xref: /openbmc/linux/sound/soc/meson/axg-fifo.c (revision abb84c46)
1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
2 //
3 // Copyright (c) 2018 BayLibre, SAS.
4 // Author: Jerome Brunet <jbrunet@baylibre.com>
5 
6 #include <linux/bitfield.h>
7 #include <linux/clk.h>
8 #include <linux/of_irq.h>
9 #include <linux/of_platform.h>
10 #include <linux/module.h>
11 #include <linux/regmap.h>
12 #include <linux/reset.h>
13 #include <sound/pcm_params.h>
14 #include <sound/soc.h>
15 #include <sound/soc-dai.h>
16 
17 #include "axg-fifo.h"
18 
19 /*
20  * This file implements the platform operations common to the playback and
21  * capture frontend DAI. The logic behind this two types of fifo is very
22  * similar but some difference exist.
23  * These differences are handled in the respective DAI drivers
24  */
25 
26 static struct snd_pcm_hardware axg_fifo_hw = {
27 	.info = (SNDRV_PCM_INFO_INTERLEAVED |
28 		 SNDRV_PCM_INFO_MMAP |
29 		 SNDRV_PCM_INFO_MMAP_VALID |
30 		 SNDRV_PCM_INFO_BLOCK_TRANSFER |
31 		 SNDRV_PCM_INFO_PAUSE |
32 		 SNDRV_PCM_INFO_NO_PERIOD_WAKEUP),
33 	.formats = AXG_FIFO_FORMATS,
34 	.rate_min = 5512,
35 	.rate_max = 192000,
36 	.channels_min = 1,
37 	.channels_max = AXG_FIFO_CH_MAX,
38 	.period_bytes_min = AXG_FIFO_BURST,
39 	.period_bytes_max = UINT_MAX,
40 	.periods_min = 2,
41 	.periods_max = UINT_MAX,
42 
43 	/* No real justification for this */
44 	.buffer_bytes_max = 1 * 1024 * 1024,
45 };
46 
47 static struct snd_soc_dai *axg_fifo_dai(struct snd_pcm_substream *ss)
48 {
49 	struct snd_soc_pcm_runtime *rtd = ss->private_data;
50 
51 	return asoc_rtd_to_cpu(rtd, 0);
52 }
53 
54 static struct axg_fifo *axg_fifo_data(struct snd_pcm_substream *ss)
55 {
56 	struct snd_soc_dai *dai = axg_fifo_dai(ss);
57 
58 	return snd_soc_dai_get_drvdata(dai);
59 }
60 
61 static struct device *axg_fifo_dev(struct snd_pcm_substream *ss)
62 {
63 	struct snd_soc_dai *dai = axg_fifo_dai(ss);
64 
65 	return dai->dev;
66 }
67 
68 static void __dma_enable(struct axg_fifo *fifo,  bool enable)
69 {
70 	regmap_update_bits(fifo->map, FIFO_CTRL0, CTRL0_DMA_EN,
71 			   enable ? CTRL0_DMA_EN : 0);
72 }
73 
74 int axg_fifo_pcm_trigger(struct snd_soc_component *component,
75 			 struct snd_pcm_substream *ss, int cmd)
76 {
77 	struct axg_fifo *fifo = axg_fifo_data(ss);
78 
79 	switch (cmd) {
80 	case SNDRV_PCM_TRIGGER_START:
81 	case SNDRV_PCM_TRIGGER_RESUME:
82 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
83 		__dma_enable(fifo, true);
84 		break;
85 	case SNDRV_PCM_TRIGGER_SUSPEND:
86 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
87 	case SNDRV_PCM_TRIGGER_STOP:
88 		__dma_enable(fifo, false);
89 		break;
90 	default:
91 		return -EINVAL;
92 	}
93 
94 	return 0;
95 }
96 EXPORT_SYMBOL_GPL(axg_fifo_pcm_trigger);
97 
98 snd_pcm_uframes_t axg_fifo_pcm_pointer(struct snd_soc_component *component,
99 				       struct snd_pcm_substream *ss)
100 {
101 	struct axg_fifo *fifo = axg_fifo_data(ss);
102 	struct snd_pcm_runtime *runtime = ss->runtime;
103 	unsigned int addr;
