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