1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // AMD ALSA SoC PDM Driver
4 //
5 //Copyright 2020 Advanced Micro Devices, Inc.
6 
7 #include <linux/platform_device.h>
8 #include <linux/module.h>
9 #include <linux/bitfield.h>
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/pm_runtime.h>
13 #include <sound/pcm_params.h>
14 #include <sound/soc.h>
15 #include <sound/soc-dai.h>
16 
17 #include "rn_acp3x.h"
18 
19 #define DRV_NAME "acp_rn_pdm_dma"
20 
21 static int pdm_gain = 3;
22 module_param(pdm_gain, int, 0644);
23 MODULE_PARM_DESC(pdm_gain, "Gain control (0-3)");
24 
25 static const struct snd_pcm_hardware acp_pdm_hardware_capture = {
26 	.info = SNDRV_PCM_INFO_INTERLEAVED |
27 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
28 		SNDRV_PCM_INFO_MMAP |
29 		SNDRV_PCM_INFO_MMAP_VALID |
30 		SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
31 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
32 	.channels_min = 2,
33 	.channels_max = 2,
34 	.rates = SNDRV_PCM_RATE_48000,
35 	.rate_min = 48000,
36 	.rate_max = 48000,
37 	.buffer_bytes_max = CAPTURE_MAX_NUM_PERIODS * CAPTURE_MAX_PERIOD_SIZE,
38 	.period_bytes_min = CAPTURE_MIN_PERIOD_SIZE,
39 	.period_bytes_max = CAPTURE_MAX_PERIOD_SIZE,
40 	.periods_min = CAPTURE_MIN_NUM_PERIODS,
41 	.periods_max = CAPTURE_MAX_NUM_PERIODS,
42 };
43 
44 static irqreturn_t pdm_irq_handler(int irq, void *dev_id)
45 {
46 	struct pdm_dev_data *rn_pdm_data;
47 	u16 cap_flag;
48 	u32 val;
49 
50 	rn_pdm_data = dev_id;
51 	if (!rn_pdm_data)
52 		return IRQ_NONE;
53 
54 	cap_flag = 0;
55 	val = rn_readl(rn_pdm_data->acp_base + ACP_EXTERNAL_INTR_STAT);
56 	if ((val & BIT(PDM_DMA_STAT)) && rn_pdm_data->capture_stream) {
57 		rn_writel(BIT(PDM_DMA_STAT), rn_pdm_data->acp_base +
58 			  ACP_EXTERNAL_INTR_STAT);
59 		snd_pcm_period_elapsed(rn_pdm_data->capture_stream);
60 		cap_flag = 1;
61 	}
62 
63 	if (cap_flag)
64 		return IRQ_HANDLED;
65 	else
66 		return IRQ_NONE;
67 }
68 
69 static void init_pdm_ring_buffer(u32 physical_addr,
70 				 u32 buffer_size,
71 				 u32 watermark_size,
72 				 void __iomem *acp_base)
73 {
74 	rn_writel(physical_addr, acp_base + ACP_WOV_RX_RINGBUFADDR);
75 	rn_writel(buffer_size, acp_base + ACP_WOV_RX_RINGBUFSIZE);
76 	rn_writel(watermark_size, acp_base + ACP_WOV_RX_INTR_WATERMARK_SIZE);
77 	rn_writel(0x01, acp_base + ACPAXI2AXI_ATU_CTRL);
78 }
79 
80 static void enable_pdm_clock(void __iomem *acp_base)
81 {
82 	u32 pdm_clk_enable, pdm_ctrl;
83 
84 	pdm_clk_enable = ACP_PDM_CLK_FREQ_MASK;
85 
86 	rn_writel(pdm_clk_enable, acp_base + ACP_WOV_CLK_CTRL);
87 	pdm_ctrl = rn_readl(acp_base + ACP_WOV_MISC_CTRL);
88 	pdm_ctrl &= ~ACP_WOV_GAIN_CONTROL;
89 	pdm_ctrl |= FIELD_PREP(ACP_WOV_GAIN_CONTROL, clamp(pdm_gain, 0, 3));
90 	rn_writel(pdm_ctrl, acp_base + ACP_WOV_MISC_CTRL);
91 }
92 
93 static void enable_pdm_interrupts(void __iomem *acp_base)
94 {
95 	u32 ext_int_ctrl;
96 
97 	ext_int_ctrl = rn_readl(acp_base + ACP_EXTERNAL_INTR_CNTL);
98 	ext_int_ctrl |= PDM_DMA_INTR_MASK;
99 	rn_writel(ext_int_ctrl, acp_base + ACP_EXTERNAL_INTR_CNTL);
