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 int stm32_sai_get_parent_clk(struct stm32_sai_data *sai);
23
24 static const struct stm32_sai_conf stm32_sai_conf_f4 = {
25 .version = STM_SAI_STM32F4,
26 .fifo_size = 8,
27 .has_spdif_pdm = false,
28 .get_sai_ck_parent = stm32_sai_get_parent_clk,
29 };
30
31 /*
32 * Default settings for STM32H7x socs and STM32MP1x.
33 * These default settings will be overridden if the soc provides
34 * support of hardware configuration registers.
35 * - STM32H7: rely on default settings
36 * - STM32MP1: retrieve settings from registers
37 */
38 static const struct stm32_sai_conf stm32_sai_conf_h7 = {
39 .version = STM_SAI_STM32H7,
40 .fifo_size = 8,
41 .has_spdif_pdm = true,
42 .get_sai_ck_parent = stm32_sai_get_parent_clk,
43 };
44
45 /*
46 * STM32MP2x:
47 * - do not use SAI parent clock source selection
48 * - do not use DMA burst mode
49 */
50 static const struct stm32_sai_conf stm32_sai_conf_mp25 = {
51 .no_dma_burst = true,
52 };
53
54 static const struct of_device_id stm32_sai_ids[] = {
55 { .compatible = "st,stm32f4-sai", .data = (void *)&stm32_sai_conf_f4 },
56 { .compatible = "st,stm32h7-sai", .data = (void *)&stm32_sai_conf_h7 },
57 { .compatible = "st,stm32mp25-sai", .data = (void *)&stm32_sai_conf_mp25 },
58 {}
59 };
60
stm32_sai_pclk_disable(struct device * dev)61 static int stm32_sai_pclk_disable(struct device *dev)
62 {
63 struct stm32_sai_data *sai = dev_get_drvdata(dev);
64
65 clk_disable_unprepare(sai->pclk);
66
67 return 0;
68 }
69
stm32_sai_pclk_enable(struct device * dev)70 static int stm32_sai_pclk_enable(struct device *dev)
71 {
72 struct stm32_sai_data *sai = dev_get_drvdata(dev);
73 int ret;
74
75 ret = clk_prepare_enable(sai->pclk);
76 if (ret) {
77 dev_err(&sai->pdev->dev, "failed to enable clock: %d\n", ret);
78 return ret;
79 }
80
81 return 0;
82 }
83
stm32_sai_sync_conf_client(struct stm32_sai_data * sai,int synci)84 static int stm32_sai_sync_conf_client(struct stm32_sai_data *sai, int synci)
85 {
86 int ret;
87
88 /* Enable peripheral clock to allow GCR register access */
89 ret = stm32_sai_pclk_enable(&sai->pdev->dev);
90 if (ret)
91 return ret;
92
93 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCIN_MASK, (synci - 1)), sai->base);
94
95 stm32_sai_pclk_disable(&sai->pdev->dev);
96
97 return 0;
98 }
99
stm32_sai_sync_conf_provider(struct stm32_sai_data * sai,int synco)100 static int stm32_sai_sync_conf_provider(struct stm32_sai_data *sai, int synco)
101 {
102 u32 prev_synco;
103 int ret;
104
105 /* Enable peripheral clock to allow GCR register access */
106 ret = stm32_sai_pclk_enable(&sai->pdev->dev);
107 if (ret)
108 return ret;
109
110 dev_dbg(&sai->pdev->dev, "Set %pOFn%s as synchro provider\n",
111 sai->pdev->dev.of_node,
112 synco == STM_SAI_SYNC_OUT_A ? "A" : "B");
113
114 prev_synco = FIELD_GET(SAI_GCR_SYNCOUT_MASK, readl_relaxed(sai->base));
115 if (prev_synco != STM_SAI_SYNC_OUT_NONE && synco != prev_synco) {
116 dev_err(&sai->pdev->dev, "%pOFn%s already set as sync provider\n",
117 sai->pdev->dev.of_node,
118 prev_synco == STM_SAI_SYNC_OUT_A ? "A" : "B");
119 stm32_sai_pclk_disable(&sai->pdev->dev);
120 return -EINVAL;
121 }
122
123 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCOUT_MASK, synco), sai->base);
124
125 stm32_sai_pclk_disable(&sai->pdev->dev);
126
127 return 0;
128 }
129
stm32_sai_set_sync(struct stm32_sai_data * sai_client,struct device_node * np_provider,int synco,int synci)130 static int stm32_sai_set_sync(struct stm32_sai_data *sai_client,
131 struct device_node *np_provider,
132 int synco, int synci)
133 {
134 struct platform_device *pdev = of_find_device_by_node(np_provider);
135 struct stm32_sai_data *sai_provider;
