hw/gpio/pl061.c

   1 /*
   2  * Arm PrimeCell PL061 General Purpose IO with additional
   3  * Luminary Micro Stellaris bits.
   4  *
   5  * Copyright (c) 2007 CodeSourcery.
   6  * Written by Paul Brook
   7  *
   8  * This code is licensed under the GPL.
   9  *
  10  * QEMU interface:
  11  *  + sysbus MMIO region 0: the device registers
  12  *  + sysbus IRQ: the GPIOINTR interrupt line
  13  *  + unnamed GPIO inputs 0..7: inputs to connect to the emulated GPIO lines
  14  *  + unnamed GPIO outputs 0..7: the emulated GPIO lines, considered as
  15  *    outputs
  16  *  + QOM property "pullups": an integer defining whether non-floating lines
  17  *    configured as inputs should be pulled up to logical 1 (ie whether in
  18  *    real hardware they have a pullup resistor on the line out of the PL061).
  19  *    This should be an 8-bit value, where bit 0 is 1 if GPIO line 0 should
  20  *    be pulled high, bit 1 configures line 1, and so on. The default is 0xff,
  21  *    indicating that all GPIO lines are pulled up to logical 1.
  22  *  + QOM property "pulldowns": an integer defining whether non-floating lines
  23  *    configured as inputs should be pulled down to logical 0 (ie whether in
  24  *    real hardware they have a pulldown resistor on the line out of the PL061).
  25  *    This should be an 8-bit value, where bit 0 is 1 if GPIO line 0 should
  26  *    be pulled low, bit 1 configures line 1, and so on. The default is 0x0.
  27  *    It is an error to set a bit in both "pullups" and "pulldowns". If a bit
  28  *    is 0 in both, then the line is considered to be floating, and it will
  29  *    not have qemu_set_irq() called on it when it is configured as an input.
  30  */
  31
  32 #include "qemu/osdep.h"
  33 #include "hw/irq.h"
  34 #include "hw/sysbus.h"
  35 #include "hw/qdev-properties.h"
  36 #include "migration/vmstate.h"
  37 #include "qapi/error.h"
  38 #include "qemu/log.h"
  39 #include "qemu/module.h"
  40 #include "qom/object.h"
  41 #include "trace.h"
  42
  43 static const uint8_t pl061_id[12] =
  44   { 0x00, 0x00, 0x00, 0x00, 0x61, 0x10, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
  45 static const uint8_t pl061_id_luminary[12] =
  46   { 0x00, 0x00, 0x00, 0x00, 0x61, 0x00, 0x18, 0x01, 0x0d, 0xf0, 0x05, 0xb1 };
  47
  48 #define TYPE_PL061 "pl061"
  49 OBJECT_DECLARE_SIMPLE_TYPE(PL061State, PL061)
  50
  51 #define N_GPIOS 8
  52
  53 struct PL061State {
  54     SysBusDevice parent_obj;
  55
  56     MemoryRegion iomem;
  57     uint32_t locked;
  58     uint32_t data;
  59     uint32_t old_out_data;
  60     uint32_t old_in_data;
  61     uint32_t dir;
  62     uint32_t isense;
  63     uint32_t ibe;
  64     uint32_t iev;
  65     uint32_t im;
  66     uint32_t istate;
  67     uint32_t afsel;
  68     uint32_t dr2r;
  69     uint32_t dr4r;
  70     uint32_t dr8r;
  71     uint32_t odr;
  72     uint32_t pur;
  73     uint32_t pdr;
  74     uint32_t slr;
  75     uint32_t den;
  76     uint32_t cr;
  77     uint32_t amsel;
  78     qemu_irq irq;
  79     qemu_irq out[N_GPIOS];
  80     const unsigned char *id;
  81     /* Properties, for non-Luminary PL061 */
  82     uint32_t pullups;
  83     uint32_t pulldowns;
  84 };
  85
  86 static const VMStateDescription vmstate_pl061 = {
  87     .name = "pl061",
  88     .version_id = 4,
  89     .minimum_version_id = 4,
  90     .fields = (const VMStateField[]) {
  91         VMSTATE_UINT32(locked, PL061State),
  92         VMSTATE_UINT32(data, PL061State),
  93         VMSTATE_UINT32(old_out_data, PL061State),
  94         VMSTATE_UINT32(old_in_data, PL061State),
  95         VMSTATE_UINT32(dir, PL061State),
  96         VMSTATE_UINT32(isense, PL061State),
  97         VMSTATE_UINT32(ibe, PL061State),
  98         VMSTATE_UINT32(iev, PL061State),
  99         VMSTATE_UINT32(im, PL061State),
 100         VMSTATE_UINT32(istate, PL061State),
 101         VMSTATE_UINT32(afsel, PL061State),
 102         VMSTATE_UINT32(dr2r, PL061State),
 103         VMSTATE_UINT32(dr4r, PL061State),
 104         VMSTATE_UINT32(dr8r, PL061State),
 105         VMSTATE_UINT32(odr, PL061State),
 106         VMSTATE_UINT32(pur, PL061State),
 107         VMSTATE_UINT32(pdr, PL061State),
 108         VMSTATE_UINT32(slr, PL061State),
 109         VMSTATE_UINT32(den, PL061State),
 110         VMSTATE_UINT32(cr, PL061State),
 111         VMSTATE_UINT32_V(amsel, PL061State, 2),
 112         VMSTATE_END_OF_LIST()
 113     }
 114 };
 115
 116 static uint8_t pl061_floating(PL061State *s)
 117 {
 118     /*
 119      * Return mask of bits which correspond to pins configured as inputs
 120      * and which are floating (neither pulled up to 1 nor down to 0).
