drivers/spi/spi-sprd-adi.c

   1 /*
   2  * Copyright (C) 2017 Spreadtrum Communications Inc.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0
   5  */
   6
   7 #include <linux/delay.h>
   8 #include <linux/hwspinlock.h>
   9 #include <linux/init.h>
  10 #include <linux/io.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/of_device.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/reboot.h>
  17 #include <linux/spi/spi.h>
  18 #include <linux/sizes.h>
  19
  20 /* Registers definitions for ADI controller */
  21 #define REG_ADI_CTRL0                   0x4
  22 #define REG_ADI_CHN_PRIL                0x8
  23 #define REG_ADI_CHN_PRIH                0xc
  24 #define REG_ADI_INT_EN                  0x10
  25 #define REG_ADI_INT_RAW                 0x14
  26 #define REG_ADI_INT_MASK                0x18
  27 #define REG_ADI_INT_CLR                 0x1c
  28 #define REG_ADI_GSSI_CFG0               0x20
  29 #define REG_ADI_GSSI_CFG1               0x24
  30 #define REG_ADI_RD_CMD                  0x28
  31 #define REG_ADI_RD_DATA                 0x2c
  32 #define REG_ADI_ARM_FIFO_STS            0x30
  33 #define REG_ADI_STS                     0x34
  34 #define REG_ADI_EVT_FIFO_STS            0x38
  35 #define REG_ADI_ARM_CMD_STS             0x3c
  36 #define REG_ADI_CHN_EN                  0x40
  37 #define REG_ADI_CHN_ADDR(id)            (0x44 + (id - 2) * 4)
  38 #define REG_ADI_CHN_EN1                 0x20c
  39
  40 /* Bits definitions for register REG_ADI_GSSI_CFG0 */
  41 #define BIT_CLK_ALL_ON                  BIT(30)
  42
  43 /* Bits definitions for register REG_ADI_RD_DATA */
  44 #define BIT_RD_CMD_BUSY                 BIT(31)
  45 #define RD_ADDR_SHIFT                   16
  46 #define RD_VALUE_MASK                   GENMASK(15, 0)
  47 #define RD_ADDR_MASK                    GENMASK(30, 16)
  48
  49 /* Bits definitions for register REG_ADI_ARM_FIFO_STS */
  50 #define BIT_FIFO_FULL                   BIT(11)
  51 #define BIT_FIFO_EMPTY                  BIT(10)
  52
  53 /*
  54  * ADI slave devices include RTC, ADC, regulator, charger, thermal and so on.
  55  * The slave devices address offset is always 0x8000 and size is 4K.
  56  */
  57 #define ADI_SLAVE_ADDR_SIZE             SZ_4K
  58 #define ADI_SLAVE_OFFSET                0x8000
  59
  60 /* Timeout (ms) for the trylock of hardware spinlocks */
  61 #define ADI_HWSPINLOCK_TIMEOUT          5000
  62 /*
  63  * ADI controller has 50 channels including 2 software channels
  64  * and 48 hardware channels.
  65  */
  66 #define ADI_HW_CHNS                     50
  67
  68 #define ADI_FIFO_DRAIN_TIMEOUT          1000
  69 #define ADI_READ_TIMEOUT                2000
  70 #define REG_ADDR_LOW_MASK               GENMASK(11, 0)
  71
  72 /* Registers definitions for PMIC watchdog controller */
  73 #define REG_WDG_LOAD_LOW                0x80
  74 #define REG_WDG_LOAD_HIGH               0x84
  75 #define REG_WDG_CTRL                    0x88
  76 #define REG_WDG_LOCK                    0xa0
  77
  78 /* Bits definitions for register REG_WDG_CTRL */
  79 #define BIT_WDG_RUN                     BIT(1)
  80 #define BIT_WDG_NEW                     BIT(2)
  81 #define BIT_WDG_RST                     BIT(3)
  82
  83 /* Registers definitions for PMIC */
  84 #define PMIC_RST_STATUS                 0xee8
  85 #define PMIC_MODULE_EN                  0xc08
  86 #define PMIC_CLK_EN                     0xc18
  87 #define BIT_WDG_EN                      BIT(2)
  88
  89 /* Definition of PMIC reset status register */
  90 #define HWRST_STATUS_SECURITY           0x02
  91 #define HWRST_STATUS_RECOVERY           0x20
  92 #define HWRST_STATUS_NORMAL             0x40
  93 #define HWRST_STATUS_ALARM              0x50
  94 #define HWRST_STATUS_SLEEP              0x60
  95 #define HWRST_STATUS_FASTBOOT           0x30
  96 #define HWRST_STATUS_SPECIAL            0x70
  97 #define HWRST_STATUS_PANIC              0x80
  98 #define HWRST_STATUS_CFTREBOOT          0x90
  99 #define HWRST_STATUS_AUTODLOADER        0xa0
 100 #define HWRST_STATUS_IQMODE             0xb0
