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   1 /*
   2  * arch/arm/mach-ixp2000/core.c
   3  *
   4  * Common routines used by all IXP2400/2800 based platforms.
   5  *
   6  * Author: Deepak Saxena <dsaxena@plexity.net>
   7  *
   8  * Copyright 2004 (C) MontaVista Software, Inc.
   9  *
  10  * Based on work Copyright (C) 2002-2003 Intel Corporation
  11  *
  12  * This file is licensed under the terms of the GNU General Public
  13  * License version 2. This program is licensed "as is" without any
  14  * warranty of any kind, whether express or implied.
  15  */
  16
  17 #include <linux/config.h>
  18 #include <linux/kernel.h>
  19 #include <linux/init.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/sched.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/serial.h>
  24 #include <linux/tty.h>
  25 #include <linux/bitops.h>
  26 #include <linux/serial_8250.h>
  27 #include <linux/mm.h>
  28
  29 #include <asm/types.h>
  30 #include <asm/setup.h>
  31 #include <asm/memory.h>
  32 #include <asm/hardware.h>
  33 #include <asm/irq.h>
  34 #include <asm/system.h>
  35 #include <asm/tlbflush.h>
  36 #include <asm/pgtable.h>
  37
  38 #include <asm/mach/map.h>
  39 #include <asm/mach/time.h>
  40 #include <asm/mach/irq.h>
  41
  42 #include <asm/arch/gpio.h>
  43
  44 static DEFINE_SPINLOCK(ixp2000_slowport_lock);
  45 static unsigned long ixp2000_slowport_irq_flags;
  46
  47 /*************************************************************************
  48  * Slowport access routines
  49  *************************************************************************/
  50 void ixp2000_acquire_slowport(struct slowport_cfg *new_cfg, struct slowport_cfg *old_cfg)
  51 {
  52         spin_lock_irqsave(&ixp2000_slowport_lock, ixp2000_slowport_irq_flags);
  53
  54         old_cfg->CCR = *IXP2000_SLOWPORT_CCR;
  55         old_cfg->WTC = *IXP2000_SLOWPORT_WTC2;
  56         old_cfg->RTC = *IXP2000_SLOWPORT_RTC2;
  57         old_cfg->PCR = *IXP2000_SLOWPORT_PCR;
  58         old_cfg->ADC = *IXP2000_SLOWPORT_ADC;
  59
  60         ixp2000_reg_write(IXP2000_SLOWPORT_CCR, new_cfg->CCR);
  61         ixp2000_reg_write(IXP2000_SLOWPORT_WTC2, new_cfg->WTC);
  62         ixp2000_reg_write(IXP2000_SLOWPORT_RTC2, new_cfg->RTC);
  63         ixp2000_reg_write(IXP2000_SLOWPORT_PCR, new_cfg->PCR);
  64         ixp2000_reg_wrb(IXP2000_SLOWPORT_ADC, new_cfg->ADC);
  65 }
  66
  67 void ixp2000_release_slowport(struct slowport_cfg *old_cfg)
  68 {
  69         ixp2000_reg_write(IXP2000_SLOWPORT_CCR, old_cfg->CCR);
  70         ixp2000_reg_write(IXP2000_SLOWPORT_WTC2, old_cfg->WTC);
  71         ixp2000_reg_write(IXP2000_SLOWPORT_RTC2, old_cfg->RTC);
  72         ixp2000_reg_write(IXP2000_SLOWPORT_PCR, old_cfg->PCR);
  73         ixp2000_reg_wrb(IXP2000_SLOWPORT_ADC, old_cfg->ADC);
  74
  75         spin_unlock_irqrestore(&ixp2000_slowport_lock,
  76                                         ixp2000_slowport_irq_flags);
  77 }
  78
  79 /*************************************************************************
  80  * Chip specific mappings shared by all IXP2000 systems
  81  *************************************************************************/
  82 static struct map_desc ixp2000_io_desc[] __initdata = {