100 }
101 
102 static void disable_pdm_interrupts(void __iomem *acp_base)
103 {
104 	u32 ext_int_ctrl;
105 
106 	ext_int_ctrl = rn_readl(acp_base + ACP_EXTERNAL_INTR_CNTL);
107 	ext_int_ctrl |= ~PDM_DMA_INTR_MASK;
108 	rn_writel(ext_int_ctrl, acp_base + ACP_EXTERNAL_INTR_CNTL);
109 }
110 
111 static bool check_pdm_dma_status(void __iomem *acp_base)
112 {
113 	bool pdm_dma_status;
114 	u32 pdm_enable, pdm_dma_enable;
115 
116 	pdm_dma_status = false;
117 	pdm_enable = rn_readl(acp_base + ACP_WOV_PDM_ENABLE);
118 	pdm_dma_enable = rn_readl(acp_base + ACP_WOV_PDM_DMA_ENABLE);
119 	if ((pdm_enable & ACP_PDM_ENABLE) && (pdm_dma_enable &
120 	     ACP_PDM_DMA_EN_STATUS))
121 		pdm_dma_status = true;
122 	return pdm_dma_status;
123 }
124 
125 static int start_pdm_dma(void __iomem *acp_base)
126 {
127 	u32 pdm_enable;
128 	u32 pdm_dma_enable;
129 	int timeout;
130 
131 	pdm_enable = 0x01;
132 	pdm_dma_enable  = 0x01;
133 
134 	enable_pdm_clock(acp_base);
135 	rn_writel(pdm_enable, acp_base + ACP_WOV_PDM_ENABLE);
136 	rn_writel(pdm_dma_enable, acp_base + ACP_WOV_PDM_DMA_ENABLE);
137 	timeout = 0;
138 	while (++timeout < ACP_COUNTER) {
139 		pdm_dma_enable = rn_readl(acp_base + ACP_WOV_PDM_DMA_ENABLE);
140 		if ((pdm_dma_enable & 0x02) == ACP_PDM_DMA_EN_STATUS)
141 			return 0;
142 		udelay(DELAY_US);
143 	}
144 	return -ETIMEDOUT;
145 }
146 
147 static int stop_pdm_dma(void __iomem *acp_base)
148 {
149 	u32 pdm_enable, pdm_dma_enable;
150 	int timeout;
151 
152 	pdm_enable = rn_readl(acp_base + ACP_WOV_PDM_ENABLE);
153 	pdm_dma_enable = rn_readl(acp_base + ACP_WOV_PDM_DMA_ENABLE);
154 	if (pdm_dma_enable & 0x01) {
155 		pdm_dma_enable = 0x02;
156 		rn_writel(pdm_dma_enable, acp_base + ACP_WOV_PDM_DMA_ENABLE);
157 		timeout = 0;
158 		while (++timeout < ACP_COUNTER) {
159 			pdm_dma_enable = rn_readl(acp_base +
160 						  ACP_WOV_PDM_DMA_ENABLE);
161 			if ((pdm_dma_enable & 0x02) == 0x00)
162 				break;
163 			udelay(DELAY_US);
164 		}
165 		if (timeout == ACP_COUNTER)
166 			return -ETIMEDOUT;
167 	}
168 	if (pdm_enable == ACP_PDM_ENABLE) {
169 		pdm_enable = ACP_PDM_DISABLE;
170 		rn_writel(pdm_enable, acp_base + ACP_WOV_PDM_ENABLE);
171 	}
172 	rn_writel(0x01, acp_base + ACP_WOV_PDM_FIFO_FLUSH);
173 	return 0;
174 }
175 
176 static void config_acp_dma(struct pdm_stream_instance *rtd, int direction)
177 {
178 	u16 page_idx;
179 	u32 low, high, val;
180 	dma_addr_t addr;
181 
182 	addr = rtd->dma_addr;
183 	val = 0;
184 
185 	/* Group Enable */
186 	rn_writel(ACP_SRAM_PTE_OFFSET | BIT(31), rtd->acp_base +
187 		  ACPAXI2AXI_ATU_BASE_ADDR_GRP_1);
188 	rn_writel(PAGE_SIZE_4K_ENABLE, rtd->acp_base +
189 		  ACPAXI2AXI_ATU_PAGE_SIZE_GRP_1);
190 
191 	for (page_idx = 0; page_idx < rtd->num_pages; page_idx++) {
192 		/* Load the low address of page int ACP SRAM through SRBM */
193 		low = lower_32_bits(addr);
194 		high = upper_32_bits(addr);
195 
196 		rn_writel(low, rtd->acp_base + ACP_SCRATCH_REG_0 + val);
197 		high |= BIT(31);
198 		rn_writel(high, rtd->acp_base + ACP_SCRATCH_REG_0 + val + 4);
