arch/x86/platform/olpc/olpc-xo1-sci.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Support for OLPC XO-1 System Control Interrupts (SCI)
   4  *
   5  * Copyright (C) 2010 One Laptop per Child
   6  * Copyright (C) 2006 Red Hat, Inc.
   7  * Copyright (C) 2006 Advanced Micro Devices, Inc.
   8  */
   9
  10 #include <linux/cs5535.h>
  11 #include <linux/device.h>
  12 #include <linux/gpio.h>
  13 #include <linux/input.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pm.h>
  17 #include <linux/pm_wakeup.h>
  18 #include <linux/power_supply.h>
  19 #include <linux/suspend.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/olpc-ec.h>
  22
  23 #include <asm/io.h>
  24 #include <asm/msr.h>
  25 #include <asm/olpc.h>
  26
  27 #define DRV_NAME        "olpc-xo1-sci"
  28 #define PFX             DRV_NAME ": "
  29
  30 static unsigned long acpi_base;
  31 static struct input_dev *power_button_idev;
  32 static struct input_dev *ebook_switch_idev;
  33 static struct input_dev *lid_switch_idev;
  34
  35 static int sci_irq;
  36
  37 static bool lid_open;
  38 static bool lid_inverted;
  39 static int lid_wake_mode;
  40
  41 enum lid_wake_modes {
  42         LID_WAKE_ALWAYS,
  43         LID_WAKE_OPEN,
  44         LID_WAKE_CLOSE,
  45 };
  46
  47 static const char * const lid_wake_mode_names[] = {
  48         [LID_WAKE_ALWAYS] = "always",
  49         [LID_WAKE_OPEN] = "open",
  50         [LID_WAKE_CLOSE] = "close",
  51 };
  52
  53 static void battery_status_changed(void)
  54 {
  55         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  56
  57         if (psy) {
  58                 power_supply_changed(psy);
  59                 power_supply_put(psy);
  60         }
  61 }
  62
  63 static void ac_status_changed(void)
  64 {
  65         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
  66
  67         if (psy) {
  68                 power_supply_changed(psy);
  69                 power_supply_put(psy);
  70         }
  71 }
  72
  73 /* Report current ebook switch state through input layer */
  74 static void send_ebook_state(void)
  75 {
  76         unsigned char state;
  77
  78         if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
  79                 pr_err(PFX "failed to get ebook state\n");
  80                 return;
  81         }
  82
  83         if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
  84                 return; /* Nothing new to report. */
  85
  86         input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
  87         input_sync(ebook_switch_idev);
  88         pm_wakeup_event(&ebook_switch_idev->dev, 0);
  89 }
  90
  91 static void flip_lid_inverter(void)
  92 {
  93         /* gpio is high; invert so we'll get l->h event interrupt */
  94         if (lid_inverted)
  95                 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
  96         else
  97                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
  98         lid_inverted = !lid_inverted;
  99 }
 100
 101 static void detect_lid_state(void)
 102 {
 103         /*
 104          * the edge detector hookup on the gpio inputs on the geode is
 105          * odd, to say the least.  See http://dev.laptop.org/ticket/5703
 106          * for details, but in a nutshell:  we don't use the edge
 107          * detectors.  instead, we make use of an anomaly:  with the both
 108          * edge detectors turned off, we still get an edge event on a
 109          * positive edge transition.  to take advantage of this, we use the
 110          * front-end inverter to ensure that that's the edge we're always
 111          * going to see next.
 112          */
 113
 114         int state;
 115
 116         state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
 117         lid_open = !state ^ !lid_inverted; /* x ^^ y */
 118         if (!state)
 119                 return;
 120
 121         flip_lid_inverter();
 122 }
 123
 124 /* Report current lid switch state through input layer */
 125 static void send_lid_state(void)
 126 {
 127         if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
 128                 return; /* Nothing new to report. */
 129
 130         input_report_switch(lid_switch_idev, SW_LID, !lid_open);
 131         input_sync(lid_switch_idev);
 132         pm_wakeup_event(&lid_switch_idev->dev, 0);
 133 }
 134
 135 static ssize_t lid_wake_mode_show(struct device *dev,
 136                                   struct device_attribute *attr, char *buf)
 137 {
 138         const char *mode = lid_wake_mode_names[lid_wake_mode];
 139         return sprintf(buf, "%s\n", mode);
 140 }
 141 static ssize_t lid_wake_mode_set(struct device *dev,
 142                                  struct device_attribute *attr,
 143                                  const char *buf, size_t count)
 144 {
 145         int i;
 146         for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
 147                 const char *mode = lid_wake_mode_names[i];
 148                 if (strlen(mode) != count || strncasecmp(mode, buf, count))
 149                         continue;
 150
 151                 lid_wake_mode = i;
 152                 return count;
 153         }
 154         return -EINVAL;
 155 }
 156 static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
 157                    lid_wake_mode_set);
 158
 159 static struct attribute *lid_attrs[] = {
 160         &dev_attr_lid_wake_mode.attr,
 161         NULL,
 162 };
 163 ATTRIBUTE_GROUPS(lid);
 164
 165 /*
 166  * Process all items in the EC's SCI queue.
