PCI: Layerscape: Add Layerscape PCIe driver

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

Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Change-Id: I799aa1cd488a44b4ba9c198694f75d56b2294a03
Reviewed-on: http://git.am.freescale.net:8181/19711
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Mingkai Hu <Mingkai.Hu@freescale.com>
Reviewed-by: Zhengxiong Jin <Jason.Jin@freescale.com>

3 files changed, 283 insertions, 0 deletions

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 3d95048..d6b60f6 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -19,4 +19,12 @@ config PCI_TEGRA
 	bool "NVIDIA Tegra PCIe controller"
 	depends on ARCH_TEGRA
 
+config PCI_LAYERSCAPE
+	bool "Freescale Layerscape PCIe controller"
+	depends on OF
+	select PCIE_DW
+	select MFD_SYSCON
+	help
+	  Say Y here if you want PCIe controller support on Layerscape SoCs.
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index c9a997b..e293b51 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -2,3 +2,4 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
 obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
 obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
 obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
+obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
diff --git a/drivers/pci/host/pci-layerscape.c b/drivers/pci/host/pci-layerscape.c
new file mode 100644
index 0000000..8f5e65e
--- /dev/null
+++ b/drivers/pci/host/pci-layerscape.c
@@ -0,0 +1,274 @@
+/*
+ * 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 <linux/bitrev.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 */
+
+/* SCFG MSI register */
+#define SCFG_SPIMSICR		0x40
+#define SCFG_SPIMSICLRCR	0x90
+
+#define MSI_LS1021A_ADDR		0x1570040
+#define MSI_LS1021A_DATA(pex_idx)	(0xb3 + pex_idx)
+
+/* 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 = bitrev32(state);
+	state = (state >> LTSSM_STATE_SHIFT) & LTSSM_STATE_MASK;
+
+	if (state < LTSSM_PCIE_L0)
+		return 0;
+
+	return 1;
+}
+
+static u32 ls_pcie_get_msi_addr(struct pcie_port *pp)
+{
+	return MSI_LS1021A_ADDR;
+}
+
+static u32 ls_pcie_get_msi_data(struct pcie_port *pp, int pos)
+{
+	struct ls_pcie *pcie = to_ls_pcie(pp);
+
+	return MSI_LS1021A_DATA(pcie->index);
+}
+
+static irqreturn_t ls_pcie_msi_irq_handler(int irq, void *data)
+{
+	struct pcie_port *pp = data;
+	struct ls_pcie *pcie = to_ls_pcie(pp);
+	unsigned int msi_irq;
+
+	/* clear the interrupt */
+	regmap_write(pcie->scfg, SCFG_SPIMSICLRCR,
+		     MSI_LS1021A_DATA(pcie->index));
+
+	msi_irq = irq_find_mapping(pp->irq_domain, 0);
+	if (!msi_irq) {
+		/*
+		 * that's weird who triggered this?
+		 * just clear it
+		 */
+		dev_err(pcie->dev, "unexpected MSI\n");
+		return IRQ_NONE;
+	}
+
+	generic_handle_irq(msi_irq);
+	return IRQ_HANDLED;
+}
+
+static void ls_pcie_msi_clear_irq(struct pcie_port *pp, int irq)
+{
+}
+
+static void ls_pcie_msi_set_irq(struct pcie_port *pp, int irq)
+{
+}
+
+static void ls1021a_pcie_msi_fixup(struct pcie_port *pp)
+{
+	int i;
+
+	/*
+	 * LS1021A has only one MSI interrupt
+	 * Set all msi interrupts as used except the first one
+	 */
+	for (i = 1; i < MAX_MSI_IRQS; i++)
+		set_bit(i, pp->msi_irq_in_use);
+}
+
+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;
+		}
+	}
+
+	if (of_device_is_compatible(pcie->dev->of_node, "fsl,ls1021a-pcie")) {
+		/*
+		 * 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);
+
+		ls1021a_pcie_msi_fixup(pp);
+	}
+}
+
+static struct pcie_host_ops ls_pcie_host_ops = {
+	.link_up = ls_pcie_link_up,
+	.host_init = ls_pcie_host_init,
+	.msi_set_irq = ls_pcie_msi_set_irq,
+	.msi_clear_irq = ls_pcie_msi_clear_irq,
+	.get_msi_addr = ls_pcie_get_msi_addr,
+	.get_msi_data = ls_pcie_get_msi_data,
+};
+
+static int ls_add_pcie_port(struct ls_pcie *pcie)
+{
+	struct pcie_port *pp;
+	int ret;
+
+	if (!pcie)
+		return -EINVAL;
+
+	pp = &pcie->pp;
+	pp->dev = pcie->dev;
+	pp->dbi_base = pcie->dbi;
+	pp->msi_irq = pcie->msi_irq;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		ret = devm_request_irq(pp->dev, pp->msi_irq,
+					ls_pcie_msi_irq_handler,
+					IRQF_SHARED, "ls-pcie-msi", pp);
+		if (ret) {
+			dev_err(pp->dev, "failed to request msi irq\n");
+			return ret;
+		}
+	}
+
+	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];
+
+	pcie->msi_irq = platform_get_irq_byname(pdev, "msi");
+	if (pcie->msi_irq < 0) {
+		dev_err(&pdev->dev,
+			"failed to get MSI IRQ: %d\n", pcie->msi_irq);
+		return pcie->msi_irq;
+	}
+
+	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");