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