arch/mips/sni/rm200.c

   1 /*
   2  * RM200 specific code
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 2006,2007 Thomas Bogendoerfer (tsbogend@alpha.franken.de)
   9  *
  10  * i8259 parts ripped out of arch/mips/kernel/i8259.c
  11  */
  12
  13 #include <linux/delay.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/serial_8250.h>
  18 #include <linux/io.h>
  19
  20 #include <asm/sni.h>
  21 #include <asm/time.h>
  22 #include <asm/irq_cpu.h>
  23
  24 #define RM200_I8259A_IRQ_BASE 32
  25
  26 #define MEMPORT(_base,_irq)                             \
  27         {                                               \
  28                 .mapbase        = _base,                \
  29                 .irq            = _irq,                 \
  30                 .uartclk        = 1843200,              \
  31                 .iotype         = UPIO_MEM,             \
  32                 .flags          = UPF_BOOT_AUTOCONF|UPF_IOREMAP, \
  33         }
  34
  35 static struct plat_serial8250_port rm200_data[] = {
  36         MEMPORT(0x160003f8, RM200_I8259A_IRQ_BASE + 4),
  37         MEMPORT(0x160002f8, RM200_I8259A_IRQ_BASE + 3),
  38         { },
  39 };
  40
  41 static struct platform_device rm200_serial8250_device = {
  42         .name                   = "serial8250",
  43         .id                     = PLAT8250_DEV_PLATFORM,
  44         .dev                    = {
  45                 .platform_data  = rm200_data,
  46         },
  47 };
  48
  49 static struct resource rm200_ds1216_rsrc[] = {
  50         {
  51                 .start = 0x1cd41ffc,
  52                 .end   = 0x1cd41fff,
  53                 .flags = IORESOURCE_MEM
  54         }
  55 };
  56
  57 static struct platform_device rm200_ds1216_device = {
  58         .name           = "rtc-ds1216",
  59         .num_resources  = ARRAY_SIZE(rm200_ds1216_rsrc),
  60         .resource       = rm200_ds1216_rsrc
  61 };
  62
  63 static struct resource snirm_82596_rm200_rsrc[] = {
  64         {
  65                 .start = 0x18000000,
  66                 .end   = 0x180fffff,
  67                 .flags = IORESOURCE_MEM
  68         },
  69         {
  70                 .start = 0x1b000000,
  71                 .end   = 0x1b000004,
  72                 .flags = IORESOURCE_MEM
  73         },
  74         {
  75                 .start = 0x1ff00000,
  76                 .end   = 0x1ff00020,
  77                 .flags = IORESOURCE_MEM
  78         },
  79         {
  80                 .start = 27,
  81                 .end   = 27,
  82                 .flags = IORESOURCE_IRQ
  83         },
  84         {
  85                 .flags = 0x00
  86         }
  87 };
  88
  89 static struct platform_device snirm_82596_rm200_pdev = {
  90         .name           = "snirm_82596",
  91         .num_resources  = ARRAY_SIZE(snirm_82596_rm200_rsrc),
  92         .resource       = snirm_82596_rm200_rsrc
  93 };
  94
  95 static struct resource snirm_53c710_rm200_rsrc[] = {
  96         {
  97                 .start = 0x19000000,
  98                 .end   = 0x190fffff,
  99                 .flags = IORESOURCE_MEM
 100         },
 101         {
 102                 .start = 26,
 103                 .end   = 26,
 104                 .flags = IORESOURCE_IRQ
 105         }
 106 };
 107
 108 static struct platform_device snirm_53c710_rm200_pdev = {
 109         .name           = "snirm_53c710",
 110         .num_resources  = ARRAY_SIZE(snirm_53c710_rm200_rsrc),
 111         .resource       = snirm_53c710_rm200_rsrc
 112 };
 113
 114 static int __init snirm_setup_devinit(void)
 115 {
 116         if (sni_brd_type == SNI_BRD_RM200) {
 117                 platform_device_register(&rm200_serial8250_device);
 118                 platform_device_register(&rm200_ds1216_device);
 119                 platform_device_register(&snirm_82596_rm200_pdev);
