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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * tegra20_ac97.c - Tegra20 AC97 platform driver
  4 *
  5 * Copyright (c) 2012 Lucas Stach <dev@lynxeye.de>
  6 *
  7 * Partly based on code copyright/by:
  8 *
  9 * Copyright (c) 2011,2012 Toradex Inc.
 10 */
 11
 12#include <linux/clk.h>
 13#include <linux/delay.h>
 14#include <linux/device.h>
 15#include <linux/gpio.h>
 16#include <linux/io.h>
 17#include <linux/jiffies.h>
 18#include <linux/module.h>
 19#include <linux/of.h>
 20#include <linux/of_gpio.h>
 21#include <linux/platform_device.h>
 22#include <linux/pm_runtime.h>
 23#include <linux/regmap.h>
 24#include <linux/reset.h>
 25#include <linux/slab.h>
 26#include <sound/core.h>
 27#include <sound/pcm.h>
 28#include <sound/pcm_params.h>
 29#include <sound/soc.h>
 30#include <sound/dmaengine_pcm.h>
 31
 32#include "tegra20_ac97.h"
 33
 34#define DRV_NAME "tegra20-ac97"
 35
 36static struct tegra20_ac97 *workdata;
 37
 38static void tegra20_ac97_codec_reset(struct snd_ac97 *ac97)
 39{
 40	u32 readback;
 41	unsigned long timeout;
 42
 43	/* reset line is not driven by DAC pad group, have to toggle GPIO */
 44	gpio_set_value(workdata->reset_gpio, 0);
 45	udelay(2);
 46
 47	gpio_set_value(workdata->reset_gpio, 1);
 48	udelay(2);
 49
 50	timeout = jiffies + msecs_to_jiffies(100);
 51
 52	do {
 53		regmap_read(workdata->regmap, TEGRA20_AC97_STATUS1, &readback);
 54		if (readback & TEGRA20_AC97_STATUS1_CODEC1_RDY)
 55			break;
 56		usleep_range(1000, 2000);
 57	} while (!time_after(jiffies, timeout));
 58}
 59
 60static void tegra20_ac97_codec_warm_reset(struct snd_ac97 *ac97)
 61{
 62	u32 readback;
 63	unsigned long timeout;
 64
 65	/*
 66	 * although sync line is driven by the DAC pad group warm reset using
 67	 * the controller cmd is not working, have to toggle sync line
 68	 * manually.
 69	 */
 70	gpio_request(workdata->sync_gpio, "codec-sync");
 71
 72	gpio_direction_output(workdata->sync_gpio, 1);
 73
 74	udelay(2);
 75	gpio_set_value(workdata->sync_gpio, 0);
 76	udelay(2);
 77	gpio_free(workdata->sync_gpio);
 78
 79	timeout = jiffies + msecs_to_jiffies(100);
 80
 81	do {
 82		regmap_read(workdata->regmap, TEGRA20_AC97_STATUS1, &readback);
 83		if (readback & TEGRA20_AC97_STATUS1_CODEC1_RDY)
 84			break;
 85		usleep_range(1000, 2000);
 86	} while (!time_after(jiffies, timeout));
 87}
 88
 89static unsigned short tegra20_ac97_codec_read(struct snd_ac97 *ac97_snd,
 90					      unsigned short reg)
 91{
 92	u32 readback;
 93	unsigned long timeout;
 94
 95	regmap_write(workdata->regmap, TEGRA20_AC97_CMD,
 96		     (((reg | 0x80) << TEGRA20_AC97_CMD_CMD_ADDR_SHIFT) &
 97		      TEGRA20_AC97_CMD_CMD_ADDR_MASK) |
 98		     TEGRA20_AC97_CMD_BUSY);
 99
100	timeout = jiffies + msecs_to_jiffies(100);
101
102	do {
103		regmap_read(workdata->regmap, TEGRA20_AC97_STATUS1, &readback);
104		if (readback & TEGRA20_AC97_STATUS1_STA_VALID1)
105			break;
106		usleep_range(1000, 2000);
107	} while (!time_after(jiffies, timeout));
108
109	return ((readback & TEGRA20_AC97_STATUS1_STA_DATA1_MASK) >>
110		TEGRA20_AC97_STATUS1_STA_DATA1_SHIFT);
111}
112
113static void tegra20_ac97_codec_write(struct snd_ac97 *ac97_snd,
114				     unsigned short reg, unsigned short val)
115{
116	u32 readback;
117	unsigned long timeout;
118
