arch/arm/mach-ixp4xx/common-pci.c

   1 /*
   2  * arch/arm/mach-ixp4xx/common-pci.c
   3  *
   4  * IXP4XX PCI routines for all platforms
   5  *
   6  * Maintainer: Deepak Saxena <dsaxena@plexity.net>
   7  *
   8  * Copyright (C) 2002 Intel Corporation.
   9  * Copyright (C) 2003 Greg Ungerer <gerg@snapgear.com>
  10  * Copyright (C) 2003-2004 MontaVista Software, Inc.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  *
  16  */
  17
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/pci.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/mm.h>
  23 #include <linux/init.h>
  24 #include <linux/ioport.h>
  25 #include <linux/slab.h>
  26 #include <linux/delay.h>
  27 #include <linux/device.h>
  28 #include <linux/io.h>
  29 #include <linux/export.h>
  30 #include <asm/dma-mapping.h>
  31
  32 #include <asm/cputype.h>
  33 #include <asm/irq.h>
  34 #include <asm/sizes.h>
  35 #include <asm/mach/pci.h>
  36 #include <mach/hardware.h>
  37
  38
  39 /*
  40  * IXP4xx PCI read function is dependent on whether we are
  41  * running A0 or B0 (AppleGate) silicon.
  42  */
  43 int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data);
  44
  45 /*
  46  * Base address for PCI register region
  47  */
  48 unsigned long ixp4xx_pci_reg_base = 0;
  49
  50 /*
  51  * PCI cfg an I/O routines are done by programming a
  52  * command/byte enable register, and then read/writing
  53  * the data from a data register. We need to ensure
  54  * these transactions are atomic or we will end up
  55  * with corrupt data on the bus or in a driver.
  56  */
  57 static DEFINE_RAW_SPINLOCK(ixp4xx_pci_lock);
  58
  59 /*
  60  * Read from PCI config space
  61  */
  62 static void crp_read(u32 ad_cbe, u32 *data)
  63 {
  64         unsigned long flags;
  65         raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
  66         *PCI_CRP_AD_CBE = ad_cbe;
  67         *data = *PCI_CRP_RDATA;
  68         raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
  69 }
  70
  71 /*
  72  * Write to PCI config space
  73  */
  74 static void crp_write(u32 ad_cbe, u32 data)
  75 {
  76         unsigned long flags;
  77         raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
  78         *PCI_CRP_AD_CBE = CRP_AD_CBE_WRITE | ad_cbe;
  79         *PCI_CRP_WDATA = data;
  80         raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
  81 }
  82
  83 static inline int check_master_abort(void)
  84 {
  85         /* check Master Abort bit after access */
  86         unsigned long isr = *PCI_ISR;
  87
  88         if (isr & PCI_ISR_PFE) {
  89                 /* make sure the Master Abort bit is reset */
  90                 *PCI_ISR = PCI_ISR_PFE;
  91                 pr_debug("%s failed\n", __func__);
  92                 return 1;
  93         }
  94
  95         return 0;
  96 }
  97
  98 int ixp4xx_pci_read_errata(u32 addr, u32 cmd, u32* data)
  99 {
 100         unsigned long flags;
 101         int retval = 0;
 102         int i;
 103
 104         raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
 105
 106         *PCI_NP_AD = addr;
 107
 108         /*
 109          * PCI workaround  - only works if NP PCI space reads have
 110          * no side effects!!! Read 8 times. last one will be good.
