[PATCH v2 2/5] pci:host: Add Altera PCIe host controller driver

Ley Foon Tan
2015-07-31T10:15:12Z

This patch adds the Altera PCIe host controller driver.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
---
drivers/pci/host/Kconfig | 8 +
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pcie-altera.c | 526 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 535 insertions(+)
create mode 100644 drivers/pci/host/pcie-altera.c

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 675c2d1..108500a 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 ARCH_SOCFPGA
+ select PCI_MSI_IRQ_DOMAIN if PCI_MSI
+ help
+ Say Y here if you want to enable PCIe controller support for Altera
+ SoCFPGA family of SoCs.
+
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..3ec51c7
--- /dev/null
+++ b/drivers/pci/host/pcie-altera.c
@@ -0,0 +1,526 @@
+/*
+ * 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/interrupt.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 A2P_ADDR_MAP_LO0 0x1000
+#define A2P_ADDR_MAP_HI0 0x1004
+#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) (((reqid) << 16) | (tag << 8) | 0xF)
+#define TLP_CFG_DW2(bus, devfn, offset) \
+ (((bus) << 24) | ((devfn) << 16) | (offset))
+#define TLP_REQ_ID(bus, devfn) (((bus) << 8) | (devfn))
+#define TLP_COMPL_STATUS(hdr) (((hdr) & 0xE0) >> 13)
+#define TLP_HDR_SIZE 3
+#define TLP_LOOP 10
+
+#define INTX_NUM 4
+
+/* Address translation table entry size */
+#define ATT_ENTRY_SIZE 8
+
+#define DWORD_MASK 3
+
+struct altera_pcie {
+ struct platform_device *pdev;
+ struct resource *txs;
+ void __iomem *cra_base;
+ int hwirq;
+ 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);
+
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, altera_pcie_retrain);
+
+static inline void cra_writel(struct altera_pcie *pcie, u32 value, u32 reg)
+{
+ writel_relaxed(value, pcie->cra_base + reg);
+}
+
+static inline u32 cra_readl(struct altera_pcie *pcie, u32 reg)
+{
+ return readl_relaxed(pcie->cra_base + reg);
+}
+
+static void tlp_read_rx(struct altera_pcie *pcie,
+ struct tlp_rp_regpair_t *tlp_rp_regdata)
+{
+ tlp_rp_regdata->ctrl = cra_readl(pcie, RP_RXCPL_STATUS);
+ tlp_rp_regdata->reg0 = cra_readl(pcie, RP_RXCPL_REG0);
+ tlp_rp_regdata->reg1 = cra_readl(pcie, RP_RXCPL_REG1);
+}
+
+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 RC.
+ */
+ 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;
+ struct tlp_rp_regpair_t tlp_rp_regdata;
+
+ for (loop = TLP_LOOP; loop > 0; loop--) {
+ tlp_read_rx(pcie, &tlp_rp_regdata);
+ if (tlp_rp_regdata.ctrl & RP_RXCPL_EOP) {
+ if (value)
+ *value = tlp_rp_regdata.reg0;
+ return PCIBIOS_SUCCESSFUL;
+ }
+ }
+
+ return -ENOENT;
+}
+
+static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers, u32 data)
+{
+ 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);
+
+ 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, u32 *value)
+{
+ int ret;
+ 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);
+ headers[2] = TLP_CFG_DW2(bus, devfn, where);
+
+ tlp_write_packet(pcie, headers, 0);
+
+ ret = tlp_read_packet(pcie, value);
+ if (ret)
+ *value = ~0UL; /* return 0xFFFFFFFF if error */
+
+ return ret;
+}
+
+static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
+ int where, u32 value)
+{
+ u32 headers[TLP_HDR_SIZE];
+
+ 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);
+ headers[2] = TLP_CFG_DW2(bus, devfn, where);
+
+ tlp_write_packet(pcie, headers, value);
+
+ tlp_read_packet(pcie, NULL);
+
+ /* Keep an eye out for changes to the root bus number */
+ 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;
+
+ if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn))) {
+ *value = ~0UL;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ ret = tlp_cfg_dword_read(pcie, bus->number, devfn,
+ (where & ~DWORD_MASK), value);
+ if (ret != PCIBIOS_SUCCESSFUL)
+ return ret;
+
+ if (size == 1)
+ *value = (*value >> (8 * (where & 0x3))) & 0xff;
