xref: /openbmc/linux/sound/soc/stm/stm32_sai.c (revision efc162cb)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * STM32 ALSA SoC Digital Audio Interface (SAI) driver.
4  *
5  * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
6  * Author(s): Olivier Moysan <olivier.moysan@st.com> for STMicroelectronics.
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/delay.h>
12 #include <linux/module.h>
13 #include <linux/of_platform.h>
14 #include <linux/pinctrl/consumer.h>
15 #include <linux/reset.h>
16 
17 #include <sound/dmaengine_pcm.h>
18 #include <sound/core.h>
19 
20 #include "stm32_sai.h"
21 
22 static const struct stm32_sai_conf stm32_sai_conf_f4 = {
23 	.version = STM_SAI_STM32F4,
24 	.fifo_size = 8,
25 	.has_spdif_pdm = false,
26 };
27 
28 /*
29  * Default settings for stm32 H7 socs and next.
30  * These default settings will be overridden if the soc provides
31  * support of hardware configuration registers.
32  */
33 static const struct stm32_sai_conf stm32_sai_conf_h7 = {
34 	.version = STM_SAI_STM32H7,
35 	.fifo_size = 8,
36 	.has_spdif_pdm = true,
37 };
38 
39 static const struct of_device_id stm32_sai_ids[] = {
40 	{ .compatible = "st,stm32f4-sai", .data = (void *)&stm32_sai_conf_f4 },
41 	{ .compatible = "st,stm32h7-sai", .data = (void *)&stm32_sai_conf_h7 },
42 	{}
43 };
44 
stm32_sai_pclk_disable(struct device * dev)45 static int stm32_sai_pclk_disable(struct device *dev)
46 {
47 	struct stm32_sai_data *sai = dev_get_drvdata(dev);
48 
49 	clk_disable_unprepare(sai->pclk);
50 
51 	return 0;
52 }
53 
stm32_sai_pclk_enable(struct device * dev)54 static int stm32_sai_pclk_enable(struct device *dev)
55 {
56 	struct stm32_sai_data *sai = dev_get_drvdata(dev);
57 	int ret;
58 
59 	ret = clk_prepare_enable(sai->pclk);
60 	if (ret) {
61 		dev_err(&sai->pdev->dev, "failed to enable clock: %d\n", ret);
62 		return ret;
63 	}
64 
65 	return 0;
66 }
67 
stm32_sai_sync_conf_client(struct stm32_sai_data * sai,int synci)68 static int stm32_sai_sync_conf_client(struct stm32_sai_data *sai, int synci)
69 {
70 	int ret;
71 
72 	/* Enable peripheral clock to allow GCR register access */
73 	ret = stm32_sai_pclk_enable(&sai->pdev->dev);
74 	if (ret)
75 		return ret;
76 
77 	writel_relaxed(FIELD_PREP(SAI_GCR_SYNCIN_MASK, (synci - 1)), sai->base);
78 
79 	stm32_sai_pclk_disable(&sai->pdev->dev);
80 
81 	return 0;
82 }
83 
stm32_sai_sync_conf_provider(struct stm32_sai_data * sai,int synco)84 static int stm32_sai_sync_conf_provider(struct stm32_sai_data *sai, int synco)
85 {
86 	u32 prev_synco;
87 	int ret;
88 
89 	/* Enable peripheral clock to allow GCR register access */
90 	ret = stm32_sai_pclk_enable(&sai->pdev->dev);
91 	if (ret)
92 		return ret;
93 
94 	dev_dbg(&sai->pdev->dev, "Set %pOFn%s as synchro provider\n",
95 		sai->pdev->dev.of_node,
96 		synco == STM_SAI_SYNC_OUT_A ? "A" : "B");
97 
98 	prev_synco = FIELD_GET(SAI_GCR_SYNCOUT_MASK, readl_relaxed(sai->base));
99 	if (prev_synco != STM_SAI_SYNC_OUT_NONE && synco != prev_synco) {
