[PATCH v11 3/6] pci:host: Add Altera PCIe host controller driver
Ley Foon Tan
lftan at altera.com
Thu Oct 22 02:27:28 PDT 2015
This patch adds the Altera PCIe host controller driver.
Signed-off-by: Ley Foon Tan <lftan at altera.com>
Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>
---
drivers/pci/host/Kconfig | 8 +
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pcie-altera.c | 579 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 588 insertions(+)
create mode 100644 drivers/pci/host/pcie-altera.c
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index d5e58ba..a67c9de 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -145,4 +145,12 @@ config PCIE_IPROC_BCMA
Say Y here if you want to use the Broadcom iProc PCIe controller
through the BCMA bus interface
+config PCIE_ALTERA
+ tristate "Altera PCIe controller"
+ depends on ARM || NIOS2
+ select PCI_DOMAINS
+ help
+ Say Y here if you want to enable PCIe controller support on Altera
+ FPGA.
+
endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 140d66f..6954f76 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o
obj-$(CONFIG_PCIE_IPROC) += pcie-iproc.o
obj-$(CONFIG_PCIE_IPROC_PLATFORM) += pcie-iproc-platform.o
obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
+obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c
new file mode 100644
index 0000000..3503d9c
--- /dev/null
+++ b/drivers/pci/host/pcie-altera.c
@@ -0,0 +1,579 @@
+/*
+ * Copyright Altera Corporation (C) 2013-2015. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define RP_TX_REG0 0x2000
+#define RP_TX_REG1 0x2004
+#define RP_TX_CNTRL 0x2008
+#define RP_TX_EOP 0x2
+#define RP_TX_SOP 0x1
+#define RP_RXCPL_STATUS 0x2010
+#define RP_RXCPL_EOP 0x2
+#define RP_RXCPL_SOP 0x1
+#define RP_RXCPL_REG0 0x2014
+#define RP_RXCPL_REG1 0x2018
+#define P2A_INT_STATUS 0x3060
+#define P2A_INT_STS_ALL 0xf
+#define P2A_INT_ENABLE 0x3070
+#define P2A_INT_ENA_ALL 0xf
+#define RP_LTSSM 0x3c64
+#define LTSSM_L0 0xf
+
+/* TLP configuration type 0 and 1 */
+#define TLP_FMTTYPE_CFGRD0 0x04 /* Configuration Read Type 0 */
+#define TLP_FMTTYPE_CFGWR0 0x44 /* Configuration Write Type 0 */
+#define TLP_FMTTYPE_CFGRD1 0x05 /* Configuration Read Type 1 */
+#define TLP_FMTTYPE_CFGWR1 0x45 /* Configuration Write Type 1 */
+#define TLP_PAYLOAD_SIZE 0x01
+#define TLP_READ_TAG 0x1d
+#define TLP_WRITE_TAG 0x10
+#define TLP_CFG_DW0(fmttype) (((fmttype) << 24) | TLP_PAYLOAD_SIZE)
+#define TLP_CFG_DW1(reqid, tag, be) (((reqid) << 16) | (tag << 8) | (be))
+#define TLP_CFG_DW2(bus, devfn, offset) \
+ (((bus) << 24) | ((devfn) << 16) | (offset))
+#define TLP_REQ_ID(bus, devfn) (((bus) << 8) | (devfn))
+#define TLP_HDR_SIZE 3
+#define TLP_LOOP 500
+
+#define INTX_NUM 4
+
+#define DWORD_MASK 3
+
+struct altera_pcie {
+ struct platform_device *pdev;
+ void __iomem *cra_base;
+ int irq;
+ u8 root_bus_nr;
+ struct irq_domain *irq_domain;
+ struct resource bus_range;
+ struct list_head resources;
+};
+
+struct tlp_rp_regpair_t {
+ u32 ctrl;
+ u32 reg0;
+ u32 reg1;
+};
+
+static void altera_pcie_retrain(struct pci_dev *dev)
+{
+ u16 linkcap, linkstat;
+
+ /*
+ * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
+ * current speed is 2.5 GB/s.
+ */
+ pcie_capability_read_word(dev, PCI_EXP_LNKCAP, &linkcap);
+
+ if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
+ return;
+
+ pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
+ if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB)
+ pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
+ PCI_EXP_LNKCTL_RL);
+}
+
+static void altera_pcie_fixup_res(struct pci_dev *dev)
+{
+ /*
+ * Prevent enumeration of root complex resources.