  83         {
  84                 .virtual        = IXP2000_CAP_VIRT_BASE,
  85                 .pfn            = __phys_to_pfn(IXP2000_CAP_PHYS_BASE),
  86                 .length         = IXP2000_CAP_SIZE,
  87                 .type           = MT_IXP2000_DEVICE,
  88         }, {
  89                 .virtual        = IXP2000_INTCTL_VIRT_BASE,
  90                 .pfn            = __phys_to_pfn(IXP2000_INTCTL_PHYS_BASE),
  91                 .length         = IXP2000_INTCTL_SIZE,
  92                 .type           = MT_IXP2000_DEVICE,
  93         }, {
  94                 .virtual        = IXP2000_PCI_CREG_VIRT_BASE,
  95                 .pfn            = __phys_to_pfn(IXP2000_PCI_CREG_PHYS_BASE),
  96                 .length         = IXP2000_PCI_CREG_SIZE,
  97                 .type           = MT_IXP2000_DEVICE,
  98         }, {
  99                 .virtual        = IXP2000_PCI_CSR_VIRT_BASE,
 100                 .pfn            = __phys_to_pfn(IXP2000_PCI_CSR_PHYS_BASE),
 101                 .length         = IXP2000_PCI_CSR_SIZE,
 102                 .type           = MT_IXP2000_DEVICE,
 103         }, {
 104                 .virtual        = IXP2000_MSF_VIRT_BASE,
 105                 .pfn            = __phys_to_pfn(IXP2000_MSF_PHYS_BASE),
 106                 .length         = IXP2000_MSF_SIZE,
 107                 .type           = MT_IXP2000_DEVICE,
 108         }, {
 109                 .virtual        = IXP2000_SCRATCH_RING_VIRT_BASE,
 110                 .pfn            = __phys_to_pfn(IXP2000_SCRATCH_RING_PHYS_BASE),
 111                 .length         = IXP2000_SCRATCH_RING_SIZE,
 112                 .type           = MT_IXP2000_DEVICE,
 113         }, {
 114                 .virtual        = IXP2000_SRAM0_VIRT_BASE,
 115                 .pfn            = __phys_to_pfn(IXP2000_SRAM0_PHYS_BASE),
 116                 .length         = IXP2000_SRAM0_SIZE,
 117                 .type           = MT_IXP2000_DEVICE,
 118         }, {
 119                 .virtual        = IXP2000_PCI_IO_VIRT_BASE,
 120                 .pfn            = __phys_to_pfn(IXP2000_PCI_IO_PHYS_BASE),
 121                 .length         = IXP2000_PCI_IO_SIZE,
 122                 .type           = MT_IXP2000_DEVICE,
 123         }, {
 124                 .virtual        = IXP2000_PCI_CFG0_VIRT_BASE,
 125                 .pfn            = __phys_to_pfn(IXP2000_PCI_CFG0_PHYS_BASE),
 126                 .length         = IXP2000_PCI_CFG0_SIZE,
 127                 .type           = MT_IXP2000_DEVICE,
 128         }, {
 129                 .virtual        = IXP2000_PCI_CFG1_VIRT_BASE,
 130                 .pfn            = __phys_to_pfn(IXP2000_PCI_CFG1_PHYS_BASE),
 131                 .length         = IXP2000_PCI_CFG1_SIZE,
 132                 .type           = MT_IXP2000_DEVICE,
 133         }
 134 };
 135
 136 void __init ixp2000_map_io(void)
 137 {
 138         /*
 139          * On IXP2400 CPUs we need to use MT_IXP2000_DEVICE so that
 140          * XCB=101 (to avoid triggering erratum #66), and given that
 141          * this mode speeds up I/O accesses and we have write buffer
 142          * flushes in the right places anyway, it doesn't hurt to use
 143          * XCB=101 for all IXP2000s.