 121      */
 122     uint8_t floating;
 123
 124     if (s->id == pl061_id_luminary) {
 125         /*
 126          * If both PUR and PDR bits are clear, there is neither a pullup
 127          * nor a pulldown in place, and the output truly floats.
 128          */
 129         floating = ~(s->pur | s->pdr);
 130     } else {
 131         floating = ~(s->pullups | s->pulldowns);
 132     }
 133     return floating & ~s->dir;
 134 }
 135
 136 static uint8_t pl061_pullups(PL061State *s)
 137 {
 138     /*
 139      * Return mask of bits which correspond to pins configured as inputs
 140      * and which are pulled up to 1.
 141      */
 142     uint8_t pullups;
 143
 144     if (s->id == pl061_id_luminary) {
 145         /*
 146          * The Luminary variant of the PL061 has an extra registers which
 147          * the guest can use to configure whether lines should be pullup
 148          * or pulldown.
 149          */
 150         pullups = s->pur;
 151     } else {
 152         pullups = s->pullups;
 153     }
 154     return pullups & ~s->dir;
 155 }
 156
 157 static void pl061_update(PL061State *s)
 158 {
 159     uint8_t changed;
 160     uint8_t mask;
 161     uint8_t out;
 162     int i;
 163     uint8_t pullups = pl061_pullups(s);
 164     uint8_t floating = pl061_floating(s);
 165
 166     trace_pl061_update(DEVICE(s)->canonical_path, s->dir, s->data,
 167                        pullups, floating);
 168
 169     /*
 170      * Pins configured as output are driven from the data register;
 171      * otherwise if they're pulled up they're 1, and if they're floating
 172      * then we give them the same value they had previously, so we don't
 173      * report any change to the other end.
 174      */
 175     out = (s->data & s->dir) | pullups | (s->old_out_data & floating);
 176     changed = s->old_out_data ^ out;
 177     if (changed) {
 178         s->old_out_data = out;
 179         for (i = 0; i < N_GPIOS; i++) {
 180             mask = 1 << i;
 181             if (changed & mask) {
 182                 int level = (out & mask) != 0;
 183                 trace_pl061_set_output(DEVICE(s)->canonical_path, i, level);
 184                 qemu_set_irq(s->out[i], level);
 185             }
 186         }
 187     }
 188
 189     /* Inputs */
 190     changed = (s->old_in_data ^ s->data) & ~s->dir;
 191     if (changed) {
 192         s->old_in_data = s->data;
 193         for (i = 0; i < N_GPIOS; i++) {
 194             mask = 1 << i;
 195             if (changed & mask) {
 196                 trace_pl061_input_change(DEVICE(s)->canonical_path, i,
 197                                          (s->data & mask) != 0);
 198
 199                 if (!(s->isense & mask)) {
 200                     /* Edge interrupt */
 201                     if (s->ibe & mask) {
 202                         /* Any edge triggers the interrupt */
 203                         s->istate |= mask;
 204                     } else {
 205                         /* Edge is selected by IEV */
 206                         s->istate |= ~(s->data ^ s->iev) & mask;
 207                     }
 208                 }
 209             }
 210         }
 211     }
 212
 213     /* Level interrupt */
 214     s->istate |= ~(s->data ^ s->iev) & s->isense;
 215
 216     trace_pl061_update_istate(DEVICE(s)->canonical_path,
 217                               s->istate, s->im, (s->istate & s->im) != 0);
 218
 219     qemu_set_irq(s->irq, (s->istate & s->im) != 0);
 220 }
 221
 222 static uint64_t pl061_read(void *opaque, hwaddr offset,
 223                            unsigned size)
 224 {
 225     PL061State *s = (PL061State *)opaque;
 226     uint64_t r = 0;
 227
 228     switch (offset) {
 229     case 0x0 ... 0x3ff: /* Data */