 111          */
 112         for (i = 0; i < 8; i++) {
 113                 *PCI_NP_CBE = cmd;
 114                 *data = *PCI_NP_RDATA;
 115                 *data = *PCI_NP_RDATA;
 116         }
 117
 118         if(check_master_abort())
 119                 retval = 1;
 120
 121         raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 122         return retval;
 123 }
 124
 125 int ixp4xx_pci_read_no_errata(u32 addr, u32 cmd, u32* data)
 126 {
 127         unsigned long flags;
 128         int retval = 0;
 129
 130         raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
 131
 132         *PCI_NP_AD = addr;
 133
 134         /* set up and execute the read */
 135         *PCI_NP_CBE = cmd;
 136
 137         /* the result of the read is now in NP_RDATA */
 138         *data = *PCI_NP_RDATA;
 139
 140         if(check_master_abort())
 141                 retval = 1;
 142
 143         raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 144         return retval;
 145 }
 146
 147 int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data)
 148 {
 149         unsigned long flags;
 150         int retval = 0;
 151
 152         raw_spin_lock_irqsave(&ixp4xx_pci_lock, flags);
 153
 154         *PCI_NP_AD = addr;
 155
 156         /* set up the write */
 157         *PCI_NP_CBE = cmd;
 158
 159         /* execute the write by writing to NP_WDATA */
 160         *PCI_NP_WDATA = data;
 161
 162         if(check_master_abort())
 163                 retval = 1;
 164
 165         raw_spin_unlock_irqrestore(&ixp4xx_pci_lock, flags);
 166         return retval;
 167 }
 168
 169 static u32 ixp4xx_config_addr(u8 bus_num, u16 devfn, int where)
 170 {
 171         u32 addr;
 172         if (!bus_num) {
 173                 /* type 0 */
 174                 addr = BIT(32-PCI_SLOT(devfn)) | ((PCI_FUNC(devfn)) << 8) |
 175                     (where & ~3);
 176         } else {
 177                 /* type 1 */
 178                 addr = (bus_num << 16) | ((PCI_SLOT(devfn)) << 11) |
 179                         ((PCI_FUNC(devfn)) << 8) | (where & ~3) | 1;
 180         }
 181         return addr;
 182 }
 183
 184 /*
 185  * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
 186  * 0 and 3 are not valid indexes...
 187  */
 188 static u32 bytemask[] = {
 189         /*0*/   0,
 190         /*1*/   0xff,
 191         /*2*/   0xffff,
 192         /*3*/   0,
 193         /*4*/   0xffffffff,
 194 };
 195
 196 static u32 local_byte_lane_enable_bits(u32 n, int size)
 197 {
 198         if (size == 1)
 199                 return (0xf & ~BIT(n)) << CRP_AD_CBE_BESL;
 200         if (size == 2)
 201                 return (0xf & ~(BIT(n) | BIT(n+1))) << CRP_AD_CBE_BESL;
 202         if (size == 4)
 203                 return 0;
 204         return 0xffffffff;
 205 }
 206
 207 static int local_read_config(int where, int size, u32 *value)
 208 {
 209         u32 n, data;
 210         pr_debug("local_read_config from %d size %d\n", where, size);
 211         n = where % 4;
 212         crp_read(where & ~3, &data);
 213         *value = (data >> (8*n)) & bytemask[size];
 214         pr_debug("local_read_config read %#x\n", *value);
 215         return PCIBIOS_SUCCESSFUL;
 216 }
 217
 218 static int local_write_config(int where, int size, u32 value)
 219 {
 220         u32 n, byte_enables, data;
 221         pr_debug("local_write_config %#x to %d size %d\n", value, where, size);
 222         n = where % 4;
 223         byte_enables = local_byte_lane_enable_bits(n, size);
 224         if (byte_enables == 0xffffffff)
 225                 return PCIBIOS_BAD_REGISTER_NUMBER;
 226         data = value << (8*n);
 227         crp_write((where & ~3) | byte_enables, data);
 228         return PCIBIOS_SUCCESSFUL;
 229 }
 230
 231 static u32 byte_lane_enable_bits(u32 n, int size)
 232 {
 233         if (size == 1)
 234                 return (0xf & ~BIT(n)) << 4;
 235         if (size == 2)
 236                 return (0xf & ~(BIT(n) | BIT(n+1))) << 4;
 237         if (size == 4)
 238                 return 0;
 239         return 0xffffffff;
 240 }
 241
 242 static int ixp4xx_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
 243 {
 244         u32 n, byte_enables, addr, data;
 245         u8 bus_num = bus->number;
 246
 247         pr_debug("read_config from %d size %d dev %d:%d:%d\n", where, size,
 248                 bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));
 249
 250         *value = 0xffffffff;
 251         n = where % 4;
 252         byte_enables = byte_lane_enable_bits(n, size);
 253         if (byte_enables == 0xffffffff)
 254                 return PCIBIOS_BAD_REGISTER_NUMBER;
 255
 256         addr = ixp4xx_config_addr(bus_num, devfn, where);
