drivers/mailbox/mtk-cmdq-mailbox.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (c) 2018 MediaTek Inc.
   4
   5 #include <linux/bitops.h>
   6 #include <linux/clk.h>
   7 #include <linux/clk-provider.h>
   8 #include <linux/dma-mapping.h>
   9 #include <linux/errno.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/io.h>
  12 #include <linux/iopoll.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/mailbox_controller.h>
  17 #include <linux/mailbox/mtk-cmdq-mailbox.h>
  18 #include <linux/of_device.h>
  19
  20 #define CMDQ_OP_CODE_MASK               (0xff << CMDQ_OP_CODE_SHIFT)
  21 #define CMDQ_IRQ_MASK                   0xffff
  22 #define CMDQ_NUM_CMD(t)                 (t->cmd_buf_size / CMDQ_INST_SIZE)
  23
  24 #define CMDQ_CURR_IRQ_STATUS            0x10
  25 #define CMDQ_THR_SLOT_CYCLES            0x30
  26 #define CMDQ_THR_BASE                   0x100
  27 #define CMDQ_THR_SIZE                   0x80
  28 #define CMDQ_THR_WARM_RESET             0x00
  29 #define CMDQ_THR_ENABLE_TASK            0x04
  30 #define CMDQ_THR_SUSPEND_TASK           0x08
  31 #define CMDQ_THR_CURR_STATUS            0x0c
  32 #define CMDQ_THR_IRQ_STATUS             0x10
  33 #define CMDQ_THR_IRQ_ENABLE             0x14
  34 #define CMDQ_THR_CURR_ADDR              0x20
  35 #define CMDQ_THR_END_ADDR               0x24
  36 #define CMDQ_THR_WAIT_TOKEN             0x30
  37 #define CMDQ_THR_PRIORITY               0x40
  38
  39 #define CMDQ_THR_ACTIVE_SLOT_CYCLES     0x3200
  40 #define CMDQ_THR_ENABLED                0x1
  41 #define CMDQ_THR_DISABLED               0x0
  42 #define CMDQ_THR_SUSPEND                0x1
  43 #define CMDQ_THR_RESUME                 0x0
  44 #define CMDQ_THR_STATUS_SUSPENDED       BIT(1)
  45 #define CMDQ_THR_DO_WARM_RESET          BIT(0)
  46 #define CMDQ_THR_IRQ_DONE               0x1
  47 #define CMDQ_THR_IRQ_ERROR              0x12
  48 #define CMDQ_THR_IRQ_EN                 (CMDQ_THR_IRQ_ERROR | CMDQ_THR_IRQ_DONE)
  49 #define CMDQ_THR_IS_WAITING             BIT(31)
  50
  51 #define CMDQ_JUMP_BY_OFFSET             0x10000000
  52 #define CMDQ_JUMP_BY_PA                 0x10000001
  53
  54 struct cmdq_thread {
  55         struct mbox_chan        *chan;
  56         void __iomem            *base;
  57         struct list_head        task_busy_list;
  58         u32                     priority;
  59         bool                    atomic_exec;
  60 };
  61
  62 struct cmdq_task {
  63         struct cmdq             *cmdq;
  64         struct list_head        list_entry;
  65         dma_addr_t              pa_base;
  66         struct cmdq_thread      *thread;
  67         struct cmdq_pkt         *pkt; /* the packet sent from mailbox client */
  68 };
  69
  70 struct cmdq {
  71         struct mbox_controller  mbox;
  72         void __iomem            *base;
  73         u32                     irq;
  74         u32                     thread_nr;
  75         struct cmdq_thread      *thread;
  76         struct clk              *clock;
  77         bool                    suspended;
  78 };
  79
  80 static int cmdq_thread_suspend(struct cmdq *cmdq, struct cmdq_thread *thread)
  81 {
  82         u32 status;
  83
  84         writel(CMDQ_THR_SUSPEND, thread->base + CMDQ_THR_SUSPEND_TASK);
  85
  86         /* If already disabled, treat as suspended successful. */
  87         if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
  88                 return 0;
  89
  90         if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_STATUS,
  91                         status, status & CMDQ_THR_STATUS_SUSPENDED, 0, 10)) {
  92                 dev_err(cmdq->mbox.dev, "suspend GCE thread 0x%x failed\n",
  93                         (u32)(thread->base - cmdq->base));
  94                 return -EFAULT;
  95         }
  96
  97         return 0;
  98 }
  99
 100 static void cmdq_thread_resume(struct cmdq_thread *thread)
 101 {
 102         writel(CMDQ_THR_RESUME, thread->base + CMDQ_THR_SUSPEND_TASK);
 103 }
 104
 105 static void cmdq_init(struct cmdq *cmdq)
 106 {
 107         WARN_ON(clk_enable(cmdq->clock) < 0);
 108         writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
 109         clk_disable(cmdq->clock);
 110 }
 111
 112 static int cmdq_thread_reset(struct cmdq *cmdq, struct cmdq_thread *thread)
 113 {
 114         u32 warm_reset;
 115
 116         writel(CMDQ_THR_DO_WARM_RESET, thread->base + CMDQ_THR_WARM_RESET);
