arch/mips/pci/pci-alchemy.c

   1 /*
   2  * Alchemy PCI host mode support.
   3  *
   4  * Copyright 2001-2003, 2007-2008 MontaVista Software Inc.
   5  * Author: MontaVista Software, Inc. <source@mvista.com>
   6  *
   7  * Support for all devices (greater than 16) added by David Gathright.
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/export.h>
  12 #include <linux/types.h>
  13 #include <linux/pci.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/syscore_ops.h>
  18 #include <linux/vmalloc.h>
  19
  20 #include <asm/dma-coherence.h>
  21 #include <asm/mach-au1x00/au1000.h>
  22 #include <asm/tlbmisc.h>
  23
  24 #ifdef CONFIG_PCI_DEBUG
  25 #define DBG(x...) printk(KERN_DEBUG x)
  26 #else
  27 #define DBG(x...) do {} while (0)
  28 #endif
  29
  30 #define PCI_ACCESS_READ         0
  31 #define PCI_ACCESS_WRITE        1
  32
  33 struct alchemy_pci_context {
  34         struct pci_controller alchemy_pci_ctrl; /* leave as first member! */
  35         void __iomem *regs;                     /* ctrl base */
  36         /* tools for wired entry for config space access */
  37         unsigned long last_elo0;
  38         unsigned long last_elo1;
  39         int wired_entry;
  40         struct vm_struct *pci_cfg_vm;
  41
  42         unsigned long pm[12];
  43
  44         int (*board_map_irq)(const struct pci_dev *d, u8 slot, u8 pin);
  45         int (*board_pci_idsel)(unsigned int devsel, int assert);
  46 };
  47
  48 /* for syscore_ops. There's only one PCI controller on Alchemy chips, so this
  49  * should suffice for now.
  50  */
  51 static struct alchemy_pci_context *__alchemy_pci_ctx;
  52
  53
  54 /* IO/MEM resources for PCI. Keep the memres in sync with __fixup_bigphys_addr
  55  * in arch/mips/alchemy/common/setup.c
  56  */
  57 static struct resource alchemy_pci_def_memres = {
  58         .start  = ALCHEMY_PCI_MEMWIN_START,
  59         .end    = ALCHEMY_PCI_MEMWIN_END,
  60         .name   = "PCI memory space",
  61         .flags  = IORESOURCE_MEM
  62 };
  63
  64 static struct resource alchemy_pci_def_iores = {
  65         .start  = ALCHEMY_PCI_IOWIN_START,
  66         .end    = ALCHEMY_PCI_IOWIN_END,
  67         .name   = "PCI IO space",
  68         .flags  = IORESOURCE_IO
  69 };
  70
  71 static void mod_wired_entry(int entry, unsigned long entrylo0,
  72                 unsigned long entrylo1, unsigned long entryhi,
  73                 unsigned long pagemask)
  74 {
  75         unsigned long old_pagemask;
  76         unsigned long old_ctx;
  77
  78         /* Save old context and create impossible VPN2 value */
  79         old_ctx = read_c0_entryhi() & 0xff;
  80         old_pagemask = read_c0_pagemask();
  81         write_c0_index(entry);
  82         write_c0_pagemask(pagemask);
  83         write_c0_entryhi(entryhi);
  84         write_c0_entrylo0(entrylo0);
  85         write_c0_entrylo1(entrylo1);
  86         tlb_write_indexed();
  87         write_c0_entryhi(old_ctx);
  88         write_c0_pagemask(old_pagemask);
  89 }
  90
  91 static void alchemy_pci_wired_entry(struct alchemy_pci_context *ctx)
  92 {
  93         ctx->wired_entry = read_c0_wired();
  94         add_wired_entry(0, 0, (unsigned long)ctx->pci_cfg_vm->addr, PM_4K);
  95         ctx->last_elo0 = ctx->last_elo1 = ~0;
  96 }
  97
  98 static int config_access(unsigned char access_type, struct pci_bus *bus,
  99                          unsigned int dev_fn, unsigned char where, u32 *data)
 100 {
 101         struct alchemy_pci_context *ctx = bus->sysdata;
 102         unsigned int device = PCI_SLOT(dev_fn);
 103         unsigned int function = PCI_FUNC(dev_fn);
 104         unsigned long offset, status, cfg_base, flags, entryLo0, entryLo1, r;
 105         int error = PCIBIOS_SUCCESSFUL;
 106
 107         if (device > 19) {
 108                 *data = 0xffffffff;
 109                 return -1;
 110         }
 111
 112         local_irq_save(flags);
 113         r = __raw_readl(ctx->regs + PCI_REG_STATCMD) & 0x0000ffff;
 114         r |= PCI_STATCMD_STATUS(0x2000);
 115         __raw_writel(r, ctx->regs + PCI_REG_STATCMD);
 116         wmb();
 117
 118         /* Allow board vendors to implement their own off-chip IDSEL.