199 		val += 8;
200 		addr += PAGE_SIZE;
201 	}
202 }
203 
204 static int acp_pdm_dma_open(struct snd_soc_component *component,
205 			    struct snd_pcm_substream *substream)
206 {
207 	struct snd_pcm_runtime *runtime;
208 	struct pdm_dev_data *adata;
209 	struct pdm_stream_instance *pdm_data;
210 	int ret;
211 
212 	runtime = substream->runtime;
213 	adata = dev_get_drvdata(component->dev);
214 	pdm_data = kzalloc(sizeof(*pdm_data), GFP_KERNEL);
215 	if (!pdm_data)
216 		return -EINVAL;
217 
218 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
219 		runtime->hw = acp_pdm_hardware_capture;
220 
221 	ret = snd_pcm_hw_constraint_integer(runtime,
222 					    SNDRV_PCM_HW_PARAM_PERIODS);
223 	if (ret < 0) {
224 		dev_err(component->dev, "set integer constraint failed\n");
225 		kfree(pdm_data);
226 		return ret;
227 	}
228 
229 	enable_pdm_interrupts(adata->acp_base);
230 
231 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
232 		adata->capture_stream = substream;
233 
234 	pdm_data->acp_base = adata->acp_base;
235 	runtime->private_data = pdm_data;
236 	return ret;
237 }
238 
239 static int acp_pdm_dma_hw_params(struct snd_soc_component *component,
240 				 struct snd_pcm_substream *substream,
241 				 struct snd_pcm_hw_params *params)
242 {
243 	struct pdm_stream_instance *rtd;
244 	size_t size, period_bytes;
245 
246 	rtd = substream->runtime->private_data;
247 	if (!rtd)
248 		return -EINVAL;
249 	size = params_buffer_bytes(params);
250 	period_bytes = params_period_bytes(params);
251 	rtd->dma_addr = substream->runtime->dma_addr;
252 	rtd->num_pages = (PAGE_ALIGN(size) >> PAGE_SHIFT);
253 	config_acp_dma(rtd, substream->stream);
254 	init_pdm_ring_buffer(MEM_WINDOW_START, size, period_bytes,
255 			     rtd->acp_base);
256 	return 0;
257 }
258 
259 static u64 acp_pdm_get_byte_count(struct pdm_stream_instance *rtd,
260 				  int direction)
261 {
262 	union acp_pdm_dma_count byte_count;
263 
264 	byte_count.bcount.high =
265 			rn_readl(rtd->acp_base +
266 				 ACP_WOV_RX_LINEARPOSITIONCNTR_HIGH);
267 	byte_count.bcount.low =
268 			rn_readl(rtd->acp_base +
269 				 ACP_WOV_RX_LINEARPOSITIONCNTR_LOW);
270 	return byte_count.bytescount;
271 }
272 
273 static snd_pcm_uframes_t acp_pdm_dma_pointer(struct snd_soc_component *comp,
274 					     struct snd_pcm_substream *stream)
275 {
276 	struct pdm_stream_instance *rtd;
277 	u32 pos, buffersize;
278 	u64 bytescount;
279 
280 	rtd = stream->runtime->private_data;
281 	buffersize = frames_to_bytes(stream->runtime,
282 				     stream->runtime->buffer_size);
283 	bytescount = acp_pdm_get_byte_count(rtd, stream->stream);
284 	if (bytescount > rtd->bytescount)
285 		bytescount -= rtd->bytescount;
286 	pos = do_div(bytescount, buffersize);
287 	return bytes_to_frames(stream->runtime, pos);
288 }
289 
290 static int acp_pdm_dma_new(struct snd_soc_component *component,
291 			   struct snd_soc_pcm_runtime *rtd)
292 {
293 	struct device *parent = component->dev->parent;
294 
295 	snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