 117         if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_WARM_RESET,
 118                         warm_reset, !(warm_reset & CMDQ_THR_DO_WARM_RESET),
 119                         0, 10)) {
 120                 dev_err(cmdq->mbox.dev, "reset GCE thread 0x%x failed\n",
 121                         (u32)(thread->base - cmdq->base));
 122                 return -EFAULT;
 123         }
 124
 125         return 0;
 126 }
 127
 128 static void cmdq_thread_disable(struct cmdq *cmdq, struct cmdq_thread *thread)
 129 {
 130         cmdq_thread_reset(cmdq, thread);
 131         writel(CMDQ_THR_DISABLED, thread->base + CMDQ_THR_ENABLE_TASK);
 132 }
 133
 134 /* notify GCE to re-fetch commands by setting GCE thread PC */
 135 static void cmdq_thread_invalidate_fetched_data(struct cmdq_thread *thread)
 136 {
 137         writel(readl(thread->base + CMDQ_THR_CURR_ADDR),
 138                thread->base + CMDQ_THR_CURR_ADDR);
 139 }
 140
 141 static void cmdq_task_insert_into_thread(struct cmdq_task *task)
 142 {
 143         struct device *dev = task->cmdq->mbox.dev;
 144         struct cmdq_thread *thread = task->thread;
 145         struct cmdq_task *prev_task = list_last_entry(
 146                         &thread->task_busy_list, typeof(*task), list_entry);
 147         u64 *prev_task_base = prev_task->pkt->va_base;
 148
 149         /* let previous task jump to this task */
 150         dma_sync_single_for_cpu(dev, prev_task->pa_base,
 151                                 prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
 152         prev_task_base[CMDQ_NUM_CMD(prev_task->pkt) - 1] =
 153                 (u64)CMDQ_JUMP_BY_PA << 32 | task->pa_base;
 154         dma_sync_single_for_device(dev, prev_task->pa_base,
 155                                    prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
 156
 157         cmdq_thread_invalidate_fetched_data(thread);
 158 }
 159
 160 static bool cmdq_command_is_wfe(u64 cmd)
 161 {
 162         u64 wfe_option = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
 163         u64 wfe_op = (u64)(CMDQ_CODE_WFE << CMDQ_OP_CODE_SHIFT) << 32;
 164         u64 wfe_mask = (u64)CMDQ_OP_CODE_MASK << 32 | 0xffffffff;
 165
 166         return ((cmd & wfe_mask) == (wfe_op | wfe_option));
 167 }
 168
 169 /* we assume tasks in the same display GCE thread are waiting the same event. */
 170 static void cmdq_task_remove_wfe(struct cmdq_task *task)
 171 {
 172         struct device *dev = task->cmdq->mbox.dev;
 173         u64 *base = task->pkt->va_base;
 174         int i;
 175
 176         dma_sync_single_for_cpu(dev, task->pa_base, task->pkt->cmd_buf_size,
 177                                 DMA_TO_DEVICE);
 178         for (i = 0; i < CMDQ_NUM_CMD(task->pkt); i++)
 179                 if (cmdq_command_is_wfe(base[i]))
 180                         base[i] = (u64)CMDQ_JUMP_BY_OFFSET << 32 |
 181                                   CMDQ_JUMP_PASS;
 182         dma_sync_single_for_device(dev, task->pa_base, task->pkt->cmd_buf_size,
 183                                    DMA_TO_DEVICE);
 184 }
 185
 186 static bool cmdq_thread_is_in_wfe(struct cmdq_thread *thread)
 187 {
 188         return readl(thread->base + CMDQ_THR_WAIT_TOKEN) & CMDQ_THR_IS_WAITING;
 189 }
 190
 191 static void cmdq_thread_wait_end(struct cmdq_thread *thread,
 192                                  unsigned long end_pa)
 193 {
 194         struct device *dev = thread->chan->mbox->dev;
 195         unsigned long curr_pa;
 196
 197         if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_ADDR,
 198                         curr_pa, curr_pa == end_pa, 1, 20))
 199                 dev_err(dev, "GCE thread cannot run to end.\n");
 200 }
 201
 202 static void cmdq_task_exec_done(struct cmdq_task *task, enum cmdq_cb_status sta)
 203 {
 204         struct cmdq_task_cb *cb = &task->pkt->async_cb;
 205         struct cmdq_cb_data data;
 206
 207         WARN_ON(cb->cb == (cmdq_async_flush_cb)NULL);
 208         data.sta = sta;
 209         data.data = cb->data;
 210         cb->cb(data);
 211
 212         list_del(&task->list_entry);
 213 }
 214
 215 static void cmdq_task_handle_error(struct cmdq_task *task)
 216 {
 217         struct cmdq_thread *thread = task->thread;
 218         struct cmdq_task *next_task;
 219
 220         dev_err(task->cmdq->mbox.dev, "task 0x%p error\n", task);
