xref: /openbmc/linux/sound/soc/qcom/lpass-platform.c (revision 4eb5928d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2010-2011,2013-2015 The Linux Foundation. All rights reserved.
4  *
5  * lpass-platform.c -- ALSA SoC platform driver for QTi LPASS
6  */
7 
8 #include <linux/dma-mapping.h>
9 #include <linux/export.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <sound/pcm_params.h>
14 #include <linux/regmap.h>
15 #include <sound/soc.h>
16 #include "lpass-lpaif-reg.h"
17 #include "lpass.h"
18 
19 #define DRV_NAME "lpass-platform"
20 
21 struct lpass_pcm_data {
22 	int dma_ch;
23 	int i2s_port;
24 };
25 
26 #define LPASS_PLATFORM_BUFFER_SIZE	(16 * 1024)
27 #define LPASS_PLATFORM_PERIODS		2
28 
29 static const struct snd_pcm_hardware lpass_platform_pcm_hardware = {
30 	.info			=	SNDRV_PCM_INFO_MMAP |
31 					SNDRV_PCM_INFO_MMAP_VALID |
32 					SNDRV_PCM_INFO_INTERLEAVED |
33 					SNDRV_PCM_INFO_PAUSE |
34 					SNDRV_PCM_INFO_RESUME,
35 	.formats		=	SNDRV_PCM_FMTBIT_S16 |
36 					SNDRV_PCM_FMTBIT_S24 |
37 					SNDRV_PCM_FMTBIT_S32,
38 	.rates			=	SNDRV_PCM_RATE_8000_192000,
39 	.rate_min		=	8000,
40 	.rate_max		=	192000,
41 	.channels_min		=	1,
42 	.channels_max		=	8,
43 	.buffer_bytes_max	=	LPASS_PLATFORM_BUFFER_SIZE,
44 	.period_bytes_max	=	LPASS_PLATFORM_BUFFER_SIZE /
45 						LPASS_PLATFORM_PERIODS,
46 	.period_bytes_min	=	LPASS_PLATFORM_BUFFER_SIZE /
47 						LPASS_PLATFORM_PERIODS,
48 	.periods_min		=	LPASS_PLATFORM_PERIODS,
49 	.periods_max		=	LPASS_PLATFORM_PERIODS,
50 	.fifo_size		=	0,
51 };
52 
53 static int lpass_platform_pcmops_open(struct snd_soc_component *component,
54 				      struct snd_pcm_substream *substream)
55 {
56 	struct snd_pcm_runtime *runtime = substream->runtime;
57 	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
58 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(soc_runtime, 0);
59 	struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
60 	struct lpass_variant *v = drvdata->variant;
61 	int ret, dma_ch, dir = substream->stream;
62 	struct lpass_pcm_data *data;
63 
64 	data = devm_kzalloc(soc_runtime->dev, sizeof(*data), GFP_KERNEL);
65 	if (!data)
66 		return -ENOMEM;
67 
68 	data->i2s_port = cpu_dai->driver->id;
69 	runtime->private_data = data;
70 
71 	if (v->alloc_dma_channel)
72 		dma_ch = v->alloc_dma_channel(drvdata, dir);
73 	else
74 		dma_ch = 0;
75 
76 	if (dma_ch < 0)
77 		return dma_ch;
78 
79 	drvdata->substream[dma_ch] = substream;
80 
81 	ret = regmap_write(drvdata->lpaif_map,
82 			LPAIF_DMACTL_REG(v, dma_ch, dir), 0);
83 	if (ret) {
84 		dev_err(soc_runtime->dev,
85 			"error writing to rdmactl reg: %d\n", ret);
86 		return ret;
87 	}
88 
89 	data->dma_ch = dma_ch;
90 
91 	snd_soc_set_runtime_hwparams(substream, &lpass_platform_pcm_hardware);
92 
93 	runtime->dma_bytes = lpass_platform_pcm_hardware.buffer_bytes_max;
94 
95 	ret = snd_pcm_hw_constraint_integer(runtime,
96 			SNDRV_PCM_HW_PARAM_PERIODS);
97 	if (ret < 0) {
98 		dev_err(soc_runtime->dev, "setting constraints failed: %d\n",
