]> Pileus Git - ~andy/linux/blob - drivers/iio/dac/ad5064.c
Merge remote-tracking branch 'regulator/topic/lp8788' into v3.9-rc8
[~andy/linux] / drivers / iio / dac / ad5064.c
1 /*
2  * AD5024, AD5025, AD5044, AD5045, AD5064, AD5064-1, AD5065, AD5628, AD5629R,
3  * AD5648, AD5666, AD5668, AD5669R Digital to analog converters driver
4  *
5  * Copyright 2011 Analog Devices Inc.
6  *
7  * Licensed under the GPL-2.
8  */
9
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/spi/spi.h>
15 #include <linux/i2c.h>
16 #include <linux/slab.h>
17 #include <linux/sysfs.h>
18 #include <linux/regulator/consumer.h>
19 #include <asm/unaligned.h>
20
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23
24 #define AD5064_MAX_DAC_CHANNELS                 8
25 #define AD5064_MAX_VREFS                        4
26
27 #define AD5064_ADDR(x)                          ((x) << 20)
28 #define AD5064_CMD(x)                           ((x) << 24)
29
30 #define AD5064_ADDR_ALL_DAC                     0xF
31
32 #define AD5064_CMD_WRITE_INPUT_N                0x0
33 #define AD5064_CMD_UPDATE_DAC_N                 0x1
34 #define AD5064_CMD_WRITE_INPUT_N_UPDATE_ALL     0x2
35 #define AD5064_CMD_WRITE_INPUT_N_UPDATE_N       0x3
36 #define AD5064_CMD_POWERDOWN_DAC                0x4
37 #define AD5064_CMD_CLEAR                        0x5
38 #define AD5064_CMD_LDAC_MASK                    0x6
39 #define AD5064_CMD_RESET                        0x7
40 #define AD5064_CMD_CONFIG                       0x8
41
42 #define AD5064_CONFIG_DAISY_CHAIN_ENABLE        BIT(1)
43 #define AD5064_CONFIG_INT_VREF_ENABLE           BIT(0)
44
45 #define AD5064_LDAC_PWRDN_NONE                  0x0
46 #define AD5064_LDAC_PWRDN_1K                    0x1
47 #define AD5064_LDAC_PWRDN_100K                  0x2
48 #define AD5064_LDAC_PWRDN_3STATE                0x3
49
50 /**
51  * struct ad5064_chip_info - chip specific information
52  * @shared_vref:        whether the vref supply is shared between channels
53  * @internal_vref:      internal reference voltage. 0 if the chip has no internal
54  *                      vref.
55  * @channel:            channel specification
56  * @num_channels:       number of channels
57  */
58
59 struct ad5064_chip_info {
60         bool shared_vref;
61         unsigned long internal_vref;
62         const struct iio_chan_spec *channels;
63         unsigned int num_channels;
64 };
65
66 struct ad5064_state;
67
68 typedef int (*ad5064_write_func)(struct ad5064_state *st, unsigned int cmd,
69                 unsigned int addr, unsigned int val);
70
71 /**
72  * struct ad5064_state - driver instance specific data
73  * @dev:                the device for this driver instance
74  * @chip_info:          chip model specific constants, available modes etc
75  * @vref_reg:           vref supply regulators
76  * @pwr_down:           whether channel is powered down
77  * @pwr_down_mode:      channel's current power down mode
78  * @dac_cache:          current DAC raw value (chip does not support readback)
79  * @use_internal_vref:  set to true if the internal reference voltage should be
80  *                      used.
81  * @write:              register write callback
82  * @data:               i2c/spi transfer buffers
83  */
84
85 struct ad5064_state {
86         struct device                   *dev;
87         const struct ad5064_chip_info   *chip_info;
88         struct regulator_bulk_data      vref_reg[AD5064_MAX_VREFS];
89         bool                            pwr_down[AD5064_MAX_DAC_CHANNELS];
90         u8                              pwr_down_mode[AD5064_MAX_DAC_CHANNELS];
91         unsigned int                    dac_cache[AD5064_MAX_DAC_CHANNELS];
92         bool                            use_internal_vref;
93
94         ad5064_write_func               write;
95
96         /*
97          * DMA (thus cache coherency maintenance) requires the
98          * transfer buffers to live in their own cache lines.
