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path: root/drivers/pci/controller/pcie-altera.c
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Diffstat (limited to 'drivers/pci/controller/pcie-altera.c')
-rw-r--r--drivers/pci/controller/pcie-altera.c645
1 files changed, 645 insertions, 0 deletions
diff --git a/drivers/pci/controller/pcie-altera.c b/drivers/pci/controller/pcie-altera.c
new file mode 100644
index 000000000000..7d05e51205b3
--- /dev/null
+++ b/drivers/pci/controller/pcie-altera.c
@@ -0,0 +1,645 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright Altera Corporation (C) 2013-2015. All rights reserved
+ *
+ * Author: Ley Foon Tan <lftan@altera.com>
+ * Description: Altera PCIe host controller driver
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/init.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>
+
+#include "../pci.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 RP_LTSSM_MASK 0x1f
+#define LTSSM_L0 0xf
+
+#define PCIE_CAP_OFFSET 0x80
+/* 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 RP_DEVFN 0
+#define TLP_REQ_ID(bus, devfn) (((bus) << 8) | (devfn))
+#define TLP_CFGRD_DW0(pcie, bus) \
+ ((((bus == pcie->root_bus_nr) ? TLP_FMTTYPE_CFGRD0 \
+ : TLP_FMTTYPE_CFGRD1) << 24) | \
+ TLP_PAYLOAD_SIZE)
+#define TLP_CFGWR_DW0(pcie, bus) \
+ ((((bus == pcie->root_bus_nr) ? TLP_FMTTYPE_CFGWR0 \
+ : TLP_FMTTYPE_CFGWR1) << 24) | \
+ TLP_PAYLOAD_SIZE)
+#define TLP_CFG_DW1(pcie, tag, be) \
+ (((TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN)) << 16) | (tag << 8) | (be))
+#define TLP_CFG_DW2(bus, devfn, offset) \
+ (((bus) << 24) | ((devfn) << 16) | (offset))
+#define TLP_COMP_STATUS(s) (((s) >> 13) & 7)
+#define TLP_HDR_SIZE 3
+#define TLP_LOOP 500
+
+#define LINK_UP_TIMEOUT HZ
+#define LINK_RETRAIN_TIMEOUT HZ
+
+#define DWORD_MASK 3
+
+struct altera_pcie {
+ struct platform_device *pdev;
+ void __iomem *cra_base; /* DT Cra */
+ 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 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 bool altera_pcie_link_up(struct altera_pcie *pcie)
+{
+ return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
+}
+
+/*
+ * Altera PCIe port uses BAR0 of RC's configuration space as the translation
+ * from PCI bus to native BUS. Entire DDR region is mapped into PCIe space
+ * using these registers, so it can be reached by DMA from EP devices.
+ * This BAR0 will also access to MSI vector when receiving MSI/MSIX interrupt
+ * from EP devices, eventually trigger interrupt to GIC. The BAR0 of bridge
+ * should be hidden during enumeration to avoid the sizing and resource
+ * allocation by PCIe core.
+ */
+static bool altera_pcie_hide_rc_bar(struct pci_bus *bus, unsigned int devfn,
+ int offset)
+{
+ if (pci_is_root_bus(bus) && (devfn == 0) &&
+ (offset == PCI_BASE_ADDRESS_0))
+ return true;
+
+ return false;
+}
+
+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_valid_device(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_up(pcie))
+ return false;
+ }
+
+ /* access only one slot on each root port */
+ if (bus->number == pcie->root_bus_nr && dev > 0)
+ return false;
+
+ return true;
+}
+
+static int tlp_read_packet(struct altera_pcie *pcie, u32 *value)
+{
+ int i;
+ bool sop = false;
+ u32 ctrl;
+ u32 reg0, reg1;
+ u32 comp_status = 1;
+
+ /*
+ * Minimum 2 loops to read TLP headers and 1 loop to read data
+ * payload.