119	regmap_write(workdata->regmap, TEGRA20_AC97_CMD,
120		     ((reg << TEGRA20_AC97_CMD_CMD_ADDR_SHIFT) &
121		      TEGRA20_AC97_CMD_CMD_ADDR_MASK) |
122		     ((val << TEGRA20_AC97_CMD_CMD_DATA_SHIFT) &
123		      TEGRA20_AC97_CMD_CMD_DATA_MASK) |
124		     TEGRA20_AC97_CMD_BUSY);
125
126	timeout = jiffies + msecs_to_jiffies(100);
127
128	do {
129		regmap_read(workdata->regmap, TEGRA20_AC97_CMD, &readback);
130		if (!(readback & TEGRA20_AC97_CMD_BUSY))
131			break;
132		usleep_range(1000, 2000);
133	} while (!time_after(jiffies, timeout));
134}
135
136static struct snd_ac97_bus_ops tegra20_ac97_ops = {
137	.read		= tegra20_ac97_codec_read,
138	.write		= tegra20_ac97_codec_write,
139	.reset		= tegra20_ac97_codec_reset,
140	.warm_reset	= tegra20_ac97_codec_warm_reset,
141};
142
143static inline void tegra20_ac97_start_playback(struct tegra20_ac97 *ac97)
144{
145	regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
146			   TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN,
147			   TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN);
148
149	regmap_update_bits(ac97->regmap, TEGRA20_AC97_CTRL,
150			   TEGRA20_AC97_CTRL_PCM_DAC_EN |
151			   TEGRA20_AC97_CTRL_STM_EN,
152			   TEGRA20_AC97_CTRL_PCM_DAC_EN |
153			   TEGRA20_AC97_CTRL_STM_EN);
154}
155
156static inline void tegra20_ac97_stop_playback(struct tegra20_ac97 *ac97)
157{
158	regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
159			   TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN, 0);
160
161	regmap_update_bits(ac97->regmap, TEGRA20_AC97_CTRL,
162			   TEGRA20_AC97_CTRL_PCM_DAC_EN, 0);
163}
164
165static inline void tegra20_ac97_start_capture(struct tegra20_ac97 *ac97)
166{
167	regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
168			   TEGRA20_AC97_FIFO_SCR_REC_FULL_EN,
169			   TEGRA20_AC97_FIFO_SCR_REC_FULL_EN);
170}
171
172static inline void tegra20_ac97_stop_capture(struct tegra20_ac97 *ac97)
173{
174	regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
175			   TEGRA20_AC97_FIFO_SCR_REC_FULL_EN, 0);
176}
177
178static int tegra20_ac97_trigger(struct snd_pcm_substream *substream, int cmd,
179				struct snd_soc_dai *dai)
180{
181	struct tegra20_ac97 *ac97 = snd_soc_dai_get_drvdata(dai);
182
183	switch (cmd) {
184	case SNDRV_PCM_TRIGGER_START:
185	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
186	case SNDRV_PCM_TRIGGER_RESUME:
187		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
188			tegra20_ac97_start_playback(ac97);
189		else
190			tegra20_ac97_start_capture(ac97);
191		break;
192	case SNDRV_PCM_TRIGGER_STOP:
193	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
194	case SNDRV_PCM_TRIGGER_SUSPEND:
195		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
196			tegra20_ac97_stop_playback(ac97);
197		else
198			tegra20_ac97_stop_capture(ac97);
199		break;
200	default:
201		return -EINVAL;
202	}
203
204	return 0;
205}
206
207static const struct snd_soc_dai_ops tegra20_ac97_dai_ops = {
208	.trigger	= tegra20_ac97_trigger,
209};
210
211static int tegra20_ac97_probe(struct snd_soc_dai *dai)
212{
213	struct tegra20_ac97 *ac97 = snd_soc_dai_get_drvdata(dai);
214
215	dai->capture_dma_data = &ac97->capture_dma_data;
216	dai->playback_dma_data = &ac97->playback_dma_data;
217
218	return 0;
219}
220
221static struct snd_soc_dai_driver tegra20_ac97_dai = {
222	.name = "tegra-ac97-pcm",
