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/init.h>
  8#include <linux/kernel.h>
  9#include <linux/module.h>
 10#include <linux/platform_device.h>
 11#include <linux/slab.h>
 12#include <linux/of.h>
 13#include <linux/clk.h>
 14#include <linux/regmap.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/initval.h>
 21#include <sound/dmaengine_pcm.h>
 22
 23#define AXI_SPDIF_REG_CTRL	0x0
 24#define AXI_SPDIF_REG_STAT	0x4
 25#define AXI_SPDIF_REG_TX_FIFO	0xc
 26
 27#define AXI_SPDIF_CTRL_TXDATA BIT(1)
 28#define AXI_SPDIF_CTRL_TXEN BIT(0)
 29#define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8
 30#define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8)
 31
 32#define AXI_SPDIF_FREQ_44100	(0x0 << 6)
 33#define AXI_SPDIF_FREQ_48000	(0x1 << 6)
 34#define AXI_SPDIF_FREQ_32000	(0x2 << 6)
 35#define AXI_SPDIF_FREQ_NA	(0x3 << 6)
 36
 37struct axi_spdif {
 38	struct regmap *regmap;
 39	struct clk *clk;
 40	struct clk *clk_ref;
 41
 42	struct snd_dmaengine_dai_dma_data dma_data;
 43
 44	struct snd_ratnum ratnum;
 45	struct snd_pcm_hw_constraint_ratnums rate_constraints;
 46};
 47
 48static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
 49	struct snd_soc_dai *dai)
 50{
 51	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
 52	unsigned int val;
 53
 54	switch (cmd) {
 55	case SNDRV_PCM_TRIGGER_START:
 56	case SNDRV_PCM_TRIGGER_RESUME:
 57	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 58		val = AXI_SPDIF_CTRL_TXDATA;
 59		break;
 60	case SNDRV_PCM_TRIGGER_STOP:
 61	case SNDRV_PCM_TRIGGER_SUSPEND:
 62	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 63		val = 0;
 64		break;
 65	default:
 66		return -EINVAL;
 67	}
 68
 69	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
 70		AXI_SPDIF_CTRL_TXDATA, val);
 71
 72	return 0;
 73}
 74
 75static int axi_spdif_hw_params(struct snd_pcm_substream *substream,
 76	struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
 77{
 78	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
 79	unsigned int rate = params_rate(params);
 80	unsigned int clkdiv, stat;
 81
 82	switch (params_rate(params)) {
 83	case 32000:
 84		stat = AXI_SPDIF_FREQ_32000;
 85		break;
 86	case 44100:
 87		stat = AXI_SPDIF_FREQ_44100;
 88		break;
 89	case 48000:
 90		stat = AXI_SPDIF_FREQ_48000;
 91		break;
 92	default:
 93		stat = AXI_SPDIF_FREQ_NA;
 94		break;
 95	}
 96
 97	clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref),
 98			rate * 64 * 2) - 1;
 99	clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET;
100
101	regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat);
102	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
103		AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv);
104
105	return 0;
106}
107
108static int axi_spdif_dai_probe(struct snd_soc_dai *dai)
109{
110	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
111
112	snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL);
113
114	return 0;
115}
116
117static int axi_spdif_startup(struct snd_pcm_substream *substream,
118	struct snd_soc_dai *dai)
119{
120	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
121	int ret;
122
123	ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
124			   SNDRV_PCM_HW_PARAM_RATE,
125			   &spdif->rate_constraints);
126	if (ret)
127		return ret;
128
129	ret = clk_prepare_enable(spdif->clk_ref);
130	if (ret)
131		return ret;
132
133	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
134		AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN);
135
136	return 0;
137}
138
