arch/arm/mach-cns3xxx/pcie.c

   1 /*
   2  * PCI-E support for CNS3xxx
   3  *
   4  * Copyright 2008 Cavium Networks
   5  *                Richard Liu <richard.liu@caviumnetworks.com>
   6  * Copyright 2010 MontaVista Software, LLC.
   7  *                Anton Vorontsov <avorontsov@mvista.com>
   8  *
   9  * This file is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License, Version 2, as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/kernel.h>
  16 #include <linux/bug.h>
  17 #include <linux/pci.h>
  18 #include <linux/io.h>
  19 #include <linux/ioport.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/ptrace.h>
  22 #include <asm/mach/map.h>
  23 #include <mach/cns3xxx.h>
  24 #include "core.h"
  25
  26 enum cns3xxx_access_type {
  27         CNS3XXX_HOST_TYPE = 0,
  28         CNS3XXX_CFG0_TYPE,
  29         CNS3XXX_CFG1_TYPE,
  30         CNS3XXX_NUM_ACCESS_TYPES,
  31 };
  32
  33 struct cns3xxx_pcie {
  34         struct map_desc cfg_bases[CNS3XXX_NUM_ACCESS_TYPES];
  35         unsigned int irqs[2];
  36         struct resource res_io;
  37         struct resource res_mem;
  38         struct hw_pci hw_pci;
  39
  40         bool linked;
  41 };
  42
  43 static struct cns3xxx_pcie cns3xxx_pcie[]; /* forward decl. */
  44
  45 static struct cns3xxx_pcie *sysdata_to_cnspci(void *sysdata)
  46 {
  47         struct pci_sys_data *root = sysdata;
  48
  49         return &cns3xxx_pcie[root->domain];
  50 }
  51
  52 static struct cns3xxx_pcie *pdev_to_cnspci(struct pci_dev *dev)
  53 {
  54         return sysdata_to_cnspci(dev->sysdata);
  55 }
  56
  57 static struct cns3xxx_pcie *pbus_to_cnspci(struct pci_bus *bus)
  58 {
  59         return sysdata_to_cnspci(bus->sysdata);
  60 }
  61
  62 static void __iomem *cns3xxx_pci_cfg_base(struct pci_bus *bus,
  63                                   unsigned int devfn, int where)
  64 {
  65         struct cns3xxx_pcie *cnspci = pbus_to_cnspci(bus);
  66         int busno = bus->number;
  67         int slot = PCI_SLOT(devfn);
  68         int offset;
  69         enum cns3xxx_access_type type;
  70         void __iomem *base;
  71
  72         /* If there is no link, just show the CNS PCI bridge. */
  73         if (!cnspci->linked && (busno > 0 || slot > 0))
  74                 return NULL;
  75
  76         /*
  77          * The CNS PCI bridge doesn't fit into the PCI hierarchy, though
  78          * we still want to access it. For this to work, we must place
  79          * the first device on the same bus as the CNS PCI bridge.
  80          */
  81         if (busno == 0) {
  82                 if (slot > 1)
  83                         return NULL;
  84                 type = slot;
  85         } else {
  86                 type = CNS3XXX_CFG1_TYPE;
  87         }
  88
  89         base = (void __iomem *)cnspci->cfg_bases[type].virtual;
  90         offset = ((busno & 0xf) << 20) | (devfn << 12) | (where & 0xffc);
  91
  92         return base + offset;
  93 }
  94
  95 static int cns3xxx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
  96                                    int where, int size, u32 *val)
  97 {
  98         u32 v;
  99         void __iomem *base;
 100         u32 mask = (0x1ull << (size * 8)) - 1;
 101         int shift = (where % 4) * 8;
 102
 103         base = cns3xxx_pci_cfg_base(bus, devfn, where);
 104         if (!base) {
 105                 *val = 0xffffffff;
 106                 return PCIBIOS_SUCCESSFUL;
 107         }
 108
 109         v = __raw_readl(base);
 110
 111         if (bus->number == 0 && devfn == 0 &&
 112                         (where & 0xffc) == PCI_CLASS_REVISION) {
 113                 /*
 114                  * RC's class is 0xb, but Linux PCI driver needs 0x604
 115                  * for a PCIe bridge. So we must fixup the class code
 116                  * to 0x604 here.