99          */
100         union {
101                 u8 i2c[3];
102                 __be32 spi;
103         } data ____cacheline_aligned;
104 };
105
106 enum ad5064_type {
107         ID_AD5024,
108         ID_AD5025,
109         ID_AD5044,
110         ID_AD5045,
111         ID_AD5064,
112         ID_AD5064_1,
113         ID_AD5065,
114         ID_AD5628_1,
115         ID_AD5628_2,
116         ID_AD5648_1,
117         ID_AD5648_2,
118         ID_AD5666_1,
119         ID_AD5666_2,
120         ID_AD5668_1,
121         ID_AD5668_2,
122 };
123
124 static int ad5064_write(struct ad5064_state *st, unsigned int cmd,
125         unsigned int addr, unsigned int val, unsigned int shift)
126 {
127         val <<= shift;
128
129         return st->write(st, cmd, addr, val);
130 }
131
132 static int ad5064_sync_powerdown_mode(struct ad5064_state *st,
133         const struct iio_chan_spec *chan)
134 {
135         unsigned int val;
136         int ret;
137
138         val = (0x1 << chan->address);
139
140         if (st->pwr_down[chan->channel])
141                 val |= st->pwr_down_mode[chan->channel] << 8;
142
143         ret = ad5064_write(st, AD5064_CMD_POWERDOWN_DAC, 0, val, 0);
144
145         return ret;
146 }
147
148 static const char * const ad5064_powerdown_modes[] = {
149         "1kohm_to_gnd",
150         "100kohm_to_gnd",
151         "three_state",
152 };
153
154 static int ad5064_get_powerdown_mode(struct iio_dev *indio_dev,
155         const struct iio_chan_spec *chan)
156 {
157         struct ad5064_state *st = iio_priv(indio_dev);
158
159         return st->pwr_down_mode[chan->channel] - 1;
160 }
161
162 static int ad5064_set_powerdown_mode(struct iio_dev *indio_dev,
163         const struct iio_chan_spec *chan, unsigned int mode)
164 {
165         struct ad5064_state *st = iio_priv(indio_dev);
166         int ret;
167
168         mutex_lock(&indio_dev->mlock);
169         st->pwr_down_mode[chan->channel] = mode + 1;
170
171         ret = ad5064_sync_powerdown_mode(st, chan);
172         mutex_unlock(&indio_dev->mlock);
173
174         return ret;
175 }
176
177 static const struct iio_enum ad5064_powerdown_mode_enum = {
178         .items = ad5064_powerdown_modes,
179         .num_items = ARRAY_SIZE(ad5064_powerdown_modes),
180         .get = ad5064_get_powerdown_mode,
181         .set = ad5064_set_powerdown_mode,
182 };
183
184 static ssize_t ad5064_read_dac_powerdown(struct iio_dev *indio_dev,
185         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
186 {
187         struct ad5064_state *st = iio_priv(indio_dev);
188
189         return sprintf(buf, "%d\n", st->pwr_down[chan->channel]);
190 }
191
192 static ssize_t ad5064_write_dac_powerdown(struct iio_dev *indio_dev,
193          uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
194          size_t len)
195 {
196         struct ad5064_state *st = iio_priv(indio_dev);
197         bool pwr_down;
198         int ret;
199
200         ret = strtobool(buf, &pwr_down);
201         if (ret)
202                 return ret;
203
204         mutex_lock(&indio_dev->mlock);
205         st->pwr_down[chan->channel] = pwr_down;
206
207         ret = ad5064_sync_powerdown_mode(st, chan);
208         mutex_unlock(&indio_dev->mlock);
209         return ret ? ret : len;
210 }
211
212 static int ad5064_get_vref(struct ad5064_state *st,
213         struct iio_chan_spec const *chan)
214 {
215         unsigned int i;
216
217         if (st->use_internal_vref)
218                 return st->chip_info->internal_vref;
219
220         i = st->chip_info->shared_vref ? 0 : chan->channel;
221         return regulator_get_voltage(st->vref_reg[i].consumer);
222 }
223
224 static int ad5064_read_raw(struct iio_dev *indio_dev,
225                            struct iio_chan_spec const *chan,
226                            int *val,
227                            int *val2,
228                            long m)
229 {