+ else if (size == 2)
+ *value = (*value >> (8 * (where & 0x2))) & 0xffff;
+
+ 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 = value;
+ u32 shift = 8 * (where & 3);
+ int ret;
+
+ if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn)))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ /* write partial */
+ if (size != sizeof(u32)) {
+ ret = tlp_cfg_dword_read(pcie, bus->number, devfn,
+ where & ~DWORD_MASK, &data32);
+ if (ret)
+ return ret;
+
+ if (size == 2)
+ data32 = (data32 & ~(0xffff << shift)) |
+ ((value & 0xffff) << shift);
+ else if (size == 1)
+ data32 = (data32 & ~(0xff << shift)) |
+ ((value & 0xff) << shift);
+ }
+
+ return tlp_cfg_dword_write(pcie, bus->number, devfn,
+ (where & ~DWORD_MASK), 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);
+ set_irq_flags(irq, IRQF_VALID);
+
+ return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+ .map = altera_pcie_intx_map,
+};
+
+static irqreturn_t altera_pcie_isr(int irq, void *arg)
+{
+ struct altera_pcie *pcie = arg;
+ u32 status, i;
+
+ status = cra_readl(pcie, P2A_INT_STATUS) & P2A_INT_STS_ALL;
+
+ /* clear interrupts */
+ cra_writel(pcie, status, P2A_INT_STATUS);
+
+ for (i = 0; i < INTX_NUM; i++) {
+ if (status & (1 << i))
+ generic_handle_irq(irq_find_mapping(pcie->irq_domain,
+ i + 1));
+ }
+
+ return IRQ_HANDLED;
+}
+
+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;
+ resource_size_t iobase;
+ struct resource_entry *win;
+ int offset = 0;
+
+ err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pcie->resources,
+ &iobase);
+ 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);
+ cra_writel(pcie, res->start,
+ A2P_ADDR_MAP_LO0 + offset);
+ cra_writel(pcie, 0,
+ A2P_ADDR_MAP_HI0 + offset);
+ offset += ATT_ENTRY_SIZE;
+ 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 void altera_pcie_free_irq_domain(struct altera_pcie *pcie)
+{
+ int i;
+ u32 irq;
+
+ for (i = 0; i < INTX_NUM; i++) {
+ irq = irq_find_mapping(pcie->irq_domain, i);
+ if (irq > 0)
+ irq_dispose_mapping(irq);
+ }
+
+ irq_domain_remove(pcie->irq_domain);
+}
+
+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 PTR_ERR(pcie->irq_domain);
+ }
+
+ return 0;
+}
+
+static int altera_pcie_parse_dt(struct altera_pcie *pcie)
+{
+ struct resource *cra;
+ int ret;
+ struct platform_device *pdev = pcie->pdev;
+
+ cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
+ pcie->cra_base = devm_ioremap_resource(&pdev->dev, cra);
+ if (IS_ERR(pcie->cra_base)) {
+ dev_err(&pdev->dev, "get Cra resource failed\n");
+ return PTR_ERR(pcie->cra_base);
+ }
+
+ /* setup IRQ */
+ pcie->hwirq = platform_get_irq(pdev, 0);
+ if (pcie->hwirq <= 0) {
+ dev_err(&pdev->dev, "failed to get IRQ: %d\n", pcie->hwirq);
+ return -EINVAL;
+ }
+ ret = devm_request_irq(&pdev->dev, pcie->hwirq, altera_pcie_isr,
+ IRQF_SHARED, pdev->name, pcie);
+
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request irq %d\n", pcie->hwirq);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int altera_pcie_probe(struct platform_device *pdev)
+{
+ struct altera_pcie *pcie;
+ struct pci_bus *bus;
+ 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;
+ }
+
+ pcie->root_bus_nr = 0;
+
+ /* 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;
+
+ pci_assign_unassigned_bus_resources(bus);
+ pci_bus_add_devices(bus);
+
+ platform_set_drvdata(pdev, pcie);
+ return ret;
+}
+
+static int __exit altera_pcie_remove(struct platform_device *pdev)
+{
+ struct altera_pcie *pcie = platform_get_drvdata(pdev);
+
+ altera_pcie_free_irq_domain(pcie);
+ platform_set_drvdata(pdev, NULL);
+ return 0;
+}
+
+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,
+ .remove = altera_pcie_remove,
+ .driver = {
+ .name = "altera-pcie",
+ .of_match_table = altera_pcie_of_match,
+ },
+};
+
+module_platform_driver(altera_pcie_driver);
+
+MODULE_AUTHOR("Ley Foon Tan <lftan@altera.com>");
+MODULE_DESCRIPTION("Altera PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
--
1.8.2.1