99 			ret);
100 		return -EINVAL;
101 	}
102 
103 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
104 
105 	return 0;
106 }
107 
108 static int lpass_platform_pcmops_close(struct snd_soc_component *component,
109 				       struct snd_pcm_substream *substream)
110 {
111 	struct snd_pcm_runtime *runtime = substream->runtime;
112 	struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
113 	struct lpass_variant *v = drvdata->variant;
114 	struct lpass_pcm_data *data;
115 
116 	data = runtime->private_data;
117 	drvdata->substream[data->dma_ch] = NULL;
118 	if (v->free_dma_channel)
119 		v->free_dma_channel(drvdata, data->dma_ch);
120 
121 	return 0;
122 }
123 
124 static int lpass_platform_pcmops_hw_params(struct snd_soc_component *component,
125 					   struct snd_pcm_substream *substream,
126 					   struct snd_pcm_hw_params *params)
127 {
128 	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
129 	struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
130 	struct snd_pcm_runtime *rt = substream->runtime;
131 	struct lpass_pcm_data *pcm_data = rt->private_data;
132 	struct lpass_variant *v = drvdata->variant;
133 	snd_pcm_format_t format = params_format(params);
134 	unsigned int channels = params_channels(params);
135 	unsigned int regval;
136 	int ch, dir = substream->stream;
137 	int bitwidth;
138 	int ret, dma_port = pcm_data->i2s_port + v->dmactl_audif_start;
139 
140 	ch = pcm_data->dma_ch;
141 
142 	bitwidth = snd_pcm_format_width(format);
143 	if (bitwidth < 0) {
144 		dev_err(soc_runtime->dev, "invalid bit width given: %d\n",
145 				bitwidth);
146 		return bitwidth;
147 	}
148 
149 	regval = LPAIF_DMACTL_BURSTEN_INCR4 |
150 			LPAIF_DMACTL_AUDINTF(dma_port) |
151 			LPAIF_DMACTL_FIFOWM_8;
152 
153 	switch (bitwidth) {
154 	case 16:
155 		switch (channels) {
156 		case 1:
157 		case 2:
158 			regval |= LPAIF_DMACTL_WPSCNT_ONE;
159 			break;
160 		case 4:
161 			regval |= LPAIF_DMACTL_WPSCNT_TWO;
162 			break;
163 		case 6:
164 			regval |= LPAIF_DMACTL_WPSCNT_THREE;
165 			break;
166 		case 8:
167 			regval |= LPAIF_DMACTL_WPSCNT_FOUR;
168 			break;
169 		default:
170 			dev_err(soc_runtime->dev,
171 				"invalid PCM config given: bw=%d, ch=%u\n",
172 				bitwidth, channels);
173 			return -EINVAL;
174 		}
175 		break;
176 	case 24:
177 	case 32:
178 		switch (channels) {
179 		case 1:
180 			regval |= LPAIF_DMACTL_WPSCNT_ONE;
181 			break;
182 		case 2:
183 			regval |= LPAIF_DMACTL_WPSCNT_TWO;
184 			break;
185 		case 4:
186 			regval |= LPAIF_DMACTL_WPSCNT_FOUR;
187 			break;
188 		case 6:
189 			regval |= LPAIF_DMACTL_WPSCNT_SIX;
190 			break;
191 		case 8:
192 			regval |= LPAIF_DMACTL_WPSCNT_EIGHT;
193 			break;
194 		default:
195 			dev_err(soc_runtime->dev,
196 				"invalid PCM config given: bw=%d, ch=%u\n",
197 				bitwidth, channels);
198 			return -EINVAL;
199 		}
200 		break;
201 	default:
202 		dev_err(soc_runtime->dev, "invalid PCM config given: bw=%d, ch=%u\n",
203 			bitwidth, channels);
204 		return -EINVAL;
205 	}