104 
105 	regmap_read(fifo->map, FIFO_STATUS2, &addr);
106 
107 	return bytes_to_frames(runtime, addr - (unsigned int)runtime->dma_addr);
108 }
109 EXPORT_SYMBOL_GPL(axg_fifo_pcm_pointer);
110 
111 int axg_fifo_pcm_hw_params(struct snd_soc_component *component,
112 			   struct snd_pcm_substream *ss,
113 			   struct snd_pcm_hw_params *params)
114 {
115 	struct snd_pcm_runtime *runtime = ss->runtime;
116 	struct axg_fifo *fifo = axg_fifo_data(ss);
117 	unsigned int burst_num, period, threshold, irq_en;
118 	dma_addr_t end_ptr;
119 
120 	period = params_period_bytes(params);
121 
122 	/* Setup dma memory pointers */
123 	end_ptr = runtime->dma_addr + runtime->dma_bytes - AXG_FIFO_BURST;
124 	regmap_write(fifo->map, FIFO_START_ADDR, runtime->dma_addr);
125 	regmap_write(fifo->map, FIFO_FINISH_ADDR, end_ptr);
126 
127 	/* Setup interrupt periodicity */
128 	burst_num = period / AXG_FIFO_BURST;
129 	regmap_write(fifo->map, FIFO_INT_ADDR, burst_num);
130 
131 	/*
132 	 * Start the fifo request on the smallest of the following:
133 	 * - Half the fifo size
134 	 * - Half the period size
135 	 */
136 	threshold = min(period / 2, fifo->depth / 2);
137 
138 	/*
139 	 * With the threshold in bytes, register value is:
140 	 * V = (threshold / burst) - 1
141 	 */
142 	threshold /= AXG_FIFO_BURST;
143 	regmap_field_write(fifo->field_threshold,
144 			   threshold ? threshold - 1 : 0);
145 
146 	/* Enable irq if necessary  */
147 	irq_en = runtime->no_period_wakeup ? 0 : FIFO_INT_COUNT_REPEAT;
148 	regmap_update_bits(fifo->map, FIFO_CTRL0,
149 			   CTRL0_INT_EN,
150 			   FIELD_PREP(CTRL0_INT_EN, irq_en));
151 
152 	return 0;
153 }
154 EXPORT_SYMBOL_GPL(axg_fifo_pcm_hw_params);
155 
156 int g12a_fifo_pcm_hw_params(struct snd_soc_component *component,
157 			    struct snd_pcm_substream *ss,
158 			    struct snd_pcm_hw_params *params)
159 {
160 	struct axg_fifo *fifo = axg_fifo_data(ss);
161 	struct snd_pcm_runtime *runtime = ss->runtime;
162 	int ret;
163 
164 	ret = axg_fifo_pcm_hw_params(component, ss, params);
165 	if (ret)
166 		return ret;
167 
168 	/* Set the initial memory address of the DMA */
169 	regmap_write(fifo->map, FIFO_INIT_ADDR, runtime->dma_addr);
170 
171 	return 0;
172 }
173 EXPORT_SYMBOL_GPL(g12a_fifo_pcm_hw_params);
174 
175 int axg_fifo_pcm_hw_free(struct snd_soc_component *component,
176 			 struct snd_pcm_substream *ss)
177 {
178 	struct axg_fifo *fifo = axg_fifo_data(ss);
179 
180 	/* Disable irqs */
181 	regmap_update_bits(fifo->map, FIFO_CTRL0,
182 			   CTRL0_INT_EN, 0);
183 
184 	return 0;
185 }
186 EXPORT_SYMBOL_GPL(axg_fifo_pcm_hw_free);
187 
188 static void axg_fifo_ack_irq(struct axg_fifo *fifo, u8 mask)
189 {
190 	regmap_update_bits(fifo->map, FIFO_CTRL1,
191 			   CTRL1_INT_CLR,
192 			   FIELD_PREP(CTRL1_INT_CLR, mask));
193 
194 	/* Clear must also be cleared */
195 	regmap_update_bits(fifo->map, FIFO_CTRL1,
196 			   CTRL1_INT_CLR,
197 			   FIELD_PREP(CTRL1_INT_CLR, 0));
198 }
199 
200 static irqreturn_t axg_fifo_pcm_irq_block(int irq, void *dev_id)