 257         if (ixp4xx_pci_read(addr, byte_enables | NP_CMD_CONFIGREAD, &data))
 258                 return PCIBIOS_DEVICE_NOT_FOUND;
 259
 260         *value = (data >> (8*n)) & bytemask[size];
 261         pr_debug("read_config_byte read %#x\n", *value);
 262         return PCIBIOS_SUCCESSFUL;
 263 }
 264
 265 static int ixp4xx_pci_write_config(struct pci_bus *bus,  unsigned int devfn, int where, int size, u32 value)
 266 {
 267         u32 n, byte_enables, addr, data;
 268         u8 bus_num = bus->number;
 269
 270         pr_debug("write_config_byte %#x to %d size %d dev %d:%d:%d\n", value, where,
 271                 size, bus_num, PCI_SLOT(devfn), PCI_FUNC(devfn));
 272
 273         n = where % 4;
 274         byte_enables = byte_lane_enable_bits(n, size);
 275         if (byte_enables == 0xffffffff)
 276                 return PCIBIOS_BAD_REGISTER_NUMBER;
 277
 278         addr = ixp4xx_config_addr(bus_num, devfn, where);
 279         data = value << (8*n);
 280         if (ixp4xx_pci_write(addr, byte_enables | NP_CMD_CONFIGWRITE, data))
 281                 return PCIBIOS_DEVICE_NOT_FOUND;
 282
 283         return PCIBIOS_SUCCESSFUL;
 284 }
 285
 286 struct pci_ops ixp4xx_ops = {
 287         .read =  ixp4xx_pci_read_config,
 288         .write = ixp4xx_pci_write_config,
 289 };
 290
 291 /*
 292  * PCI abort handler
 293  */
 294 static int abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 295 {
 296         u32 isr, status;
 297
 298         isr = *PCI_ISR;
 299         local_read_config(PCI_STATUS, 2, &status);
 300         pr_debug("PCI: abort_handler addr = %#lx, isr = %#x, "
 301                 "status = %#x\n", addr, isr, status);
 302
 303         /* make sure the Master Abort bit is reset */
 304         *PCI_ISR = PCI_ISR_PFE;
 305         status |= PCI_STATUS_REC_MASTER_ABORT;
 306         local_write_config(PCI_STATUS, 2, status);
 307
 308         /*
 309          * If it was an imprecise abort, then we need to correct the
 310          * return address to be _after_ the instruction.
 311          */
 312         if (fsr & (1 << 10))
 313                 regs->ARM_pc += 4;
 314
 315         return 0;
 316 }
 317
 318 void __init ixp4xx_pci_preinit(void)
 319 {
 320         unsigned long cpuid = read_cpuid_id();
 321
 322 #ifdef CONFIG_IXP4XX_INDIRECT_PCI
 323         pcibios_min_mem = 0x10000000; /* 1 GB of indirect PCI MMIO space */
 324 #else
 325         pcibios_min_mem = 0x48000000; /* 64 MB of PCI MMIO space */
 326 #endif
 327         /*
 328          * Determine which PCI read method to use.
 329          * Rev 0 IXP425 requires workaround.
 330          */
 331         if (!(cpuid & 0xf) && cpu_is_ixp42x()) {
 332                 printk("PCI: IXP42x A0 silicon detected - "
 333                         "PCI Non-Prefetch Workaround Enabled\n");
 334                 ixp4xx_pci_read = ixp4xx_pci_read_errata;
 335         } else
 336                 ixp4xx_pci_read = ixp4xx_pci_read_no_errata;
 337
 338
 339         /* hook in our fault handler for PCI errors */
 340         hook_fault_code(16+6, abort_handler, SIGBUS, 0,
 341                         "imprecise external abort");
 342
 343         pr_debug("setup PCI-AHB(inbound) and AHB-PCI(outbound) address mappings\n");
 344
 345         /*
 346          * We use identity AHB->PCI address translation
 347          * in the 0x48000000 to 0x4bffffff address space
 348          */
 349         *PCI_PCIMEMBASE = 0x48494A4B;
 350
 351         /*
 352          * We also use identity PCI->AHB address translation
 353          * in 4 16MB BARs that begin at the physical memory start
 354          */
 355         *PCI_AHBMEMBASE = (PHYS_OFFSET & 0xFF000000) +
 356                 ((PHYS_OFFSET & 0xFF000000) >> 8) +
 357                 ((PHYS_OFFSET & 0xFF000000) >> 16) +
 358                 ((PHYS_OFFSET & 0xFF000000) >> 24) +
 359                 0x00010203;
 360
 361         if (*PCI_CSR & PCI_CSR_HOST) {
 362                 printk("PCI: IXP4xx is host\n");
 363
 364                 pr_debug("setup BARs in controller\n");
 365
 366                 /*
 367                  * We configure the PCI inbound memory windows to be
 368                  * 1:1 mapped to SDRAM
 369                  */
 370                 local_write_config(PCI_BASE_ADDRESS_0, 4, PHYS_OFFSET);
 371                 local_write_config(PCI_BASE_ADDRESS_1, 4, PHYS_OFFSET + SZ_16M);
 372                 local_write_config(PCI_BASE_ADDRESS_2, 4, PHYS_OFFSET + SZ_32M);
 373                 local_write_config(PCI_BASE_ADDRESS_3, 4,
 374                                         PHYS_OFFSET + SZ_32M + SZ_16M);
 375
 376                 /*
 377                  * Enable CSR window at 64 MiB to allow PCI masters
 378                  * to continue prefetching past 64 MiB boundary.