 230         r = s->data & (offset >> 2);
 231         break;
 232     case 0x400: /* Direction */
 233         r = s->dir;
 234         break;
 235     case 0x404: /* Interrupt sense */
 236         r = s->isense;
 237         break;
 238     case 0x408: /* Interrupt both edges */
 239         r = s->ibe;
 240         break;
 241     case 0x40c: /* Interrupt event */
 242         r = s->iev;
 243         break;
 244     case 0x410: /* Interrupt mask */
 245         r = s->im;
 246         break;
 247     case 0x414: /* Raw interrupt status */
 248         r = s->istate;
 249         break;
 250     case 0x418: /* Masked interrupt status */
 251         r = s->istate & s->im;
 252         break;
 253     case 0x420: /* Alternate function select */
 254         r = s->afsel;
 255         break;
 256     case 0x500: /* 2mA drive */
 257         if (s->id != pl061_id_luminary) {
 258             goto bad_offset;
 259         }
 260         r = s->dr2r;
 261         break;
 262     case 0x504: /* 4mA drive */
 263         if (s->id != pl061_id_luminary) {
 264             goto bad_offset;
 265         }
 266         r = s->dr4r;
 267         break;
 268     case 0x508: /* 8mA drive */
 269         if (s->id != pl061_id_luminary) {
 270             goto bad_offset;
 271         }
 272         r = s->dr8r;
 273         break;
 274     case 0x50c: /* Open drain */
 275         if (s->id != pl061_id_luminary) {
 276             goto bad_offset;
 277         }
 278         r = s->odr;
 279         break;
 280     case 0x510: /* Pull-up */
 281         if (s->id != pl061_id_luminary) {
 282             goto bad_offset;
 283         }
 284         r = s->pur;
 285         break;
 286     case 0x514: /* Pull-down */
 287         if (s->id != pl061_id_luminary) {
 288             goto bad_offset;
 289         }
 290         r = s->pdr;
 291         break;
 292     case 0x518: /* Slew rate control */
 293         if (s->id != pl061_id_luminary) {
 294             goto bad_offset;
 295         }
 296         r = s->slr;
 297         break;
 298     case 0x51c: /* Digital enable */
 299         if (s->id != pl061_id_luminary) {
 300             goto bad_offset;
 301         }
 302         r = s->den;
 303         break;
 304     case 0x520: /* Lock */
 305         if (s->id != pl061_id_luminary) {
 306             goto bad_offset;
 307         }
 308         r = s->locked;
 309         break;
 310     case 0x524: /* Commit */
 311         if (s->id != pl061_id_luminary) {
 312             goto bad_offset;
 313         }
 314         r = s->cr;
 315         break;
 316     case 0x528: /* Analog mode select */
 317         if (s->id != pl061_id_luminary) {
 318             goto bad_offset;
 319         }
 320         r = s->amsel;
 321         break;
 322     case 0xfd0 ... 0xfff: /* ID registers */
 323         r = s->id[(offset - 0xfd0) >> 2];
 324         break;
 325     default:
 326     bad_offset:
 327         qemu_log_mask(LOG_GUEST_ERROR,
 328                       "pl061_read: Bad offset %x\n", (int)offset);
 329         break;
 330     }
 331
 332     trace_pl061_read(DEVICE(s)->canonical_path, offset, r);
 333     return r;
 334 }
 335
 336 static void pl061_write(void *opaque, hwaddr offset,
 337                         uint64_t value, unsigned size)
 338 {
 339     PL061State *s = (PL061State *)opaque;
 340     uint8_t mask;
 341
 342     trace_pl061_write(DEVICE(s)->canonical_path, offset, value);
 343
 344     switch (offset) {
 345     case 0 ... 0x3ff:
 346         mask = (offset >> 2) & s->dir;
 347         s->data = (s->data & ~mask) | (value & mask);
 348         pl061_update(s);
 349         return;
 350     case 0x400: /* Direction */
 351         s->dir = value & 0xff;