 120                 platform_device_register(&snirm_53c710_rm200_pdev);
 121                 sni_eisa_root_init();
 122         }
 123         return 0;
 124 }
 125
 126 device_initcall(snirm_setup_devinit);
 127
 128 /*
 129  * RM200 has an ISA and an EISA bus. The iSA bus is only used
 130  * for onboard devices and also has twi i8259 PICs. Since these
 131  * PICs are no accessible via inb/outb the following code uses
 132  * readb/writeb to access them
 133  */
 134
 135 DEFINE_SPINLOCK(sni_rm200_i8259A_lock);
 136 #define PIC_CMD    0x00
 137 #define PIC_IMR    0x01
 138 #define PIC_ISR    PIC_CMD
 139 #define PIC_POLL   PIC_ISR
 140 #define PIC_OCW3   PIC_ISR
 141
 142 /* i8259A PIC related value */
 143 #define PIC_CASCADE_IR          2
 144 #define MASTER_ICW4_DEFAULT     0x01
 145 #define SLAVE_ICW4_DEFAULT      0x01
 146
 147 /*
 148  * This contains the irq mask for both 8259A irq controllers,
 149  */
 150 static unsigned int rm200_cached_irq_mask = 0xffff;
 151 static __iomem u8 *rm200_pic_master;
 152 static __iomem u8 *rm200_pic_slave;
 153
 154 #define cached_master_mask      (rm200_cached_irq_mask)
 155 #define cached_slave_mask       (rm200_cached_irq_mask >> 8)
 156
 157 static void sni_rm200_disable_8259A_irq(unsigned int irq)
 158 {
 159         unsigned int mask;
 160         unsigned long flags;
 161
 162         irq -= RM200_I8259A_IRQ_BASE;
 163         mask = 1 << irq;
 164         spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
 165         rm200_cached_irq_mask |= mask;
 166         if (irq & 8)
 167                 writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
 168         else
 169                 writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
 170         spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
 171 }
 172
 173 static void sni_rm200_enable_8259A_irq(unsigned int irq)
 174 {
 175         unsigned int mask;
 176         unsigned long flags;
 177
 178         irq -= RM200_I8259A_IRQ_BASE;
 179         mask = ~(1 << irq);
 180         spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
 181         rm200_cached_irq_mask &= mask;
 182         if (irq & 8)
 183                 writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
 184         else
 185                 writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
 186         spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
 187 }
 188
 189 static inline int sni_rm200_i8259A_irq_real(unsigned int irq)
 190 {
 191         int value;
 192         int irqmask = 1 << irq;
 193
 194         if (irq < 8) {
 195                 writeb(0x0B, rm200_pic_master + PIC_CMD);
 196                 value = readb(rm200_pic_master + PIC_CMD) & irqmask;
 197                 writeb(0x0A, rm200_pic_master + PIC_CMD);
 198                 return value;
 199         }
 200         writeb(0x0B, rm200_pic_slave + PIC_CMD); /* ISR register */
 201         value = readb(rm200_pic_slave + PIC_CMD) & (irqmask >> 8);
 202         writeb(0x0A, rm200_pic_slave + PIC_CMD);
 203         return value;
 204 }
 205
 206 /*
 207  * Careful! The 8259A is a fragile beast, it pretty
 208  * much _has_ to be done exactly like this (mask it
 209  * first, _then_ send the EOI, and the order of EOI
 210  * to the two 8259s is important!
 211  */
 212 void sni_rm200_mask_and_ack_8259A(unsigned int irq)
 213 {
 214         unsigned int irqmask;
 215         unsigned long flags;
 216
 217         irq -= RM200_I8259A_IRQ_BASE;
 218         irqmask = 1 << irq;
 219         spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
 220         /*
 221          * Lightweight spurious IRQ detection. We do not want
 222          * to overdo spurious IRQ handling - it's usually a sign
 223          * of hardware problems, so we only do the checks we can
 224          * do without slowing down good hardware unnecessarily.