 119          * If it doesn't succeed, may as well bail out at this point.
 120          */
 121         if (ctx->board_pci_idsel(device, 1) == 0) {
 122                 *data = 0xffffffff;
 123                 local_irq_restore(flags);
 124                 return -1;
 125         }
 126
 127         /* Setup the config window */
 128         if (bus->number == 0)
 129                 cfg_base = (1 << device) << 11;
 130         else
 131                 cfg_base = 0x80000000 | (bus->number << 16) | (device << 11);
 132
 133         /* Setup the lower bits of the 36-bit address */
 134         offset = (function << 8) | (where & ~0x3);
 135         /* Pick up any address that falls below the page mask */
 136         offset |= cfg_base & ~PAGE_MASK;
 137
 138         /* Page boundary */
 139         cfg_base = cfg_base & PAGE_MASK;
 140
 141         /* To improve performance, if the current device is the same as
 142          * the last device accessed, we don't touch the TLB.
 143          */
 144         entryLo0 = (6 << 26) | (cfg_base >> 6) | (2 << 3) | 7;
 145         entryLo1 = (6 << 26) | (cfg_base >> 6) | (0x1000 >> 6) | (2 << 3) | 7;
 146         if ((entryLo0 != ctx->last_elo0) || (entryLo1 != ctx->last_elo1)) {
 147                 mod_wired_entry(ctx->wired_entry, entryLo0, entryLo1,
 148                                 (unsigned long)ctx->pci_cfg_vm->addr, PM_4K);
 149                 ctx->last_elo0 = entryLo0;
 150                 ctx->last_elo1 = entryLo1;
 151         }
 152
 153         if (access_type == PCI_ACCESS_WRITE)
 154                 __raw_writel(*data, ctx->pci_cfg_vm->addr + offset);
 155         else
 156                 *data = __raw_readl(ctx->pci_cfg_vm->addr + offset);
 157         wmb();
 158
 159         DBG("alchemy-pci: cfg access %d bus %u dev %u at %x dat %x conf %lx\n",
 160             access_type, bus->number, device, where, *data, offset);
 161
 162         /* check for errors, master abort */
 163         status = __raw_readl(ctx->regs + PCI_REG_STATCMD);
 164         if (status & (1 << 29)) {
 165                 *data = 0xffffffff;
 166                 error = -1;
 167                 DBG("alchemy-pci: master abort on cfg access %d bus %d dev %d\n",
 168                     access_type, bus->number, device);
 169         } else if ((status >> 28) & 0xf) {
 170                 DBG("alchemy-pci: PCI ERR detected: dev %d, status %lx\n",
 171                     device, (status >> 28) & 0xf);
 172
 173                 /* clear errors */
 174                 __raw_writel(status & 0xf000ffff, ctx->regs + PCI_REG_STATCMD);
 175
 176                 *data = 0xffffffff;
 177                 error = -1;
 178         }
 179
 180         /* Take away the IDSEL. */
 181         (void)ctx->board_pci_idsel(device, 0);
 182
 183         local_irq_restore(flags);
 184         return error;
 185 }
 186
 187 static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
 188                             int where,  u8 *val)
 189 {
 190         u32 data;
 191         int ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
 192
 193         if (where & 1)
 194                 data >>= 8;
 195         if (where & 2)
 196                 data >>= 16;
 197         *val = data & 0xff;
 198         return ret;
 199 }
 200
 201 static int read_config_word(struct pci_bus *bus, unsigned int devfn,
 202                             int where, u16 *val)
 203 {
 204         u32 data;
 205         int ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
 206
 207         if (where & 2)
 208                 data >>= 16;
 209         *val = data & 0xffff;
 210         return ret;
 211 }
 212
 213 static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
 214                              int where, u32 *val)
 215 {
 216         return config_access(PCI_ACCESS_READ, bus, devfn, where, val);
 217 }
