1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012-2013, Analog Devices Inc.
4 * Author: Lars-Peter Clausen <lars@metafoo.de>
5 */
6
7#include <linux/clk.h>
8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/regmap.h>
14#include <linux/slab.h>
15
16#include <sound/core.h>
17#include <sound/pcm.h>
18#include <sound/pcm_params.h>
19#include <sound/soc.h>
20#include <sound/dmaengine_pcm.h>
21
22#define AXI_I2S_REG_RESET	0x00
23#define AXI_I2S_REG_CTRL	0x04
24#define AXI_I2S_REG_CLK_CTRL	0x08
25#define AXI_I2S_REG_STATUS	0x10
26
27#define AXI_I2S_REG_RX_FIFO	0x28
28#define AXI_I2S_REG_TX_FIFO	0x2C
29
30#define AXI_I2S_RESET_GLOBAL	BIT(0)
31#define AXI_I2S_RESET_TX_FIFO	BIT(1)
32#define AXI_I2S_RESET_RX_FIFO	BIT(2)
33
34#define AXI_I2S_CTRL_TX_EN	BIT(0)
35#define AXI_I2S_CTRL_RX_EN	BIT(1)
36
37/* The frame size is configurable, but for now we always set it 64 bit */
38#define AXI_I2S_BITS_PER_FRAME 64
39
40struct axi_i2s {
41	struct regmap *regmap;
42	struct clk *clk;
43	struct clk *clk_ref;
44
45	bool   has_capture;
46	bool   has_playback;
47
48	struct snd_soc_dai_driver dai_driver;
49
50	struct snd_dmaengine_dai_dma_data capture_dma_data;
51	struct snd_dmaengine_dai_dma_data playback_dma_data;
52
53	struct snd_ratnum ratnum;
54	struct snd_pcm_hw_constraint_ratnums rate_constraints;
55};
56
57static int axi_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
58	struct snd_soc_dai *dai)
59{
60	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
61	unsigned int mask, val;
62
63	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
64		mask = AXI_I2S_CTRL_RX_EN;
65	else
66		mask = AXI_I2S_CTRL_TX_EN;
67
68	switch (cmd) {
69	case SNDRV_PCM_TRIGGER_START:
70	case SNDRV_PCM_TRIGGER_RESUME:
71	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
72		val = mask;
73		break;
74	case SNDRV_PCM_TRIGGER_STOP:
75	case SNDRV_PCM_TRIGGER_SUSPEND:
76	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
77		val = 0;
78		break;
79	default:
80		return -EINVAL;
81	}
82
83	regmap_update_bits(i2s->regmap, AXI_I2S_REG_CTRL, mask, val);
84
85	return 0;
86}
87
88static int axi_i2s_hw_params(struct snd_pcm_substream *substream,
89	struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
90{
91	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
92	unsigned int bclk_div, word_size;
93	unsigned int bclk_rate;
94
95	bclk_rate = params_rate(params) * AXI_I2S_BITS_PER_FRAME;
96
97	word_size = AXI_I2S_BITS_PER_FRAME / 2 - 1;
98	bclk_div = DIV_ROUND_UP(clk_get_rate(i2s->clk_ref), bclk_rate) / 2 - 1;
99
100	regmap_write(i2s->regmap, AXI_I2S_REG_CLK_CTRL, (word_size << 16) |
101		bclk_div);
102
103	return 0;
104}
105
106static int axi_i2s_startup(struct snd_pcm_substream *substream,
107	struct snd_soc_dai *dai)
108{
109	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
110	uint32_t mask;
111	int ret;
112
113	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
114		mask = AXI_I2S_RESET_RX_FIFO;
115	else
116		mask = AXI_I2S_RESET_TX_FIFO;
117
118	regmap_write(i2s->regmap, AXI_I2S_REG_RESET, mask);
119
120	ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
121			   SNDRV_PCM_HW_PARAM_RATE,
122			   &i2s->rate_constraints);
123	if (ret)
124		return ret;
125
126	return clk_prepare_enable(i2s->clk_ref);
127}
128
129static void axi_i2s_shutdown(struct snd_pcm_substream *substream,
130	struct snd_soc_dai *dai)
131{
132	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
133
134	clk_disable_unprepare(i2s->clk_ref);
135}
136
137static int axi_i2s_dai_probe(struct snd_soc_dai *dai)
138{
139	struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
140
141	snd_soc_dai_init_dma_data(
142		dai,
143		i2s->has_playback ? &i2s->playback_dma_data : NULL,
144		i2s->has_capture  ? &i2s->capture_dma_data  : NULL);
145
146	return 0;
147}
148
149static const struct snd_soc_dai_ops axi_i2s_dai_ops = {
150	.probe = axi_i2s_dai_probe,
151	.startup = axi_i2s_startup,
152	.shutdown = axi_i2s_shutdown,
153	.trigger = axi_i2s_trigger,
154	.hw_params = axi_i2s_hw_params,
155};
156
157static struct snd_soc_dai_driver axi_i2s_dai = {
158	.ops = &axi_i2s_dai_ops,