 117                  */
 118                 v &= 0xff;
 119                 v |= 0x604 << 16;
 120         }
 121
 122         *val = (v >> shift) & mask;
 123
 124         return PCIBIOS_SUCCESSFUL;
 125 }
 126
 127 static int cns3xxx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
 128                                     int where, int size, u32 val)
 129 {
 130         u32 v;
 131         void __iomem *base;
 132         u32 mask = (0x1ull << (size * 8)) - 1;
 133         int shift = (where % 4) * 8;
 134
 135         base = cns3xxx_pci_cfg_base(bus, devfn, where);
 136         if (!base)
 137                 return PCIBIOS_SUCCESSFUL;
 138
 139         v = __raw_readl(base);
 140
 141         v &= ~(mask << shift);
 142         v |= (val & mask) << shift;
 143
 144         __raw_writel(v, base);
 145
 146         return PCIBIOS_SUCCESSFUL;
 147 }
 148
 149 static int cns3xxx_pci_setup(int nr, struct pci_sys_data *sys)
 150 {
 151         struct cns3xxx_pcie *cnspci = sysdata_to_cnspci(sys);
 152         struct resource *res_io = &cnspci->res_io;
 153         struct resource *res_mem = &cnspci->res_mem;
 154         struct resource **sysres = sys->resource;
 155
 156         BUG_ON(request_resource(&iomem_resource, res_io) ||
 157                request_resource(&iomem_resource, res_mem));
 158
 159         sysres[0] = res_io;
 160         sysres[1] = res_mem;
 161
 162         return 1;
 163 }
 164
 165 static struct pci_ops cns3xxx_pcie_ops = {
 166         .read = cns3xxx_pci_read_config,
 167         .write = cns3xxx_pci_write_config,
 168 };
 169
 170 static struct pci_bus *cns3xxx_pci_scan_bus(int nr, struct pci_sys_data *sys)
 171 {
 172         return pci_scan_bus(sys->busnr, &cns3xxx_pcie_ops, sys);
 173 }
 174
 175 static int cns3xxx_pcie_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
 176 {
 177         struct cns3xxx_pcie *cnspci = pdev_to_cnspci(dev);
 178         int irq = cnspci->irqs[slot];
 179
 180         pr_info("PCIe map irq: %04d:%02x:%02x.%02x slot %d, pin %d, irq: %d\n",
 181                 pci_domain_nr(dev->bus), dev->bus->number, PCI_SLOT(dev->devfn),
 182                 PCI_FUNC(dev->devfn), slot, pin, irq);
 183
 184         return irq;
 185 }
 186
 187 static struct cns3xxx_pcie cns3xxx_pcie[] = {
 188         [0] = {
 189                 .cfg_bases = {
 190                         [CNS3XXX_HOST_TYPE] = {
 191                                 .virtual = CNS3XXX_PCIE0_HOST_BASE_VIRT,
 192                                 .pfn = __phys_to_pfn(CNS3XXX_PCIE0_HOST_BASE),
 193                                 .length = SZ_16M,
 194                                 .type = MT_DEVICE,
 195                         },
 196                         [CNS3XXX_CFG0_TYPE] = {
 197                                 .virtual = CNS3XXX_PCIE0_CFG0_BASE_VIRT,
 198                                 .pfn = __phys_to_pfn(CNS3XXX_PCIE0_CFG0_BASE),
 199                                 .length = SZ_16M,
 200                                 .type = MT_DEVICE,
 201                         },
 202                         [CNS3XXX_CFG1_TYPE] = {
 203                                 .virtual = CNS3XXX_PCIE0_CFG1_BASE_VIRT,
 204                                 .pfn = __phys_to_pfn(CNS3XXX_PCIE0_CFG1_BASE),
 205                                 .length = SZ_16M,
 206                                 .type = MT_DEVICE,
 207                         },
 208                 },
 209                 .res_io = {
 210                         .name = "PCIe0 I/O space",
 211                         .start = CNS3XXX_PCIE0_IO_BASE,