 167  *
 168  * This is handled in a workqueue because olpc_ec_cmd can be slow (and
 169  * can even timeout).
 170  *
 171  * If propagate_events is false, the queue is drained without events being
 172  * generated for the interrupts.
 173  */
 174 static void process_sci_queue(bool propagate_events)
 175 {
 176         int r;
 177         u16 data;
 178
 179         do {
 180                 r = olpc_ec_sci_query(&data);
 181                 if (r || !data)
 182                         break;
 183
 184                 pr_debug(PFX "SCI 0x%x received\n", data);
 185
 186                 switch (data) {
 187                 case EC_SCI_SRC_BATERR:
 188                 case EC_SCI_SRC_BATSOC:
 189                 case EC_SCI_SRC_BATTERY:
 190                 case EC_SCI_SRC_BATCRIT:
 191                         battery_status_changed();
 192                         break;
 193                 case EC_SCI_SRC_ACPWR:
 194                         ac_status_changed();
 195                         break;
 196                 }
 197
 198                 if (data == EC_SCI_SRC_EBOOK && propagate_events)
 199                         send_ebook_state();
 200         } while (data);
 201
 202         if (r)
 203                 pr_err(PFX "Failed to clear SCI queue");
 204 }
 205
 206 static void process_sci_queue_work(struct work_struct *work)
 207 {
 208         process_sci_queue(true);
 209 }
 210
 211 static DECLARE_WORK(sci_work, process_sci_queue_work);
 212
 213 static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
 214 {
 215         struct platform_device *pdev = dev_id;
 216         u32 sts;
 217         u32 gpe;
 218
 219         sts = inl(acpi_base + CS5536_PM1_STS);
 220         outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
 221
 222         gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
 223         outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
 224
 225         dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
 226
 227         if (sts & CS5536_PWRBTN_FLAG) {
 228                 if (!(sts & CS5536_WAK_FLAG)) {
 229                         /* Only report power button input when it was pressed
 230                          * during regular operation (as opposed to when it
 231                          * was used to wake the system). */
 232                         input_report_key(power_button_idev, KEY_POWER, 1);
 233                         input_sync(power_button_idev);
 234                         input_report_key(power_button_idev, KEY_POWER, 0);
 235                         input_sync(power_button_idev);
 236                 }
 237                 /* Report the wakeup event in all cases. */
 238                 pm_wakeup_event(&power_button_idev->dev, 0);
 239         }
 240
 241         if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
 242                         (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
 243                 /* When the system is woken by the RTC alarm, report the
 244                  * event on the rtc device. */
 245                 struct device *rtc = bus_find_device_by_name(
 246                         &platform_bus_type, NULL, "rtc_cmos");
 247                 if (rtc) {
 248                         pm_wakeup_event(rtc, 0);
 249                         put_device(rtc);
 250                 }
 251         }
 252
 253         if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
 254                 cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
 255                 schedule_work(&sci_work);
 256         }
 257
 258         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
 259         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
 260         detect_lid_state();
 261         send_lid_state();
 262
 263         return IRQ_HANDLED;
 264 }
 265
 266 static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
 267 {
 268         if (device_may_wakeup(&power_button_idev->dev))
 269                 olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
 270         else
 271                 olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
 272
 273         if (device_may_wakeup(&ebook_switch_idev->dev))
 274                 olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
 275         else
 276                 olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
 277
 278         if (!device_may_wakeup(&lid_switch_idev->dev)) {
 279                 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 280         } else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
 281                    (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
 282                 flip_lid_inverter();
 283
 284                 /* we may have just caused an event */
 285                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
 286                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
 287
 288                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 289         }
 290
 291         return 0;
 292 }
 293
 294 static int xo1_sci_resume(struct platform_device *pdev)
 295 {
 296         /*
 297          * We don't know what may have happened while we were asleep.
 298          * Reestablish our lid setup so we're sure to catch all transitions.
