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

   1 /*
   2  * Support for OLPC XO-1 System Control Interrupts (SCI)
   3  *
   4  * Copyright (C) 2010 One Laptop per Child
   5  * Copyright (C) 2006 Red Hat, Inc.
   6  * Copyright (C) 2006 Advanced Micro Devices, Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #include <linux/cs5535.h>
  15 #include <linux/device.h>
  16 #include <linux/gpio.h>
  17 #include <linux/input.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pm.h>
  21 #include <linux/pm_wakeup.h>
  22 #include <linux/mfd/core.h>
  23 #include <linux/power_supply.h>
  24 #include <linux/suspend.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/olpc-ec.h>
  27
  28 #include <asm/io.h>
  29 #include <asm/msr.h>
  30 #include <asm/olpc.h>
  31
  32 #define DRV_NAME        "olpc-xo1-sci"
  33 #define PFX             DRV_NAME ": "
  34
  35 static unsigned long acpi_base;
  36 static struct input_dev *power_button_idev;
  37 static struct input_dev *ebook_switch_idev;
  38 static struct input_dev *lid_switch_idev;
  39
  40 static int sci_irq;
  41
  42 static bool lid_open;
  43 static bool lid_inverted;
  44 static int lid_wake_mode;
  45
  46 enum lid_wake_modes {
  47         LID_WAKE_ALWAYS,
  48         LID_WAKE_OPEN,
  49         LID_WAKE_CLOSE,
  50 };
  51
  52 static const char * const lid_wake_mode_names[] = {
  53         [LID_WAKE_ALWAYS] = "always",
  54         [LID_WAKE_OPEN] = "open",
  55         [LID_WAKE_CLOSE] = "close",
  56 };
  57
  58 static void battery_status_changed(void)
  59 {
  60         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  61
  62         if (psy) {
  63                 power_supply_changed(psy);
  64                 power_supply_put(psy);
  65         }
  66 }
  67
  68 static void ac_status_changed(void)
  69 {
  70         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
  71
  72         if (psy) {
  73                 power_supply_changed(psy);
  74                 power_supply_put(psy);
  75         }
  76 }
  77
  78 /* Report current ebook switch state through input layer */
  79 static void send_ebook_state(void)
  80 {
  81         unsigned char state;
  82
  83         if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
  84                 pr_err(PFX "failed to get ebook state\n");
  85                 return;
  86         }
  87
  88         if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
  89                 return; /* Nothing new to report. */
  90
  91         input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
  92         input_sync(ebook_switch_idev);
  93         pm_wakeup_event(&ebook_switch_idev->dev, 0);
  94 }
  95
  96 static void flip_lid_inverter(void)
  97 {
  98         /* gpio is high; invert so we'll get l->h event interrupt */
  99         if (lid_inverted)
 100                 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
 101         else
 102                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
 103         lid_inverted = !lid_inverted;
 104 }
 105
 106 static void detect_lid_state(void)
 107 {
 108         /*
 109          * the edge detector hookup on the gpio inputs on the geode is
 110          * odd, to say the least.  See http://dev.laptop.org/ticket/5703
 111          * for details, but in a nutshell:  we don't use the edge
 112          * detectors.  instead, we make use of an anomoly:  with the both
 113          * edge detectors turned off, we still get an edge event on a
 114          * positive edge transition.  to take advantage of this, we use the
 115          * front-end inverter to ensure that that's the edge we're always
 116          * going to see next.
 117          */
 118
 119         int state;
 120
 121         state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
 122         lid_open = !state ^ !lid_inverted; /* x ^^ y */
 123         if (!state)
 124                 return;
 125
 126         flip_lid_inverter();
 127 }
 128
 129 /* Report current lid switch state through input layer */
 130 static void send_lid_state(void)
 131 {
 132         if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
 133                 return; /* Nothing new to report. */
 134
 135         input_report_switch(lid_switch_idev, SW_LID, !lid_open);
 136         input_sync(lid_switch_idev);
 137         pm_wakeup_event(&lid_switch_idev->dev, 0);
 138 }
 139
 140 static ssize_t lid_wake_mode_show(struct device *dev,
 141                                   struct device_attribute *attr, char *buf)
 142 {
 143         const char *mode = lid_wake_mode_names[lid_wake_mode];
 144         return sprintf(buf, "%s\n", mode);
 145 }
 146 static ssize_t lid_wake_mode_set(struct device *dev,
 147                                  struct device_attribute *attr,
 148                                  const char *buf, size_t count)
 149 {
 150         int i;
 151         for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
 152                 const char *mode = lid_wake_mode_names[i];
 153                 if (strlen(mode) != count || strncasecmp(mode, buf, count))
 154                         continue;
 155
 156                 lid_wake_mode = i;
 157                 return count;
 158         }
 159         return -EINVAL;
 160 }
 161 static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
 162                    lid_wake_mode_set);
 163
 164 /*
 165  * Process all items in the EC's SCI queue.