 221         WARN_ON(cmdq_thread_suspend(task->cmdq, thread) < 0);
 222         next_task = list_first_entry_or_null(&thread->task_busy_list,
 223                         struct cmdq_task, list_entry);
 224         if (next_task)
 225                 writel(next_task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
 226         cmdq_thread_resume(thread);
 227 }
 228
 229 static void cmdq_thread_irq_handler(struct cmdq *cmdq,
 230                                     struct cmdq_thread *thread)
 231 {
 232         struct cmdq_task *task, *tmp, *curr_task = NULL;
 233         u32 curr_pa, irq_flag, task_end_pa;
 234         bool err;
 235
 236         irq_flag = readl(thread->base + CMDQ_THR_IRQ_STATUS);
 237         writel(~irq_flag, thread->base + CMDQ_THR_IRQ_STATUS);
 238
 239         /*
 240          * When ISR call this function, another CPU core could run
 241          * "release task" right before we acquire the spin lock, and thus
 242          * reset / disable this GCE thread, so we need to check the enable
 243          * bit of this GCE thread.
 244          */
 245         if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
 246                 return;
 247
 248         if (irq_flag & CMDQ_THR_IRQ_ERROR)
 249                 err = true;
 250         else if (irq_flag & CMDQ_THR_IRQ_DONE)
 251                 err = false;
 252         else
 253                 return;
 254
 255         curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
 256
 257         list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
 258                                  list_entry) {
 259                 task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
 260                 if (curr_pa >= task->pa_base && curr_pa < task_end_pa)
 261                         curr_task = task;
 262
 263                 if (!curr_task || curr_pa == task_end_pa - CMDQ_INST_SIZE) {
 264                         cmdq_task_exec_done(task, CMDQ_CB_NORMAL);
 265                         kfree(task);
 266                 } else if (err) {
 267                         cmdq_task_exec_done(task, CMDQ_CB_ERROR);
 268                         cmdq_task_handle_error(curr_task);
 269                         kfree(task);
 270                 }
 271
 272                 if (curr_task)
 273                         break;
 274         }
 275
 276         if (list_empty(&thread->task_busy_list)) {
 277                 cmdq_thread_disable(cmdq, thread);
 278                 clk_disable(cmdq->clock);
 279         }
 280 }
 281
 282 static irqreturn_t cmdq_irq_handler(int irq, void *dev)
 283 {
 284         struct cmdq *cmdq = dev;
 285         unsigned long irq_status, flags = 0L;
 286         int bit;
 287
 288         irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & CMDQ_IRQ_MASK;
 289         if (!(irq_status ^ CMDQ_IRQ_MASK))
 290                 return IRQ_NONE;
 291
 292         for_each_clear_bit(bit, &irq_status, fls(CMDQ_IRQ_MASK)) {
 293                 struct cmdq_thread *thread = &cmdq->thread[bit];
 294
 295                 spin_lock_irqsave(&thread->chan->lock, flags);
 296                 cmdq_thread_irq_handler(cmdq, thread);
 297                 spin_unlock_irqrestore(&thread->chan->lock, flags);
 298         }
 299
 300         return IRQ_HANDLED;
 301 }
 302
 303 static int cmdq_suspend(struct device *dev)
 304 {
 305         struct cmdq *cmdq = dev_get_drvdata(dev);
 306         struct cmdq_thread *thread;
 307         int i;
 308         bool task_running = false;
 309
 310         cmdq->suspended = true;
 311
 312         for (i = 0; i < cmdq->thread_nr; i++) {
 313                 thread = &cmdq->thread[i];
 314                 if (!list_empty(&thread->task_busy_list)) {
 315                         task_running = true;
 316                         break;
 317                 }
 318         }
 319
 320         if (task_running)
 321                 dev_warn(dev, "exist running task(s) in suspend\n");
 322
 323         clk_unprepare(cmdq->clock);
 324
 325         return 0;
 326 }
 327
 328 static int cmdq_resume(struct device *dev)
 329 {
 330         struct cmdq *cmdq = dev_get_drvdata(dev);
 331
 332         WARN_ON(clk_prepare(cmdq->clock) < 0);
 333         cmdq->suspended = false;
 334         return 0;
 335 }
 336
 337 static int cmdq_remove(struct platform_device *pdev)
 338 {
 339         struct cmdq *cmdq = platform_get_drvdata(pdev);
 340