 144          */
 145         iotable_init(ixp2000_io_desc, ARRAY_SIZE(ixp2000_io_desc));
 146
 147         /* Set slowport to 8-bit mode.  */
 148         ixp2000_reg_wrb(IXP2000_SLOWPORT_FRM, 1);
 149 }
 150
 151
 152 /*************************************************************************
 153  * Serial port support for IXP2000
 154  *************************************************************************/
 155 static struct plat_serial8250_port ixp2000_serial_port[] = {
 156         {
 157                 .mapbase        = IXP2000_UART_PHYS_BASE,
 158                 .membase        = (char *)(IXP2000_UART_VIRT_BASE + 3),
 159                 .irq            = IRQ_IXP2000_UART,
 160                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
 161                 .iotype         = UPIO_MEM,
 162                 .regshift       = 2,
 163                 .uartclk        = 50000000,
 164         },
 165         { },
 166 };
 167
 168 static struct resource ixp2000_uart_resource = {
 169         .start          = IXP2000_UART_PHYS_BASE,
 170         .end            = IXP2000_UART_PHYS_BASE + 0x1f,
 171         .flags          = IORESOURCE_MEM,
 172 };
 173
 174 static struct platform_device ixp2000_serial_device = {
 175         .name           = "serial8250",
 176         .id             = PLAT8250_DEV_PLATFORM,
 177         .dev            = {
 178                 .platform_data          = ixp2000_serial_port,
 179         },
 180         .num_resources  = 1,
 181         .resource       = &ixp2000_uart_resource,
 182 };
 183
 184 void __init ixp2000_uart_init(void)
 185 {
 186         platform_device_register(&ixp2000_serial_device);
 187 }
 188
 189
 190 /*************************************************************************
 191  * Timer-tick functions for IXP2000
 192  *************************************************************************/
 193 static unsigned ticks_per_jiffy;
 194 static unsigned ticks_per_usec;
 195 static unsigned next_jiffy_time;
 196 static volatile unsigned long *missing_jiffy_timer_csr;
 197
 198 unsigned long ixp2000_gettimeoffset (void)
 199 {
 200         unsigned long offset;
 201
 202         offset = next_jiffy_time - *missing_jiffy_timer_csr;
 203
 204         return offset / ticks_per_usec;
 205 }
 206
 207 static int ixp2000_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 208 {
 209         write_seqlock(&xtime_lock);
 210
 211         /* clear timer 1 */
 212         ixp2000_reg_wrb(IXP2000_T1_CLR, 1);
 213
 214         while ((next_jiffy_time - *missing_jiffy_timer_csr) > ticks_per_jiffy) {
 215                 timer_tick(regs);
 216                 next_jiffy_time -= ticks_per_jiffy;
 217         }
 218
 219         write_sequnlock(&xtime_lock);
 220
 221         return IRQ_HANDLED;
 222 }
 223
 224 static struct irqaction ixp2000_timer_irq = {
 225         .name           = "IXP2000 Timer Tick",
 226         .flags          = SA_INTERRUPT | SA_TIMER,
 227         .handler        = ixp2000_timer_interrupt,
 228 };
 229
 230 void __init ixp2000_init_time(unsigned long tick_rate)
 231 {
 232         ticks_per_jiffy = (tick_rate + HZ/2) / HZ;
 233         ticks_per_usec = tick_rate / 1000000;
 234
 235         /*
 236          * We use timer 1 as our timer interrupt.
 237          */
 238         ixp2000_reg_write(IXP2000_T1_CLR, 0);
 239         ixp2000_reg_write(IXP2000_T1_CLD, ticks_per_jiffy - 1);
 240         ixp2000_reg_write(IXP2000_T1_CTL, (1 << 7));
 241
 242         /*
 243          * We use a second timer as a monotonic counter for tracking
 244          * missed jiffies.  The IXP2000 has four timers, but if we're
 245          * on an A-step IXP2800, timer 2 and 3 don't work, so on those
 246          * chips we use timer 4.  Timer 4 is the only timer that can
 247          * be used for the watchdog, so we use timer 2 if we're on a
 248          * non-buggy chip.