230         struct ad5064_state *st = iio_priv(indio_dev);
231         int scale_uv;
232
233         switch (m) {
234         case IIO_CHAN_INFO_RAW:
235                 *val = st->dac_cache[chan->channel];
236                 return IIO_VAL_INT;
237         case IIO_CHAN_INFO_SCALE:
238                 scale_uv = ad5064_get_vref(st, chan);
239                 if (scale_uv < 0)
240                         return scale_uv;
241
242                 scale_uv = (scale_uv * 100) >> chan->scan_type.realbits;
243                 *val =  scale_uv / 100000;
244                 *val2 = (scale_uv % 100000) * 10;
245                 return IIO_VAL_INT_PLUS_MICRO;
246         default:
247                 break;
248         }
249         return -EINVAL;
250 }
251
252 static int ad5064_write_raw(struct iio_dev *indio_dev,
253         struct iio_chan_spec const *chan, int val, int val2, long mask)
254 {
255         struct ad5064_state *st = iio_priv(indio_dev);
256         int ret;
257
258         switch (mask) {
259         case IIO_CHAN_INFO_RAW:
260                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
261                         return -EINVAL;
262
263                 mutex_lock(&indio_dev->mlock);
264                 ret = ad5064_write(st, AD5064_CMD_WRITE_INPUT_N_UPDATE_N,
265                                 chan->address, val, chan->scan_type.shift);
266                 if (ret == 0)
267                         st->dac_cache[chan->channel] = val;
268                 mutex_unlock(&indio_dev->mlock);
269                 break;
270         default:
271                 ret = -EINVAL;
272         }
273
274         return ret;
275 }
276
277 static const struct iio_info ad5064_info = {
278         .read_raw = ad5064_read_raw,
279         .write_raw = ad5064_write_raw,
280         .driver_module = THIS_MODULE,
281 };
282
283 static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
284         {
285                 .name = "powerdown",
286                 .read = ad5064_read_dac_powerdown,
287                 .write = ad5064_write_dac_powerdown,
288         },
289         IIO_ENUM("powerdown_mode", false, &ad5064_powerdown_mode_enum),
290         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5064_powerdown_mode_enum),
291         { },
292 };
293
294 #define AD5064_CHANNEL(chan, addr, bits) {                      \
295         .type = IIO_VOLTAGE,                                    \
296         .indexed = 1,                                           \
297         .output = 1,                                            \
298         .channel = (chan),                                      \
299         .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |           \
300         IIO_CHAN_INFO_SCALE_SEPARATE_BIT,                       \
301         .address = addr,                                        \
302         .scan_type = IIO_ST('u', (bits), 16, 20 - (bits)),      \
303         .ext_info = ad5064_ext_info,                            \
304 }
305
306 #define DECLARE_AD5064_CHANNELS(name, bits) \
307 const struct iio_chan_spec name[] = { \
308         AD5064_CHANNEL(0, 0, bits), \
309         AD5064_CHANNEL(1, 1, bits), \
310         AD5064_CHANNEL(2, 2, bits), \
311         AD5064_CHANNEL(3, 3, bits), \
312         AD5064_CHANNEL(4, 4, bits), \
313         AD5064_CHANNEL(5, 5, bits), \
314         AD5064_CHANNEL(6, 6, bits), \
315         AD5064_CHANNEL(7, 7, bits), \
316 }
317
318 #define DECLARE_AD5065_CHANNELS(name, bits) \
319 const struct iio_chan_spec name[] = { \
320         AD5064_CHANNEL(0, 0, bits), \
321         AD5064_CHANNEL(1, 3, bits), \
322 }
323
324 static DECLARE_AD5064_CHANNELS(ad5024_channels, 12);
325 static DECLARE_AD5064_CHANNELS(ad5044_channels, 14);
326 static DECLARE_AD5064_CHANNELS(ad5064_channels, 16);
327
328 static DECLARE_AD5065_CHANNELS(ad5025_channels, 12);
329 static DECLARE_AD5065_CHANNELS(ad5045_channels, 14);
