arch/arm/mach-cns3xxx/pcie.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * PCI-E support for CNS3xxx
   4  *
   5  * Copyright 2008 Cavium Networks
   6  *                Richard Liu <richard.liu@caviumnetworks.com>
   7  * Copyright 2010 MontaVista Software, LLC.
   8  *                Anton Vorontsov <avorontsov@mvista.com>
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/bug.h>
  14 #include <linux/pci.h>
  15 #include <linux/io.h>
  16 #include <linux/ioport.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/ptrace.h>
  19 #include <asm/mach/map.h>
  20 #include "cns3xxx.h"
  21 #include "core.h"
  22
  23 struct cns3xxx_pcie {
  24         void __iomem *host_regs; /* PCI config registers for host bridge */
  25         void __iomem *cfg0_regs; /* PCI Type 0 config registers */
  26         void __iomem *cfg1_regs; /* PCI Type 1 config registers */
  27         unsigned int irqs[2];
  28         struct resource res_io;
  29         struct resource res_mem;
  30         int port;
  31         bool linked;
  32 };
  33
  34 static struct cns3xxx_pcie *sysdata_to_cnspci(void *sysdata)
  35 {
  36         struct pci_sys_data *root = sysdata;
  37
  38         return root->private_data;
  39 }
  40
  41 static struct cns3xxx_pcie *pdev_to_cnspci(const struct pci_dev *dev)
  42 {
  43         return sysdata_to_cnspci(dev->sysdata);
  44 }
  45
  46 static struct cns3xxx_pcie *pbus_to_cnspci(struct pci_bus *bus)
  47 {
  48         return sysdata_to_cnspci(bus->sysdata);
  49 }
  50
  51 static void __iomem *cns3xxx_pci_map_bus(struct pci_bus *bus,
  52                                          unsigned int devfn, int where)
  53 {
  54         struct cns3xxx_pcie *cnspci = pbus_to_cnspci(bus);
  55         int busno = bus->number;
  56         int slot = PCI_SLOT(devfn);
  57         void __iomem *base;
  58
  59         /* If there is no link, just show the CNS PCI bridge. */
  60         if (!cnspci->linked && busno > 0)
  61                 return NULL;
  62
  63         /*
  64          * The CNS PCI bridge doesn't fit into the PCI hierarchy, though
  65          * we still want to access it.
  66          * We place the host bridge on bus 0, and the directly connected
  67          * device on bus 1, slot 0.
  68          */
  69         if (busno == 0) { /* internal PCIe bus, host bridge device */
  70                 if (devfn == 0) /* device# and function# are ignored by hw */
  71                         base = cnspci->host_regs;
  72                 else
  73                         return NULL; /* no such device */
  74
  75         } else if (busno == 1) { /* directly connected PCIe device */
  76                 if (slot == 0) /* device# is ignored by hw */
  77                         base = cnspci->cfg0_regs;
  78                 else
  79                         return NULL; /* no such device */
  80         } else /* remote PCI bus */
  81                 base = cnspci->cfg1_regs + ((busno & 0xf) << 20);
  82
  83         return base + where + (devfn << 12);
  84 }
  85
  86 static int cns3xxx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
  87                                    int where, int size, u32 *val)
  88 {
  89         int ret;
  90         u32 mask = (0x1ull << (size * 8)) - 1;
  91         int shift = (where % 4) * 8;
  92
  93         ret = pci_generic_config_read(bus, devfn, where, size, val);
  94
  95         if (ret == PCIBIOS_SUCCESSFUL && !bus->number && !devfn &&
  96             (where & 0xffc) == PCI_CLASS_REVISION)
  97                 /*
  98                  * RC's class is 0xb, but Linux PCI driver needs 0x604
  99                  * for a PCIe bridge. So we must fixup the class code
 100                  * to 0x604 here.