+ */
+ for (i = 0; i < TLP_LOOP; i++) {
+ 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;
+ comp_status = TLP_COMP_STATUS(reg1);
+ }
+
+ if (ctrl & RP_RXCPL_EOP) {
+ if (comp_status)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ if (value)
+ *value = reg0;
+
+ return PCIBIOS_SUCCESSFUL;
+ }
+ }
+ udelay(5);
+ }
+
+ return PCIBIOS_DEVICE_NOT_FOUND;
+}
+
+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];
+
+ headers[0] = TLP_CFGRD_DW0(pcie, bus);
+ headers[1] = TLP_CFG_DW1(pcie, 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;
+
+ headers[0] = TLP_CFGWR_DW0(pcie, bus);
+ headers[1] = TLP_CFG_DW1(pcie, 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;
+
+ /*
+ * Monitor 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 altera_pcie *pcie, u8 busno,
+ unsigned int devfn, int where, int size,
+ u32 *value)
+{
+ int ret;
+ u32 data;
+ u8 byte_en;
+
+ 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, busno, 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 altera_pcie *pcie, u8 busno,
+ unsigned int devfn, int where, int size,
+ u32 value)
+{
+ u32 data32;
+ u32 shift = 8 * (where & 3);
+ u8 byte_en;
+
+ 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, busno, devfn, (where & ~DWORD_MASK),
+ byte_en, data32);
+}
+
+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;
+
+ if (altera_pcie_hide_rc_bar(bus, devfn, where))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ if (!altera_pcie_valid_device(pcie, bus, PCI_SLOT(devfn))) {
+ *value = 0xffffffff;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ return _altera_pcie_cfg_read(pcie, bus->number, devfn, where, size,
+ value);
+}
+
+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;
+
+ if (altera_pcie_hide_rc_bar(bus, devfn, where))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ if (!altera_pcie_valid_device(pcie, bus, PCI_SLOT(devfn)))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ return _altera_pcie_cfg_write(pcie, bus->number, devfn, where, size,
+ value);
+}
+
+static struct pci_ops altera_pcie_ops = {
+ .read = altera_pcie_cfg_read,
+ .write = altera_pcie_cfg_write,
+};
+
+static int altera_read_cap_word(struct altera_pcie *pcie, u8 busno,
+ unsigned int devfn, int offset, u16 *value)
+{
+ u32 data;
+ int ret;
+
+ ret = _altera_pcie_cfg_read(pcie, busno, devfn,
+ PCIE_CAP_OFFSET + offset, sizeof(*value),
+ &data);
+ *value = data;
+ return ret;
+}
+
+static int altera_write_cap_word(struct altera_pcie *pcie, u8 busno,
+ unsigned int devfn, int offset, u16 value)
+{
+ return _altera_pcie_cfg_write(pcie, busno, devfn,
+ PCIE_CAP_OFFSET + offset, sizeof(value),
+ value);
+}
+
+static void altera_wait_link_retrain(struct altera_pcie *pcie)
+{
+ struct device *dev = &pcie->pdev->dev;
+ u16 reg16;
+ unsigned long start_jiffies;
+
+ /* Wait for link training end. */
+ start_jiffies = jiffies;
+ for (;;) {
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
+ PCI_EXP_LNKSTA, &reg16);
+ if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ break;
+
+ if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) {
+ dev_err(dev, "link retrain timeout\n");
+ break;
+ }
+ udelay(100);
+ }
+
+ /* Wait for link is up */
+ start_jiffies = jiffies;
+ for (;;) {
+ if (altera_pcie_link_up(pcie))
+ break;
+
+ if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) {
+ dev_err(dev, "link up timeout\n");
+ break;
+ }
+ udelay(100);
+ }
+}
+
+static void altera_pcie_retrain(struct altera_pcie *pcie)
+{
+ u16 linkcap, linkstat, linkctl;
+
+ if (!altera_pcie_link_up(pcie))
+ return;
+
+ /*
+ * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
+ * current speed is 2.5 GB/s.