 212                         .end = CNS3XXX_PCIE0_IO_BASE + SZ_16M - 1,
 213                         .flags = IORESOURCE_IO,
 214                 },
 215                 .res_mem = {
 216                         .name = "PCIe0 non-prefetchable",
 217                         .start = CNS3XXX_PCIE0_MEM_BASE,
 218                         .end = CNS3XXX_PCIE0_MEM_BASE + SZ_16M - 1,
 219                         .flags = IORESOURCE_MEM,
 220                 },
 221                 .irqs = { IRQ_CNS3XXX_PCIE0_RC, IRQ_CNS3XXX_PCIE0_DEVICE, },
 222                 .hw_pci = {
 223                         .domain = 0,
 224                         .swizzle = pci_std_swizzle,
 225                         .nr_controllers = 1,
 226                         .setup = cns3xxx_pci_setup,
 227                         .scan = cns3xxx_pci_scan_bus,
 228                         .map_irq = cns3xxx_pcie_map_irq,
 229                 },
 230         },
 231         [1] = {
 232                 .cfg_bases = {
 233                         [CNS3XXX_HOST_TYPE] = {
 234                                 .virtual = CNS3XXX_PCIE1_HOST_BASE_VIRT,
 235                                 .pfn = __phys_to_pfn(CNS3XXX_PCIE1_HOST_BASE),
 236                                 .length = SZ_16M,
 237                                 .type = MT_DEVICE,
 238                         },
 239                         [CNS3XXX_CFG0_TYPE] = {
 240                                 .virtual = CNS3XXX_PCIE1_CFG0_BASE_VIRT,
 241                                 .pfn = __phys_to_pfn(CNS3XXX_PCIE1_CFG0_BASE),
 242                                 .length = SZ_16M,
 243                                 .type = MT_DEVICE,
 244                         },
 245                         [CNS3XXX_CFG1_TYPE] = {
 246                                 .virtual = CNS3XXX_PCIE1_CFG1_BASE_VIRT,
 247                                 .pfn = __phys_to_pfn(CNS3XXX_PCIE1_CFG1_BASE),
 248                                 .length = SZ_16M,
 249                                 .type = MT_DEVICE,
 250                         },
 251                 },
 252                 .res_io = {
 253                         .name = "PCIe1 I/O space",
 254                         .start = CNS3XXX_PCIE1_IO_BASE,
 255                         .end = CNS3XXX_PCIE1_IO_BASE + SZ_16M - 1,
 256                         .flags = IORESOURCE_IO,
 257                 },
 258                 .res_mem = {
 259                         .name = "PCIe1 non-prefetchable",
 260                         .start = CNS3XXX_PCIE1_MEM_BASE,
 261                         .end = CNS3XXX_PCIE1_MEM_BASE + SZ_16M - 1,
 262                         .flags = IORESOURCE_MEM,
 263                 },
 264                 .irqs = { IRQ_CNS3XXX_PCIE1_RC, IRQ_CNS3XXX_PCIE1_DEVICE, },
 265                 .hw_pci = {
 266                         .domain = 1,
 267                         .swizzle = pci_std_swizzle,
 268                         .nr_controllers = 1,
 269                         .setup = cns3xxx_pci_setup,
 270                         .scan = cns3xxx_pci_scan_bus,
 271                         .map_irq = cns3xxx_pcie_map_irq,
 272                 },
 273         },
 274 };
 275
 276 static void __init cns3xxx_pcie_check_link(struct cns3xxx_pcie *cnspci)
 277 {
 278         int port = cnspci->hw_pci.domain;
 279         u32 reg;
 280         unsigned long time;
 281
 282         reg = __raw_readl(MISC_PCIE_CTRL(port));
 283         /*
 284          * Enable Application Request to 1, it will exit L1 automatically,
 285          * but when chip back, it will use another clock, still can use 0x1.