296 				       parent, MIN_BUFFER, MAX_BUFFER);
297 	return 0;
298 }
299 
300 static int acp_pdm_dma_close(struct snd_soc_component *component,
301 			     struct snd_pcm_substream *substream)
302 {
303 	struct pdm_dev_data *adata = dev_get_drvdata(component->dev);
304 
305 	disable_pdm_interrupts(adata->acp_base);
306 	adata->capture_stream = NULL;
307 	return 0;
308 }
309 
310 static int acp_pdm_dai_trigger(struct snd_pcm_substream *substream,
311 			       int cmd, struct snd_soc_dai *dai)
312 {
313 	struct pdm_stream_instance *rtd;
314 	int ret;
315 	bool pdm_status;
316 	unsigned int ch_mask;
317 
318 	rtd = substream->runtime->private_data;
319 	ret = 0;
320 	switch (substream->runtime->channels) {
321 	case TWO_CH:
322 		ch_mask = 0x00;
323 		break;
324 	default:
325 		return -EINVAL;
326 	}
327 	switch (cmd) {
328 	case SNDRV_PCM_TRIGGER_START:
329 	case SNDRV_PCM_TRIGGER_RESUME:
330 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
331 		rn_writel(ch_mask, rtd->acp_base + ACP_WOV_PDM_NO_OF_CHANNELS);
332 		rn_writel(PDM_DECIMATION_FACTOR, rtd->acp_base +
333 			  ACP_WOV_PDM_DECIMATION_FACTOR);
334 		rtd->bytescount = acp_pdm_get_byte_count(rtd,
335 							 substream->stream);
336 		pdm_status = check_pdm_dma_status(rtd->acp_base);
337 		if (!pdm_status)
338 			ret = start_pdm_dma(rtd->acp_base);
339 		break;
340 	case SNDRV_PCM_TRIGGER_STOP:
341 	case SNDRV_PCM_TRIGGER_SUSPEND:
342 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
343 		pdm_status = check_pdm_dma_status(rtd->acp_base);
344 		if (pdm_status)
345 			ret = stop_pdm_dma(rtd->acp_base);
346 		break;
347 	default:
348 		ret = -EINVAL;
349 		break;
350 	}
351 	return ret;
352 }
353 
354 static const struct snd_soc_dai_ops acp_pdm_dai_ops = {
355 	.trigger   = acp_pdm_dai_trigger,
356 };
357 
358 static struct snd_soc_dai_driver acp_pdm_dai_driver = {
359 	.capture = {
360 		.rates = SNDRV_PCM_RATE_48000,
361 		.formats = SNDRV_PCM_FMTBIT_S24_LE |
362 			   SNDRV_PCM_FMTBIT_S32_LE,
363 		.channels_min = 2,
364 		.channels_max = 2,
365 		.rate_min = 48000,
366 		.rate_max = 48000,
367 	},
368 	.ops = &acp_pdm_dai_ops,
369 };
370 
371 static const struct snd_soc_component_driver acp_pdm_component = {
372 	.name			= DRV_NAME,
373 	.open			= acp_pdm_dma_open,
374 	.close			= acp_pdm_dma_close,
375 	.hw_params		= acp_pdm_dma_hw_params,
376 	.pointer		= acp_pdm_dma_pointer,
377 	.pcm_construct		= acp_pdm_dma_new,
378 	.legacy_dai_naming	= 1,
379 };
380 
381 static int acp_pdm_audio_probe(struct platform_device *pdev)
382 {
383 	struct resource *res;
384 	struct pdm_dev_data *adata;
385 	unsigned int irqflags;
386 	int status;
387 
388 	if (!pdev->dev.platform_data) {
389 		dev_err(&pdev->dev, "platform_data not retrieved\n");
390 		return -ENODEV;
391 	}
392 	irqflags = *((unsigned int *)(pdev->dev.platform_data));
393 
394 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
395 	if (!res) {
396 		dev_err(&pdev->dev, "IORESOURCE_MEM FAILED\n");
397 		return -ENODEV;
398 	}
399 
400 	adata = devm_kzalloc(&pdev->dev, sizeof(*adata), GFP_KERNEL);