+ */
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKCAP,
+ &linkcap);
+ if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
+ return;
+
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKSTA,
+ &linkstat);
+ if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
+ PCI_EXP_LNKCTL, &linkctl);
+ linkctl |= PCI_EXP_LNKCTL_RL;
+ altera_write_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
+ PCI_EXP_LNKCTL, linkctl);
+
+ altera_wait_link_retrain(pcie);
+ }
+}
+
+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,
+ .xlate = pci_irqd_intx_xlate,
+};
+
+static void altera_pcie_isr(struct irq_desc *desc)
+{
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct altera_pcie *pcie;
+ struct device *dev;
+ unsigned long status;
+ u32 bit;
+ u32 virq;
+
+ chained_irq_enter(chip, desc);
+ pcie = irq_desc_get_handler_data(desc);
+ dev = &pcie->pdev->dev;
+
+ while ((status = cra_readl(pcie, P2A_INT_STATUS)
+ & P2A_INT_STS_ALL) != 0) {
+ for_each_set_bit(bit, &status, PCI_NUM_INTX) {
+ /* clear interrupts */
+ cra_writel(pcie, 1 << bit, P2A_INT_STATUS);
+
+ virq = irq_find_mapping(pcie->irq_domain, bit);
+ if (virq)
+ generic_handle_irq(virq);
+ else
+ dev_err(dev, "unexpected IRQ, INT%d\n", bit);
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+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 resource_entry *win;
+
+ err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff,
+ &pcie->resources, NULL);
+ if (err)
+ return err;
+
+ err = devm_request_pci_bus_resources(dev, &pcie->resources);
+ if (err)
+ goto out_release_res;
+
+ resource_list_for_each_entry(win, &pcie->resources) {
+ struct resource *res = win->res;
+
+ if (resource_type(res) == IORESOURCE_MEM)
+ res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+ }
+
+ if (res_valid)
+ return 0;
+
+ dev_err(dev, "non-prefetchable memory resource required\n");
+ err = -EINVAL;
+
+out_release_res:
+ pci_free_resource_list(&pcie->resources);
+ 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, PCI_NUM_INTX,
+ &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 device *dev = &pcie->pdev->dev;
+ struct platform_device *pdev = pcie->pdev;
+ struct resource *cra;
+
+ cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
+ pcie->cra_base = devm_ioremap_resource(dev, cra);
+ if (IS_ERR(pcie->cra_base))
+ return PTR_ERR(pcie->cra_base);
+
+ /* setup IRQ */
+ pcie->irq = platform_get_irq(pdev, 0);
+ if (pcie->irq < 0) {
+ dev_err(dev, "failed to get IRQ: %d\n", pcie->irq);
+ return pcie->irq;
+ }
+
+ irq_set_chained_handler_and_data(pcie->irq, altera_pcie_isr, pcie);
+ return 0;
+}
+
+static void altera_pcie_host_init(struct altera_pcie *pcie)
+{
+ altera_pcie_retrain(pcie);
+}
+
+static int altera_pcie_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct altera_pcie *pcie;
+ struct pci_bus *bus;
+ struct pci_bus *child;
+ struct pci_host_bridge *bridge;
+ int ret;
+
+ bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
+ if (!bridge)
+ return -ENOMEM;
+
+ pcie = pci_host_bridge_priv(bridge);
+ pcie->pdev = pdev;
+
+ ret = altera_pcie_parse_dt(pcie);
+ if (ret) {
+ dev_err(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(dev, "Failed add resources\n");
+ return ret;
+ }
+
+ ret = altera_pcie_init_irq_domain(pcie);
+ if (ret) {
+ dev_err(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);
+ altera_pcie_host_init(pcie);
+
+ list_splice_init(&pcie->resources, &bridge->windows);
+ bridge->dev.parent = dev;
+ bridge->sysdata = pcie;
+ bridge->busnr = pcie->root_bus_nr;
+ bridge->ops = &altera_pcie_ops;
+ bridge->map_irq = of_irq_parse_and_map_pci;
+ bridge->swizzle_irq = pci_common_swizzle;
+
+ ret = pci_scan_root_bus_bridge(bridge);
+ if (ret < 0)
+ return ret;
+
+ bus = bridge->bus;
+
+ pci_assign_unassigned_bus_resources(bus);
+
+ /* Configure PCI Express setting. */
+ list_for_each_entry(child, &bus->children, node)
+ pcie_bus_configure_settings(child);
+
+ pci_bus_add_devices(bus);
+ return ret;
+}
+
+static const struct of_device_id altera_pcie_of_match[] = {
+ { .compatible = "altr,pcie-root-port-1.0", },
+ {},
+};
+
+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,
+ },
+};
+
+builtin_platform_driver(altera_pcie_driver);