 341         clk_unprepare(cmdq->clock);
 342
 343         return 0;
 344 }
 345
 346 static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
 347 {
 348         struct cmdq_pkt *pkt = (struct cmdq_pkt *)data;
 349         struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
 350         struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
 351         struct cmdq_task *task;
 352         unsigned long curr_pa, end_pa;
 353
 354         /* Client should not flush new tasks if suspended. */
 355         WARN_ON(cmdq->suspended);
 356
 357         task = kzalloc(sizeof(*task), GFP_ATOMIC);
 358         if (!task)
 359                 return -ENOMEM;
 360
 361         task->cmdq = cmdq;
 362         INIT_LIST_HEAD(&task->list_entry);
 363         task->pa_base = pkt->pa_base;
 364         task->thread = thread;
 365         task->pkt = pkt;
 366
 367         if (list_empty(&thread->task_busy_list)) {
 368                 WARN_ON(clk_enable(cmdq->clock) < 0);
 369                 WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);
 370
 371                 writel(task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
 372                 writel(task->pa_base + pkt->cmd_buf_size,
 373                        thread->base + CMDQ_THR_END_ADDR);
 374                 writel(thread->priority, thread->base + CMDQ_THR_PRIORITY);
 375                 writel(CMDQ_THR_IRQ_EN, thread->base + CMDQ_THR_IRQ_ENABLE);
 376                 writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
 377         } else {
 378                 WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
 379                 curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
 380                 end_pa = readl(thread->base + CMDQ_THR_END_ADDR);
 381
 382                 /*
 383                  * Atomic execution should remove the following wfe, i.e. only
 384                  * wait event at first task, and prevent to pause when running.
 385                  */
 386                 if (thread->atomic_exec) {
 387                         /* GCE is executing if command is not WFE */
 388                         if (!cmdq_thread_is_in_wfe(thread)) {
 389                                 cmdq_thread_resume(thread);
 390                                 cmdq_thread_wait_end(thread, end_pa);
 391                                 WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
 392                                 /* set to this task directly */
 393                                 writel(task->pa_base,
 394                                        thread->base + CMDQ_THR_CURR_ADDR);
 395                         } else {
 396                                 cmdq_task_insert_into_thread(task);
 397                                 cmdq_task_remove_wfe(task);
 398                                 smp_mb(); /* modify jump before enable thread */
 399                         }
 400                 } else {
 401                         /* check boundary */
 402                         if (curr_pa == end_pa - CMDQ_INST_SIZE ||
 403                             curr_pa == end_pa) {
 404                                 /* set to this task directly */
 405                                 writel(task->pa_base,
 406                                        thread->base + CMDQ_THR_CURR_ADDR);
 407                         } else {
 408                                 cmdq_task_insert_into_thread(task);
 409                                 smp_mb(); /* modify jump before enable thread */
 410                         }
 411                 }
 412                 writel(task->pa_base + pkt->cmd_buf_size,
 413                        thread->base + CMDQ_THR_END_ADDR);
 414                 cmdq_thread_resume(thread);
 415         }
 416         list_move_tail(&task->list_entry, &thread->task_busy_list);
 417
 418         return 0;
 419 }
 420
 421 static int cmdq_mbox_startup(struct mbox_chan *chan)
 422 {
 423         return 0;
 424 }
 425
 426 static void cmdq_mbox_shutdown(struct mbox_chan *chan)
 427 {
 428 }
 429
 430 static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
 431         .send_data = cmdq_mbox_send_data,
 432         .startup = cmdq_mbox_startup,
 433         .shutdown = cmdq_mbox_shutdown,
 434 };
 435
 436 static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
 437                 const struct of_phandle_args *sp)
 438 {
 439         int ind = sp->args[0];