 101                  */
 102                 *val = ((((*val << shift) & 0xff) | (0x604 << 16)) >> shift) & mask;
 103
 104         return ret;
 105 }
 106
 107 static int cns3xxx_pci_setup(int nr, struct pci_sys_data *sys)
 108 {
 109         struct cns3xxx_pcie *cnspci = sysdata_to_cnspci(sys);
 110         struct resource *res_io = &cnspci->res_io;
 111         struct resource *res_mem = &cnspci->res_mem;
 112
 113         BUG_ON(request_resource(&iomem_resource, res_io) ||
 114                request_resource(&iomem_resource, res_mem));
 115
 116         pci_add_resource_offset(&sys->resources, res_io, sys->io_offset);
 117         pci_add_resource_offset(&sys->resources, res_mem, sys->mem_offset);
 118
 119         return 1;
 120 }
 121
 122 static struct pci_ops cns3xxx_pcie_ops = {
 123         .map_bus = cns3xxx_pci_map_bus,
 124         .read = cns3xxx_pci_read_config,
 125         .write = pci_generic_config_write,
 126 };
 127
 128 static int cns3xxx_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 129 {
 130         struct cns3xxx_pcie *cnspci = pdev_to_cnspci(dev);
 131         int irq = cnspci->irqs[!!dev->bus->number];
 132
 133         pr_info("PCIe map irq: %04d:%02x:%02x.%02x slot %d, pin %d, irq: %d\n",
 134                 pci_domain_nr(dev->bus), dev->bus->number, PCI_SLOT(dev->devfn),
 135                 PCI_FUNC(dev->devfn), slot, pin, irq);
 136
 137         return irq;
 138 }
 139
 140 static struct cns3xxx_pcie cns3xxx_pcie[] = {
 141         [0] = {
 142                 .host_regs = (void __iomem *)CNS3XXX_PCIE0_HOST_BASE_VIRT,
 143                 .cfg0_regs = (void __iomem *)CNS3XXX_PCIE0_CFG0_BASE_VIRT,
 144                 .cfg1_regs = (void __iomem *)CNS3XXX_PCIE0_CFG1_BASE_VIRT,
 145                 .res_io = {
 146                         .name = "PCIe0 I/O space",
 147                         .start = CNS3XXX_PCIE0_IO_BASE,
 148                         .end = CNS3XXX_PCIE0_CFG0_BASE - 1, /* 16 MiB */
 149                         .flags = IORESOURCE_IO,
 150                 },
 151                 .res_mem = {
 152                         .name = "PCIe0 non-prefetchable",
 153                         .start = CNS3XXX_PCIE0_MEM_BASE,
 154                         .end = CNS3XXX_PCIE0_HOST_BASE - 1, /* 176 MiB */
 155                         .flags = IORESOURCE_MEM,
 156                 },
 157                 .irqs = { IRQ_CNS3XXX_PCIE0_RC, IRQ_CNS3XXX_PCIE0_DEVICE, },
 158                 .port = 0,
 159         },
 160         [1] = {
 161                 .host_regs = (void __iomem *)CNS3XXX_PCIE1_HOST_BASE_VIRT,
 162                 .cfg0_regs = (void __iomem *)CNS3XXX_PCIE1_CFG0_BASE_VIRT,
 163                 .cfg1_regs = (void __iomem *)CNS3XXX_PCIE1_CFG1_BASE_VIRT,
 164                 .res_io = {
 165                         .name = "PCIe1 I/O space",
 166                         .start = CNS3XXX_PCIE1_IO_BASE,
 167                         .end = CNS3XXX_PCIE1_CFG0_BASE - 1, /* 16 MiB */
 168                         .flags = IORESOURCE_IO,
 169                 },
 170                 .res_mem = {
 171                         .name = "PCIe1 non-prefetchable",
 172                         .start = CNS3XXX_PCIE1_MEM_BASE,
 173                         .end = CNS3XXX_PCIE1_HOST_BASE - 1, /* 176 MiB */
 174                         .flags = IORESOURCE_MEM,
 175                 },
 176                 .irqs = { IRQ_CNS3XXX_PCIE1_RC, IRQ_CNS3XXX_PCIE1_DEVICE, },
 177                 .port = 1,
 178         },
 179 };
 180
 181 static void __init cns3xxx_pcie_check_link(struct cns3xxx_pcie *cnspci)
 182 {
 183         int port = cnspci->port;
 184         u32 reg;
 185         unsigned long time;
 186
 187         reg = __raw_readl(MISC_PCIE_CTRL(port));
 188         /*
 189          * Enable Application Request to 1, it will exit L1 automatically,
 190          * but when chip back, it will use another clock, still can use 0x1.