 225          *
 226          * Note that IRQ7 and IRQ15 (the two spurious IRQs
 227          * usually resulting from the 8259A-1|2 PICs) occur
 228          * even if the IRQ is masked in the 8259A. Thus we
 229          * can check spurious 8259A IRQs without doing the
 230          * quite slow i8259A_irq_real() call for every IRQ.
 231          * This does not cover 100% of spurious interrupts,
 232          * but should be enough to warn the user that there
 233          * is something bad going on ...
 234          */
 235         if (rm200_cached_irq_mask & irqmask)
 236                 goto spurious_8259A_irq;
 237         rm200_cached_irq_mask |= irqmask;
 238
 239 handle_real_irq:
 240         if (irq & 8) {
 241                 readb(rm200_pic_slave + PIC_IMR);
 242                 writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
 243                 writeb(0x60+(irq & 7), rm200_pic_slave + PIC_CMD);
 244                 writeb(0x60+PIC_CASCADE_IR, rm200_pic_master + PIC_CMD);
 245         } else {
 246                 readb(rm200_pic_master + PIC_IMR);
 247                 writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
 248                 writeb(0x60+irq, rm200_pic_master + PIC_CMD);
 249         }
 250         spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
 251         return;
 252
 253 spurious_8259A_irq:
 254         /*
 255          * this is the slow path - should happen rarely.
 256          */
 257         if (sni_rm200_i8259A_irq_real(irq))
 258                 /*
 259                  * oops, the IRQ _is_ in service according to the
 260                  * 8259A - not spurious, go handle it.
 261                  */
 262                 goto handle_real_irq;
 263
 264         {
 265                 static int spurious_irq_mask;
 266                 /*
 267                  * At this point we can be sure the IRQ is spurious,
 268                  * lets ACK and report it. [once per IRQ]
 269                  */
 270                 if (!(spurious_irq_mask & irqmask)) {
 271                         printk(KERN_DEBUG
 272                                "spurious RM200 8259A interrupt: IRQ%d.\n", irq);
 273                         spurious_irq_mask |= irqmask;
 274                 }
 275                 atomic_inc(&irq_err_count);
 276                 /*
 277                  * Theoretically we do not have to handle this IRQ,
 278                  * but in Linux this does not cause problems and is
 279                  * simpler for us.
 280                  */
 281                 goto handle_real_irq;
 282         }
 283 }
 284
 285 static struct irq_chip sni_rm200_i8259A_chip = {
 286         .name           = "RM200-XT-PIC",
 287         .mask           = sni_rm200_disable_8259A_irq,
 288         .unmask         = sni_rm200_enable_8259A_irq,
 289         .mask_ack       = sni_rm200_mask_and_ack_8259A,
 290 };
 291
 292 /*
 293  * Do the traditional i8259 interrupt polling thing.  This is for the few
 294  * cases where no better interrupt acknowledge method is available and we
 295  * absolutely must touch the i8259.
 296  */
 297 static inline int sni_rm200_i8259_irq(void)
 298 {
 299         int irq;
 300
 301         spin_lock(&sni_rm200_i8259A_lock);
 302
 303         /* Perform an interrupt acknowledge cycle on controller 1. */
 304         writeb(0x0C, rm200_pic_master + PIC_CMD);       /* prepare for poll */
 305         irq = readb(rm200_pic_master + PIC_CMD) & 7;
 306         if (irq == PIC_CASCADE_IR) {
 307                 /*
 308                  * Interrupt is cascaded so perform interrupt
 309                  * acknowledge on controller 2.
