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