330 static DECLARE_AD5065_CHANNELS(ad5065_channels, 16);
331
332 static const struct ad5064_chip_info ad5064_chip_info_tbl[] = {
333         [ID_AD5024] = {
334                 .shared_vref = false,
335                 .channels = ad5024_channels,
336                 .num_channels = 4,
337         },
338         [ID_AD5025] = {
339                 .shared_vref = false,
340                 .channels = ad5025_channels,
341                 .num_channels = 2,
342         },
343         [ID_AD5044] = {
344                 .shared_vref = false,
345                 .channels = ad5044_channels,
346                 .num_channels = 4,
347         },
348         [ID_AD5045] = {
349                 .shared_vref = false,
350                 .channels = ad5045_channels,
351                 .num_channels = 2,
352         },
353         [ID_AD5064] = {
354                 .shared_vref = false,
355                 .channels = ad5064_channels,
356                 .num_channels = 4,
357         },
358         [ID_AD5064_1] = {
359                 .shared_vref = true,
360                 .channels = ad5064_channels,
361                 .num_channels = 4,
362         },
363         [ID_AD5065] = {
364                 .shared_vref = false,
365                 .channels = ad5065_channels,
366                 .num_channels = 2,
367         },
368         [ID_AD5628_1] = {
369                 .shared_vref = true,
370                 .internal_vref = 2500000,
371                 .channels = ad5024_channels,
372                 .num_channels = 8,
373         },
374         [ID_AD5628_2] = {
375                 .shared_vref = true,
376                 .internal_vref = 5000000,
377                 .channels = ad5024_channels,
378                 .num_channels = 8,
379         },
380         [ID_AD5648_1] = {
381                 .shared_vref = true,
382                 .internal_vref = 2500000,
383                 .channels = ad5044_channels,
384                 .num_channels = 8,
385         },
386         [ID_AD5648_2] = {
387                 .shared_vref = true,
388                 .internal_vref = 5000000,
389                 .channels = ad5044_channels,
390                 .num_channels = 8,
391         },
392         [ID_AD5666_1] = {
393                 .shared_vref = true,
394                 .internal_vref = 2500000,
395                 .channels = ad5064_channels,
396                 .num_channels = 4,
397         },
398         [ID_AD5666_2] = {
399                 .shared_vref = true,
400                 .internal_vref = 5000000,
401                 .channels = ad5064_channels,
402                 .num_channels = 4,
403         },
404         [ID_AD5668_1] = {
405                 .shared_vref = true,
406                 .internal_vref = 2500000,
407                 .channels = ad5064_channels,
408                 .num_channels = 8,
409         },
410         [ID_AD5668_2] = {
411                 .shared_vref = true,
412                 .internal_vref = 5000000,
413                 .channels = ad5064_channels,
414                 .num_channels = 8,
415         },
416 };
417
418 static inline unsigned int ad5064_num_vref(struct ad5064_state *st)
419 {
420         return st->chip_info->shared_vref ? 1 : st->chip_info->num_channels;
421 }
422
423 static const char * const ad5064_vref_names[] = {
424         "vrefA",
425         "vrefB",
426         "vrefC",
427         "vrefD",
428 };
429
430 static const char * const ad5064_vref_name(struct ad5064_state *st,
431         unsigned int vref)
432 {
433         return st->chip_info->shared_vref ? "vref" : ad5064_vref_names[vref];
434 }
435
436 static int ad5064_probe(struct device *dev, enum ad5064_type type,
437                         const char *name, ad5064_write_func write)
438 {
439         struct iio_dev *indio_dev;
440         struct ad5064_state *st;
441         unsigned int midscale;
442         unsigned int i;
443         int ret;