 166  *
 167  * This is handled in a workqueue because olpc_ec_cmd can be slow (and
 168  * can even timeout).
 169  *
 170  * If propagate_events is false, the queue is drained without events being
 171  * generated for the interrupts.
 172  */
 173 static void process_sci_queue(bool propagate_events)
 174 {
 175         int r;
 176         u16 data;
 177
 178         do {
 179                 r = olpc_ec_sci_query(&data);
 180                 if (r || !data)
 181                         break;
 182
 183                 pr_debug(PFX "SCI 0x%x received\n", data);
 184
 185                 switch (data) {
 186                 case EC_SCI_SRC_BATERR:
 187                 case EC_SCI_SRC_BATSOC:
 188                 case EC_SCI_SRC_BATTERY:
 189                 case EC_SCI_SRC_BATCRIT:
 190                         battery_status_changed();
 191                         break;
 192                 case EC_SCI_SRC_ACPWR:
 193                         ac_status_changed();
 194                         break;
 195                 }
 196
 197                 if (data == EC_SCI_SRC_EBOOK && propagate_events)
 198                         send_ebook_state();
 199         } while (data);
 200
 201         if (r)
 202                 pr_err(PFX "Failed to clear SCI queue");
 203 }
 204
 205 static void process_sci_queue_work(struct work_struct *work)
 206 {
 207         process_sci_queue(true);
 208 }
 209
 210 static DECLARE_WORK(sci_work, process_sci_queue_work);
 211
 212 static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
 213 {
 214         struct platform_device *pdev = dev_id;
 215         u32 sts;
 216         u32 gpe;
 217
 218         sts = inl(acpi_base + CS5536_PM1_STS);
 219         outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
 220
 221         gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
 222         outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
 223
 224         dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
 225
 226         if (sts & CS5536_PWRBTN_FLAG) {
 227                 if (!(sts & CS5536_WAK_FLAG)) {
 228                         /* Only report power button input when it was pressed
 229                          * during regular operation (as opposed to when it
 230                          * was used to wake the system). */
 231                         input_report_key(power_button_idev, KEY_POWER, 1);
 232                         input_sync(power_button_idev);
 233                         input_report_key(power_button_idev, KEY_POWER, 0);
 234                         input_sync(power_button_idev);
 235                 }
 236                 /* Report the wakeup event in all cases. */
 237                 pm_wakeup_event(&power_button_idev->dev, 0);
 238         }
 239
 240         if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
 241                         (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
 242                 /* When the system is woken by the RTC alarm, report the
 243                  * event on the rtc device. */
 244                 struct device *rtc = bus_find_device_by_name(
 245                         &platform_bus_type, NULL, "rtc_cmos");
 246                 if (rtc) {
 247                         pm_wakeup_event(rtc, 0);
 248                         put_device(rtc);
 249                 }
 250         }
 251
 252         if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
 253                 cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
 254                 schedule_work(&sci_work);
 255         }
 256
 257         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
 258         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
 259         detect_lid_state();
 260         send_lid_state();
 261
 262         return IRQ_HANDLED;
 263 }
 264
 265 static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
 266 {
 267         if (device_may_wakeup(&power_button_idev->dev))
 268                 olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
 269         else
 270                 olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
 271
 272         if (device_may_wakeup(&ebook_switch_idev->dev))
 273                 olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
 274         else
 275                 olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
 276
 277         if (!device_may_wakeup(&lid_switch_idev->dev)) {
 278                 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 279         } else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
 280                    (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
 281                 flip_lid_inverter();
 282
 283                 /* we may have just caused an event */
 284                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
 285                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
 286
 287                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int xo1_sci_resume(struct platform_device *pdev)
 294 {
 295         /*
 296          * We don't know what may have happened while we were asleep.
 297          * Reestablish our lid setup so we're sure to catch all transitions.
