1 // SPDX-License-Identifier: GPL-2.0-only
2 //
3 // tegra_audio_graph_card.c - Audio Graph based Tegra Machine Driver
4 //
5 // Copyright (c) 2020-2021 NVIDIA CORPORATION.  All rights reserved.
6 
7 #include <linux/math64.h>
8 #include <linux/module.h>
9 #include <linux/of_device.h>
10 #include <linux/platform_device.h>
11 #include <sound/graph_card.h>
12 #include <sound/pcm_params.h>
13 
14 #define MAX_PLLA_OUT0_DIV 128
15 
16 #define simple_to_tegra_priv(simple) \
17 		container_of(simple, struct tegra_audio_priv, simple)
18 
19 enum srate_type {
20 	/*
21 	 * Sample rates multiple of 8000 Hz and below are supported:
22 	 * ( 8000, 16000, 32000, 48000, 96000, 192000 Hz )
23 	 */
24 	x8_RATE,
25 
26 	/*
27 	 * Sample rates multiple of 11025 Hz and below are supported:
28 	 * ( 11025, 22050, 44100, 88200, 176400 Hz )
29 	 */
30 	x11_RATE,
31 
32 	NUM_RATE_TYPE,
33 };
34 
35 struct tegra_audio_priv {
36 	struct asoc_simple_priv simple;
37 	struct clk *clk_plla_out0;
38 	struct clk *clk_plla;
39 };
40 
41 /* Tegra audio chip data */
42 struct tegra_audio_cdata {
43 	unsigned int plla_rates[NUM_RATE_TYPE];
44 	unsigned int plla_out0_rates[NUM_RATE_TYPE];
45 };
46 
47 /* Setup PLL clock as per the given sample rate */
48 static int tegra_audio_graph_update_pll(struct snd_pcm_substream *substream,
49 					struct snd_pcm_hw_params *params)
50 {
51 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
52 	struct asoc_simple_priv *simple = snd_soc_card_get_drvdata(rtd->card);
53 	struct tegra_audio_priv *priv = simple_to_tegra_priv(simple);
54 	struct device *dev = rtd->card->dev;
55 	const struct tegra_audio_cdata *data = of_device_get_match_data(dev);
56 	unsigned int plla_rate, plla_out0_rate, bclk;
57 	unsigned int srate = params_rate(params);
58 	int err;
59 
60 	switch (srate) {
61 	case 11025:
62 	case 22050:
63 	case 44100:
64 	case 88200:
65 	case 176400:
66 		plla_out0_rate = data->plla_out0_rates[x11_RATE];
67 		plla_rate = data->plla_rates[x11_RATE];
68 		break;
69 	case 8000:
70 	case 16000:
71 	case 32000:
72 	case 48000:
73 	case 96000:
74 	case 192000:
75 		plla_out0_rate = data->plla_out0_rates[x8_RATE];
76 		plla_rate = data->plla_rates[x8_RATE];
77 		break;
78 	default:
79 		dev_err(rtd->card->dev, "Unsupported sample rate %u\n",
80 			srate);
81 		return -EINVAL;
82 	}
83 
84 	/*
85 	 * Below is the clock relation:
86 	 *
87 	 *	PLLA
88 	 *	  |
89 	 *	  |--> PLLA_OUT0
90 	 *		  |
91 	 *		  |---> I2S modules
92 	 *		  |
93 	 *		  |---> DMIC modules
94 	 *		  |
95 	 *		  |---> DSPK modules
96 	 *
97 	 *
98 	 * Default PLLA_OUT0 rate might be too high when I/O is running
99 	 * at minimum PCM configurations. This may result in incorrect
100 	 * clock rates and glitchy audio. The maximum divider is 128
101 	 * and any thing higher than that won't work. Thus reduce PLLA_OUT0
102 	 * to work for lower configurations.
103 	 *
104 	 * This problem is seen for I2S only, as DMIC and DSPK minimum
105 	 * clock requirements are under allowed divider limits.
106 	 */
107 	bclk = srate * params_channels(params) * params_width(params);
108 	if (div_u64(plla_out0_rate, bclk) > MAX_PLLA_OUT0_DIV)
109 		plla_out0_rate >>= 1;
110 
111 	dev_dbg(rtd->card->dev,
112 		"Update clock rates: PLLA(= %u Hz) and PLLA_OUT0(= %u Hz)\n",
113 		plla_rate, plla_out0_rate);
114 
115 	/* Set PLLA rate */
116 	err = clk_set_rate(priv->clk_plla, plla_rate);
117 	if (err) {
118 		dev_err(rtd->card->dev,
119 			"Can't set plla rate for %u, err: %d\n",
120 			plla_rate, err);
121 		return err;
122 	}
123 
124 	/* Set PLLA_OUT0 rate */
125 	err = clk_set_rate(priv->clk_plla_out0, plla_out0_rate);
126 	if (err) {
127 		dev_err(rtd->card->dev,
128 			"Can't set plla_out0 rate %u, err: %d\n",
129 			plla_out0_rate, err);
130 		return err;
131 	}
132 
133 	return err;
134 }
135 
136 static int tegra_audio_graph_hw_params(struct snd_pcm_substream *substream,
137 				       struct snd_pcm_hw_params *params)
138 {
139 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
140 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
141 	int err;
142 
143 	/*
144 	 * This gets called for each DAI link (FE or BE) when DPCM is used.