+ */
+ if (pci_is_root_bus(dev->bus) && dev->devfn == 0) {
+ int i;
+
+ for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+ dev->resource[i].start = 0;
+ dev->resource[i].end = 0;
+ dev->resource[i].flags = 0;
+ }
+ }
+}
+
+static void altera_pcie_fixups(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ altera_pcie_retrain(dev);
+ altera_pcie_fixup_res(dev);
+ }
+}
+
+static inline void cra_writel(struct altera_pcie *pcie, const u32 value,
+ const u32 reg)
+{
+ writel_relaxed(value, pcie->cra_base + reg);
+}
+
+static inline u32 cra_readl(struct altera_pcie *pcie, const u32 reg)
+{
+ return readl_relaxed(pcie->cra_base + reg);
+}
+
+static void tlp_write_tx(struct altera_pcie *pcie,
+ struct tlp_rp_regpair_t *tlp_rp_regdata)
+{
+ cra_writel(pcie, tlp_rp_regdata->reg0, RP_TX_REG0);
+ cra_writel(pcie, tlp_rp_regdata->reg1, RP_TX_REG1);
+ cra_writel(pcie, tlp_rp_regdata->ctrl, RP_TX_CNTRL);
+}
+
+static bool altera_pcie_link_is_up(struct altera_pcie *pcie)
+{
+ return !!(cra_readl(pcie, RP_LTSSM) & LTSSM_L0);
+}
+
+static bool altera_pcie_valid_config(struct altera_pcie *pcie,
+ struct pci_bus *bus, int dev)
+{
+ /* If there is no link, then there is no device */
+ if (bus->number != pcie->root_bus_nr) {
+ if (!altera_pcie_link_is_up(pcie))
+ return false;
+ }
+
+ /* access only one slot on each root port */
+ if (bus->number == pcie->root_bus_nr && dev > 0)
+ return false;
+
+ /*
+ * Do not read more than one device on the bus directly attached
+ * to root port, root port can only attach to one downstream port.
+ */
+ if (bus->primary == pcie->root_bus_nr && dev > 0)
+ return false;
+
+ return true;
+}
+
+static int tlp_read_packet(struct altera_pcie *pcie, u32 *value)
+{
+ u8 loop;
+ bool sop = 0;
+ u32 ctrl;
+ u32 reg0, reg1;
+
+ /*
+ * Minimum 2 loops to read TLP headers and 1 loop to read data
+ * payload.
+ */
+ for (loop = 0; loop < TLP_LOOP; loop++) {
+ ctrl = cra_readl(pcie, RP_RXCPL_STATUS);
+ if ((ctrl & RP_RXCPL_SOP) || (ctrl & RP_RXCPL_EOP) || sop) {
+ reg0 = cra_readl(pcie, RP_RXCPL_REG0);
+ reg1 = cra_readl(pcie, RP_RXCPL_REG1);
+
+ if (ctrl & RP_RXCPL_SOP)
+ sop = true;
+
+ if (ctrl & RP_RXCPL_EOP) {
+ if (value)
+ *value = reg0;
+ return PCIBIOS_SUCCESSFUL;
+ }
+ }
+ udelay(5);
+ }
+
+ return -ENOENT;
+}
+
+static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
+ u32 data, bool align)
+{
+ struct tlp_rp_regpair_t tlp_rp_regdata;
+
+ tlp_rp_regdata.reg0 = headers[0];
+ tlp_rp_regdata.reg1 = headers[1];
+ tlp_rp_regdata.ctrl = RP_TX_SOP;
+ tlp_write_tx(pcie, &tlp_rp_regdata);
+
+ if (align) {
+ tlp_rp_regdata.reg0 = headers[2];
+ tlp_rp_regdata.reg1 = 0;
+ tlp_rp_regdata.ctrl = 0;
+ tlp_write_tx(pcie, &tlp_rp_regdata);
+
+ tlp_rp_regdata.reg0 = data;
+ tlp_rp_regdata.reg1 = 0;
+ } else {
+ tlp_rp_regdata.reg0 = headers[2];
+ tlp_rp_regdata.reg1 = data;
+ }
+
+ tlp_rp_regdata.ctrl = RP_TX_EOP;
+ tlp_write_tx(pcie, &tlp_rp_regdata);
+}
+
+static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
+ int where, u8 byte_en, u32 *value)
+{
+ u32 headers[TLP_HDR_SIZE];
+
+ if (bus == pcie->root_bus_nr)
+ headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD0);
+ else
+ headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD1);
+
+ headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, devfn),
+ TLP_READ_TAG, byte_en);
+ headers[2] = TLP_CFG_DW2(bus, devfn, where);
+
+ tlp_write_packet(pcie, headers, 0, false);
+
+ return tlp_read_packet(pcie, value);
+}
+
+static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
+ int where, u8 byte_en, u32 value)
+{
+ u32 headers[TLP_HDR_SIZE];
+ int ret;
+
+ if (bus == pcie->root_bus_nr)
+ headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR0);
+ else
+ headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR1);
+
+ headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, devfn),
+ TLP_WRITE_TAG, byte_en);
+ headers[2] = TLP_CFG_DW2(bus, devfn, where);
+
+ /* check alignment to Qword */
+ if ((where & 0x7) == 0)
+ tlp_write_packet(pcie, headers, value, true);
+ else
+ tlp_write_packet(pcie, headers, value, false);
+
+ ret = tlp_read_packet(pcie, NULL);
+ if (ret != PCIBIOS_SUCCESSFUL)
+ return ret;
+
+ /*
+ * Monitoring changes to PCI_PRIMARY_BUS register on root port
+ * and update local copy of root bus number accordingly.
