linux/arch/x86/platform/olpc/olpc-xo1-sci.c
<<
>>
Prefs
   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
  30static unsigned long acpi_base;
  31static struct input_dev *power_button_idev;
  32static struct input_dev *ebook_switch_idev;
  33static struct input_dev *lid_switch_idev;
  34
  35static int sci_irq;
  36
  37static bool lid_open;
  38static bool lid_inverted;
  39static int lid_wake_mode;
  40
  41enum lid_wake_modes {
  42        LID_WAKE_ALWAYS,
  43        LID_WAKE_OPEN,
  44        LID_WAKE_CLOSE,
  45};
  46
  47static const char * const lid_wake_mode_names[] = {
  48        [LID_WAKE_ALWAYS] = "always",
  49        [LID_WAKE_OPEN] = "open",
  50        [LID_WAKE_CLOSE] = "close",
  51};
  52
  53static 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
  63static 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 */
  74static 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
  91static 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
 101static 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 */
 125static 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
 135static 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}
 141static 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}
 156static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
 157                   lid_wake_mode_set);
 158
 159static struct attribute *lid_attrs[] = {
 160        &dev_attr_lid_wake_mode.attr,
 161        NULL,
 162};
 163ATTRIBUTE_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 */
 174static 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
 206static void process_sci_queue_work(struct work_struct *work)
 207{
 208        process_sci_queue(true);
 209}
 210
 211static DECLARE_WORK(sci_work, process_sci_queue_work);
 212
 213static 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
 266static 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
 294static 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
 313static 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
 355static 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
 394static void free_ec_sci(void)
 395{
 396        gpio_free(OLPC_GPIO_ECSCI);
 397}
 398
 399static 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
 431static void free_lid_events(void)
 432{
 433        gpio_free(OLPC_GPIO_LID);
 434}
 435
 436static 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
 461static void free_power_button(void)
 462{
 463        input_unregister_device(power_button_idev);
 464}
 465
 466static 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
 491static void free_ebook_switch(void)
 492{
 493        input_unregister_device(ebook_switch_idev);
 494}
 495
 496static 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
 520err_register:
 521        input_free_device(lid_switch_idev);
 522        return r;
 523}
 524
 525static void free_lid_switch(void)
 526{
 527        input_unregister_device(lid_switch_idev);
 528}
 529
 530static 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
 588err_sci:
 589        free_ec_sci();
 590err_ecsci:
 591        free_lid_events();
 592err_lidevt:
 593        free_lid_switch();
 594err_lid:
 595        free_ebook_switch();
 596err_ebook:
 597        free_power_button();
 598        return r;
 599}
 600
 601static 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
 614static 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
 625static int __init xo1_sci_init(void)
 626{
 627        return platform_driver_register(&xo1_sci_driver);
 628}
 629arch_initcall(xo1_sci_init);
 630