 101 #define HWRST_STATUS_SPRDISK            0xc0
 102 #define HWRST_STATUS_FACTORYTEST        0xe0
 103 #define HWRST_STATUS_WATCHDOG           0xf0
 104
 105 /* Use default timeout 50 ms that converts to watchdog values */
 106 #define WDG_LOAD_VAL                    ((50 * 1000) / 32768)
 107 #define WDG_LOAD_MASK                   GENMASK(15, 0)
 108 #define WDG_UNLOCK_KEY                  0xe551
 109
 110 struct sprd_adi {
 111         struct spi_controller   *ctlr;
 112         struct device           *dev;
 113         void __iomem            *base;
 114         struct hwspinlock       *hwlock;
 115         unsigned long           slave_vbase;
 116         unsigned long           slave_pbase;
 117         struct notifier_block   restart_handler;
 118 };
 119
 120 static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
 121 {
 122         if (paddr < sadi->slave_pbase || paddr >
 123             (sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
 124                 dev_err(sadi->dev,
 125                         "slave physical address is incorrect, addr = 0x%x\n",
 126                         paddr);
 127                 return -EINVAL;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
 134 {
 135         return (paddr - sadi->slave_pbase + sadi->slave_vbase);
 136 }
 137
 138 static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
 139 {
 140         u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
 141         u32 sts;
 142
 143         do {
 144                 sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
 145                 if (sts & BIT_FIFO_EMPTY)
 146                         break;
 147
 148                 cpu_relax();
 149         } while (--timeout);
 150
 151         if (timeout == 0) {
 152                 dev_err(sadi->dev, "drain write fifo timeout\n");
 153                 return -EBUSY;
 154         }
 155
 156         return 0;
 157 }
 158
 159 static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
 160 {
 161         return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
 162 }
 163
 164 static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
 165 {
 166         int read_timeout = ADI_READ_TIMEOUT;
 167         unsigned long flags;
 168         u32 val, rd_addr;
 169         int ret = 0;
 170
 171         if (sadi->hwlock) {
 172                 ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
 173                                                   ADI_HWSPINLOCK_TIMEOUT,
 174                                                   &flags);
 175                 if (ret) {
 176                         dev_err(sadi->dev, "get the hw lock failed\n");
 177                         return ret;
 178                 }
 179         }
 180
 181         /*
 182          * Set the physical register address need to read into RD_CMD register,
 183          * then ADI controller will start to transfer automatically.
 184          */
 185         writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);
 186
 187         /*
 188          * Wait read operation complete, the BIT_RD_CMD_BUSY will be set
 189          * simultaneously when writing read command to register, and the
 190          * BIT_RD_CMD_BUSY will be cleared after the read operation is
 191          * completed.
 192          */
 193         do {
 194                 val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
 195                 if (!(val & BIT_RD_CMD_BUSY))
 196                         break;
 197
 198                 cpu_relax();
 199         } while (--read_timeout);
 200
 201         if (read_timeout == 0) {
 202                 dev_err(sadi->dev, "ADI read timeout\n");
 203                 ret = -EBUSY;
 204                 goto out;
 205         }
 206
 207         /*
 208          * The return value includes data and read register address, from bit 0
 209          * to bit 15 are data, and from bit 16 to bit 30 are read register
 210          * address. Then we can check the returned register address to validate
 211          * data.