139static void axi_spdif_shutdown(struct snd_pcm_substream *substream,
140	struct snd_soc_dai *dai)
141{
142	struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
143
144	regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
145		AXI_SPDIF_CTRL_TXEN, 0);
146
147	clk_disable_unprepare(spdif->clk_ref);
148}
149
150static const struct snd_soc_dai_ops axi_spdif_dai_ops = {
151	.startup = axi_spdif_startup,
152	.shutdown = axi_spdif_shutdown,
153	.trigger = axi_spdif_trigger,
154	.hw_params = axi_spdif_hw_params,
155};
156
157static struct snd_soc_dai_driver axi_spdif_dai = {
158	.probe = axi_spdif_dai_probe,
159	.playback = {
160		.channels_min = 2,
161		.channels_max = 2,
162		.rates = SNDRV_PCM_RATE_KNOT,
163		.formats = SNDRV_PCM_FMTBIT_S16_LE,
164	},
165	.ops = &axi_spdif_dai_ops,
166};
167
168static const struct snd_soc_component_driver axi_spdif_component = {
169	.name = "axi-spdif",
170	.legacy_dai_naming = 1,
171};
172
173static const struct regmap_config axi_spdif_regmap_config = {
174	.reg_bits = 32,
175	.reg_stride = 4,
176	.val_bits = 32,
177	.max_register = AXI_SPDIF_REG_STAT,
178};
179
180static int axi_spdif_probe(struct platform_device *pdev)
181{
182	struct axi_spdif *spdif;
183	struct resource *res;
184	void __iomem *base;
185	int ret;
186
187	spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL);
188	if (!spdif)
189		return -ENOMEM;
190
191	platform_set_drvdata(pdev, spdif);
192
193	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
194	if (IS_ERR(base))
195		return PTR_ERR(base);
196
197	spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base,
198					    &axi_spdif_regmap_config);
199	if (IS_ERR(spdif->regmap))
200		return PTR_ERR(spdif->regmap);
201
202	spdif->clk = devm_clk_get(&pdev->dev, "axi");
203	if (IS_ERR(spdif->clk))
204		return PTR_ERR(spdif->clk);
205
206	spdif->clk_ref = devm_clk_get(&pdev->dev, "ref");
207	if (IS_ERR(spdif->clk_ref))
208		return PTR_ERR(spdif->clk_ref);
209
210	ret = clk_prepare_enable(spdif->clk);
211	if (ret)
212		return ret;
213
214	spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO;
215	spdif->dma_data.addr_width = 4;
216	spdif->dma_data.maxburst = 1;
217
218	spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128;
219	spdif->ratnum.den_step = 1;
220	spdif->ratnum.den_min = 1;
221	spdif->ratnum.den_max = 64;
222
223	spdif->rate_constraints.rats = &spdif->ratnum;
224	spdif->rate_constraints.nrats = 1;
225
226	ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component,
227					 &axi_spdif_dai, 1);
228	if (ret)
229		goto err_clk_disable;
230
231	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
232	if (ret)
233		goto err_clk_disable;
234
235	return 0;
236
237err_clk_disable:
238	clk_disable_unprepare(spdif->clk);
239	return ret;
240}
241
242static int axi_spdif_dev_remove(struct platform_device *pdev)
243{
244	struct axi_spdif *spdif = platform_get_drvdata(pdev);
245
246	clk_disable_unprepare(spdif->clk);
247
248	return 0;
249}
250
251static const struct of_device_id axi_spdif_of_match[] = {
252	{ .compatible = "adi,axi-spdif-tx-1.00.a", },
253	{},
254};
255MODULE_DEVICE_TABLE(of, axi_spdif_of_match);
256
257static struct platform_driver axi_spdif_driver = {
258	.driver = {
259		.name = "axi-spdif",
260		.of_match_table = axi_spdif_of_match,
261	},
262	.probe = axi_spdif_probe,
263	.remove = axi_spdif_dev_remove,
264};
265module_platform_driver(axi_spdif_driver);
266
267MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
268MODULE_DESCRIPTION("AXI SPDIF driver");
269MODULE_LICENSE("GPL");