 299          */
 300         detect_lid_state();
 301         send_lid_state();
 302         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 303
 304         /* Enable all EC events */
 305         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 306
 307         /* Power/battery status might have changed too */
 308         battery_status_changed();
 309         ac_status_changed();
 310         return 0;
 311 }
 312
 313 static int setup_sci_interrupt(struct platform_device *pdev)
 314 {
 315         u32 lo, hi;
 316         u32 sts;
 317         int r;
 318
 319         rdmsr(0x51400020, lo, hi);
 320         sci_irq = (lo >> 20) & 15;
 321
 322         if (sci_irq) {
 323                 dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
 324         } else {
 325                 /* Zero means masked */
 326                 dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
 327                 sci_irq = 3;
 328                 lo |= 0x00300000;
 329                 wrmsrl(0x51400020, lo);
 330         }
 331
 332         /* Select level triggered in PIC */
 333         if (sci_irq < 8) {
 334                 lo = inb(CS5536_PIC_INT_SEL1);
 335                 lo |= 1 << sci_irq;
 336                 outb(lo, CS5536_PIC_INT_SEL1);
 337         } else {
 338                 lo = inb(CS5536_PIC_INT_SEL2);
 339                 lo |= 1 << (sci_irq - 8);
 340                 outb(lo, CS5536_PIC_INT_SEL2);
 341         }
 342
 343         /* Enable interesting SCI events, and clear pending interrupts */
 344         sts = inl(acpi_base + CS5536_PM1_STS);
 345         outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
 346              acpi_base + CS5536_PM1_STS);
 347
 348         r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
 349         if (r)
 350                 dev_err(&pdev->dev, "can't request interrupt\n");
 351
 352         return r;
 353 }
 354
 355 static int setup_ec_sci(void)
 356 {
 357         int r;
 358
 359         r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
 360         if (r)
 361                 return r;
 362
 363         gpio_direction_input(OLPC_GPIO_ECSCI);
 364
 365         /* Clear pending EC SCI events */
 366         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
 367         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
 368
 369         /*
 370          * Enable EC SCI events, and map them to both a PME and the SCI
 371          * interrupt.
 372          *
 373          * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
 374          * be mapped to regular interrupts *or* Geode-specific Power
 375          * Management Events (PMEs) - events that bring the system out of
 376          * suspend. In this case, we want both of those things - the system
 377          * wakeup, *and* the ability to get an interrupt when an event occurs.
 378          *
 379          * To achieve this, we map the GPIO to a PME, and then we use one
 380          * of the many generic knobs on the CS5535 PIC to additionally map the
 381          * PME to the regular SCI interrupt line.
 382          */
 383         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
 384
 385         /* Set the SCI to cause a PME event on group 7 */
 386         cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
 387
 388         /* And have group 7 also fire the SCI interrupt */
 389         cs5535_pic_unreqz_select_high(7, sci_irq);
 390
 391         return 0;
 392 }
 393
 394 static void free_ec_sci(void)
 395 {
 396         gpio_free(OLPC_GPIO_ECSCI);
 397 }
 398
 399 static int setup_lid_events(void)
 400 {
 401         int r;
 402
 403         r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
 404         if (r)
 405                 return r;
 406
 407         gpio_direction_input(OLPC_GPIO_LID);
 408
 409         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
 410         lid_inverted = 0;
 411
 412         /* Clear edge detection and event enable for now */
 413         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 414         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
 415         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
 416         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
 417         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
 418
 419         /* Set the LID to cause an PME event on group 6 */
 420         cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
 421
 422         /* Set PME group 6 to fire the SCI interrupt */
 423         cs5535_gpio_set_irq(6, sci_irq);
 424
 425         /* Enable the event */
 426         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 427
 428         return 0;
 429 }
 430
 431 static void free_lid_events(void)
 432 {
 433         gpio_free(OLPC_GPIO_LID);
 434 }
 435
 436 static int setup_power_button(struct platform_device *pdev)
 437 {
 438         int r;
 439
 440         power_button_idev = input_allocate_device();
 441         if (!power_button_idev)
 442                 return -ENOMEM;
 443
 444         power_button_idev->name = "Power Button";
 445         power_button_idev->phys = DRV_NAME "/input0";
 446         set_bit(EV_KEY, power_button_idev->evbit);
 447         set_bit(KEY_POWER, power_button_idev->keybit);
 448
 449         power_button_idev->dev.parent = &pdev->dev;