206 
207 	ret = regmap_write(drvdata->lpaif_map,
208 			LPAIF_DMACTL_REG(v, ch, dir), regval);
209 	if (ret) {
210 		dev_err(soc_runtime->dev, "error writing to rdmactl reg: %d\n",
211 			ret);
212 		return ret;
213 	}
214 
215 	return 0;
216 }
217 
218 static int lpass_platform_pcmops_hw_free(struct snd_soc_component *component,
219 					 struct snd_pcm_substream *substream)
220 {
221 	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
222 	struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
223 	struct snd_pcm_runtime *rt = substream->runtime;
224 	struct lpass_pcm_data *pcm_data = rt->private_data;
225 	struct lpass_variant *v = drvdata->variant;
226 	unsigned int reg;
227 	int ret;
228 
229 	reg = LPAIF_DMACTL_REG(v, pcm_data->dma_ch, substream->stream);
230 	ret = regmap_write(drvdata->lpaif_map, reg, 0);
231 	if (ret)
232 		dev_err(soc_runtime->dev, "error writing to rdmactl reg: %d\n",
233 			ret);
234 
235 	return ret;
236 }
237 
238 static int lpass_platform_pcmops_prepare(struct snd_soc_component *component,
239 					 struct snd_pcm_substream *substream)
240 {
241 	struct snd_pcm_runtime *runtime = substream->runtime;
242 	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
243 	struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
244 	struct snd_pcm_runtime *rt = substream->runtime;
245 	struct lpass_pcm_data *pcm_data = rt->private_data;
246 	struct lpass_variant *v = drvdata->variant;
247 	int ret, ch, dir = substream->stream;
248 
249 	ch = pcm_data->dma_ch;
250 
251 	ret = regmap_write(drvdata->lpaif_map,
252 			LPAIF_DMABASE_REG(v, ch, dir),
253 			runtime->dma_addr);
254 	if (ret) {
255 		dev_err(soc_runtime->dev, "error writing to rdmabase reg: %d\n",
256 			ret);
257 		return ret;
258 	}
259 
260 	ret = regmap_write(drvdata->lpaif_map,
261 			LPAIF_DMABUFF_REG(v, ch, dir),
262 			(snd_pcm_lib_buffer_bytes(substream) >> 2) - 1);
263 	if (ret) {
264 		dev_err(soc_runtime->dev, "error writing to rdmabuff reg: %d\n",
265 			ret);
266 		return ret;
267 	}
268 
269 	ret = regmap_write(drvdata->lpaif_map,
270 			LPAIF_DMAPER_REG(v, ch, dir),
271 			(snd_pcm_lib_period_bytes(substream) >> 2) - 1);
272 	if (ret) {
273 		dev_err(soc_runtime->dev, "error writing to rdmaper reg: %d\n",
274 			ret);
275 		return ret;
276 	}
277 
278 	ret = regmap_update_bits(drvdata->lpaif_map,
279 			LPAIF_DMACTL_REG(v, ch, dir),
280 			LPAIF_DMACTL_ENABLE_MASK, LPAIF_DMACTL_ENABLE_ON);
281 	if (ret) {
282 		dev_err(soc_runtime->dev, "error writing to rdmactl reg: %d\n",
283 			ret);
284 		return ret;
285 	}
286 
287 	return 0;
288 }
289 
290 static int lpass_platform_pcmops_trigger(struct snd_soc_component *component,
291 					 struct snd_pcm_substream *substream,
292 					 int cmd)
293 {
294 	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
295 	struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
296 	struct snd_pcm_runtime *rt = substream->runtime;
297 	struct lpass_pcm_data *pcm_data = rt->private_data;
298 	struct lpass_variant *v = drvdata->variant;