 218
 219 static int write_config_byte(struct pci_bus *bus, unsigned int devfn,
 220                              int where, u8 val)
 221 {
 222         u32 data = 0;
 223
 224         if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
 225                 return -1;
 226
 227         data = (data & ~(0xff << ((where & 3) << 3))) |
 228                (val << ((where & 3) << 3));
 229
 230         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
 231                 return -1;
 232
 233         return PCIBIOS_SUCCESSFUL;
 234 }
 235
 236 static int write_config_word(struct pci_bus *bus, unsigned int devfn,
 237                              int where, u16 val)
 238 {
 239         u32 data = 0;
 240
 241         if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
 242                 return -1;
 243
 244         data = (data & ~(0xffff << ((where & 3) << 3))) |
 245                (val << ((where & 3) << 3));
 246
 247         if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
 248                 return -1;
 249
 250         return PCIBIOS_SUCCESSFUL;
 251 }
 252
 253 static int write_config_dword(struct pci_bus *bus, unsigned int devfn,
 254                               int where, u32 val)
 255 {
 256         return config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val);
 257 }
 258
 259 static int alchemy_pci_read(struct pci_bus *bus, unsigned int devfn,
 260                        int where, int size, u32 *val)
 261 {
 262         switch (size) {
 263         case 1: {
 264                         u8 _val;
 265                         int rc = read_config_byte(bus, devfn, where, &_val);
 266
 267                         *val = _val;
 268                         return rc;
 269                 }
 270         case 2: {
 271                         u16 _val;
 272                         int rc = read_config_word(bus, devfn, where, &_val);
 273
 274                         *val = _val;
 275                         return rc;
 276                 }
 277         default:
 278                 return read_config_dword(bus, devfn, where, val);
 279         }
 280 }
 281
 282 static int alchemy_pci_write(struct pci_bus *bus, unsigned int devfn,
 283                              int where, int size, u32 val)
 284 {
 285         switch (size) {
 286         case 1:
 287                 return write_config_byte(bus, devfn, where, (u8) val);
 288         case 2:
 289                 return write_config_word(bus, devfn, where, (u16) val);
 290         default:
 291                 return write_config_dword(bus, devfn, where, val);
 292         }
 293 }
 294
 295 static struct pci_ops alchemy_pci_ops = {
 296         .read   = alchemy_pci_read,
 297         .write  = alchemy_pci_write,
 298 };
 299
 300 static int alchemy_pci_def_idsel(unsigned int devsel, int assert)
 301 {
 302         return 1;       /* success */
 303 }
 304
 305 /* save PCI controller register contents. */
 306 static int alchemy_pci_suspend(void)
 307 {
 308         struct alchemy_pci_context *ctx = __alchemy_pci_ctx;
 309         if (!ctx)
 310                 return 0;
 311
 312         ctx->pm[0]  = __raw_readl(ctx->regs + PCI_REG_CMEM);
 313         ctx->pm[1]  = __raw_readl(ctx->regs + PCI_REG_CONFIG) & 0x0009ffff;
 314         ctx->pm[2]  = __raw_readl(ctx->regs + PCI_REG_B2BMASK_CCH);
 315         ctx->pm[3]  = __raw_readl(ctx->regs + PCI_REG_B2BBASE0_VID);
 316         ctx->pm[4]  = __raw_readl(ctx->regs + PCI_REG_B2BBASE1_SID);
 317         ctx->pm[5]  = __raw_readl(ctx->regs + PCI_REG_MWMASK_DEV);
 318         ctx->pm[6]  = __raw_readl(ctx->regs + PCI_REG_MWBASE_REV_CCL);
 319         ctx->pm[7]  = __raw_readl(ctx->regs + PCI_REG_ID);
 320         ctx->pm[8]  = __raw_readl(ctx->regs + PCI_REG_CLASSREV);
 321         ctx->pm[9]  = __raw_readl(ctx->regs + PCI_REG_PARAM);
 322         ctx->pm[10] = __raw_readl(ctx->regs + PCI_REG_MBAR);