 249          */
 250         if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) {
 251                 printk(KERN_INFO "Enabling IXP2800 erratum #25 workaround\n");
 252
 253                 ixp2000_reg_write(IXP2000_T4_CLR, 0);
 254                 ixp2000_reg_write(IXP2000_T4_CLD, -1);
 255                 ixp2000_reg_wrb(IXP2000_T4_CTL, (1 << 7));
 256                 missing_jiffy_timer_csr = IXP2000_T4_CSR;
 257         } else {
 258                 ixp2000_reg_write(IXP2000_T2_CLR, 0);
 259                 ixp2000_reg_write(IXP2000_T2_CLD, -1);
 260                 ixp2000_reg_wrb(IXP2000_T2_CTL, (1 << 7));
 261                 missing_jiffy_timer_csr = IXP2000_T2_CSR;
 262         }
 263         next_jiffy_time = 0xffffffff;
 264
 265         /* register for interrupt */
 266         setup_irq(IRQ_IXP2000_TIMER1, &ixp2000_timer_irq);
 267 }
 268
 269 /*************************************************************************
 270  * GPIO helpers
 271  *************************************************************************/
 272 static unsigned long GPIO_IRQ_falling_edge;
 273 static unsigned long GPIO_IRQ_rising_edge;
 274 static unsigned long GPIO_IRQ_level_low;
 275 static unsigned long GPIO_IRQ_level_high;
 276
 277 static void update_gpio_int_csrs(void)
 278 {
 279         ixp2000_reg_write(IXP2000_GPIO_FEDR, GPIO_IRQ_falling_edge);
 280         ixp2000_reg_write(IXP2000_GPIO_REDR, GPIO_IRQ_rising_edge);
 281         ixp2000_reg_write(IXP2000_GPIO_LSLR, GPIO_IRQ_level_low);
 282         ixp2000_reg_wrb(IXP2000_GPIO_LSHR, GPIO_IRQ_level_high);
 283 }
 284
 285 void gpio_line_config(int line, int direction)
 286 {
 287         unsigned long flags;
 288
 289         local_irq_save(flags);
 290         if (direction == GPIO_OUT) {
 291                 irq_desc[line + IRQ_IXP2000_GPIO0].valid = 0;
 292
 293                 /* if it's an output, it ain't an interrupt anymore */
 294                 GPIO_IRQ_falling_edge &= ~(1 << line);
 295                 GPIO_IRQ_rising_edge &= ~(1 << line);
 296                 GPIO_IRQ_level_low &= ~(1 << line);
 297                 GPIO_IRQ_level_high &= ~(1 << line);
 298                 update_gpio_int_csrs();
 299
 300                 ixp2000_reg_wrb(IXP2000_GPIO_PDSR, 1 << line);
 301         } else if (direction == GPIO_IN) {
 302                 ixp2000_reg_wrb(IXP2000_GPIO_PDCR, 1 << line);
 303         }
 304         local_irq_restore(flags);
 305 }
 306
 307
 308 /*************************************************************************
 309  * IRQ handling IXP2000
 310  *************************************************************************/
 311 static void ixp2000_GPIO_irq_handler(unsigned int irq, struct irqdesc *desc, struct pt_regs *regs)
 312 {
 313         int i;
 314         unsigned long status = *IXP2000_GPIO_INST;
 315
 316         for (i = 0; i <= 7; i++) {
 317                 if (status & (1<<i)) {
 318                         desc = irq_desc + i + IRQ_IXP2000_GPIO0;
 319                         desc_handle_irq(i + IRQ_IXP2000_GPIO0, desc, regs);
 320                 }
 321         }
 322 }
 323
 324 static int ixp2000_GPIO_irq_type(unsigned int irq, unsigned int type)
 325 {
 326         int line = irq - IRQ_IXP2000_GPIO0;
 327
 328         /*
 329          * First, configure this GPIO line as an input.
 330          */
 331         ixp2000_reg_write(IXP2000_GPIO_PDCR, 1 << line);
 332
 333         /*
 334          * Then, set the proper trigger type.
 335          */
 336         if (type & IRQT_FALLING)
 337                 GPIO_IRQ_falling_edge |= 1 << line;
 338         else
 339                 GPIO_IRQ_falling_edge &= ~(1 << line);
 340         if (type & IRQT_RISING)
 341                 GPIO_IRQ_rising_edge |= 1 << line;
 342         else
 343                 GPIO_IRQ_rising_edge &= ~(1 << line);
 344         if (type & IRQT_LOW)
 345                 GPIO_IRQ_level_low |= 1 << line;
 346         else
 347                 GPIO_IRQ_level_low &= ~(1 << line);
 348         if (type & IRQT_HIGH)
 349                 GPIO_IRQ_level_high |= 1 << line;
 350         else
 351                 GPIO_IRQ_level_high &= ~(1 << line);
 352         update_gpio_int_csrs();
 353
 354         /*
 355          * Finally, mark the corresponding IRQ as valid.