299 	int ret, ch, dir = substream->stream;
300 
301 	ch = pcm_data->dma_ch;
302 
303 	switch (cmd) {
304 	case SNDRV_PCM_TRIGGER_START:
305 	case SNDRV_PCM_TRIGGER_RESUME:
306 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
307 		/* clear status before enabling interrupts */
308 		ret = regmap_write(drvdata->lpaif_map,
309 				LPAIF_IRQCLEAR_REG(v, LPAIF_IRQ_PORT_HOST),
310 				LPAIF_IRQ_ALL(ch));
311 		if (ret) {
312 			dev_err(soc_runtime->dev,
313 				"error writing to irqclear reg: %d\n", ret);
314 			return ret;
315 		}
316 
317 		ret = regmap_update_bits(drvdata->lpaif_map,
318 				LPAIF_IRQEN_REG(v, LPAIF_IRQ_PORT_HOST),
319 				LPAIF_IRQ_ALL(ch),
320 				LPAIF_IRQ_ALL(ch));
321 		if (ret) {
322 			dev_err(soc_runtime->dev,
323 				"error writing to irqen reg: %d\n", ret);
324 			return ret;
325 		}
326 
327 		ret = regmap_update_bits(drvdata->lpaif_map,
328 				LPAIF_DMACTL_REG(v, ch, dir),
329 				LPAIF_DMACTL_ENABLE_MASK,
330 				LPAIF_DMACTL_ENABLE_ON);
331 		if (ret) {
332 			dev_err(soc_runtime->dev,
333 				"error writing to rdmactl reg: %d\n", ret);
334 			return ret;
335 		}
336 		break;
337 	case SNDRV_PCM_TRIGGER_STOP:
338 	case SNDRV_PCM_TRIGGER_SUSPEND:
339 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
340 		ret = regmap_update_bits(drvdata->lpaif_map,
341 				LPAIF_DMACTL_REG(v, ch, dir),
342 				LPAIF_DMACTL_ENABLE_MASK,
343 				LPAIF_DMACTL_ENABLE_OFF);
344 		if (ret) {
345 			dev_err(soc_runtime->dev,
346 				"error writing to rdmactl reg: %d\n", ret);
347 			return ret;
348 		}
349 
350 		ret = regmap_update_bits(drvdata->lpaif_map,
351 				LPAIF_IRQEN_REG(v, LPAIF_IRQ_PORT_HOST),
352 				LPAIF_IRQ_ALL(ch), 0);
353 		if (ret) {
354 			dev_err(soc_runtime->dev,
355 				"error writing to irqen reg: %d\n", ret);
356 			return ret;
357 		}
358 		break;
359 	}
360 
361 	return 0;
362 }
363 
364 static snd_pcm_uframes_t lpass_platform_pcmops_pointer(
365 		struct snd_soc_component *component,
366 		struct snd_pcm_substream *substream)
367 {
368 	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
369 	struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
370 	struct snd_pcm_runtime *rt = substream->runtime;
371 	struct lpass_pcm_data *pcm_data = rt->private_data;
372 	struct lpass_variant *v = drvdata->variant;
373 	unsigned int base_addr, curr_addr;
374 	int ret, ch, dir = substream->stream;
375 
376 	ch = pcm_data->dma_ch;
377 
378 	ret = regmap_read(drvdata->lpaif_map,
379 			LPAIF_DMABASE_REG(v, ch, dir), &base_addr);
380 	if (ret) {
381 		dev_err(soc_runtime->dev,
382 			"error reading from rdmabase reg: %d\n", ret);
383 		return ret;
384 	}
385 
386 	ret = regmap_read(drvdata->lpaif_map,
387 			LPAIF_DMACURR_REG(v, ch, dir), &curr_addr);
388 	if (ret) {
389 		dev_err(soc_runtime->dev,
390 			"error reading from rdmacurr reg: %d\n", ret);
391 		return ret;
392 	}
393 
394 	return bytes_to_frames(substream->runtime, curr_addr - base_addr);
395 }
396 
397 static int lpass_platform_pcmops_mmap(struct snd_soc_component *component,