223	.probe = tegra20_ac97_probe,
224	.playback = {
225		.stream_name = "PCM Playback",
226		.channels_min = 2,
227		.channels_max = 2,
228		.rates = SNDRV_PCM_RATE_8000_48000,
229		.formats = SNDRV_PCM_FMTBIT_S16_LE,
230	},
231	.capture = {
232		.stream_name = "PCM Capture",
233		.channels_min = 2,
234		.channels_max = 2,
235		.rates = SNDRV_PCM_RATE_8000_48000,
236		.formats = SNDRV_PCM_FMTBIT_S16_LE,
237	},
238	.ops = &tegra20_ac97_dai_ops,
239};
240
241static const struct snd_soc_component_driver tegra20_ac97_component = {
242	.name			= DRV_NAME,
243	.legacy_dai_naming	= 1,
244};
245
246static bool tegra20_ac97_wr_rd_reg(struct device *dev, unsigned int reg)
247{
248	switch (reg) {
249	case TEGRA20_AC97_CTRL:
250	case TEGRA20_AC97_CMD:
251	case TEGRA20_AC97_STATUS1:
252	case TEGRA20_AC97_FIFO1_SCR:
253	case TEGRA20_AC97_FIFO_TX1:
254	case TEGRA20_AC97_FIFO_RX1:
255		return true;
256	default:
257		break;
258	}
259
260	return false;
261}
262
263static bool tegra20_ac97_volatile_reg(struct device *dev, unsigned int reg)
264{
265	switch (reg) {
266	case TEGRA20_AC97_STATUS1:
267	case TEGRA20_AC97_FIFO1_SCR:
268	case TEGRA20_AC97_FIFO_TX1:
269	case TEGRA20_AC97_FIFO_RX1:
270		return true;
271	default:
272		break;
273	}
274
275	return false;
276}
277
278static bool tegra20_ac97_precious_reg(struct device *dev, unsigned int reg)
279{
280	switch (reg) {
281	case TEGRA20_AC97_FIFO_TX1:
282	case TEGRA20_AC97_FIFO_RX1:
283		return true;
284	default:
285		break;
286	}
287
288	return false;
289}
290
291static const struct regmap_config tegra20_ac97_regmap_config = {
292	.reg_bits = 32,
293	.reg_stride = 4,
294	.val_bits = 32,
295	.max_register = TEGRA20_AC97_FIFO_RX1,
296	.writeable_reg = tegra20_ac97_wr_rd_reg,
297	.readable_reg = tegra20_ac97_wr_rd_reg,
298	.volatile_reg = tegra20_ac97_volatile_reg,
299	.precious_reg = tegra20_ac97_precious_reg,
300	.cache_type = REGCACHE_FLAT,
301};
302
303static int tegra20_ac97_platform_probe(struct platform_device *pdev)
304{
305	struct tegra20_ac97 *ac97;
306	struct resource *mem;
307	void __iomem *regs;
308	int ret = 0;
309
310	ac97 = devm_kzalloc(&pdev->dev, sizeof(struct tegra20_ac97),
311			    GFP_KERNEL);
312	if (!ac97) {
313		ret = -ENOMEM;
314		goto err;
315	}
316	dev_set_drvdata(&pdev->dev, ac97);
317
318	ac97->reset = devm_reset_control_get_exclusive(&pdev->dev, "ac97");
319	if (IS_ERR(ac97->reset)) {
320		dev_err(&pdev->dev, "Can't retrieve ac97 reset\n");
321		return PTR_ERR(ac97->reset);
322	}
323
324	ac97->clk_ac97 = devm_clk_get(&pdev->dev, NULL);
325	if (IS_ERR(ac97->clk_ac97)) {
326		dev_err(&pdev->dev, "Can't retrieve ac97 clock\n");
327		ret = PTR_ERR(ac97->clk_ac97);
328		goto err;
329	}
330
331	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
332	regs = devm_ioremap_resource(&pdev->dev, mem);
333	if (IS_ERR(regs)) {
334		ret = PTR_ERR(regs);
335		goto err_clk_put;
336	}
337
338	ac97->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
339					    &tegra20_ac97_regmap_config);
340	if (IS_ERR(ac97->regmap)) {
341		dev_err(&pdev->dev, "regmap init failed\n");
342		ret = PTR_ERR(ac97->regmap);
343		goto err_clk_put;
344	}
345
346	ac97->reset_gpio = of_get_named_gpio(pdev->dev.of_node,
347					     "nvidia,codec-reset-gpio", 0);
348	if (gpio_is_valid(ac97->reset_gpio)) {
349		ret = devm_gpio_request_one(&pdev->dev, ac97->reset_gpio,