+ */
+ if ((bus == pcie->root_bus_nr) && (where == PCI_PRIMARY_BUS))
+ pcie->root_bus_nr = (u8)(value);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *value)
+{
+ struct altera_pcie *pcie = bus->sysdata;
+ int ret;
+ u32 data;
+ u8 byte_en;
+
+ if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn))) {
+ *value = 0xffffffff;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ switch (size) {
+ case 1:
+ byte_en = 1 << (where & 3);
+ break;
+ case 2:
+ byte_en = 3 << (where & 3);
+ break;
+ default:
+ byte_en = 0xf;
+ break;
+ }
+
+ ret = tlp_cfg_dword_read(pcie, bus->number, devfn,
+ (where & ~DWORD_MASK), byte_en, &data);
+ if (ret != PCIBIOS_SUCCESSFUL)
+ return ret;
+
+ switch (size) {
+ case 1:
+ *value = (data >> (8 * (where & 0x3))) & 0xff;
+ break;
+ case 2:
+ *value = (data >> (8 * (where & 0x2))) & 0xffff;
+ break;
+ default:
+ *value = data;
+ break;
+ }
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int altera_pcie_cfg_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 value)
+{
+ struct altera_pcie *pcie = bus->sysdata;
+ u32 data32;
+ u32 shift = 8 * (where & 3);
+ u8 byte_en;
+
+ if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn)))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ switch (size) {
+ case 1:
+ data32 = (value & 0xff) << shift;
+ byte_en = 1 << (where & 3);
+ break;
+ case 2:
+ data32 = (value & 0xffff) << shift;
+ byte_en = 3 << (where & 3);
+ break;
+ default:
+ data32 = value;
+ byte_en = 0xf;
+ break;
+ }
+
+ return tlp_cfg_dword_write(pcie, bus->number, devfn,
+ (where & ~DWORD_MASK), byte_en, data32);
+}
+
+static struct pci_ops altera_pcie_ops = {
+ .read = altera_pcie_cfg_read,
+ .write = altera_pcie_cfg_write,
+};
+
+static int altera_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);
+
+ return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+ .map = altera_pcie_intx_map,
+};
+
+static void altera_pcie_isr(struct irq_desc *desc)
+{
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct altera_pcie *pcie;
+ unsigned long status;
+ u32 bit;
+ u32 virq;
+
+ chained_irq_enter(chip, desc);
+ pcie = irq_desc_get_handler_data(desc);
+
+ while ((status = cra_readl(pcie, P2A_INT_STATUS)
+ & P2A_INT_STS_ALL) != 0) {
+ for_each_set_bit(bit, &status, INTX_NUM) {
+ /* clear interrupts */
+ cra_writel(pcie, 1 << bit, P2A_INT_STATUS);
+
+ virq = irq_find_mapping(pcie->irq_domain, bit + 1);
+ if (virq)
+ generic_handle_irq(virq);
+ else
+ dev_err(&pcie->pdev->dev, "unexpected IRQ\n");
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void altera_pcie_release_of_pci_ranges(struct altera_pcie *pcie)
+{
+ pci_free_resource_list(&pcie->resources);
+}
+
+static int altera_pcie_parse_request_of_pci_ranges(struct altera_pcie *pcie)
+{
+ int err, res_valid = 0;
+ struct device *dev = &pcie->pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct resource_entry *win;
+
+ err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pcie->resources,
+ NULL);
+ if (err)
+ return err;
+
+ resource_list_for_each_entry(win, &pcie->resources) {
+ struct resource *parent, *res = win->res;
+
+ switch (resource_type(res)) {
+ case IORESOURCE_MEM:
+ parent = &iomem_resource;
+ res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+ break;
+ default:
+ continue;
+ }
+
+ err = devm_request_resource(dev, parent, res);
+ if (err)
+ goto out_release_res;
+ }
+