 356          */
 357         irq_desc[irq].valid = 1;
 358
 359         return 0;
 360 }
 361
 362 static void ixp2000_GPIO_irq_mask_ack(unsigned int irq)
 363 {
 364         ixp2000_reg_write(IXP2000_GPIO_INCR, (1 << (irq - IRQ_IXP2000_GPIO0)));
 365
 366         ixp2000_reg_write(IXP2000_GPIO_EDSR, (1 << (irq - IRQ_IXP2000_GPIO0)));
 367         ixp2000_reg_write(IXP2000_GPIO_LDSR, (1 << (irq - IRQ_IXP2000_GPIO0)));
 368         ixp2000_reg_wrb(IXP2000_GPIO_INST, (1 << (irq - IRQ_IXP2000_GPIO0)));
 369 }
 370
 371 static void ixp2000_GPIO_irq_mask(unsigned int irq)
 372 {
 373         ixp2000_reg_wrb(IXP2000_GPIO_INCR, (1 << (irq - IRQ_IXP2000_GPIO0)));
 374 }
 375
 376 static void ixp2000_GPIO_irq_unmask(unsigned int irq)
 377 {
 378         ixp2000_reg_write(IXP2000_GPIO_INSR, (1 << (irq - IRQ_IXP2000_GPIO0)));
 379 }
 380
 381 static struct irqchip ixp2000_GPIO_irq_chip = {
 382         .ack            = ixp2000_GPIO_irq_mask_ack,
 383         .mask           = ixp2000_GPIO_irq_mask,
 384         .unmask         = ixp2000_GPIO_irq_unmask,
 385         .set_type       = ixp2000_GPIO_irq_type,
 386 };
 387
 388 static void ixp2000_pci_irq_mask(unsigned int irq)
 389 {
 390         unsigned long temp = *IXP2000_PCI_XSCALE_INT_ENABLE;
 391         if (irq == IRQ_IXP2000_PCIA)
 392                 ixp2000_reg_wrb(IXP2000_PCI_XSCALE_INT_ENABLE, (temp & ~(1 << 26)));
 393         else if (irq == IRQ_IXP2000_PCIB)
 394                 ixp2000_reg_wrb(IXP2000_PCI_XSCALE_INT_ENABLE, (temp & ~(1 << 27)));
 395 }
 396
 397 static void ixp2000_pci_irq_unmask(unsigned int irq)
 398 {
 399         unsigned long temp = *IXP2000_PCI_XSCALE_INT_ENABLE;
 400         if (irq == IRQ_IXP2000_PCIA)
 401                 ixp2000_reg_write(IXP2000_PCI_XSCALE_INT_ENABLE, (temp | (1 << 26)));
 402         else if (irq == IRQ_IXP2000_PCIB)
 403                 ixp2000_reg_write(IXP2000_PCI_XSCALE_INT_ENABLE, (temp | (1 << 27)));
 404 }
 405
 406 /*
 407  * Error interrupts. These are used extensively by the microengine drivers
 408  */
 409 static void ixp2000_err_irq_handler(unsigned int irq, struct irqdesc *desc,  struct pt_regs *regs)
 410 {
 411         int i;
 412         unsigned long status = *IXP2000_IRQ_ERR_STATUS;
 413
 414         for(i = 31; i >= 0; i--) {
 415                 if(status & (1 << i)) {
 416                         desc = irq_desc + IRQ_IXP2000_DRAM0_MIN_ERR + i;
 417                         desc->handle(IRQ_IXP2000_DRAM0_MIN_ERR + i, desc, regs);
 418                 }
 419         }
 420 }
 421
 422 static void ixp2000_err_irq_mask(unsigned int irq)
 423 {
 424         ixp2000_reg_write(IXP2000_IRQ_ERR_ENABLE_CLR,
 425                         (1 << (irq - IRQ_IXP2000_DRAM0_MIN_ERR)));
 426 }
 427
 428 static void ixp2000_err_irq_unmask(unsigned int irq)
 429 {
 430         ixp2000_reg_write(IXP2000_IRQ_ERR_ENABLE_SET,
 431                         (1 << (irq - IRQ_IXP2000_DRAM0_MIN_ERR)));
 432 }
 433
 434 static struct irqchip ixp2000_err_irq_chip = {
 435         .ack    = ixp2000_err_irq_mask,
 436         .mask   = ixp2000_err_irq_mask,
 437         .unmask = ixp2000_err_irq_unmask
 438 };
 439
 440 static struct irqchip ixp2000_pci_irq_chip = {
 441         .ack    = ixp2000_pci_irq_mask,
 442         .mask   = ixp2000_pci_irq_mask,
 443         .unmask = ixp2000_pci_irq_unmask
 444 };
 445
 446 static void ixp2000_irq_mask(unsigned int irq)
 447 {
 448         ixp2000_reg_wrb(IXP2000_IRQ_ENABLE_CLR, (1 << irq));
 449 }