 379                  */
 380                 local_write_config(PCI_BASE_ADDRESS_4, 4, PHYS_OFFSET + SZ_64M);
 381
 382                 /*
 383                  * Enable the IO window to be way up high, at 0xfffffc00
 384                  */
 385                 local_write_config(PCI_BASE_ADDRESS_5, 4, 0xfffffc01);
 386                 local_write_config(0x40, 4, 0x000080FF); /* No TRDY time limit */
 387         } else {
 388                 printk("PCI: IXP4xx is target - No bus scan performed\n");
 389         }
 390
 391         printk("PCI: IXP4xx Using %s access for memory space\n",
 392 #ifndef CONFIG_IXP4XX_INDIRECT_PCI
 393                         "direct"
 394 #else
 395                         "indirect"
 396 #endif
 397                 );
 398
 399         pr_debug("clear error bits in ISR\n");
 400         *PCI_ISR = PCI_ISR_PSE | PCI_ISR_PFE | PCI_ISR_PPE | PCI_ISR_AHBE;
 401
 402         /*
 403          * Set Initialize Complete in PCI Control Register: allow IXP4XX to
 404          * respond to PCI configuration cycles. Specify that the AHB bus is
 405          * operating in big endian mode. Set up byte lane swapping between
 406          * little-endian PCI and the big-endian AHB bus
 407          */
 408 #ifdef __ARMEB__
 409         *PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE | PCI_CSR_PDS | PCI_CSR_ADS;
 410 #else
 411         *PCI_CSR = PCI_CSR_IC | PCI_CSR_ABE;
 412 #endif
 413
 414         pr_debug("DONE\n");
 415 }
 416
 417 int ixp4xx_setup(int nr, struct pci_sys_data *sys)
 418 {
 419         struct resource *res;
 420
 421         if (nr >= 1)
 422                 return 0;
 423
 424         res = kzalloc(sizeof(*res) * 2, GFP_KERNEL);
 425         if (res == NULL) {
 426                 /*
 427                  * If we're out of memory this early, something is wrong,
 428                  * so we might as well catch it here.
 429                  */
 430                 panic("PCI: unable to allocate resources?\n");
 431         }
 432
 433         local_write_config(PCI_COMMAND, 2, PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
 434
 435         res[0].name = "PCI I/O Space";
 436         res[0].start = 0x00000000;
 437         res[0].end = 0x0000ffff;
 438         res[0].flags = IORESOURCE_IO;
 439
 440         res[1].name = "PCI Memory Space";
 441         res[1].start = PCIBIOS_MIN_MEM;
 442         res[1].end = PCIBIOS_MAX_MEM;
 443         res[1].flags = IORESOURCE_MEM;
 444
 445         request_resource(&ioport_resource, &res[0]);
 446         request_resource(&iomem_resource, &res[1]);
 447
 448         pci_add_resource_offset(&sys->resources, &res[0], sys->io_offset);
 449         pci_add_resource_offset(&sys->resources, &res[1], sys->mem_offset);
 450
 451         return 1;
 452 }
 453
 454 EXPORT_SYMBOL(ixp4xx_pci_read);
 455 EXPORT_SYMBOL(ixp4xx_pci_write);