 212          */
 213         rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;
 214
 215         if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
 216                 dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
 217                         reg_paddr, val);
 218                 ret = -EIO;
 219                 goto out;
 220         }
 221
 222         *read_val = val & RD_VALUE_MASK;
 223
 224 out:
 225         if (sadi->hwlock)
 226                 hwspin_unlock_irqrestore(sadi->hwlock, &flags);
 227         return ret;
 228 }
 229
 230 static int sprd_adi_write(struct sprd_adi *sadi, u32 reg_paddr, u32 val)
 231 {
 232         unsigned long reg = sprd_adi_to_vaddr(sadi, reg_paddr);
 233         u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
 234         unsigned long flags;
 235         int ret;
 236
 237         if (sadi->hwlock) {
 238                 ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
 239                                                   ADI_HWSPINLOCK_TIMEOUT,
 240                                                   &flags);
 241                 if (ret) {
 242                         dev_err(sadi->dev, "get the hw lock failed\n");
 243                         return ret;
 244                 }
 245         }
 246
 247         ret = sprd_adi_drain_fifo(sadi);
 248         if (ret < 0)
 249                 goto out;
 250
 251         /*
 252          * we should wait for write fifo is empty before writing data to PMIC
 253          * registers.
 254          */
 255         do {
 256                 if (!sprd_adi_fifo_is_full(sadi)) {
 257                         writel_relaxed(val, (void __iomem *)reg);
 258                         break;
 259                 }
 260
 261                 cpu_relax();
 262         } while (--timeout);
 263
 264         if (timeout == 0) {
 265                 dev_err(sadi->dev, "write fifo is full\n");
 266                 ret = -EBUSY;
 267         }
 268
 269 out:
 270         if (sadi->hwlock)
 271                 hwspin_unlock_irqrestore(sadi->hwlock, &flags);
 272         return ret;
 273 }
 274
 275 static int sprd_adi_transfer_one(struct spi_controller *ctlr,
 276                                  struct spi_device *spi_dev,
 277                                  struct spi_transfer *t)
 278 {
 279         struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
 280         u32 phy_reg, val;
 281         int ret;
 282
 283         if (t->rx_buf) {
 284                 phy_reg = *(u32 *)t->rx_buf + sadi->slave_pbase;
 285
 286                 ret = sprd_adi_check_paddr(sadi, phy_reg);
 287                 if (ret)
 288                         return ret;
 289
 290                 ret = sprd_adi_read(sadi, phy_reg, &val);
 291                 if (ret)
 292                         return ret;
 293
 294                 *(u32 *)t->rx_buf = val;
 295         } else if (t->tx_buf) {
 296                 u32 *p = (u32 *)t->tx_buf;
 297
 298                 /*
 299                  * Get the physical register address need to write and convert
 300                  * the physical address to virtual address. Since we need
 301                  * virtual register address to write.
 302                  */
 303                 phy_reg = *p++ + sadi->slave_pbase;
 304                 ret = sprd_adi_check_paddr(sadi, phy_reg);
 305                 if (ret)
 306                         return ret;
 307
 308                 val = *p;
 309                 ret = sprd_adi_write(sadi, phy_reg, val);
 310                 if (ret)
 311                         return ret;
 312         } else {
 313                 dev_err(sadi->dev, "no buffer for transfer\n");
 314                 return -EINVAL;
 315         }
 316
 317         return 0;
 318 }
 319
 320 static void sprd_adi_set_wdt_rst_mode(struct sprd_adi *sadi)
 321 {
 322 #ifdef CONFIG_SPRD_WATCHDOG
 323         u32 val;
 324
 325         /* Set default watchdog reboot mode */
 326         sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
 327         val |= HWRST_STATUS_WATCHDOG;
 328         sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);
 329 #endif
 330 }
 331
 332 static int sprd_adi_restart_handler(struct notifier_block *this,
 333                                     unsigned long mode, void *cmd)
 334 {
 335         struct sprd_adi *sadi = container_of(this, struct sprd_adi,
 336                                              restart_handler);
 337         u32 val, reboot_mode = 0;
 338
 339         if (!cmd)
 340                 reboot_mode = HWRST_STATUS_NORMAL;
 341         else if (!strncmp(cmd, "recovery", 8))
 342                 reboot_mode = HWRST_STATUS_RECOVERY;
 343         else if (!strncmp(cmd, "alarm", 5))