 440         struct cmdq_thread *thread;
 441
 442         if (ind >= mbox->num_chans)
 443                 return ERR_PTR(-EINVAL);
 444
 445         thread = (struct cmdq_thread *)mbox->chans[ind].con_priv;
 446         thread->priority = sp->args[1];
 447         thread->atomic_exec = (sp->args[2] != 0);
 448         thread->chan = &mbox->chans[ind];
 449
 450         return &mbox->chans[ind];
 451 }
 452
 453 static int cmdq_probe(struct platform_device *pdev)
 454 {
 455         struct device *dev = &pdev->dev;
 456         struct resource *res;
 457         struct cmdq *cmdq;
 458         int err, i;
 459
 460         cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
 461         if (!cmdq)
 462                 return -ENOMEM;
 463
 464         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 465         cmdq->base = devm_ioremap_resource(dev, res);
 466         if (IS_ERR(cmdq->base)) {
 467                 dev_err(dev, "failed to ioremap gce\n");
 468                 return PTR_ERR(cmdq->base);
 469         }
 470
 471         cmdq->irq = platform_get_irq(pdev, 0);
 472         if (!cmdq->irq) {
 473                 dev_err(dev, "failed to get irq\n");
 474                 return -EINVAL;
 475         }
 476         err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
 477                                "mtk_cmdq", cmdq);
 478         if (err < 0) {
 479                 dev_err(dev, "failed to register ISR (%d)\n", err);
 480                 return err;
 481         }
 482
 483         dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
 484                 dev, cmdq->base, cmdq->irq);
 485
 486         cmdq->clock = devm_clk_get(dev, "gce");
 487         if (IS_ERR(cmdq->clock)) {
 488                 dev_err(dev, "failed to get gce clk\n");
 489                 return PTR_ERR(cmdq->clock);
 490         }
 491
 492         cmdq->thread_nr = (u32)(unsigned long)of_device_get_match_data(dev);
 493         cmdq->mbox.dev = dev;
 494         cmdq->mbox.chans = devm_kcalloc(dev, cmdq->thread_nr,
 495                                         sizeof(*cmdq->mbox.chans), GFP_KERNEL);
 496         if (!cmdq->mbox.chans)
 497                 return -ENOMEM;
 498
 499         cmdq->mbox.num_chans = cmdq->thread_nr;
 500         cmdq->mbox.ops = &cmdq_mbox_chan_ops;
 501         cmdq->mbox.of_xlate = cmdq_xlate;
 502
 503         /* make use of TXDONE_BY_ACK */
 504         cmdq->mbox.txdone_irq = false;
 505         cmdq->mbox.txdone_poll = false;
 506
 507         cmdq->thread = devm_kcalloc(dev, cmdq->thread_nr,
 508                                         sizeof(*cmdq->thread), GFP_KERNEL);
 509         if (!cmdq->thread)
 510                 return -ENOMEM;
 511
 512         for (i = 0; i < cmdq->thread_nr; i++) {
 513                 cmdq->thread[i].base = cmdq->base + CMDQ_THR_BASE +
 514                                 CMDQ_THR_SIZE * i;
 515                 INIT_LIST_HEAD(&cmdq->thread[i].task_busy_list);
 516                 cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i];
 517         }
 518
 519         err = devm_mbox_controller_register(dev, &cmdq->mbox);
 520         if (err < 0) {
 521                 dev_err(dev, "failed to register mailbox: %d\n", err);
 522                 return err;
 523         }
 524
 525         platform_set_drvdata(pdev, cmdq);
 526         WARN_ON(clk_prepare(cmdq->clock) < 0);
 527
 528         cmdq_init(cmdq);
 529
 530         return 0;
 531 }
 532
 533 static const struct dev_pm_ops cmdq_pm_ops = {
 534         .suspend = cmdq_suspend,
 535         .resume = cmdq_resume,
 536 };
 537
 538 static const struct of_device_id cmdq_of_ids[] = {
 539         {.compatible = "mediatek,mt8173-gce", .data = (void *)16},
 540         {}
 541 };
 542
 543 static struct platform_driver cmdq_drv = {
 544         .probe = cmdq_probe,
 545         .remove = cmdq_remove,
 546         .driver = {
 547                 .name = "mtk_cmdq",
 548                 .pm = &cmdq_pm_ops,
 549                 .of_match_table = cmdq_of_ids,
 550         }
 551 };
 552
 553 static int __init cmdq_drv_init(void)
 554 {
 555         return platform_driver_register(&cmdq_drv);
 556 }
 557
 558 static void __exit cmdq_drv_exit(void)
 559 {
 560         platform_driver_unregister(&cmdq_drv);
 561 }
 562
 563 subsys_initcall(cmdq_drv_init);
 564 module_exit(cmdq_drv_exit);
 565
 566 MODULE_LICENSE("GPL v2");