 286          */
 287         reg |= 0x3;
 288         __raw_writel(reg, MISC_PCIE_CTRL(port));
 289
 290         pr_info("PCIe: Port[%d] Enable PCIe LTSSM\n", port);
 291         pr_info("PCIe: Port[%d] Check data link layer...", port);
 292
 293         time = jiffies;
 294         while (1) {
 295                 reg = __raw_readl(MISC_PCIE_PM_DEBUG(port));
 296                 if (reg & 0x1) {
 297                         pr_info("Link up.\n");
 298                         cnspci->linked = 1;
 299                         break;
 300                 } else if (time_after(jiffies, time + 50)) {
 301                         pr_info("Device not found.\n");
 302                         break;
 303                 }
 304         }
 305 }
 306
 307 static void __init cns3xxx_pcie_hw_init(struct cns3xxx_pcie *cnspci)
 308 {
 309         int port = cnspci->hw_pci.domain;
 310         struct pci_sys_data sd = {
 311                 .domain = port,
 312         };
 313         struct pci_bus bus = {
 314                 .number = 0,
 315                 .ops = &cns3xxx_pcie_ops,
 316                 .sysdata = &sd,
 317         };
 318         u32 io_base = cnspci->res_io.start >> 16;
 319         u32 mem_base = cnspci->res_mem.start >> 16;
 320         u32 host_base = cnspci->cfg_bases[CNS3XXX_HOST_TYPE].pfn;
 321         u32 cfg0_base = cnspci->cfg_bases[CNS3XXX_CFG0_TYPE].pfn;
 322         u32 devfn = 0;
 323         u8 tmp8;
 324         u16 pos;
 325         u16 dc;
 326
 327         host_base = (__pfn_to_phys(host_base) - 1) >> 16;
 328         cfg0_base = (__pfn_to_phys(cfg0_base) - 1) >> 16;
 329
 330         pci_bus_write_config_byte(&bus, devfn, PCI_PRIMARY_BUS, 0);
 331         pci_bus_write_config_byte(&bus, devfn, PCI_SECONDARY_BUS, 1);
 332         pci_bus_write_config_byte(&bus, devfn, PCI_SUBORDINATE_BUS, 1);
 333
 334         pci_bus_read_config_byte(&bus, devfn, PCI_PRIMARY_BUS, &tmp8);
 335         pci_bus_read_config_byte(&bus, devfn, PCI_SECONDARY_BUS, &tmp8);
 336         pci_bus_read_config_byte(&bus, devfn, PCI_SUBORDINATE_BUS, &tmp8);
 337
 338         pci_bus_write_config_word(&bus, devfn, PCI_MEMORY_BASE, mem_base);
 339         pci_bus_write_config_word(&bus, devfn, PCI_MEMORY_LIMIT, host_base);
 340         pci_bus_write_config_word(&bus, devfn, PCI_IO_BASE_UPPER16, io_base);
 341         pci_bus_write_config_word(&bus, devfn, PCI_IO_LIMIT_UPPER16, cfg0_base);
 342
 343         if (!cnspci->linked)
 344                 return;
 345
 346         /* Set Device Max_Read_Request_Size to 128 byte */
 347         devfn = PCI_DEVFN(1, 0);
 348         pos = pci_bus_find_capability(&bus, devfn, PCI_CAP_ID_EXP);
 349         pci_bus_read_config_word(&bus, devfn, pos + PCI_EXP_DEVCTL, &dc);
 350         dc &= ~(0x3 << 12);     /* Clear Device Control Register [14:12] */
 351         pci_bus_write_config_word(&bus, devfn, pos + PCI_EXP_DEVCTL, dc);
 352         pci_bus_read_config_word(&bus, devfn, pos + PCI_EXP_DEVCTL, &dc);
 353         if (!(dc & (0x3 << 12)))
 354                 pr_info("PCIe: Set Device Max_Read_Request_Size to 128 byte\n");
 355
 356         /* Disable PCIe0 Interrupt Mask INTA to INTD */
 357         __raw_writel(~0x3FFF, MISC_PCIE_INT_MASK(port));
 358 }
 359
 360 static int cns3xxx_pcie_abort_handler(unsigned long addr, unsigned int fsr,
 361                                       struct pt_regs *regs)
 362 {
 363         if (fsr & (1 << 10))
 364                 regs->ARM_pc += 4;
 365         return 0;
 366 }
 367
 368 static int __init cns3xxx_pcie_init(void)
 369 {
 370         int i;
 371
 372         hook_fault_code(16 + 6, cns3xxx_pcie_abort_handler, SIGBUS, 0,
 373                         "imprecise external abort");
 374
 375         for (i = 0; i < ARRAY_SIZE(cns3xxx_pcie); i++) {
 376                 iotable_init(cns3xxx_pcie[i].cfg_bases,
 377                              ARRAY_SIZE(cns3xxx_pcie[i].cfg_bases));
 378                 cns3xxx_pwr_clk_en(0x1 << PM_CLK_GATE_REG_OFFSET_PCIE(i));
 379                 cns3xxx_pwr_soft_rst(0x1 << PM_SOFT_RST_REG_OFFST_PCIE(i));
 380                 cns3xxx_pcie_check_link(&cns3xxx_pcie[i]);
 381                 cns3xxx_pcie_hw_init(&cns3xxx_pcie[i]);
 382                 pci_common_init(&cns3xxx_pcie[i].hw_pci);
 383         }
 384
 385         pci_assign_unassigned_resources();
 386
 387         return 0;
 388 }
 389 device_initcall(cns3xxx_pcie_init);