 298          */
 299         detect_lid_state();
 300         send_lid_state();
 301         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 302
 303         /* Enable all EC events */
 304         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 305
 306         /* Power/battery status might have changed too */
 307         battery_status_changed();
 308         ac_status_changed();
 309         return 0;
 310 }
 311
 312 static int setup_sci_interrupt(struct platform_device *pdev)
 313 {
 314         u32 lo, hi;
 315         u32 sts;
 316         int r;
 317
 318         rdmsr(0x51400020, lo, hi);
 319         sci_irq = (lo >> 20) & 15;
 320
 321         if (sci_irq) {
 322                 dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
 323         } else {
 324                 /* Zero means masked */
 325                 dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
 326                 sci_irq = 3;
 327                 lo |= 0x00300000;
 328                 wrmsrl(0x51400020, lo);
 329         }
 330
 331         /* Select level triggered in PIC */
 332         if (sci_irq < 8) {
 333                 lo = inb(CS5536_PIC_INT_SEL1);
 334                 lo |= 1 << sci_irq;
 335                 outb(lo, CS5536_PIC_INT_SEL1);
 336         } else {
 337                 lo = inb(CS5536_PIC_INT_SEL2);
 338                 lo |= 1 << (sci_irq - 8);
 339                 outb(lo, CS5536_PIC_INT_SEL2);
 340         }
 341
 342         /* Enable interesting SCI events, and clear pending interrupts */
 343         sts = inl(acpi_base + CS5536_PM1_STS);
 344         outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
 345              acpi_base + CS5536_PM1_STS);
 346
 347         r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
 348         if (r)
 349                 dev_err(&pdev->dev, "can't request interrupt\n");
 350
 351         return r;
 352 }
 353
 354 static int setup_ec_sci(void)
 355 {
 356         int r;
 357
 358         r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
 359         if (r)
 360                 return r;
 361
 362         gpio_direction_input(OLPC_GPIO_ECSCI);
 363
 364         /* Clear pending EC SCI events */
 365         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
 366         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
 367
 368         /*
 369          * Enable EC SCI events, and map them to both a PME and the SCI
 370          * interrupt.
 371          *
 372          * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
 373          * be mapped to regular interrupts *or* Geode-specific Power
 374          * Management Events (PMEs) - events that bring the system out of
 375          * suspend. In this case, we want both of those things - the system
 376          * wakeup, *and* the ability to get an interrupt when an event occurs.
 377          *
 378          * To achieve this, we map the GPIO to a PME, and then we use one
 379          * of the many generic knobs on the CS5535 PIC to additionally map the
 380          * PME to the regular SCI interrupt line.
 381          */
 382         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
 383
 384         /* Set the SCI to cause a PME event on group 7 */
 385         cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
 386
 387         /* And have group 7 also fire the SCI interrupt */
 388         cs5535_pic_unreqz_select_high(7, sci_irq);
 389
 390         return 0;
 391 }
 392
 393 static void free_ec_sci(void)
 394 {
 395         gpio_free(OLPC_GPIO_ECSCI);
 396 }
 397
 398 static int setup_lid_events(void)
 399 {
 400         int r;
 401
 402         r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
 403         if (r)
 404                 return r;
 405
 406         gpio_direction_input(OLPC_GPIO_LID);
 407
 408         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
 409         lid_inverted = 0;
 410
 411         /* Clear edge detection and event enable for now */
 412         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 413         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
 414         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
 415         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
 416         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
 417
 418         /* Set the LID to cause an PME event on group 6 */
 419         cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
 420
 421         /* Set PME group 6 to fire the SCI interrupt */
 422         cs5535_gpio_set_irq(6, sci_irq);
 423
 424         /* Enable the event */
 425         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
 426
 427         return 0;
 428 }
 429
 430 static void free_lid_events(void)
 431 {
 432         gpio_free(OLPC_GPIO_LID);
 433 }
 434
 435 static int setup_power_button(struct platform_device *pdev)
 436 {
 437         int r;
 438
 439         power_button_idev = input_allocate_device();
 440         if (!power_button_idev)
 441                 return -ENOMEM;
 442
 443         power_button_idev->name = "Power Button";
 444         power_button_idev->phys = DRV_NAME "/input0";
 445         set_bit(EV_KEY, power_button_idev->evbit);
 446         set_bit(KEY_POWER, power_button_idev->keybit);
 447
 448         power_button_idev->dev.parent = &pdev->dev;
 449         device_init_wakeup(&power_button_idev->dev, 1);
 450
 451         r = input_register_device(power_button_idev);
 452         if (r) {
 453                 dev_err(&pdev->dev, "failed to register power button: %d\n", r);
 454                 input_free_device(power_button_idev);