 344                 reboot_mode = HWRST_STATUS_ALARM;
 345         else if (!strncmp(cmd, "fastsleep", 9))
 346                 reboot_mode = HWRST_STATUS_SLEEP;
 347         else if (!strncmp(cmd, "bootloader", 10))
 348                 reboot_mode = HWRST_STATUS_FASTBOOT;
 349         else if (!strncmp(cmd, "panic", 5))
 350                 reboot_mode = HWRST_STATUS_PANIC;
 351         else if (!strncmp(cmd, "special", 7))
 352                 reboot_mode = HWRST_STATUS_SPECIAL;
 353         else if (!strncmp(cmd, "cftreboot", 9))
 354                 reboot_mode = HWRST_STATUS_CFTREBOOT;
 355         else if (!strncmp(cmd, "autodloader", 11))
 356                 reboot_mode = HWRST_STATUS_AUTODLOADER;
 357         else if (!strncmp(cmd, "iqmode", 6))
 358                 reboot_mode = HWRST_STATUS_IQMODE;
 359         else if (!strncmp(cmd, "sprdisk", 7))
 360                 reboot_mode = HWRST_STATUS_SPRDISK;
 361         else if (!strncmp(cmd, "tospanic", 8))
 362                 reboot_mode = HWRST_STATUS_SECURITY;
 363         else if (!strncmp(cmd, "factorytest", 11))
 364                 reboot_mode = HWRST_STATUS_FACTORYTEST;
 365         else
 366                 reboot_mode = HWRST_STATUS_NORMAL;
 367
 368         /* Record the reboot mode */
 369         sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
 370         val &= ~HWRST_STATUS_WATCHDOG;
 371         val |= reboot_mode;
 372         sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);
 373
 374         /* Enable the interface clock of the watchdog */
 375         sprd_adi_read(sadi, sadi->slave_pbase + PMIC_MODULE_EN, &val);
 376         val |= BIT_WDG_EN;
 377         sprd_adi_write(sadi, sadi->slave_pbase + PMIC_MODULE_EN, val);
 378
 379         /* Enable the work clock of the watchdog */
 380         sprd_adi_read(sadi, sadi->slave_pbase + PMIC_CLK_EN, &val);
 381         val |= BIT_WDG_EN;
 382         sprd_adi_write(sadi, sadi->slave_pbase + PMIC_CLK_EN, val);
 383
 384         /* Unlock the watchdog */
 385         sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, WDG_UNLOCK_KEY);
 386
 387         sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
 388         val |= BIT_WDG_NEW;
 389         sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);
 390
 391         /* Load the watchdog timeout value, 50ms is always enough. */
 392         sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_LOW,
 393                        WDG_LOAD_VAL & WDG_LOAD_MASK);
 394         sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_HIGH, 0);
 395
 396         /* Start the watchdog to reset system */
 397         sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
 398         val |= BIT_WDG_RUN | BIT_WDG_RST;
 399         sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);
 400
 401         /* Lock the watchdog */
 402         sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, ~WDG_UNLOCK_KEY);
 403
 404         mdelay(1000);
 405
 406         dev_emerg(sadi->dev, "Unable to restart system\n");
 407         return NOTIFY_DONE;
 408 }
 409
 410 static void sprd_adi_hw_init(struct sprd_adi *sadi)
 411 {
 412         struct device_node *np = sadi->dev->of_node;
 413         int i, size, chn_cnt;
 414         const __be32 *list;
 415         u32 tmp;
 416
 417         /* Set all channels as default priority */
 418         writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
 419         writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);
 420
 421         /* Set clock auto gate mode */
 422         tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
 423         tmp &= ~BIT_CLK_ALL_ON;
 424         writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);
 425
 426         /* Set hardware channels setting */
 427         list = of_get_property(np, "sprd,hw-channels", &size);
 428         if (!list || !size) {
 429                 dev_info(sadi->dev, "no hw channels setting in node\n");
 430                 return;
 431         }
 432
 433         chn_cnt = size / 8;
 434         for (i = 0; i < chn_cnt; i++) {
 435                 u32 value;
 436                 u32 chn_id = be32_to_cpu(*list++);
 437                 u32 chn_config = be32_to_cpu(*list++);
 438
 439                 /* Channel 0 and 1 are software channels */
 440                 if (chn_id < 2)
 441                         continue;
 442
 443                 writel_relaxed(chn_config, sadi->base +
 444                                REG_ADI_CHN_ADDR(chn_id));
 445
 446                 if (chn_id < 32) {
 447                         value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
 448                         value |= BIT(chn_id);
