diff options
Diffstat (limited to 'drivers/pci/host/pcie-altera.c')
| -rw-r--r-- | drivers/pci/host/pcie-altera.c | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c new file mode 100644 index 000000000000..e5dda38bdde5 --- /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); +} +DECLARE_PCI_FIXUP_EARLY(0x1172, PCI_ANY_ID, altera_pcie_retrain); + +/* + * 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 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; + + /* + * 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 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_hide_rc_bar(bus, devfn, where)) + return PCIBIOS_BAD_REGISTER_NUMBER; + + 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_hide_rc_bar(bus, devfn, where)) + return PCIBIOS_BAD_REGISTER_NUMBER; + + 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, INT%d\n", bit); + } + } + + 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; + + pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); + 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); + + 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@altera.com>"); +MODULE_DESCRIPTION("Altera PCIe host controller driver"); +MODULE_LICENSE("GPL v2"); |