 352         break;
 353     case 0x404: /* Interrupt sense */
 354         s->isense = value & 0xff;
 355         break;
 356     case 0x408: /* Interrupt both edges */
 357         s->ibe = value & 0xff;
 358         break;
 359     case 0x40c: /* Interrupt event */
 360         s->iev = value & 0xff;
 361         break;
 362     case 0x410: /* Interrupt mask */
 363         s->im = value & 0xff;
 364         break;
 365     case 0x41c: /* Interrupt clear */
 366         s->istate &= ~value;
 367         break;
 368     case 0x420: /* Alternate function select */
 369         mask = s->cr;
 370         s->afsel = (s->afsel & ~mask) | (value & mask);
 371         break;
 372     case 0x500: /* 2mA drive */
 373         if (s->id != pl061_id_luminary) {
 374             goto bad_offset;
 375         }
 376         s->dr2r = value & 0xff;
 377         break;
 378     case 0x504: /* 4mA drive */
 379         if (s->id != pl061_id_luminary) {
 380             goto bad_offset;
 381         }
 382         s->dr4r = value & 0xff;
 383         break;
 384     case 0x508: /* 8mA drive */
 385         if (s->id != pl061_id_luminary) {
 386             goto bad_offset;
 387         }
 388         s->dr8r = value & 0xff;
 389         break;
 390     case 0x50c: /* Open drain */
 391         if (s->id != pl061_id_luminary) {
 392             goto bad_offset;
 393         }
 394         s->odr = value & 0xff;
 395         break;
 396     case 0x510: /* Pull-up */
 397         if (s->id != pl061_id_luminary) {
 398             goto bad_offset;
 399         }
 400         s->pur = value & 0xff;
 401         break;
 402     case 0x514: /* Pull-down */
 403         if (s->id != pl061_id_luminary) {
 404             goto bad_offset;
 405         }
 406         s->pdr = value & 0xff;
 407         break;
 408     case 0x518: /* Slew rate control */
 409         if (s->id != pl061_id_luminary) {
 410             goto bad_offset;
 411         }
 412         s->slr = value & 0xff;
 413         break;
 414     case 0x51c: /* Digital enable */
 415         if (s->id != pl061_id_luminary) {
 416             goto bad_offset;
 417         }
 418         s->den = value & 0xff;
 419         break;
 420     case 0x520: /* Lock */
 421         if (s->id != pl061_id_luminary) {
 422             goto bad_offset;
 423         }
 424         s->locked = (value != 0xacce551);
 425         break;
 426     case 0x524: /* Commit */
 427         if (s->id != pl061_id_luminary) {
 428             goto bad_offset;
 429         }
 430         if (!s->locked)
 431             s->cr = value & 0xff;
 432         break;
 433     case 0x528:
 434         if (s->id != pl061_id_luminary) {
 435             goto bad_offset;
 436         }
 437         s->amsel = value & 0xff;
 438         break;
 439     default:
 440     bad_offset:
 441         qemu_log_mask(LOG_GUEST_ERROR,
 442                       "pl061_write: Bad offset %x\n", (int)offset);
 443         return;
 444     }
 445     pl061_update(s);
 446     return;
 447 }
 448
 449 static void pl061_enter_reset(Object *obj, ResetType type)
 450 {
 451     PL061State *s = PL061(obj);
 452
 453     trace_pl061_reset(DEVICE(s)->canonical_path);
 454
 455     /* reset values from PL061 TRM, Stellaris LM3S5P31 & LM3S8962 Data Sheet */
 456
 457     /*
 458      * FIXME: For the LM3S6965, not all of the PL061 instances have the
 459      * same reset values for GPIOPUR, GPIOAFSEL and GPIODEN, so in theory
 460      * we should allow the board to configure these via properties.
 461      * In practice, we don't wire anything up to the affected GPIO lines
 462      * (PB7, PC0, PC1, PC2, PC3 -- they're used for JTAG), so we can
 463      * get away with this inaccuracy.