 191          */
 192         reg |= 0x3;
 193         __raw_writel(reg, MISC_PCIE_CTRL(port));
 194
 195         pr_info("PCIe: Port[%d] Enable PCIe LTSSM\n", port);
 196         pr_info("PCIe: Port[%d] Check data link layer...", port);
 197
 198         time = jiffies;
 199         while (1) {
 200                 reg = __raw_readl(MISC_PCIE_PM_DEBUG(port));
 201                 if (reg & 0x1) {
 202                         pr_info("Link up.\n");
 203                         cnspci->linked = 1;
 204                         break;
 205                 } else if (time_after(jiffies, time + 50)) {
 206                         pr_info("Device not found.\n");
 207                         break;
 208                 }
 209         }
 210 }
 211
 212 static void cns3xxx_write_config(struct cns3xxx_pcie *cnspci,
 213                                          int where, int size, u32 val)
 214 {
 215         void __iomem *base = cnspci->host_regs + (where & 0xffc);
 216         u32 v;
 217         u32 mask = (0x1ull << (size * 8)) - 1;
 218         int shift = (where % 4) * 8;
 219
 220         v = readl_relaxed(base);
 221
 222         v &= ~(mask << shift);
 223         v |= (val & mask) << shift;
 224
 225         writel_relaxed(v, base);
 226         readl_relaxed(base);
 227 }
 228
 229 static void __init cns3xxx_pcie_hw_init(struct cns3xxx_pcie *cnspci)
 230 {
 231         u16 mem_base  = cnspci->res_mem.start >> 16;
 232         u16 mem_limit = cnspci->res_mem.end   >> 16;
 233         u16 io_base   = cnspci->res_io.start  >> 16;
 234         u16 io_limit  = cnspci->res_io.end    >> 16;
 235
 236         cns3xxx_write_config(cnspci, PCI_PRIMARY_BUS, 1, 0);
 237         cns3xxx_write_config(cnspci, PCI_SECONDARY_BUS, 1, 1);
 238         cns3xxx_write_config(cnspci, PCI_SUBORDINATE_BUS, 1, 1);
 239         cns3xxx_write_config(cnspci, PCI_MEMORY_BASE, 2, mem_base);
 240         cns3xxx_write_config(cnspci, PCI_MEMORY_LIMIT, 2, mem_limit);
 241         cns3xxx_write_config(cnspci, PCI_IO_BASE_UPPER16, 2, io_base);
 242         cns3xxx_write_config(cnspci, PCI_IO_LIMIT_UPPER16, 2, io_limit);
 243
 244         if (!cnspci->linked)
 245                 return;
 246
 247         /* Set Device Max_Read_Request_Size to 128 byte */
 248         pcie_bus_config = PCIE_BUS_PEER2PEER;
 249
 250         /* Disable PCIe0 Interrupt Mask INTA to INTD */
 251         __raw_writel(~0x3FFF, MISC_PCIE_INT_MASK(cnspci->port));
 252 }
 253
 254 static int cns3xxx_pcie_abort_handler(unsigned long addr, unsigned int fsr,
 255                                       struct pt_regs *regs)
 256 {
 257         if (fsr & (1 << 10))
 258                 regs->ARM_pc += 4;
 259         return 0;
 260 }
 261
 262 void __init cns3xxx_pcie_init_late(void)
 263 {
 264         int i;
 265         void *private_data;
 266         struct hw_pci hw_pci = {
 267                .nr_controllers = 1,
 268                .ops = &cns3xxx_pcie_ops,
 269                .setup = cns3xxx_pci_setup,
 270                .map_irq = cns3xxx_pcie_map_irq,
 271                .private_data = &private_data,
 272         };
 273
 274         pcibios_min_io = 0;
 275         pcibios_min_mem = 0;
 276
 277         hook_fault_code(16 + 6, cns3xxx_pcie_abort_handler, SIGBUS, 0,
 278                         "imprecise external abort");
 279
 280         for (i = 0; i < ARRAY_SIZE(cns3xxx_pcie); i++) {
 281                 cns3xxx_pwr_clk_en(0x1 << PM_CLK_GATE_REG_OFFSET_PCIE(i));
 282                 cns3xxx_pwr_soft_rst(0x1 << PM_SOFT_RST_REG_OFFST_PCIE(i));
 283                 cns3xxx_pcie_check_link(&cns3xxx_pcie[i]);
 284                 cns3xxx_pcie_hw_init(&cns3xxx_pcie[i]);
 285                 private_data = &cns3xxx_pcie[i];
 286                 pci_common_init(&hw_pci);
 287         }
 288
 289         pci_assign_unassigned_resources();
 290 }