444
445         indio_dev = iio_device_alloc(sizeof(*st));
446         if (indio_dev == NULL)
447                 return  -ENOMEM;
448
449         st = iio_priv(indio_dev);
450         dev_set_drvdata(dev, indio_dev);
451
452         st->chip_info = &ad5064_chip_info_tbl[type];
453         st->dev = dev;
454         st->write = write;
455
456         for (i = 0; i < ad5064_num_vref(st); ++i)
457                 st->vref_reg[i].supply = ad5064_vref_name(st, i);
458
459         ret = regulator_bulk_get(dev, ad5064_num_vref(st),
460                 st->vref_reg);
461         if (ret) {
462                 if (!st->chip_info->internal_vref)
463                         goto error_free;
464                 st->use_internal_vref = true;
465                 ret = ad5064_write(st, AD5064_CMD_CONFIG, 0,
466                         AD5064_CONFIG_INT_VREF_ENABLE, 0);
467                 if (ret) {
468                         dev_err(dev, "Failed to enable internal vref: %d\n",
469                                 ret);
470                         goto error_free;
471                 }
472         } else {
473                 ret = regulator_bulk_enable(ad5064_num_vref(st), st->vref_reg);
474                 if (ret)
475                         goto error_free_reg;
476         }
477
478         indio_dev->dev.parent = dev;
479         indio_dev->name = name;
480         indio_dev->info = &ad5064_info;
481         indio_dev->modes = INDIO_DIRECT_MODE;
482         indio_dev->channels = st->chip_info->channels;
483         indio_dev->num_channels = st->chip_info->num_channels;
484
485         midscale = (1 << indio_dev->channels[0].scan_type.realbits) /  2;
486
487         for (i = 0; i < st->chip_info->num_channels; ++i) {
488                 st->pwr_down_mode[i] = AD5064_LDAC_PWRDN_1K;
489                 st->dac_cache[i] = midscale;
490         }
491
492         ret = iio_device_register(indio_dev);
493         if (ret)
494                 goto error_disable_reg;
495
496         return 0;
497
498 error_disable_reg:
499         if (!st->use_internal_vref)
500                 regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
501 error_free_reg:
502         if (!st->use_internal_vref)
503                 regulator_bulk_free(ad5064_num_vref(st), st->vref_reg);
504 error_free:
505         iio_device_free(indio_dev);
506
507         return ret;
508 }
509
510 static int ad5064_remove(struct device *dev)
511 {
512         struct iio_dev *indio_dev = dev_get_drvdata(dev);
513         struct ad5064_state *st = iio_priv(indio_dev);
514
515         iio_device_unregister(indio_dev);
516
517         if (!st->use_internal_vref) {
518                 regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
519                 regulator_bulk_free(ad5064_num_vref(st), st->vref_reg);
520         }
521
522         iio_device_free(indio_dev);
523
524         return 0;
525 }
526
527 #if IS_ENABLED(CONFIG_SPI_MASTER)
528
529 static int ad5064_spi_write(struct ad5064_state *st, unsigned int cmd,
530         unsigned int addr, unsigned int val)
531 {
532         struct spi_device *spi = to_spi_device(st->dev);
533
534         st->data.spi = cpu_to_be32(AD5064_CMD(cmd) | AD5064_ADDR(addr) | val);
535         return spi_write(spi, &st->data.spi, sizeof(st->data.spi));
536 }
537
538 static int ad5064_spi_probe(struct spi_device *spi)
539 {
540         const struct spi_device_id *id = spi_get_device_id(spi);
541
542         return ad5064_probe(&spi->dev, id->driver_data, id->name,
543                                 ad5064_spi_write);
544 }
545
546 static int ad5064_spi_remove(struct spi_device *spi)
547 {
548         return ad5064_remove(&spi->dev);
549 }
550
551 static const struct spi_device_id ad5064_spi_ids[] = {
552         {"ad5024", ID_AD5024},
553         {"ad5025", ID_AD5025},
554         {"ad5044", ID_AD5044},
555         {"ad5045", ID_AD5045},
556         {"ad5064", ID_AD5064},