201 {
202 	struct snd_pcm_substream *ss = dev_id;
203 	struct axg_fifo *fifo = axg_fifo_data(ss);
204 	unsigned int status;
205 
206 	regmap_read(fifo->map, FIFO_STATUS1, &status);
207 	status = FIELD_GET(STATUS1_INT_STS, status);
208 	axg_fifo_ack_irq(fifo, status);
209 
210 	/* Use the thread to call period elapsed on nonatomic links */
211 	if (status & FIFO_INT_COUNT_REPEAT)
212 		return IRQ_WAKE_THREAD;
213 
214 	dev_dbg(axg_fifo_dev(ss), "unexpected irq - STS 0x%02x\n",
215 		status);
216 
217 	return IRQ_NONE;
218 }
219 
220 static irqreturn_t axg_fifo_pcm_irq_block_thread(int irq, void *dev_id)
221 {
222 	struct snd_pcm_substream *ss = dev_id;
223 
224 	snd_pcm_period_elapsed(ss);
225 
226 	return IRQ_HANDLED;
227 }
228 
229 int axg_fifo_pcm_open(struct snd_soc_component *component,
230 		      struct snd_pcm_substream *ss)
231 {
232 	struct axg_fifo *fifo = axg_fifo_data(ss);
233 	struct device *dev = axg_fifo_dev(ss);
234 	int ret;
235 
236 	snd_soc_set_runtime_hwparams(ss, &axg_fifo_hw);
237 
238 	/*
239 	 * Make sure the buffer and period size are multiple of the FIFO
240 	 * burst
241 	 */
242 	ret = snd_pcm_hw_constraint_step(ss->runtime, 0,
243 					 SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
244 					 AXG_FIFO_BURST);
245 	if (ret)
246 		return ret;
247 
248 	ret = snd_pcm_hw_constraint_step(ss->runtime, 0,
249 					 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
250 					 AXG_FIFO_BURST);
251 	if (ret)
252 		return ret;
253 
254 	ret = request_threaded_irq(fifo->irq, axg_fifo_pcm_irq_block,
255 				   axg_fifo_pcm_irq_block_thread,
256 				   IRQF_ONESHOT, dev_name(dev), ss);
257 	if (ret)
258 		return ret;
259 
260 	/* Enable pclk to access registers and clock the fifo ip */
261 	ret = clk_prepare_enable(fifo->pclk);
262 	if (ret)
263 		goto free_irq;
264 
265 	/* Setup status2 so it reports the memory pointer */
266 	regmap_update_bits(fifo->map, FIFO_CTRL1,
267 			   CTRL1_STATUS2_SEL,
268 			   FIELD_PREP(CTRL1_STATUS2_SEL, STATUS2_SEL_DDR_READ));
269 
270 	/* Make sure the dma is initially disabled */
271 	__dma_enable(fifo, false);
272 
273 	/* Disable irqs until params are ready */
274 	regmap_update_bits(fifo->map, FIFO_CTRL0,
275 			   CTRL0_INT_EN, 0);
276 
277 	/* Clear any pending interrupt */
278 	axg_fifo_ack_irq(fifo, FIFO_INT_MASK);
279 
280 	/* Take memory arbitror out of reset */
281 	ret = reset_control_deassert(fifo->arb);
282 	if (ret)
283 		goto free_clk;
284 
285 	return 0;
286 
287 free_clk:
288 	clk_disable_unprepare(fifo->pclk);
289 free_irq:
290 	free_irq(fifo->irq, ss);
291 	return ret;
292 }
293 EXPORT_SYMBOL_GPL(axg_fifo_pcm_open);
294 
295 int axg_fifo_pcm_close(struct snd_soc_component *component,
296 		       struct snd_pcm_substream *ss)
297 {
298 	struct axg_fifo *fifo = axg_fifo_data(ss);
299 	int ret;
300 
301 	/* Put the memory arbitror back in reset */
302 	ret = reset_control_assert(fifo->arb);
303 
304 	/* Disable fifo ip and register access */
305 	clk_disable_unprepare(fifo->pclk);