100 		dev_err(&sai->pdev->dev, "%pOFn%s already set as sync provider\n",
101 			sai->pdev->dev.of_node,
102 			prev_synco == STM_SAI_SYNC_OUT_A ? "A" : "B");
103 		stm32_sai_pclk_disable(&sai->pdev->dev);
104 		return -EINVAL;
105 	}
106 
107 	writel_relaxed(FIELD_PREP(SAI_GCR_SYNCOUT_MASK, synco), sai->base);
108 
109 	stm32_sai_pclk_disable(&sai->pdev->dev);
110 
111 	return 0;
112 }
113 
stm32_sai_set_sync(struct stm32_sai_data * sai_client,struct device_node * np_provider,int synco,int synci)114 static int stm32_sai_set_sync(struct stm32_sai_data *sai_client,
115 			      struct device_node *np_provider,
116 			      int synco, int synci)
117 {
118 	struct platform_device *pdev = of_find_device_by_node(np_provider);
119 	struct stm32_sai_data *sai_provider;
120 	int ret;
121 
122 	if (!pdev) {
123 		dev_err(&sai_client->pdev->dev,
124 			"Device not found for node %pOFn\n", np_provider);
125 		of_node_put(np_provider);
126 		return -ENODEV;
127 	}
128 
129 	sai_provider = platform_get_drvdata(pdev);
130 	if (!sai_provider) {
131 		dev_err(&sai_client->pdev->dev,
132 			"SAI sync provider data not found\n");
133 		ret = -EINVAL;
134 		goto error;
135 	}
136 
137 	/* Configure sync client */
138 	ret = stm32_sai_sync_conf_client(sai_client, synci);
139 	if (ret < 0)
140 		goto error;
141 
142 	/* Configure sync provider */
143 	ret = stm32_sai_sync_conf_provider(sai_provider, synco);
144 
145 error:
146 	put_device(&pdev->dev);
147 	of_node_put(np_provider);
148 	return ret;
149 }
150 
stm32_sai_probe(struct platform_device * pdev)151 static int stm32_sai_probe(struct platform_device *pdev)
152 {
153 	struct stm32_sai_data *sai;
154 	struct reset_control *rst;
155 	const struct of_device_id *of_id;
156 	u32 val;
157 	int ret;
158 
159 	sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL);
160 	if (!sai)
161 		return -ENOMEM;
162 
163 	sai->base = devm_platform_ioremap_resource(pdev, 0);
164 	if (IS_ERR(sai->base))
165 		return PTR_ERR(sai->base);
166 
167 	of_id = of_match_device(stm32_sai_ids, &pdev->dev);
168 	if (of_id)
169 		memcpy(&sai->conf, (const struct stm32_sai_conf *)of_id->data,
170 		       sizeof(struct stm32_sai_conf));
171 	else
172 		return -EINVAL;
173 
174 	if (!STM_SAI_IS_F4(sai)) {
175 		sai->pclk = devm_clk_get(&pdev->dev, "pclk");
176 		if (IS_ERR(sai->pclk))
177 			return dev_err_probe(&pdev->dev, PTR_ERR(sai->pclk),
178 					     "missing bus clock pclk\n");
179 	}
180 
181 	sai->clk_x8k = devm_clk_get(&pdev->dev, "x8k");
182 	if (IS_ERR(sai->clk_x8k))
183 		return dev_err_probe(&pdev->dev, PTR_ERR(sai->clk_x8k),
184 				     "missing x8k parent clock\n");
185 
186 	sai->clk_x11k = devm_clk_get(&pdev->dev, "x11k");
187 	if (IS_ERR(sai->clk_x11k))
188 		return dev_err_probe(&pdev->dev, PTR_ERR(sai->clk_x11k),
189 				     "missing x11k parent clock\n");
190 
191 	/* init irqs */
192 	sai->irq = platform_get_irq(pdev, 0);
193 	if (sai->irq < 0)
194 		return sai->irq;
195 
196 	/* reset */