 310                  */
 311                 writeb(0x0C, rm200_pic_slave + PIC_CMD); /* prepare for poll */
 312                 irq = (readb(rm200_pic_slave + PIC_CMD) & 7) + 8;
 313         }
 314
 315         if (unlikely(irq == 7)) {
 316                 /*
 317                  * This may be a spurious interrupt.
 318                  *
 319                  * Read the interrupt status register (ISR). If the most
 320                  * significant bit is not set then there is no valid
 321                  * interrupt.
 322                  */
 323                 writeb(0x0B, rm200_pic_master + PIC_ISR); /* ISR register */
 324                 if (~readb(rm200_pic_master + PIC_ISR) & 0x80)
 325                         irq = -1;
 326         }
 327
 328         spin_unlock(&sni_rm200_i8259A_lock);
 329
 330         return likely(irq >= 0) ? irq + RM200_I8259A_IRQ_BASE : irq;
 331 }
 332
 333 void sni_rm200_init_8259A(void)
 334 {
 335         unsigned long flags;
 336
 337         spin_lock_irqsave(&sni_rm200_i8259A_lock, flags);
 338
 339         writeb(0xff, rm200_pic_master + PIC_IMR);
 340         writeb(0xff, rm200_pic_slave + PIC_IMR);
 341
 342         writeb(0x11, rm200_pic_master + PIC_CMD);
 343         writeb(0, rm200_pic_master + PIC_IMR);
 344         writeb(1U << PIC_CASCADE_IR, rm200_pic_master + PIC_IMR);
 345         writeb(MASTER_ICW4_DEFAULT, rm200_pic_master + PIC_IMR);
 346         writeb(0x11, rm200_pic_slave + PIC_CMD);
 347         writeb(8, rm200_pic_slave + PIC_IMR);
 348         writeb(PIC_CASCADE_IR, rm200_pic_slave + PIC_IMR);
 349         writeb(SLAVE_ICW4_DEFAULT, rm200_pic_slave + PIC_IMR);
 350         udelay(100);            /* wait for 8259A to initialize */
 351
 352         writeb(cached_master_mask, rm200_pic_master + PIC_IMR);
 353         writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR);
 354
 355         spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags);
 356 }
 357
 358 /*
 359  * IRQ2 is cascade interrupt to second interrupt controller
 360  */
 361 static struct irqaction sni_rm200_irq2 = {
 362         .handler = no_action,
 363         .name = "cascade",
 364 };
 365
 366 static struct resource sni_rm200_pic1_resource = {
 367         .name = "onboard ISA pic1",
 368         .start = 0x16000020,
 369         .end = 0x16000023,
 370         .flags = IORESOURCE_BUSY
 371 };
 372
 373 static struct resource sni_rm200_pic2_resource = {
 374         .name = "onboard ISA pic2",
 375         .start = 0x160000a0,
 376         .end = 0x160000a3,
 377         .flags = IORESOURCE_BUSY
 378 };
 379
 380 /* ISA irq handler */
 381 static irqreturn_t sni_rm200_i8259A_irq_handler(int dummy, void *p)
 382 {
 383         int irq;
 384
 385         irq = sni_rm200_i8259_irq();
 386         if (unlikely(irq < 0))
 387                 return IRQ_NONE;
 388
 389         do_IRQ(irq);
 390         return IRQ_HANDLED;
 391 }
 392
 393 struct irqaction sni_rm200_i8259A_irq = {
 394         .handler = sni_rm200_i8259A_irq_handler,
 395         .name = "onboard ISA",
 396         .flags = IRQF_SHARED
 397 };
 398
 399 void __init sni_rm200_i8259_irqs(void)
 400 {
 401         int i;
 402
 403         rm200_pic_master = ioremap_nocache(0x16000020, 4);
 404         if (!rm200_pic_master)
