	int msi_irq;
+};
+
+#define to_ls_pcie(x)	container_of(x, struct ls_pcie, pp)
+
+static int ls_pcie_link_up(struct pcie_port *pp)
+{
+	u32 state;
+	struct ls_pcie *pcie = to_ls_pcie(pp);
+
+	regmap_read(pcie->scfg, SCFG_PEXMSCPORTSR(pcie->index), &state);
+	state = (state >> LTSSM_STATE_SHIFT) & LTSSM_STATE_MASK;
+
+	if (state < LTSSM_PCIE_L0)
+		return 0;
+
+	return 1;
+}
+
+static void ls_pcie_host_init(struct pcie_port *pp)
+{
+	struct ls_pcie *pcie = to_ls_pcie(pp);
+	int count = 0;
+	u32 val;
+
+	dw_pcie_setup_rc(pp);
+
+	while (!ls_pcie_link_up(pp)) {
+		usleep_range(100, 1000);
+		count++;
+		if (count >= 200) {
+			dev_err(pp->dev, "phy link never came up\n");
+			return;
+		}
+	}
+
+	/*
+	 * LS1021A Workaround for internal TKT228622
+	 * to fix the INTx hang issue
+	 */
+	val = ioread32(pcie->dbi + PCIE_STRFMR1);
+	val &= 0xffff;
+	iowrite32(val, pcie->dbi + PCIE_STRFMR1);
+}
+
+static struct pcie_host_ops ls_pcie_host_ops = {
+	.link_up = ls_pcie_link_up,
+	.host_init = ls_pcie_host_init,
+};
+
+static int ls_add_pcie_port(struct ls_pcie *pcie)
+{
+	struct pcie_port *pp;
+	int ret;
+
+	pp = &pcie->pp;
+	pp->dev = pcie->dev;
+	pp->dbi_base = pcie->dbi;
+	pp->root_bus_nr = -1;
+	pp->ops = &ls_pcie_host_ops;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(pp->dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __init ls_pcie_probe(struct platform_device *pdev)
+{
+	struct ls_pcie *pcie;
+	struct resource *dbi_base;
+	u32 index[2];
+	int ret;
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->dev = &pdev->dev;
+
+	dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
+	if (!dbi_base) {
+		dev_err(&pdev->dev, "missing *regs* space\n");
+		return -ENODEV;
+	}
+
+	pcie->dbi = devm_ioremap_resource(&pdev->dev, dbi_base);
+	if (IS_ERR(pcie->dbi))
+		return PTR_ERR(pcie->dbi);
+
+	pcie->scfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+						     "fsl,pcie-scfg");
+	if (IS_ERR(pcie->scfg)) {
+		dev_err(&pdev->dev, "No syscfg phandle specified\n");
+		return PTR_ERR(pcie->scfg);
+	}
+
+	ret = of_property_read_u32_array(pdev->dev.of_node,
+					 "fsl,pcie-scfg", index, 2);
+	if (ret)
+		return ret;
+	pcie->index = index[1];
+
+	ret = ls_add_pcie_port(pcie);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, pcie);
+
+	return 0;
+}
+
+static const struct of_device_id ls_pcie_of_match[] = {
+	{ .compatible = "fsl,ls1021a-pcie" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ls_pcie_of_match);
+
+static struct platform_driver ls_pcie_driver = {
+	.driver = {
+		.name = "layerscape-pcie",
+		.owner = THIS_MODULE,
+		.of_match_table = ls_pcie_of_match,
+	},
+};
+
+module_platform_driver_probe(ls_pcie_driver, ls_pcie_probe);
+
+MODULE_AUTHOR("Minghuan Lian <Minghuan.Lian@freescale.com>");
+MODULE_DESCRIPTION("Freescale Layerscape PCIe host controller driver");
+MODULE_LICENSE("GPL v2");