145 	 * We may not want to update PLLA rate for each call. So PLLA update
146 	 * must be restricted to external I/O links (I2S, DMIC or DSPK) since
147 	 * they actually depend on it. I/O modules update their clocks in
148 	 * hw_param() of their respective component driver and PLLA rate
149 	 * update here helps them to derive appropriate rates.
150 	 *
151 	 * TODO: When more HW accelerators get added (like sample rate
152 	 * converter, volume gain controller etc., which don't really
153 	 * depend on PLLA) we need a better way to filter here.
154 	 */
155 	if (cpu_dai->driver->ops && rtd->dai_link->no_pcm) {
156 		err = tegra_audio_graph_update_pll(substream, params);
157 		if (err)
158 			return err;
159 	}
160 
161 	return asoc_simple_hw_params(substream, params);
162 }
163 
164 static const struct snd_soc_ops tegra_audio_graph_ops = {
165 	.startup	= asoc_simple_startup,
166 	.shutdown	= asoc_simple_shutdown,
167 	.hw_params	= tegra_audio_graph_hw_params,
168 };
169 
170 static int tegra_audio_graph_card_probe(struct snd_soc_card *card)
171 {
172 	struct asoc_simple_priv *simple = snd_soc_card_get_drvdata(card);
173 	struct tegra_audio_priv *priv = simple_to_tegra_priv(simple);
174 
175 	priv->clk_plla = devm_clk_get(card->dev, "pll_a");
176 	if (IS_ERR(priv->clk_plla)) {
177 		dev_err(card->dev, "Can't retrieve clk pll_a\n");
178 		return PTR_ERR(priv->clk_plla);
179 	}
180 
181 	priv->clk_plla_out0 = devm_clk_get(card->dev, "plla_out0");
182 	if (IS_ERR(priv->clk_plla_out0)) {
183 		dev_err(card->dev, "Can't retrieve clk plla_out0\n");
184 		return PTR_ERR(priv->clk_plla_out0);
185 	}
186 
187 	return audio_graph_card_probe(card);
188 }
189 
190 static int tegra_audio_graph_probe(struct platform_device *pdev)
191 {
192 	struct tegra_audio_priv *priv;
193 	struct device *dev = &pdev->dev;
194 	struct snd_soc_card *card;
195 
196 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
197 	if (!priv)
198 		return -ENOMEM;
199 
200 	card = simple_priv_to_card(&priv->simple);
201 
202 	card->probe = tegra_audio_graph_card_probe;
203 
204 	/* audio_graph_parse_of() depends on below */
205 	card->component_chaining = 1;
206 	priv->simple.ops = &tegra_audio_graph_ops;
207 	priv->simple.force_dpcm = 1;
208 
209 	return audio_graph_parse_of(&priv->simple, dev);
210 }
211 
212 static const struct tegra_audio_cdata tegra210_data = {
213 	/* PLLA */
214 	.plla_rates[x8_RATE] = 368640000,
215 	.plla_rates[x11_RATE] = 338688000,
216 	/* PLLA_OUT0 */
217 	.plla_out0_rates[x8_RATE] = 49152000,
218 	.plla_out0_rates[x11_RATE] = 45158400,
219 };
220 
221 static const struct tegra_audio_cdata tegra186_data = {
222 	/* PLLA */
223 	.plla_rates[x8_RATE] = 245760000,
224 	.plla_rates[x11_RATE] = 270950400,
225 	/* PLLA_OUT0 */
226 	.plla_out0_rates[x8_RATE] = 49152000,
227 	.plla_out0_rates[x11_RATE] = 45158400,
228 };
229 
230 static const struct of_device_id graph_of_tegra_match[] = {
231 	{ .compatible = "nvidia,tegra210-audio-graph-card",
232 	  .data = &tegra210_data },
233 	{ .compatible = "nvidia,tegra186-audio-graph-card",
234 	  .data = &tegra186_data },
235 	{},
236 };
237 MODULE_DEVICE_TABLE(of, graph_of_tegra_match);
238 
239 static struct platform_driver tegra_audio_graph_card = {
240 	.driver = {
241 		.name = "tegra-audio-graph-card",
242 		.pm = &snd_soc_pm_ops,
243 		.of_match_table = graph_of_tegra_match,
244 	},
245 	.probe = tegra_audio_graph_probe,
246 	.remove = audio_graph_remove,
247 };
248 module_platform_driver(tegra_audio_graph_card);
249 
250 MODULE_LICENSE("GPL v2");
251 MODULE_DESCRIPTION("ASoC Tegra Audio Graph Sound Card");
252 MODULE_AUTHOR("Sameer Pujar <spujar@nvidia.com>");
253