diff options
Diffstat (limited to 'drivers/pci/host/pcie-altera.c')
-rw-r--r-- | drivers/pci/host/pcie-altera.c | 209 |
1 files changed, 139 insertions, 70 deletions
diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c index 2b78376..c24e965 100644 --- a/drivers/pci/host/pcie-altera.c +++ b/drivers/pci/host/pcie-altera.c @@ -1,6 +1,9 @@ /* * Copyright Altera Corporation (C) 2013-2015. All rights reserved * + * Author: Ley Foon Tan <lftan@altera.com> + * Description: Altera PCIe host controller driver + * * 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. @@ -17,7 +20,7 @@ #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/irqchip/chained_irq.h> -#include <linux/module.h> +#include <linux/init.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of_pci.h> @@ -43,6 +46,7 @@ #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 */ @@ -61,7 +65,8 @@ #define TLP_LOOP 500 #define RP_DEVFN 0 -#define LINK_UP_TIMEOUT 5000 +#define LINK_UP_TIMEOUT HZ +#define LINK_RETRAIN_TIMEOUT HZ #define INTX_NUM 4 @@ -99,38 +104,6 @@ static bool altera_pcie_link_is_up(struct altera_pcie *pcie) return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0); } -static void altera_pcie_retrain(struct pci_dev *dev) -{ - u16 linkcap, linkstat; - struct altera_pcie *pcie = dev->bus->sysdata; - int timeout = 0; - - if (!altera_pcie_link_is_up(pcie)) - return; - - /* - * 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); - while (!altera_pcie_link_is_up(pcie)) { - timeout++; - if (timeout > LINK_UP_TIMEOUT) - break; - udelay(5); - } - } -} -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 @@ -171,13 +144,6 @@ static bool altera_pcie_valid_config(struct altera_pcie *pcie, 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; } @@ -301,22 +267,14 @@ static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn, return PCIBIOS_SUCCESSFUL; } -static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn, - int where, int size, u32 *value) +static int _altera_pcie_cfg_read(struct altera_pcie *pcie, u8 busno, + 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); @@ -329,7 +287,7 @@ static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn, break; } - ret = tlp_cfg_dword_read(pcie, bus->number, devfn, + ret = tlp_cfg_dword_read(pcie, busno, devfn, (where & ~DWORD_MASK), byte_en, &data); if (ret != PCIBIOS_SUCCESSFUL) return ret; @@ -349,20 +307,14 @@ static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn, return PCIBIOS_SUCCESSFUL; } -static int altera_pcie_cfg_write(struct pci_bus *bus, unsigned int devfn, - int where, int size, u32 value) +static int _altera_pcie_cfg_write(struct altera_pcie *pcie, u8 busno, + 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; @@ -378,8 +330,40 @@ static int altera_pcie_cfg_write(struct pci_bus *bus, unsigned int devfn, break; } - return tlp_cfg_dword_write(pcie, bus->number, devfn, - (where & ~DWORD_MASK), byte_en, data32); + 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_config(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_config(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 = { @@ -387,6 +371,90 @@ static struct pci_ops altera_pcie_ops = { .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) +{ + 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(&pcie->pdev->dev, "link retrain timeout\n"); + break; + } + udelay(100); + } + + /* Wait for link is up */ + start_jiffies = jiffies; + for (;;) { + if (altera_pcie_link_is_up(pcie)) + break; + + if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) { + dev_err(&pcie->pdev->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_is_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) { @@ -508,6 +576,11 @@ static int altera_pcie_parse_dt(struct altera_pcie *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 altera_pcie *pcie; @@ -545,6 +618,7 @@ static int altera_pcie_probe(struct platform_device *pdev) 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); bus = pci_scan_root_bus(&pdev->dev, pcie->root_bus_nr, &altera_pcie_ops, pcie, &pcie->resources); @@ -568,7 +642,6 @@ 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, @@ -583,8 +656,4 @@ 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"); +device_initcall(altera_pcie_init); |