 464      */
 465     s->data = 0;
 466     s->old_in_data = 0;
 467     s->dir = 0;
 468     s->isense = 0;
 469     s->ibe = 0;
 470     s->iev = 0;
 471     s->im = 0;
 472     s->istate = 0;
 473     s->afsel = 0;
 474     s->dr2r = 0xff;
 475     s->dr4r = 0;
 476     s->dr8r = 0;
 477     s->odr = 0;
 478     s->pur = 0;
 479     s->pdr = 0;
 480     s->slr = 0;
 481     s->den = 0;
 482     s->locked = 1;
 483     s->cr = 0xff;
 484     s->amsel = 0;
 485 }
 486
 487 static void pl061_hold_reset(Object *obj, ResetType type)
 488 {
 489     PL061State *s = PL061(obj);
 490     int i, level;
 491     uint8_t floating = pl061_floating(s);
 492     uint8_t pullups = pl061_pullups(s);
 493
 494     for (i = 0; i < N_GPIOS; i++) {
 495         if (extract32(floating, i, 1)) {
 496             continue;
 497         }
 498         level = extract32(pullups, i, 1);
 499         trace_pl061_set_output(DEVICE(s)->canonical_path, i, level);
 500         qemu_set_irq(s->out[i], level);
 501     }
 502     s->old_out_data = pullups;
 503 }
 504
 505 static void pl061_set_irq(void * opaque, int irq, int level)
 506 {
 507     PL061State *s = (PL061State *)opaque;
 508     uint8_t mask;
 509
 510     mask = 1 << irq;
 511     if ((s->dir & mask) == 0) {
 512         s->data &= ~mask;
 513         if (level)
 514             s->data |= mask;
 515         pl061_update(s);
 516     }
 517 }
 518
 519 static const MemoryRegionOps pl061_ops = {
 520     .read = pl061_read,
 521     .write = pl061_write,
 522     .endianness = DEVICE_NATIVE_ENDIAN,
 523 };
 524
 525 static void pl061_luminary_init(Object *obj)
 526 {
 527     PL061State *s = PL061(obj);
 528
 529     s->id = pl061_id_luminary;
 530 }
 531
 532 static void pl061_init(Object *obj)
 533 {
 534     PL061State *s = PL061(obj);
 535     DeviceState *dev = DEVICE(obj);
 536     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 537
 538     s->id = pl061_id;
 539
 540     memory_region_init_io(&s->iomem, obj, &pl061_ops, s, "pl061", 0x1000);
 541     sysbus_init_mmio(sbd, &s->iomem);
 542     sysbus_init_irq(sbd, &s->irq);
 543     qdev_init_gpio_in(dev, pl061_set_irq, N_GPIOS);
 544     qdev_init_gpio_out(dev, s->out, N_GPIOS);
 545 }
 546
 547 static void pl061_realize(DeviceState *dev, Error **errp)
 548 {
 549     PL061State *s = PL061(dev);
 550
 551     if (s->pullups > 0xff) {
 552         error_setg(errp, "pullups property must be between 0 and 0xff");
 553         return;
 554     }
 555     if (s->pulldowns > 0xff) {
 556         error_setg(errp, "pulldowns property must be between 0 and 0xff");
 557         return;
 558     }
 559     if (s->pullups & s->pulldowns) {
 560         error_setg(errp, "no bit may be set both in pullups and pulldowns");
 561         return;
 562     }
 563 }
 564
 565 static Property pl061_props[] = {
 566     DEFINE_PROP_UINT32("pullups", PL061State, pullups, 0xff),
 567     DEFINE_PROP_UINT32("pulldowns", PL061State, pulldowns, 0x0),
 568     DEFINE_PROP_END_OF_LIST()
 569 };
 570
 571 static void pl061_class_init(ObjectClass *klass, void *data)
 572 {
 573     DeviceClass *dc = DEVICE_CLASS(klass);
 574     ResettableClass *rc = RESETTABLE_CLASS(klass);
 575
 576     dc->vmsd = &vmstate_pl061;
 577     dc->realize = pl061_realize;
 578     device_class_set_props(dc, pl061_props);
 579     rc->phases.enter = pl061_enter_reset;
 580     rc->phases.hold = pl061_hold_reset;
 581 }
 582
 583 static const TypeInfo pl061_info = {
 584     .name          = TYPE_PL061,
 585     .parent        = TYPE_SYS_BUS_DEVICE,
 586     .instance_size = sizeof(PL061State),
 587     .instance_init = pl061_init,
 588     .class_init    = pl061_class_init,
 589 };
 590
 591 static const TypeInfo pl061_luminary_info = {
 592     .name          = "pl061_luminary",
 593     .parent        = TYPE_PL061,
 594     .instance_init = pl061_luminary_init,
 595 };
 596
 597 static void pl061_register_types(void)
 598 {
 599     type_register_static(&pl061_info);
 600     type_register_static(&pl061_luminary_info);
 601 }
 602
 603 type_init(pl061_register_types)