401 	if (!adata)
402 		return -ENOMEM;
403 
404 	adata->acp_base = devm_ioremap(&pdev->dev, res->start,
405 				       resource_size(res));
406 	if (!adata->acp_base)
407 		return -ENOMEM;
408 
409 	status = platform_get_irq(pdev, 0);
410 	if (status < 0)
411 		return status;
412 	adata->pdm_irq = status;
413 
414 	adata->capture_stream = NULL;
415 
416 	dev_set_drvdata(&pdev->dev, adata);
417 	status = devm_snd_soc_register_component(&pdev->dev,
418 						 &acp_pdm_component,
419 						 &acp_pdm_dai_driver, 1);
420 	if (status) {
421 		dev_err(&pdev->dev, "Fail to register acp pdm dai\n");
422 
423 		return -ENODEV;
424 	}
425 	status = devm_request_irq(&pdev->dev, adata->pdm_irq, pdm_irq_handler,
426 				  irqflags, "ACP_PDM_IRQ", adata);
427 	if (status) {
428 		dev_err(&pdev->dev, "ACP PDM IRQ request failed\n");
429 		return -ENODEV;
430 	}
431 	pm_runtime_set_autosuspend_delay(&pdev->dev, ACP_SUSPEND_DELAY_MS);
432 	pm_runtime_use_autosuspend(&pdev->dev);
433 	pm_runtime_enable(&pdev->dev);
434 	pm_runtime_allow(&pdev->dev);
435 	return 0;
436 }
437 
438 static int acp_pdm_audio_remove(struct platform_device *pdev)
439 {
440 	pm_runtime_disable(&pdev->dev);
441 	return 0;
442 }
443 
444 static int acp_pdm_resume(struct device *dev)
445 {
446 	struct pdm_dev_data *adata;
447 	struct snd_pcm_runtime *runtime;
448 	struct pdm_stream_instance *rtd;
449 	u32 period_bytes, buffer_len;
450 
451 	adata = dev_get_drvdata(dev);
452 	if (adata->capture_stream && adata->capture_stream->runtime) {
453 		runtime = adata->capture_stream->runtime;
454 		rtd = runtime->private_data;
455 		period_bytes = frames_to_bytes(runtime, runtime->period_size);
456 		buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
457 		config_acp_dma(rtd, SNDRV_PCM_STREAM_CAPTURE);
458 		init_pdm_ring_buffer(MEM_WINDOW_START, buffer_len, period_bytes,
459 				     adata->acp_base);
460 	}
461 	enable_pdm_interrupts(adata->acp_base);
462 	return 0;
463 }
464 
465 static int acp_pdm_runtime_suspend(struct device *dev)
466 {
467 	struct pdm_dev_data *adata;
468 
469 	adata = dev_get_drvdata(dev);
470 	disable_pdm_interrupts(adata->acp_base);
471 
472 	return 0;
473 }
474 
475 static int acp_pdm_runtime_resume(struct device *dev)
476 {
477 	struct pdm_dev_data *adata;
478 
479 	adata = dev_get_drvdata(dev);
480 	enable_pdm_interrupts(adata->acp_base);
481 	return 0;
482 }
483 
484 static const struct dev_pm_ops acp_pdm_pm_ops = {
485 	.runtime_suspend = acp_pdm_runtime_suspend,
486 	.runtime_resume = acp_pdm_runtime_resume,
487 	.resume = acp_pdm_resume,
488 };
489 
490 static struct platform_driver acp_pdm_dma_driver = {
491 	.probe = acp_pdm_audio_probe,
492 	.remove = acp_pdm_audio_remove,
493 	.driver = {
494 		.name = "acp_rn_pdm_dma",
495 		.pm = &acp_pdm_pm_ops,
496 	},
497 };
498 
499 module_platform_driver(acp_pdm_dma_driver);
500 
501 MODULE_AUTHOR("Vijendar.Mukunda@amd.com");
502 MODULE_DESCRIPTION("AMD ACP3x Renior PDM Driver");
503 MODULE_LICENSE("GPL v2");
504 MODULE_ALIAS("platform:" DRV_NAME);
505