197 	rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
198 	if (IS_ERR(rst))
199 		return dev_err_probe(&pdev->dev, PTR_ERR(rst),
200 				     "Reset controller error\n");
201 
202 	reset_control_assert(rst);
203 	udelay(2);
204 	reset_control_deassert(rst);
205 
206 	/* Enable peripheral clock to allow register access */
207 	ret = clk_prepare_enable(sai->pclk);
208 	if (ret) {
209 		dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
210 		return ret;
211 	}
212 
213 	val = FIELD_GET(SAI_IDR_ID_MASK,
214 			readl_relaxed(sai->base + STM_SAI_IDR));
215 	if (val == SAI_IPIDR_NUMBER) {
216 		val = readl_relaxed(sai->base + STM_SAI_HWCFGR);
217 		sai->conf.fifo_size = FIELD_GET(SAI_HWCFGR_FIFO_SIZE, val);
218 		sai->conf.has_spdif_pdm = !!FIELD_GET(SAI_HWCFGR_SPDIF_PDM,
219 						      val);
220 
221 		val = readl_relaxed(sai->base + STM_SAI_VERR);
222 		sai->conf.version = val;
223 
224 		dev_dbg(&pdev->dev, "SAI version: %lu.%lu registered\n",
225 			FIELD_GET(SAI_VERR_MAJ_MASK, val),
226 			FIELD_GET(SAI_VERR_MIN_MASK, val));
227 	}
228 	clk_disable_unprepare(sai->pclk);
229 
230 	sai->pdev = pdev;
231 	sai->set_sync = &stm32_sai_set_sync;
232 	platform_set_drvdata(pdev, sai);
233 
234 	return devm_of_platform_populate(&pdev->dev);
235 }
236 
237 #ifdef CONFIG_PM_SLEEP
238 /*
239  * When pins are shared by two sai sub instances, pins have to be defined
240  * in sai parent node. In this case, pins state is not managed by alsa fw.
241  * These pins are managed in suspend/resume callbacks.
242  */
stm32_sai_suspend(struct device * dev)243 static int stm32_sai_suspend(struct device *dev)
244 {
245 	struct stm32_sai_data *sai = dev_get_drvdata(dev);
246 	int ret;
247 
248 	ret = stm32_sai_pclk_enable(dev);
249 	if (ret)
250 		return ret;
251 
252 	sai->gcr = readl_relaxed(sai->base);
253 	stm32_sai_pclk_disable(dev);
254 
255 	return pinctrl_pm_select_sleep_state(dev);
256 }
257 
stm32_sai_resume(struct device * dev)258 static int stm32_sai_resume(struct device *dev)
259 {
260 	struct stm32_sai_data *sai = dev_get_drvdata(dev);
261 	int ret;
262 
263 	ret = stm32_sai_pclk_enable(dev);
264 	if (ret)
265 		return ret;
266 
267 	writel_relaxed(sai->gcr, sai->base);
268 	stm32_sai_pclk_disable(dev);
269 
270 	return pinctrl_pm_select_default_state(dev);
271 }
272 #endif /* CONFIG_PM_SLEEP */
273 
274 static const struct dev_pm_ops stm32_sai_pm_ops = {
275 	SET_SYSTEM_SLEEP_PM_OPS(stm32_sai_suspend, stm32_sai_resume)
276 };
277 
278 MODULE_DEVICE_TABLE(of, stm32_sai_ids);
279 
280 static struct platform_driver stm32_sai_driver = {
281 	.driver = {
282 		.name = "st,stm32-sai",
283 		.of_match_table = stm32_sai_ids,
284 		.pm = &stm32_sai_pm_ops,
285 	},
286 	.probe = stm32_sai_probe,
287 };
288 
289 module_platform_driver(stm32_sai_driver);
290 
291 MODULE_DESCRIPTION("STM32 Soc SAI Interface");
292 MODULE_AUTHOR("Olivier Moysan <olivier.moysan@st.com>");
293 MODULE_ALIAS("platform:st,stm32-sai");
294 MODULE_LICENSE("GPL v2");
295