+ if (!res_valid) {
+ dev_err(dev, "non-prefetchable memory resource required\n");
+ err = -EINVAL;
+ goto out_release_res;
+ }
+
+ return 0;
+
+out_release_res:
+ altera_pcie_release_of_pci_ranges(pcie);
+ return err;
+}
+
+static int altera_pcie_init_irq_domain(struct altera_pcie *pcie)
+{
+ struct device *dev = &pcie->pdev->dev;
+ struct device_node *node = dev->of_node;
+
+ /* Setup INTx */
+ pcie->irq_domain = irq_domain_add_linear(node, INTX_NUM,
+ &intx_domain_ops, pcie);
+ if (!pcie->irq_domain) {
+ dev_err(dev, "Failed to get a INTx IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int altera_pcie_parse_dt(struct altera_pcie *pcie)
+{
+ struct resource *cra;
+ struct platform_device *pdev = pcie->pdev;
+
+ cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
+ if (!cra) {
+ dev_err(&pdev->dev,
+ "no Cra memory resource defined\n");
+ return -ENODEV;
+ }
+
+ pcie->cra_base = devm_ioremap_resource(&pdev->dev, cra);
+ if (IS_ERR(pcie->cra_base)) {
+ dev_err(&pdev->dev, "failed to map cra memory\n");
+ return PTR_ERR(pcie->cra_base);
+ }
+
+ /* setup IRQ */
+ pcie->irq = platform_get_irq(pdev, 0);
+ if (pcie->irq <= 0) {
+ dev_err(&pdev->dev, "failed to get IRQ: %d\n", pcie->irq);
+ return -EINVAL;
+ }
+
+ irq_set_chained_handler_and_data(pcie->irq, altera_pcie_isr, pcie);
+
+ return 0;
+}
+
+static int altera_pcie_probe(struct platform_device *pdev)
+{
+ struct altera_pcie *pcie;
+ struct pci_bus *bus;
+ struct pci_bus *child;
+ int ret;
+
+ pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;
+
+ pcie->pdev = pdev;
+
+ ret = altera_pcie_parse_dt(pcie);
+ if (ret) {
+ dev_err(&pdev->dev, "Parsing DT failed\n");
+ return ret;
+ }
+
+ INIT_LIST_HEAD(&pcie->resources);
+
+ ret = altera_pcie_parse_request_of_pci_ranges(pcie);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed add resources\n");
+ return ret;
+ }
+
+ ret = altera_pcie_init_irq_domain(pcie);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed creating IRQ Domain\n");
+ return ret;
+ }
+
+ /* clear all interrupts */
+ cra_writel(pcie, P2A_INT_STS_ALL, P2A_INT_STATUS);
+ /* enable all interrupts */
+ cra_writel(pcie, P2A_INT_ENA_ALL, P2A_INT_ENABLE);
+
+ bus = pci_scan_root_bus(&pdev->dev, pcie->root_bus_nr, &altera_pcie_ops,
+ pcie, &pcie->resources);
+ if (!bus)
+ return -ENOMEM;
+
+ altera_pcie_fixups(bus);
+ pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
+ pci_assign_unassigned_bus_resources(bus);
+ pci_bus_add_devices(bus);
+
+ /* Configure PCI Express setting. */
+ list_for_each_entry(child, &bus->children, node)
+ pcie_bus_configure_settings(child);
+
+ platform_set_drvdata(pdev, pcie);
+ return ret;
+}
+
+static const struct of_device_id altera_pcie_of_match[] = {
+ { .compatible = "altr,pcie-root-port-1.0", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, altera_pcie_of_match);
+
+static struct platform_driver altera_pcie_driver = {
+ .probe = altera_pcie_probe,
+ .driver = {
+ .name = "altera-pcie",
+ .of_match_table = altera_pcie_of_match,
+ .suppress_bind_attrs = true,
+ },
+};
+
+static int altera_pcie_init(void)
+{
+ return platform_driver_register(&altera_pcie_driver);
+}
+
+module_init(altera_pcie_init);
+
+MODULE_AUTHOR("Ley Foon Tan <lftan at altera.com>");
+MODULE_DESCRIPTION("Altera PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
--
1.8.2.1
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