[PATCH v5] PCI: Layerscape: Add Layerscape PCIe driver

[Minghuan Lian]

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

Signed-off-by: Minghuan Lian <***@freescale.com>
---
Change log:
v5:
1. Add MAINTAINERS information
2. Remove nnnecessary NULL pointer check
3. Use dev_dbg instead of dev_err in ls_pcie_msi_irq_handler()

v4:
1. Add 'depends on OF' to Kconfig

v3:
1. Add prefechable mem region and adjust mem region
2. Rename 'pcie-scfg' to 'fsl,pcie-scfg'
3. Change MSI interrupt handler
4. Use module_platform_driver_probe instead of subsys_initcall

v2:
1. Add pcie-scfg to link scfg device node and remove "fsl, ls-pcie" compatible
2. Use regmap API to access scfg.
3. remove ls1021 PCI device ID.
4. remove unused irq pme_irq and ls_pcie_list.
5. Do not set scfg bit reverse mode

.../devicetree/bindings/pci/layerscape-pci.txt | 46 ++++
MAINTAINERS | 10 +
drivers/pci/host/Kconfig | 8 +
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pci-layerscape.c | 271 +++++++++++++++++++++
5 files changed, 336 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pci/layerscape-pci.txt
create mode 100644 drivers/pci/host/pci-layerscape.c

diff --git a/Documentation/devicetree/bindings/pci/layerscape-pci.txt b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
new file mode 100644
index 0000000..d7b0026
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
@@ -0,0 +1,46 @@
+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
+ "msi": The interrupt that is asserted when an MSI is received
+ "pme": The interrupt that is asserted when PME state changes
+- 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.
+ used to get SCFG PEXN registers
+
+Example:
+
+ ***@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 */
+ <GIC_SPI 179 IRQ_TYPE_LEVEL_HIGH>, /* MSI interrupt */
+ <GIC_SPI 181 IRQ_TYPE_LEVEL_HIGH>; /* PME interrupt */
+ interrupt-names = "intr", "msi", "pme";
+ 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>;
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 07fd7e2..77f0f49 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6943,6 +6943,16 @@ L: linux-***@vger.kernel.org
S: Maintained
F: drivers/pci/host/*spear*

+PCIe DRIVER FOR FREESCALE LAYERSCAPE
+M: Minghuan Lian <***@freescale.com>
+M: Mingkai Hu <***@freescale.com>
+M: Roy Zang <tie-***@freescale.com>
+L: linuxppc-***@lists.ozlabs.org
+L: linux-***@vger.kernel.org
+L: linux-arm-***@lists.infradead.org
+S: Maintained
+F: drivers/pci/host/pci-layerscape.c
+
PCMCIA SUBSYSTEM
P: Linux PCMCIA Team
L: linux-***@lists.infradead.org
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 34134d6..5c45ce2 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -82,4 +82,12 @@ config PCIE_XILINX
Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
Host Bridge driver.

+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 182929c..fd10554 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
obj-$(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_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..60b52e1
--- /dev/null
+++ b/drivers/pci/host/pci-layerscape.c
@@ -0,0 +1,271 @@
+/*
+ * PCIe host controller driver for Freescale Layerscape SoCs
+ *
+ * Copyright (C) 2014 Freescale Semiconductor.
+ *
+ * Author: 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_dbg(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;
+
+ 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 <***@freescale.com>");
+MODULE_DESCRIPTION("Freescale Layerscape PCIe host controller driver");
+MODULE_LICENSE("GPL v2");