557         {"ad5064-1", ID_AD5064_1},
558         {"ad5065", ID_AD5065},
559         {"ad5628-1", ID_AD5628_1},
560         {"ad5628-2", ID_AD5628_2},
561         {"ad5648-1", ID_AD5648_1},
562         {"ad5648-2", ID_AD5648_2},
563         {"ad5666-1", ID_AD5666_1},
564         {"ad5666-2", ID_AD5666_2},
565         {"ad5668-1", ID_AD5668_1},
566         {"ad5668-2", ID_AD5668_2},
567         {"ad5668-3", ID_AD5668_2}, /* similar enough to ad5668-2 */
568         {}
569 };
570 MODULE_DEVICE_TABLE(spi, ad5064_spi_ids);
571
572 static struct spi_driver ad5064_spi_driver = {
573         .driver = {
574                    .name = "ad5064",
575                    .owner = THIS_MODULE,
576         },
577         .probe = ad5064_spi_probe,
578         .remove = ad5064_spi_remove,
579         .id_table = ad5064_spi_ids,
580 };
581
582 static int __init ad5064_spi_register_driver(void)
583 {
584         return spi_register_driver(&ad5064_spi_driver);
585 }
586
587 static void ad5064_spi_unregister_driver(void)
588 {
589         spi_unregister_driver(&ad5064_spi_driver);
590 }
591
592 #else
593
594 static inline int ad5064_spi_register_driver(void) { return 0; }
595 static inline void ad5064_spi_unregister_driver(void) { }
596
597 #endif
598
599 #if IS_ENABLED(CONFIG_I2C)
600
601 static int ad5064_i2c_write(struct ad5064_state *st, unsigned int cmd,
602         unsigned int addr, unsigned int val)
603 {
604         struct i2c_client *i2c = to_i2c_client(st->dev);
605
606         st->data.i2c[0] = (cmd << 4) | addr;
607         put_unaligned_be16(val, &st->data.i2c[1]);
608         return i2c_master_send(i2c, st->data.i2c, 3);
609 }
610
611 static int ad5064_i2c_probe(struct i2c_client *i2c,
612         const struct i2c_device_id *id)
613 {
614         return ad5064_probe(&i2c->dev, id->driver_data, id->name,
615                                                 ad5064_i2c_write);
616 }
617
618 static int ad5064_i2c_remove(struct i2c_client *i2c)
619 {
620         return ad5064_remove(&i2c->dev);
621 }
622
623 static const struct i2c_device_id ad5064_i2c_ids[] = {
624         {"ad5629-1", ID_AD5628_1},
625         {"ad5629-2", ID_AD5628_2},
626         {"ad5629-3", ID_AD5628_2}, /* similar enough to ad5629-2 */
627         {"ad5669-1", ID_AD5668_1},
628         {"ad5669-2", ID_AD5668_2},
629         {"ad5669-3", ID_AD5668_2}, /* similar enough to ad5669-2 */
630         {}
631 };
632 MODULE_DEVICE_TABLE(i2c, ad5064_i2c_ids);
633
634 static struct i2c_driver ad5064_i2c_driver = {
635         .driver = {
636                    .name = "ad5064",
637                    .owner = THIS_MODULE,
638         },
639         .probe = ad5064_i2c_probe,
640         .remove = ad5064_i2c_remove,
641         .id_table = ad5064_i2c_ids,
642 };
643
644 static int __init ad5064_i2c_register_driver(void)
645 {
646         return i2c_add_driver(&ad5064_i2c_driver);
647 }
648
649 static void __exit ad5064_i2c_unregister_driver(void)
650 {
651         i2c_del_driver(&ad5064_i2c_driver);
652 }
653
654 #else
655
656 static inline int ad5064_i2c_register_driver(void) { return 0; }
657 static inline void ad5064_i2c_unregister_driver(void) { }
658
659 #endif
660
661 static int __init ad5064_init(void)
662 {
663         int ret;
664
665         ret = ad5064_spi_register_driver();
666         if (ret)
667                 return ret;
668
669         ret = ad5064_i2c_register_driver();
670         if (ret) {
671                 ad5064_spi_unregister_driver();
672                 return ret;
673         }
674
675         return 0;
676 }
677 module_init(ad5064_init);
678
679 static void __exit ad5064_exit(void)
680 {
681         ad5064_i2c_unregister_driver();
682         ad5064_spi_unregister_driver();
683 }
684 module_exit(ad5064_exit);
685
686 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
687 MODULE_DESCRIPTION("Analog Devices AD5024 and similar multi-channel DACs");
688 MODULE_LICENSE("GPL v2");