306 
307 	/* remove IRQ */
308 	free_irq(fifo->irq, ss);
309 
310 	return ret;
311 }
312 EXPORT_SYMBOL_GPL(axg_fifo_pcm_close);
313 
314 int axg_fifo_pcm_new(struct snd_soc_pcm_runtime *rtd, unsigned int type)
315 {
316 	struct snd_card *card = rtd->card->snd_card;
317 	size_t size = axg_fifo_hw.buffer_bytes_max;
318 
319 	snd_pcm_set_managed_buffer(rtd->pcm->streams[type].substream,
320 				   SNDRV_DMA_TYPE_DEV, card->dev,
321 				   size, size);
322 	return 0;
323 }
324 EXPORT_SYMBOL_GPL(axg_fifo_pcm_new);
325 
326 static const struct regmap_config axg_fifo_regmap_cfg = {
327 	.reg_bits	= 32,
328 	.val_bits	= 32,
329 	.reg_stride	= 4,
330 	.max_register	= FIFO_CTRL2,
331 };
332 
333 int axg_fifo_probe(struct platform_device *pdev)
334 {
335 	struct device *dev = &pdev->dev;
336 	const struct axg_fifo_match_data *data;
337 	struct axg_fifo *fifo;
338 	void __iomem *regs;
339 	int ret;
340 
341 	data = of_device_get_match_data(dev);
342 	if (!data) {
343 		dev_err(dev, "failed to match device\n");
344 		return -ENODEV;
345 	}
346 
347 	fifo = devm_kzalloc(dev, sizeof(*fifo), GFP_KERNEL);
348 	if (!fifo)
349 		return -ENOMEM;
350 	platform_set_drvdata(pdev, fifo);
351 
352 	regs = devm_platform_ioremap_resource(pdev, 0);
353 	if (IS_ERR(regs))
354 		return PTR_ERR(regs);
355 
356 	fifo->map = devm_regmap_init_mmio(dev, regs, &axg_fifo_regmap_cfg);
357 	if (IS_ERR(fifo->map)) {
358 		dev_err(dev, "failed to init regmap: %ld\n",
359 			PTR_ERR(fifo->map));
360 		return PTR_ERR(fifo->map);
361 	}
362 
363 	fifo->pclk = devm_clk_get(dev, NULL);
364 	if (IS_ERR(fifo->pclk))
365 		return dev_err_probe(dev, PTR_ERR(fifo->pclk), "failed to get pclk\n");
366 
367 	fifo->arb = devm_reset_control_get_exclusive(dev, NULL);
368 	if (IS_ERR(fifo->arb))
369 		return dev_err_probe(dev, PTR_ERR(fifo->arb), "failed to get arb reset\n");
370 
371 	fifo->irq = of_irq_get(dev->of_node, 0);
372 	if (fifo->irq <= 0) {
373 		dev_err(dev, "failed to get irq: %d\n", fifo->irq);
374 		return fifo->irq;
375 	}
376 
377 	fifo->field_threshold =
378 		devm_regmap_field_alloc(dev, fifo->map, data->field_threshold);
379 	if (IS_ERR(fifo->field_threshold))
380 		return PTR_ERR(fifo->field_threshold);
381 
382 	ret = of_property_read_u32(dev->of_node, "amlogic,fifo-depth",
383 				   &fifo->depth);
384 	if (ret) {
385 		/* Error out for anything but a missing property */
386 		if (ret != -EINVAL)
387 			return ret;
388 		/*
389 		 * If the property is missing, it might be because of an old
390 		 * DT. In such case, assume the smallest known fifo depth
391 		 */
392 		fifo->depth = 256;
393 		dev_warn(dev, "fifo depth not found, assume %u bytes\n",
394 			 fifo->depth);
395 	}
396 
397 	return devm_snd_soc_register_component(dev, data->component_drv,
398 					       data->dai_drv, 1);
399 }
400 EXPORT_SYMBOL_GPL(axg_fifo_probe);
401 
402 MODULE_DESCRIPTION("Amlogic AXG/G12A fifo driver");
403 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
404 MODULE_LICENSE("GPL v2");
405