398 				      struct snd_pcm_substream *substream,
399 				      struct vm_area_struct *vma)
400 {
401 	struct snd_pcm_runtime *runtime = substream->runtime;
402 
403 	return dma_mmap_coherent(substream->pcm->card->dev, vma,
404 			runtime->dma_area, runtime->dma_addr,
405 			runtime->dma_bytes);
406 }
407 
408 static irqreturn_t lpass_dma_interrupt_handler(
409 			struct snd_pcm_substream *substream,
410 			struct lpass_data *drvdata,
411 			int chan, u32 interrupts)
412 {
413 	struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
414 	struct lpass_variant *v = drvdata->variant;
415 	irqreturn_t ret = IRQ_NONE;
416 	int rv;
417 
418 	if (interrupts & LPAIF_IRQ_PER(chan)) {
419 		rv = regmap_write(drvdata->lpaif_map,
420 				LPAIF_IRQCLEAR_REG(v, LPAIF_IRQ_PORT_HOST),
421 				LPAIF_IRQ_PER(chan));
422 		if (rv) {
423 			dev_err(soc_runtime->dev,
424 				"error writing to irqclear reg: %d\n", rv);
425 			return IRQ_NONE;
426 		}
427 		snd_pcm_period_elapsed(substream);
428 		ret = IRQ_HANDLED;
429 	}
430 
431 	if (interrupts & LPAIF_IRQ_XRUN(chan)) {
432 		rv = regmap_write(drvdata->lpaif_map,
433 				LPAIF_IRQCLEAR_REG(v, LPAIF_IRQ_PORT_HOST),
434 				LPAIF_IRQ_XRUN(chan));
435 		if (rv) {
436 			dev_err(soc_runtime->dev,
437 				"error writing to irqclear reg: %d\n", rv);
438 			return IRQ_NONE;
439 		}
440 		dev_warn(soc_runtime->dev, "xrun warning\n");
441 		snd_pcm_stop_xrun(substream);
442 		ret = IRQ_HANDLED;
443 	}
444 
445 	if (interrupts & LPAIF_IRQ_ERR(chan)) {
446 		rv = regmap_write(drvdata->lpaif_map,
447 				LPAIF_IRQCLEAR_REG(v, LPAIF_IRQ_PORT_HOST),
448 				LPAIF_IRQ_ERR(chan));
449 		if (rv) {
450 			dev_err(soc_runtime->dev,
451 				"error writing to irqclear reg: %d\n", rv);
452 			return IRQ_NONE;
453 		}
454 		dev_err(soc_runtime->dev, "bus access error\n");
455 		snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
456 		ret = IRQ_HANDLED;
457 	}
458 
459 	return ret;
460 }
461 
462 static irqreturn_t lpass_platform_lpaif_irq(int irq, void *data)
463 {
464 	struct lpass_data *drvdata = data;
465 	struct lpass_variant *v = drvdata->variant;
466 	unsigned int irqs;
467 	int rv, chan;
468 
469 	rv = regmap_read(drvdata->lpaif_map,
470 			LPAIF_IRQSTAT_REG(v, LPAIF_IRQ_PORT_HOST), &irqs);
471 	if (rv) {
472 		pr_err("error reading from irqstat reg: %d\n", rv);
473 		return IRQ_NONE;
474 	}
475 
476 	/* Handle per channel interrupts */
477 	for (chan = 0; chan < LPASS_MAX_DMA_CHANNELS; chan++) {
478 		if (irqs & LPAIF_IRQ_ALL(chan) && drvdata->substream[chan]) {
479 			rv = lpass_dma_interrupt_handler(
480 						drvdata->substream[chan],
481 						drvdata, chan, irqs);
482 			if (rv != IRQ_HANDLED)
483 				return rv;
484 		}
485 	}
486 
487 	return IRQ_HANDLED;
488 }
489 
490 static int lpass_platform_pcm_new(struct snd_soc_component *component,
491 				  struct snd_soc_pcm_runtime *soc_runtime)
492 {
493 	struct snd_pcm *pcm = soc_runtime->pcm;
494 	struct snd_pcm_substream *psubstream, *csubstream;