 323         ctx->pm[11] = __raw_readl(ctx->regs + PCI_REG_TIMEOUT);
 324
 325         return 0;
 326 }
 327
 328 static void alchemy_pci_resume(void)
 329 {
 330         struct alchemy_pci_context *ctx = __alchemy_pci_ctx;
 331         if (!ctx)
 332                 return;
 333
 334         __raw_writel(ctx->pm[0],  ctx->regs + PCI_REG_CMEM);
 335         __raw_writel(ctx->pm[2],  ctx->regs + PCI_REG_B2BMASK_CCH);
 336         __raw_writel(ctx->pm[3],  ctx->regs + PCI_REG_B2BBASE0_VID);
 337         __raw_writel(ctx->pm[4],  ctx->regs + PCI_REG_B2BBASE1_SID);
 338         __raw_writel(ctx->pm[5],  ctx->regs + PCI_REG_MWMASK_DEV);
 339         __raw_writel(ctx->pm[6],  ctx->regs + PCI_REG_MWBASE_REV_CCL);
 340         __raw_writel(ctx->pm[7],  ctx->regs + PCI_REG_ID);
 341         __raw_writel(ctx->pm[8],  ctx->regs + PCI_REG_CLASSREV);
 342         __raw_writel(ctx->pm[9],  ctx->regs + PCI_REG_PARAM);
 343         __raw_writel(ctx->pm[10], ctx->regs + PCI_REG_MBAR);
 344         __raw_writel(ctx->pm[11], ctx->regs + PCI_REG_TIMEOUT);
 345         wmb();
 346         __raw_writel(ctx->pm[1],  ctx->regs + PCI_REG_CONFIG);
 347         wmb();
 348
 349         /* YAMON on all db1xxx boards wipes the TLB and writes zero to C0_wired
 350          * on resume, making it necessary to recreate it as soon as possible.
 351          */
 352         ctx->wired_entry = 8191;        /* impossibly high value */
 353         alchemy_pci_wired_entry(ctx);   /* install it */
 354 }
 355
 356 static struct syscore_ops alchemy_pci_pmops = {
 357         .suspend        = alchemy_pci_suspend,
 358         .resume         = alchemy_pci_resume,
 359 };
 360
 361 static int alchemy_pci_probe(struct platform_device *pdev)
 362 {
 363         struct alchemy_pci_platdata *pd = pdev->dev.platform_data;
 364         struct alchemy_pci_context *ctx;
 365         void __iomem *virt_io;
 366         unsigned long val;
 367         struct resource *r;
 368         struct clk *c;
 369         int ret;
 370
 371         /* need at least PCI IRQ mapping table */
 372         if (!pd) {
 373                 dev_err(&pdev->dev, "need platform data for PCI setup\n");
 374                 ret = -ENODEV;
 375                 goto out;
 376         }
 377
 378         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 379         if (!ctx) {
 380                 dev_err(&pdev->dev, "no memory for pcictl context\n");
 381                 ret = -ENOMEM;
 382                 goto out;
 383         }
 384
 385         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 386         if (!r) {
 387                 dev_err(&pdev->dev, "no  pcictl ctrl regs resource\n");
 388                 ret = -ENODEV;
 389                 goto out1;
 390         }
 391
 392         if (!request_mem_region(r->start, resource_size(r), pdev->name)) {
 393                 dev_err(&pdev->dev, "cannot claim pci regs\n");
 394                 ret = -ENODEV;
 395                 goto out1;
 396         }
 397
 398         c = clk_get(&pdev->dev, "pci_clko");
 399         if (IS_ERR(c)) {
 400                 dev_err(&pdev->dev, "unable to find PCI clock\n");
 401                 ret = PTR_ERR(c);
 402                 goto out2;
 403         }
 404
 405         ret = clk_prepare_enable(c);
 406         if (ret) {
 407                 dev_err(&pdev->dev, "cannot enable PCI clock\n");
 408                 goto out6;
 409         }
 410
 411         ctx->regs = ioremap_nocache(r->start, resource_size(r));
 412         if (!ctx->regs) {
 413                 dev_err(&pdev->dev, "cannot map pci regs\n");
 414                 ret = -ENODEV;
 415                 goto out5;
 416         }
 417
 418         /* map parts of the PCI IO area */
 419         /* REVISIT: if this changes with a newer variant (doubt it) make this
 420          * a platform resource.