 450
 451 static void ixp2000_irq_unmask(unsigned int irq)
 452 {
 453         ixp2000_reg_write(IXP2000_IRQ_ENABLE_SET, (1 << irq));
 454 }
 455
 456 static struct irqchip ixp2000_irq_chip = {
 457         .ack    = ixp2000_irq_mask,
 458         .mask   = ixp2000_irq_mask,
 459         .unmask = ixp2000_irq_unmask
 460 };
 461
 462 void __init ixp2000_init_irq(void)
 463 {
 464         int irq;
 465
 466         /*
 467          * Mask all sources
 468          */
 469         ixp2000_reg_write(IXP2000_IRQ_ENABLE_CLR, 0xffffffff);
 470         ixp2000_reg_write(IXP2000_FIQ_ENABLE_CLR, 0xffffffff);
 471
 472         /* clear all GPIO edge/level detects */
 473         ixp2000_reg_write(IXP2000_GPIO_REDR, 0);
 474         ixp2000_reg_write(IXP2000_GPIO_FEDR, 0);
 475         ixp2000_reg_write(IXP2000_GPIO_LSHR, 0);
 476         ixp2000_reg_write(IXP2000_GPIO_LSLR, 0);
 477         ixp2000_reg_write(IXP2000_GPIO_INCR, -1);
 478
 479         /* clear PCI interrupt sources */
 480         ixp2000_reg_wrb(IXP2000_PCI_XSCALE_INT_ENABLE, 0);
 481
 482         /*
 483          * Certain bits in the IRQ status register of the
 484          * IXP2000 are reserved. Instead of trying to map
 485          * things non 1:1 from bit position to IRQ number,
 486          * we mark the reserved IRQs as invalid. This makes
 487          * our mask/unmask code much simpler.
 488          */
 489         for (irq = IRQ_IXP2000_SOFT_INT; irq <= IRQ_IXP2000_THDB3; irq++) {
 490                 if ((1 << irq) & IXP2000_VALID_IRQ_MASK) {
 491                         set_irq_chip(irq, &ixp2000_irq_chip);
 492                         set_irq_handler(irq, do_level_IRQ);
 493                         set_irq_flags(irq, IRQF_VALID);
 494                 } else set_irq_flags(irq, 0);
 495         }
 496
 497         for (irq = IRQ_IXP2000_DRAM0_MIN_ERR; irq <= IRQ_IXP2000_SP_INT; irq++) {
 498                 if((1 << (irq - IRQ_IXP2000_DRAM0_MIN_ERR)) &
 499                                 IXP2000_VALID_ERR_IRQ_MASK) {
 500                         set_irq_chip(irq, &ixp2000_err_irq_chip);
 501                         set_irq_handler(irq, do_level_IRQ);
 502                         set_irq_flags(irq, IRQF_VALID);
 503                 }
 504                 else
 505                         set_irq_flags(irq, 0);
 506         }
 507         set_irq_chained_handler(IRQ_IXP2000_ERRSUM, ixp2000_err_irq_handler);
 508
 509         /*
 510          * GPIO IRQs are invalid until someone sets the interrupt mode
 511          * by calling set_irq_type().
 512          */
 513         for (irq = IRQ_IXP2000_GPIO0; irq <= IRQ_IXP2000_GPIO7; irq++) {
 514                 set_irq_chip(irq, &ixp2000_GPIO_irq_chip);
 515                 set_irq_handler(irq, do_level_IRQ);
 516                 set_irq_flags(irq, 0);
 517         }
 518         set_irq_chained_handler(IRQ_IXP2000_GPIO, ixp2000_GPIO_irq_handler);
 519
 520         /*
 521          * Enable PCI irqs.  The actual PCI[AB] decoding is done in
 522          * entry-macro.S, so we don't need a chained handler for the
 523          * PCI interrupt source.
 524          */
 525         ixp2000_reg_write(IXP2000_IRQ_ENABLE_SET, (1 << IRQ_IXP2000_PCI));
 526         for (irq = IRQ_IXP2000_PCIA; irq <= IRQ_IXP2000_PCIB; irq++) {
 527                 set_irq_chip(irq, &ixp2000_pci_irq_chip);
 528                 set_irq_handler(irq, do_level_IRQ);
 529                 set_irq_flags(irq, IRQF_VALID);
 530         }
 531 }
 532