495 	int ret = -EINVAL;
496 	size_t size = lpass_platform_pcm_hardware.buffer_bytes_max;
497 
498 	psubstream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
499 	if (psubstream) {
500 		ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
501 					component->dev,
502 					size, &psubstream->dma_buffer);
503 		if (ret) {
504 			dev_err(soc_runtime->dev, "Cannot allocate buffer(s)\n");
505 			return ret;
506 		}
507 	}
508 
509 	csubstream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
510 	if (csubstream) {
511 		ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV,
512 					component->dev,
513 					size, &csubstream->dma_buffer);
514 		if (ret) {
515 			dev_err(soc_runtime->dev, "Cannot allocate buffer(s)\n");
516 			if (psubstream)
517 				snd_dma_free_pages(&psubstream->dma_buffer);
518 			return ret;
519 		}
520 
521 	}
522 
523 	return 0;
524 }
525 
526 static void lpass_platform_pcm_free(struct snd_soc_component *component,
527 				    struct snd_pcm *pcm)
528 {
529 	struct snd_pcm_substream *substream;
530 	int i;
531 
532 	for_each_pcm_streams(i) {
533 		substream = pcm->streams[i].substream;
534 		if (substream) {
535 			snd_dma_free_pages(&substream->dma_buffer);
536 			substream->dma_buffer.area = NULL;
537 			substream->dma_buffer.addr = 0;
538 		}
539 	}
540 }
541 
542 static const struct snd_soc_component_driver lpass_component_driver = {
543 	.name		= DRV_NAME,
544 	.open		= lpass_platform_pcmops_open,
545 	.close		= lpass_platform_pcmops_close,
546 	.hw_params	= lpass_platform_pcmops_hw_params,
547 	.hw_free	= lpass_platform_pcmops_hw_free,
548 	.prepare	= lpass_platform_pcmops_prepare,
549 	.trigger	= lpass_platform_pcmops_trigger,
550 	.pointer	= lpass_platform_pcmops_pointer,
551 	.mmap		= lpass_platform_pcmops_mmap,
552 	.pcm_construct	= lpass_platform_pcm_new,
553 	.pcm_destruct	= lpass_platform_pcm_free,
554 
555 };
556 
557 int asoc_qcom_lpass_platform_register(struct platform_device *pdev)
558 {
559 	struct lpass_data *drvdata = platform_get_drvdata(pdev);
560 	struct lpass_variant *v = drvdata->variant;
561 	int ret;
562 
563 	drvdata->lpaif_irq = platform_get_irq_byname(pdev, "lpass-irq-lpaif");
564 	if (drvdata->lpaif_irq < 0)
565 		return -ENODEV;
566 
567 	/* ensure audio hardware is disabled */
568 	ret = regmap_write(drvdata->lpaif_map,
569 			LPAIF_IRQEN_REG(v, LPAIF_IRQ_PORT_HOST), 0);
570 	if (ret) {
571 		dev_err(&pdev->dev, "error writing to irqen reg: %d\n", ret);
572 		return ret;
573 	}
574 
575 	ret = devm_request_irq(&pdev->dev, drvdata->lpaif_irq,
576 			lpass_platform_lpaif_irq, IRQF_TRIGGER_RISING,
577 			"lpass-irq-lpaif", drvdata);
578 	if (ret) {
579 		dev_err(&pdev->dev, "irq request failed: %d\n", ret);
580 		return ret;
581 	}
582 
583 
584 	return devm_snd_soc_register_component(&pdev->dev,
585 			&lpass_component_driver, NULL, 0);
586 }
587 EXPORT_SYMBOL_GPL(asoc_qcom_lpass_platform_register);
588 
589 MODULE_DESCRIPTION("QTi LPASS Platform Driver");
590 MODULE_LICENSE("GPL v2");
591