 405                 return;
 406         rm200_pic_slave = ioremap_nocache(0x160000a0, 4);
 407         if (!rm200_pic_master) {
 408                 iounmap(rm200_pic_master);
 409                 return;
 410         }
 411
 412         insert_resource(&iomem_resource, &sni_rm200_pic1_resource);
 413         insert_resource(&iomem_resource, &sni_rm200_pic2_resource);
 414
 415         sni_rm200_init_8259A();
 416
 417         for (i = RM200_I8259A_IRQ_BASE; i < RM200_I8259A_IRQ_BASE + 16; i++)
 418                 set_irq_chip_and_handler(i, &sni_rm200_i8259A_chip,
 419                                          handle_level_irq);
 420
 421         setup_irq(RM200_I8259A_IRQ_BASE + PIC_CASCADE_IR, &sni_rm200_irq2);
 422 }
 423
 424
 425 #define SNI_RM200_INT_STAT_REG  CKSEG1ADDR(0xbc000000)
 426 #define SNI_RM200_INT_ENA_REG   CKSEG1ADDR(0xbc080000)
 427
 428 #define SNI_RM200_INT_START  24
 429 #define SNI_RM200_INT_END    28
 430
 431 static void enable_rm200_irq(unsigned int irq)
 432 {
 433         unsigned int mask = 1 << (irq - SNI_RM200_INT_START);
 434
 435         *(volatile u8 *)SNI_RM200_INT_ENA_REG &= ~mask;
 436 }
 437
 438 void disable_rm200_irq(unsigned int irq)
 439 {
 440         unsigned int mask = 1 << (irq - SNI_RM200_INT_START);
 441
 442         *(volatile u8 *)SNI_RM200_INT_ENA_REG |= mask;
 443 }
 444
 445 void end_rm200_irq(unsigned int irq)
 446 {
 447         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
 448                 enable_rm200_irq(irq);
 449 }
 450
 451 static struct irq_chip rm200_irq_type = {
 452         .typename = "RM200",
 453         .ack = disable_rm200_irq,
 454         .mask = disable_rm200_irq,
 455         .mask_ack = disable_rm200_irq,
 456         .unmask = enable_rm200_irq,
 457         .end = end_rm200_irq,
 458 };
 459
 460 static void sni_rm200_hwint(void)
 461 {
 462         u32 pending = read_c0_cause() & read_c0_status();
 463         u8 mask;
 464         u8 stat;
 465         int irq;
 466
 467         if (pending & C_IRQ5)
 468                 do_IRQ(MIPS_CPU_IRQ_BASE + 7);
 469         else if (pending & C_IRQ0) {
 470                 clear_c0_status(IE_IRQ0);
 471                 mask = *(volatile u8 *)SNI_RM200_INT_ENA_REG ^ 0x1f;
 472                 stat = *(volatile u8 *)SNI_RM200_INT_STAT_REG ^ 0x14;
 473                 irq = ffs(stat & mask & 0x1f);
 474
 475                 if (likely(irq > 0))
 476                         do_IRQ(irq + SNI_RM200_INT_START - 1);
 477                 set_c0_status(IE_IRQ0);
 478         }
 479 }
 480
 481 void __init sni_rm200_irq_init(void)
 482 {
 483         int i;
 484
 485         * (volatile u8 *)SNI_RM200_INT_ENA_REG = 0x1f;
 486
 487         sni_rm200_i8259_irqs();
 488         mips_cpu_irq_init();
 489         /* Actually we've got more interrupts to handle ...  */
 490         for (i = SNI_RM200_INT_START; i <= SNI_RM200_INT_END; i++)
 491                 set_irq_chip_and_handler(i, &rm200_irq_type, handle_level_irq);
 492         sni_hwint = sni_rm200_hwint;
 493         change_c0_status(ST0_IM, IE_IRQ0);
 494         setup_irq(SNI_RM200_INT_START + 0, &sni_rm200_i8259A_irq);
 495         setup_irq(SNI_RM200_INT_START + 1, &sni_isa_irq);
 496 }
 497
 498 void __init sni_rm200_init(void)
 499 {
 500 }