diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/pci/controller/pcie-altera.c | 645 |
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 000000000..7d05e5120 --- /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, ®16); + 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); |