 449                         writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
 450                 } else if (chn_id < ADI_HW_CHNS) {
 451                         value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
 452                         value |= BIT(chn_id - 32);
 453                         writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
 454                 }
 455         }
 456 }
 457
 458 static int sprd_adi_probe(struct platform_device *pdev)
 459 {
 460         struct device_node *np = pdev->dev.of_node;
 461         struct spi_controller *ctlr;
 462         struct sprd_adi *sadi;
 463         struct resource *res;
 464         u32 num_chipselect;
 465         int ret;
 466
 467         if (!np) {
 468                 dev_err(&pdev->dev, "can not find the adi bus node\n");
 469                 return -ENODEV;
 470         }
 471
 472         pdev->id = of_alias_get_id(np, "spi");
 473         num_chipselect = of_get_child_count(np);
 474
 475         ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
 476         if (!ctlr)
 477                 return -ENOMEM;
 478
 479         dev_set_drvdata(&pdev->dev, ctlr);
 480         sadi = spi_controller_get_devdata(ctlr);
 481
 482         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 483         sadi->base = devm_ioremap_resource(&pdev->dev, res);
 484         if (IS_ERR(sadi->base)) {
 485                 ret = PTR_ERR(sadi->base);
 486                 goto put_ctlr;
 487         }
 488
 489         sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
 490         sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
 491         sadi->ctlr = ctlr;
 492         sadi->dev = &pdev->dev;
 493         ret = of_hwspin_lock_get_id(np, 0);
 494         if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
 495                 sadi->hwlock =
 496                         devm_hwspin_lock_request_specific(&pdev->dev, ret);
 497                 if (!sadi->hwlock) {
 498                         ret = -ENXIO;
 499                         goto put_ctlr;
 500                 }
 501         } else {
 502                 switch (ret) {
 503                 case -ENOENT:
 504                         dev_info(&pdev->dev, "no hardware spinlock supplied\n");
 505                         break;
 506                 default:
 507                         dev_err(&pdev->dev,
 508                                 "failed to find hwlock id, %d\n", ret);
 509                         /* fall-through */
 510                 case -EPROBE_DEFER:
 511                         goto put_ctlr;
 512                 }
 513         }
 514
 515         sprd_adi_hw_init(sadi);
 516         sprd_adi_set_wdt_rst_mode(sadi);
 517
 518         ctlr->dev.of_node = pdev->dev.of_node;
 519         ctlr->bus_num = pdev->id;
 520         ctlr->num_chipselect = num_chipselect;
 521         ctlr->flags = SPI_MASTER_HALF_DUPLEX;
 522         ctlr->bits_per_word_mask = 0;
 523         ctlr->transfer_one = sprd_adi_transfer_one;
 524
 525         ret = devm_spi_register_controller(&pdev->dev, ctlr);
 526         if (ret) {
 527                 dev_err(&pdev->dev, "failed to register SPI controller\n");
 528                 goto put_ctlr;
 529         }
 530
 531         sadi->restart_handler.notifier_call = sprd_adi_restart_handler;
 532         sadi->restart_handler.priority = 128;
 533         ret = register_restart_handler(&sadi->restart_handler);
 534         if (ret) {
 535                 dev_err(&pdev->dev, "can not register restart handler\n");
 536                 goto put_ctlr;
 537         }
 538
 539         return 0;
 540
 541 put_ctlr:
 542         spi_controller_put(ctlr);
 543         return ret;
 544 }
 545
 546 static int sprd_adi_remove(struct platform_device *pdev)
 547 {
 548         struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
 549         struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
 550
 551         unregister_restart_handler(&sadi->restart_handler);
 552         return 0;
 553 }
 554
 555 static const struct of_device_id sprd_adi_of_match[] = {
 556         {
 557                 .compatible = "sprd,sc9860-adi",
 558         },
 559         { },
 560 };
 561 MODULE_DEVICE_TABLE(of, sprd_adi_of_match);
 562
 563 static struct platform_driver sprd_adi_driver = {
 564         .driver = {
 565                 .name = "sprd-adi",
 566                 .of_match_table = sprd_adi_of_match,
 567         },
 568         .probe = sprd_adi_probe,
 569         .remove = sprd_adi_remove,
 570 };
 571 module_platform_driver(sprd_adi_driver);
 572
 573 MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
 574 MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
 575 MODULE_LICENSE("GPL v2");