 455         }
 456
 457         return r;
 458 }
 459
 460 static void free_power_button(void)
 461 {
 462         input_unregister_device(power_button_idev);
 463 }
 464
 465 static int setup_ebook_switch(struct platform_device *pdev)
 466 {
 467         int r;
 468
 469         ebook_switch_idev = input_allocate_device();
 470         if (!ebook_switch_idev)
 471                 return -ENOMEM;
 472
 473         ebook_switch_idev->name = "EBook Switch";
 474         ebook_switch_idev->phys = DRV_NAME "/input1";
 475         set_bit(EV_SW, ebook_switch_idev->evbit);
 476         set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
 477
 478         ebook_switch_idev->dev.parent = &pdev->dev;
 479         device_set_wakeup_capable(&ebook_switch_idev->dev, true);
 480
 481         r = input_register_device(ebook_switch_idev);
 482         if (r) {
 483                 dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
 484                 input_free_device(ebook_switch_idev);
 485         }
 486
 487         return r;
 488 }
 489
 490 static void free_ebook_switch(void)
 491 {
 492         input_unregister_device(ebook_switch_idev);
 493 }
 494
 495 static int setup_lid_switch(struct platform_device *pdev)
 496 {
 497         int r;
 498
 499         lid_switch_idev = input_allocate_device();
 500         if (!lid_switch_idev)
 501                 return -ENOMEM;
 502
 503         lid_switch_idev->name = "Lid Switch";
 504         lid_switch_idev->phys = DRV_NAME "/input2";
 505         set_bit(EV_SW, lid_switch_idev->evbit);
 506         set_bit(SW_LID, lid_switch_idev->swbit);
 507
 508         lid_switch_idev->dev.parent = &pdev->dev;
 509         device_set_wakeup_capable(&lid_switch_idev->dev, true);
 510
 511         r = input_register_device(lid_switch_idev);
 512         if (r) {
 513                 dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
 514                 goto err_register;
 515         }
 516
 517         r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
 518         if (r) {
 519                 dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
 520                 goto err_create_attr;
 521         }
 522
 523         return 0;
 524
 525 err_create_attr:
 526         input_unregister_device(lid_switch_idev);
 527         lid_switch_idev = NULL;
 528 err_register:
 529         input_free_device(lid_switch_idev);
 530         return r;
 531 }
 532
 533 static void free_lid_switch(void)
 534 {
 535         device_remove_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
 536         input_unregister_device(lid_switch_idev);
 537 }
 538
 539 static int xo1_sci_probe(struct platform_device *pdev)
 540 {
 541         struct resource *res;
 542         int r;
 543
 544         /* don't run on non-XOs */
 545         if (!machine_is_olpc())
 546                 return -ENODEV;
 547
 548         r = mfd_cell_enable(pdev);
 549         if (r)
 550                 return r;
 551
 552         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 553         if (!res) {
 554                 dev_err(&pdev->dev, "can't fetch device resource info\n");
 555                 return -EIO;
 556         }
 557         acpi_base = res->start;
 558
 559         r = setup_power_button(pdev);
 560         if (r)
 561                 return r;
 562
 563         r = setup_ebook_switch(pdev);
 564         if (r)
 565                 goto err_ebook;
 566
 567         r = setup_lid_switch(pdev);
 568         if (r)
 569                 goto err_lid;
 570
 571         r = setup_lid_events();
 572         if (r)
 573                 goto err_lidevt;
 574
 575         r = setup_ec_sci();
 576         if (r)
 577                 goto err_ecsci;
 578
 579         /* Enable PME generation for EC-generated events */
 580         outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
 581                 acpi_base + CS5536_PM_GPE0_EN);
 582
 583         /* Clear pending events */
 584         outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
 585         process_sci_queue(false);
 586
 587         /* Initial sync */
 588         send_ebook_state();
 589         detect_lid_state();
 590         send_lid_state();
 591
 592         r = setup_sci_interrupt(pdev);
 593         if (r)
 594                 goto err_sci;
 595
 596         /* Enable all EC events */
 597         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 598
 599         return r;
 600
 601 err_sci:
 602         free_ec_sci();
 603 err_ecsci:
 604         free_lid_events();
 605 err_lidevt:
 606         free_lid_switch();
 607 err_lid:
 608         free_ebook_switch();
 609 err_ebook:
 610         free_power_button();
 611         return r;
 612 }
 613
 614 static int xo1_sci_remove(struct platform_device *pdev)
 615 {
 616         mfd_cell_disable(pdev);
 617         free_irq(sci_irq, pdev);
 618         cancel_work_sync(&sci_work);
 619         free_ec_sci();
 620         free_lid_events();
 621         free_lid_switch();
 622         free_ebook_switch();
 623         free_power_button();
 624         acpi_base = 0;
 625         return 0;
 626 }
 627
 628 static struct platform_driver xo1_sci_driver = {
 629         .driver = {
 630                 .name = "olpc-xo1-sci-acpi",
 631         },
 632         .probe = xo1_sci_probe,
 633         .remove = xo1_sci_remove,
 634         .suspend = xo1_sci_suspend,
 635         .resume = xo1_sci_resume,
 636 };
 637
 638 static int __init xo1_sci_init(void)
 639 {
 640         return platform_driver_register(&xo1_sci_driver);
 641 }
 642 arch_initcall(xo1_sci_init);