 450         device_init_wakeup(&power_button_idev->dev, 1);
 451
 452         r = input_register_device(power_button_idev);
 453         if (r) {
 454                 dev_err(&pdev->dev, "failed to register power button: %d\n", r);
 455                 input_free_device(power_button_idev);
 456         }
 457
 458         return r;
 459 }
 460
 461 static void free_power_button(void)
 462 {
 463         input_unregister_device(power_button_idev);
 464 }
 465
 466 static int setup_ebook_switch(struct platform_device *pdev)
 467 {
 468         int r;
 469
 470         ebook_switch_idev = input_allocate_device();
 471         if (!ebook_switch_idev)
 472                 return -ENOMEM;
 473
 474         ebook_switch_idev->name = "EBook Switch";
 475         ebook_switch_idev->phys = DRV_NAME "/input1";
 476         set_bit(EV_SW, ebook_switch_idev->evbit);
 477         set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
 478
 479         ebook_switch_idev->dev.parent = &pdev->dev;
 480         device_set_wakeup_capable(&ebook_switch_idev->dev, true);
 481
 482         r = input_register_device(ebook_switch_idev);
 483         if (r) {
 484                 dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
 485                 input_free_device(ebook_switch_idev);
 486         }
 487
 488         return r;
 489 }
 490
 491 static void free_ebook_switch(void)
 492 {
 493         input_unregister_device(ebook_switch_idev);
 494 }
 495
 496 static int setup_lid_switch(struct platform_device *pdev)
 497 {
 498         int r;
 499
 500         lid_switch_idev = input_allocate_device();
 501         if (!lid_switch_idev)
 502                 return -ENOMEM;
 503
 504         lid_switch_idev->name = "Lid Switch";
 505         lid_switch_idev->phys = DRV_NAME "/input2";
 506         set_bit(EV_SW, lid_switch_idev->evbit);
 507         set_bit(SW_LID, lid_switch_idev->swbit);
 508
 509         lid_switch_idev->dev.parent = &pdev->dev;
 510         device_set_wakeup_capable(&lid_switch_idev->dev, true);
 511
 512         r = input_register_device(lid_switch_idev);
 513         if (r) {
 514                 dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
 515                 goto err_register;
 516         }
 517
 518         return 0;
 519
 520 err_register:
 521         input_free_device(lid_switch_idev);
 522         return r;
 523 }
 524
 525 static void free_lid_switch(void)
 526 {
 527         input_unregister_device(lid_switch_idev);
 528 }
 529
 530 static int xo1_sci_probe(struct platform_device *pdev)
 531 {
 532         struct resource *res;
 533         int r;
 534
 535         /* don't run on non-XOs */
 536         if (!machine_is_olpc())
 537                 return -ENODEV;
 538
 539         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 540         if (!res) {
 541                 dev_err(&pdev->dev, "can't fetch device resource info\n");
 542                 return -EIO;
 543         }
 544         acpi_base = res->start;
 545
 546         r = setup_power_button(pdev);
 547         if (r)
 548                 return r;
 549
 550         r = setup_ebook_switch(pdev);
 551         if (r)
 552                 goto err_ebook;
 553
 554         r = setup_lid_switch(pdev);
 555         if (r)
 556                 goto err_lid;
 557
 558         r = setup_lid_events();
 559         if (r)
 560                 goto err_lidevt;
 561
 562         r = setup_ec_sci();
 563         if (r)
 564                 goto err_ecsci;
 565
 566         /* Enable PME generation for EC-generated events */
 567         outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
 568                 acpi_base + CS5536_PM_GPE0_EN);
 569
 570         /* Clear pending events */
 571         outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
 572         process_sci_queue(false);
 573
 574         /* Initial sync */
 575         send_ebook_state();
 576         detect_lid_state();
 577         send_lid_state();
 578
 579         r = setup_sci_interrupt(pdev);
 580         if (r)
 581                 goto err_sci;
 582
 583         /* Enable all EC events */
 584         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 585
 586         return r;
 587
 588 err_sci:
 589         free_ec_sci();
 590 err_ecsci:
 591         free_lid_events();
 592 err_lidevt:
 593         free_lid_switch();
 594 err_lid:
 595         free_ebook_switch();
 596 err_ebook:
 597         free_power_button();
 598         return r;
 599 }
 600
 601 static int xo1_sci_remove(struct platform_device *pdev)
 602 {
 603         free_irq(sci_irq, pdev);
 604         cancel_work_sync(&sci_work);
 605         free_ec_sci();
 606         free_lid_events();
 607         free_lid_switch();
 608         free_ebook_switch();
 609         free_power_button();
 610         acpi_base = 0;
 611         return 0;
 612 }
 613
 614 static struct platform_driver xo1_sci_driver = {
 615         .driver = {
 616                 .name = "olpc-xo1-sci-acpi",
 617                 .dev_groups = lid_groups,
 618         },
 619         .probe = xo1_sci_probe,
 620         .remove = xo1_sci_remove,
 621         .suspend = xo1_sci_suspend,
 622         .resume = xo1_sci_resume,
 623 };
 624
 625 static int __init xo1_sci_init(void)
 626 {
 627         return platform_driver_register(&xo1_sci_driver);
 628 }
 629 arch_initcall(xo1_sci_init);