 421          */
 422         virt_io = ioremap(AU1500_PCI_IO_PHYS_ADDR, 0x00100000);
 423         if (!virt_io) {
 424                 dev_err(&pdev->dev, "cannot remap pci io space\n");
 425                 ret = -ENODEV;
 426                 goto out3;
 427         }
 428         ctx->alchemy_pci_ctrl.io_map_base = (unsigned long)virt_io;
 429
 430         /* Au1500 revisions older than AD have borked coherent PCI */
 431         if ((alchemy_get_cputype() == ALCHEMY_CPU_AU1500) &&
 432             (read_c0_prid() < 0x01030202) && !coherentio) {
 433                 val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
 434                 val |= PCI_CONFIG_NC;
 435                 __raw_writel(val, ctx->regs + PCI_REG_CONFIG);
 436                 wmb();
 437                 dev_info(&pdev->dev, "non-coherent PCI on Au1500 AA/AB/AC\n");
 438         }
 439
 440         if (pd->board_map_irq)
 441                 ctx->board_map_irq = pd->board_map_irq;
 442
 443         if (pd->board_pci_idsel)
 444                 ctx->board_pci_idsel = pd->board_pci_idsel;
 445         else
 446                 ctx->board_pci_idsel = alchemy_pci_def_idsel;
 447
 448         /* fill in relevant pci_controller members */
 449         ctx->alchemy_pci_ctrl.pci_ops = &alchemy_pci_ops;
 450         ctx->alchemy_pci_ctrl.mem_resource = &alchemy_pci_def_memres;
 451         ctx->alchemy_pci_ctrl.io_resource = &alchemy_pci_def_iores;
 452
 453         /* we can't ioremap the entire pci config space because it's too large,
 454          * nor can we dynamically ioremap it because some drivers use the
 455          * PCI config routines from within atomic contex and that becomes a
 456          * problem in get_vm_area().  Instead we use one wired TLB entry to
 457          * handle all config accesses for all busses.
 458          */
 459         ctx->pci_cfg_vm = get_vm_area(0x2000, VM_IOREMAP);
 460         if (!ctx->pci_cfg_vm) {
 461                 dev_err(&pdev->dev, "unable to get vm area\n");
 462                 ret = -ENOMEM;
 463                 goto out4;
 464         }
 465         ctx->wired_entry = 8191;        /* impossibly high value */
 466         alchemy_pci_wired_entry(ctx);   /* install it */
 467
 468         set_io_port_base((unsigned long)ctx->alchemy_pci_ctrl.io_map_base);
 469
 470         /* board may want to modify bits in the config register, do it now */
 471         val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
 472         val &= ~pd->pci_cfg_clr;
 473         val |= pd->pci_cfg_set;
 474         val &= ~PCI_CONFIG_PD;          /* clear disable bit */
 475         __raw_writel(val, ctx->regs + PCI_REG_CONFIG);
 476         wmb();
 477
 478         __alchemy_pci_ctx = ctx;
 479         platform_set_drvdata(pdev, ctx);
 480         register_syscore_ops(&alchemy_pci_pmops);
 481         register_pci_controller(&ctx->alchemy_pci_ctrl);
 482
 483         dev_info(&pdev->dev, "PCI controller at %ld MHz\n",
 484                  clk_get_rate(c) / 1000000);
 485
 486         return 0;
 487
 488 out4:
 489         iounmap(virt_io);
 490 out3:
 491         iounmap(ctx->regs);
 492 out5:
 493         clk_disable_unprepare(c);
 494 out6:
 495         clk_put(c);
 496 out2:
 497         release_mem_region(r->start, resource_size(r));
 498 out1:
 499         kfree(ctx);
 500 out:
 501         return ret;
 502 }
 503
 504 static struct platform_driver alchemy_pcictl_driver = {
 505         .probe          = alchemy_pci_probe,
 506         .driver = {
 507                 .name   = "alchemy-pci",
 508         },
 509 };
 510
 511 static int __init alchemy_pci_init(void)
 512 {
 513         /* Au1500/Au1550 have PCI */
 514         switch (alchemy_get_cputype()) {
 515         case ALCHEMY_CPU_AU1500:
 516         case ALCHEMY_CPU_AU1550:
 517                 return platform_driver_register(&alchemy_pcictl_driver);
 518         }
 519         return 0;
 520 }
 521 arch_initcall(alchemy_pci_init);
 522
 523
 524 int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 525 {
 526         struct alchemy_pci_context *ctx = dev->sysdata;
 527         if (ctx && ctx->board_map_irq)
 528                 return ctx->board_map_irq(dev, slot, pin);
 529         return -1;
 530 }
 531
 532 int pcibios_plat_dev_init(struct pci_dev *dev)
 533 {
 534         return 0;
 535 }