On 07/08/15 08:42, Ley Foon Tan wrote: > This patch adds the Altera PCIe host controller driver. > > Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx> > --- > drivers/pci/host/Kconfig | 7 + > drivers/pci/host/Makefile | 1 + > drivers/pci/host/pcie-altera.c | 532 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 540 insertions(+) > create mode 100644 drivers/pci/host/pcie-altera.c > > diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig > index 675c2d1..4b4754a 100644 > --- a/drivers/pci/host/Kconfig > +++ b/drivers/pci/host/Kconfig > @@ -145,4 +145,11 @@ 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 > + 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..37bed81 > --- /dev/null > +++ b/drivers/pci/host/pcie-altera.c > @@ -0,0 +1,532 @@ > +/* > + * 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/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 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 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(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--) { I'd prefer to see the more common idiom: for (loop = 0; loop < TLP_LOOP; 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; > + } Don't you need some form of relaxation here? A delay of some sort? Repeatedly polling the HW is usually not helping it to recover... > + } > + > + 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 void altera_pcie_isr(unsigned int irq, 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); > + > + do { > + status = cra_readl(pcie, P2A_INT_STATUS) & P2A_INT_STS_ALL; > + if (!status) > + break; > + > + do { > + bit = find_first_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_info(&pcie->pdev->dev, "unexpected IRQ\n"); > + > + /* Clear the bit from status and repeat without reading > + * again status register. */ > + __clear_bit(bit, &status); > + } while (status); > + } while (1); > + > + 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; > + resource_size_t iobase; > + struct resource_entry *win; > + > + 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); > + 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); Err, no. irq_domain_add returns NULL on error, so PTR_ERR(NULL) is still going to be zero. > + } > + > + 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"); Probably worth checking that this hasn't failed. > + 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->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; > + 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_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > + 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@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("Altera PCIe host controller driver"); > +MODULE_LICENSE("GPL v2"); > -- > 1.8.2.1 > This is starting to look better. You should get someone to review the DT parts though. Thanks, M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