159	.symmetric_rate = 1,
160};
161
162static const struct snd_soc_component_driver axi_i2s_component = {
163	.name = "axi-i2s",
164	.legacy_dai_naming = 1,
165};
166
167static const struct regmap_config axi_i2s_regmap_config = {
168	.reg_bits = 32,
169	.reg_stride = 4,
170	.val_bits = 32,
171	.max_register = AXI_I2S_REG_STATUS,
172};
173
174static void axi_i2s_parse_of(struct axi_i2s *i2s, const struct device_node *np)
175{
176	struct property *dma_names;
177	const char *dma_name;
178
179	of_property_for_each_string(np, "dma-names", dma_names, dma_name) {
180		if (strcmp(dma_name, "rx") == 0)
181			i2s->has_capture = true;
182		if (strcmp(dma_name, "tx") == 0)
183			i2s->has_playback = true;
184	}
185}
186
187static int axi_i2s_probe(struct platform_device *pdev)
188{
189	struct resource *res;
190	struct axi_i2s *i2s;
191	void __iomem *base;
192	int ret;
193
194	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
195	if (!i2s)
196		return -ENOMEM;
197
198	platform_set_drvdata(pdev, i2s);
199
200	axi_i2s_parse_of(i2s, pdev->dev.of_node);
201
202	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
203	if (IS_ERR(base))
204		return PTR_ERR(base);
205
206	i2s->regmap = devm_regmap_init_mmio(&pdev->dev, base,
207		&axi_i2s_regmap_config);
208	if (IS_ERR(i2s->regmap))
209		return PTR_ERR(i2s->regmap);
210
211	i2s->clk = devm_clk_get(&pdev->dev, "axi");
212	if (IS_ERR(i2s->clk))
213		return PTR_ERR(i2s->clk);
214
215	i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
216	if (IS_ERR(i2s->clk_ref))
217		return PTR_ERR(i2s->clk_ref);
218
219	ret = clk_prepare_enable(i2s->clk);
220	if (ret)
221		return ret;
222
223	if (i2s->has_playback) {
224		axi_i2s_dai.playback.channels_min = 2;
225		axi_i2s_dai.playback.channels_max = 2;
226		axi_i2s_dai.playback.rates = SNDRV_PCM_RATE_KNOT;
227		axi_i2s_dai.playback.formats =
228			SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE;
229
230		i2s->playback_dma_data.addr = res->start + AXI_I2S_REG_TX_FIFO;
231		i2s->playback_dma_data.addr_width = 4;
232		i2s->playback_dma_data.maxburst = 1;
233	}
234
235	if (i2s->has_capture) {
236		axi_i2s_dai.capture.channels_min = 2;
237		axi_i2s_dai.capture.channels_max = 2;
238		axi_i2s_dai.capture.rates = SNDRV_PCM_RATE_KNOT;
239		axi_i2s_dai.capture.formats =
240			SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE;
241
242		i2s->capture_dma_data.addr = res->start + AXI_I2S_REG_RX_FIFO;
243		i2s->capture_dma_data.addr_width = 4;
244		i2s->capture_dma_data.maxburst = 1;
245	}
246
247	i2s->ratnum.num = clk_get_rate(i2s->clk_ref) / 2 / AXI_I2S_BITS_PER_FRAME;
248	i2s->ratnum.den_step = 1;
249	i2s->ratnum.den_min = 1;
250	i2s->ratnum.den_max = 64;
251
252	i2s->rate_constraints.rats = &i2s->ratnum;
253	i2s->rate_constraints.nrats = 1;
254
255	regmap_write(i2s->regmap, AXI_I2S_REG_RESET, AXI_I2S_RESET_GLOBAL);
256
257	ret = devm_snd_soc_register_component(&pdev->dev, &axi_i2s_component,
258					 &axi_i2s_dai, 1);
259	if (ret)
260		goto err_clk_disable;
261
262	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
263	if (ret)
264		goto err_clk_disable;
265
266	dev_info(&pdev->dev, "probed, capture %s, playback %s\n",
267		 i2s->has_capture ? "enabled" : "disabled",
268		 i2s->has_playback ? "enabled" : "disabled");
269
270	return 0;
271
272err_clk_disable:
273	clk_disable_unprepare(i2s->clk);
274	return ret;
275}
276
277static void axi_i2s_dev_remove(struct platform_device *pdev)
278{
279	struct axi_i2s *i2s = platform_get_drvdata(pdev);
280
281	clk_disable_unprepare(i2s->clk);
282}
283
284static const struct of_device_id axi_i2s_of_match[] = {
285	{ .compatible = "adi,axi-i2s-1.00.a", },
286	{},
287};
288MODULE_DEVICE_TABLE(of, axi_i2s_of_match);
289
290static struct platform_driver axi_i2s_driver = {
291	.driver = {
292		.name = "axi-i2s",
293		.of_match_table = axi_i2s_of_match,
294	},
295	.probe = axi_i2s_probe,
296	.remove_new = axi_i2s_dev_remove,
297};
298module_platform_driver(axi_i2s_driver);
299
300MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
301MODULE_DESCRIPTION("AXI I2S driver");
302MODULE_LICENSE("GPL");
303