350					    GPIOF_OUT_INIT_HIGH, "codec-reset");
351		if (ret) {
352			dev_err(&pdev->dev, "could not get codec-reset GPIO\n");
353			goto err_clk_put;
354		}
355	} else {
356		dev_err(&pdev->dev, "no codec-reset GPIO supplied\n");
357		ret = -EINVAL;
358		goto err_clk_put;
359	}
360
361	ac97->sync_gpio = of_get_named_gpio(pdev->dev.of_node,
362					    "nvidia,codec-sync-gpio", 0);
363	if (!gpio_is_valid(ac97->sync_gpio)) {
364		dev_err(&pdev->dev, "no codec-sync GPIO supplied\n");
365		ret = -EINVAL;
366		goto err_clk_put;
367	}
368
369	ac97->capture_dma_data.addr = mem->start + TEGRA20_AC97_FIFO_RX1;
370	ac97->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
371	ac97->capture_dma_data.maxburst = 4;
372
373	ac97->playback_dma_data.addr = mem->start + TEGRA20_AC97_FIFO_TX1;
374	ac97->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
375	ac97->playback_dma_data.maxburst = 4;
376
377	ret = reset_control_assert(ac97->reset);
378	if (ret) {
379		dev_err(&pdev->dev, "Failed to assert AC'97 reset: %d\n", ret);
380		goto err_clk_put;
381	}
382
383	ret = clk_prepare_enable(ac97->clk_ac97);
384	if (ret) {
385		dev_err(&pdev->dev, "clk_enable failed: %d\n", ret);
386		goto err_clk_put;
387	}
388
389	usleep_range(10, 100);
390
391	ret = reset_control_deassert(ac97->reset);
392	if (ret) {
393		dev_err(&pdev->dev, "Failed to deassert AC'97 reset: %d\n", ret);
394		goto err_clk_disable_unprepare;
395	}
396
397	ret = snd_soc_set_ac97_ops(&tegra20_ac97_ops);
398	if (ret) {
399		dev_err(&pdev->dev, "Failed to set AC'97 ops: %d\n", ret);
400		goto err_clk_disable_unprepare;
401	}
402
403	ret = snd_soc_register_component(&pdev->dev, &tegra20_ac97_component,
404					 &tegra20_ac97_dai, 1);
405	if (ret) {
406		dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
407		ret = -ENOMEM;
408		goto err_clk_disable_unprepare;
409	}
410
411	ret = tegra_pcm_platform_register(&pdev->dev);
412	if (ret) {
413		dev_err(&pdev->dev, "Could not register PCM: %d\n", ret);
414		goto err_unregister_component;
415	}
416
417	/* XXX: crufty ASoC AC97 API - only one AC97 codec allowed */
418	workdata = ac97;
419
420	return 0;
421
422err_unregister_component:
423	snd_soc_unregister_component(&pdev->dev);
424err_clk_disable_unprepare:
425	clk_disable_unprepare(ac97->clk_ac97);
426err_clk_put:
427err:
428	snd_soc_set_ac97_ops(NULL);
429	return ret;
430}
431
432static int tegra20_ac97_platform_remove(struct platform_device *pdev)
433{
434	struct tegra20_ac97 *ac97 = dev_get_drvdata(&pdev->dev);
435
436	tegra_pcm_platform_unregister(&pdev->dev);
437	snd_soc_unregister_component(&pdev->dev);
438
439	clk_disable_unprepare(ac97->clk_ac97);
440
441	snd_soc_set_ac97_ops(NULL);
442
443	return 0;
444}
445
446static const struct of_device_id tegra20_ac97_of_match[] = {
447	{ .compatible = "nvidia,tegra20-ac97", },
448	{},
449};
450
451static struct platform_driver tegra20_ac97_driver = {
452	.driver = {
453		.name = DRV_NAME,
454		.of_match_table = tegra20_ac97_of_match,
455	},
456	.probe = tegra20_ac97_platform_probe,
457	.remove = tegra20_ac97_platform_remove,
458};
459module_platform_driver(tegra20_ac97_driver);
460
461MODULE_AUTHOR("Lucas Stach");
462MODULE_DESCRIPTION("Tegra20 AC97 ASoC driver");
463MODULE_LICENSE("GPL v2");
464MODULE_ALIAS("platform:" DRV_NAME);
465MODULE_DEVICE_TABLE(of, tegra20_ac97_of_match);