136 int ret;
137
138 if (!pdev) {
139 dev_err(&sai_client->pdev->dev,
140 "Device not found for node %pOFn\n", np_provider);
141 of_node_put(np_provider);
142 return -ENODEV;
143 }
144
145 sai_provider = platform_get_drvdata(pdev);
146 if (!sai_provider) {
147 dev_err(&sai_client->pdev->dev,
148 "SAI sync provider data not found\n");
149 ret = -EINVAL;
150 goto error;
151 }
152
153 /* Configure sync client */
154 ret = stm32_sai_sync_conf_client(sai_client, synci);
155 if (ret < 0)
156 goto error;
157
158 /* Configure sync provider */
159 ret = stm32_sai_sync_conf_provider(sai_provider, synco);
160
161 error:
162 put_device(&pdev->dev);
163 of_node_put(np_provider);
164 return ret;
165 }
166
stm32_sai_get_parent_clk(struct stm32_sai_data * sai)167 static int stm32_sai_get_parent_clk(struct stm32_sai_data *sai)
168 {
169 struct device *dev = &sai->pdev->dev;
170
171 sai->clk_x8k = devm_clk_get(dev, "x8k");
172 if (IS_ERR(sai->clk_x8k))
173 return dev_err_probe(dev, PTR_ERR(sai->clk_x8k),
174 "missing x8k parent clock\n");
175
176 sai->clk_x11k = devm_clk_get(dev, "x11k");
177 if (IS_ERR(sai->clk_x11k))
178 return dev_err_probe(dev, PTR_ERR(sai->clk_x11k),
179 "missing x11k parent clock\n");
180
181 return 0;
182 }
183
stm32_sai_probe(struct platform_device * pdev)184 static int stm32_sai_probe(struct platform_device *pdev)
185 {
186 struct stm32_sai_data *sai;
187 const struct stm32_sai_conf *conf;
188 struct reset_control *rst;
189 u32 val;
190 int ret;
191
192 sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL);
193 if (!sai)
194 return -ENOMEM;
195
196 sai->pdev = pdev;
197
198 sai->base = devm_platform_ioremap_resource(pdev, 0);
199 if (IS_ERR(sai->base))
200 return PTR_ERR(sai->base);
201
202 conf = device_get_match_data(&pdev->dev);
203 if (conf)
204 memcpy(&sai->conf, (const struct stm32_sai_conf *)conf,
205 sizeof(struct stm32_sai_conf));
206 else
207 return -EINVAL;
208
209 if (!STM_SAI_IS_F4(sai)) {
210 sai->pclk = devm_clk_get(&pdev->dev, "pclk");
211 if (IS_ERR(sai->pclk))
212 return dev_err_probe(&pdev->dev, PTR_ERR(sai->pclk),
213 "missing bus clock pclk\n");
214 }
215
216 if (sai->conf.get_sai_ck_parent) {
217 ret = sai->conf.get_sai_ck_parent(sai);
218 if (ret)
219 return ret;
220 }
221
222 /* init irqs */
223 sai->irq = platform_get_irq(pdev, 0);
224 if (sai->irq < 0)
225 return sai->irq;
226
227 /* reset */
228 rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
229 if (IS_ERR(rst))
230 return dev_err_probe(&pdev->dev, PTR_ERR(rst),
231 "Reset controller error\n");
232
233 reset_control_assert(rst);
234 udelay(2);
235 reset_control_deassert(rst);
236
237 /* Enable peripheral clock to allow register access */
238 ret = clk_prepare_enable(sai->pclk);
239 if (ret) {
240 dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
241 return ret;
242 }
243
244 val = FIELD_GET(SAI_IDR_ID_MASK,
245 readl_relaxed(sai->base + STM_SAI_IDR));
246 if (val == SAI_IPIDR_NUMBER) {
247 val = readl_relaxed(sai->base + STM_SAI_HWCFGR);
248 sai->conf.fifo_size = FIELD_GET(SAI_HWCFGR_FIFO_SIZE, val);
249 sai->conf.has_spdif_pdm = !!FIELD_GET(SAI_HWCFGR_SPDIF_PDM,
250 val);
251
252 val = readl_relaxed(sai->base + STM_SAI_VERR);
253 sai->conf.version = val;
254
255 dev_dbg(&pdev->dev, "SAI version: %lu.%lu registered\n",
256 FIELD_GET(SAI_VERR_MAJ_MASK, val),
257 FIELD_GET(SAI_VERR_MIN_MASK, val));
258 }
259 clk_disable_unprepare(sai->pclk);
260
261 sai->set_sync = &stm32_sai_set_sync;
262 platform_set_drvdata(pdev, sai);
263
264 return devm_of_platform_populate(&pdev->dev);
265 }
266
267 /*
268 * When pins are shared by two sai sub instances, pins have to be defined
269 * in sai parent node. In this case, pins state is not managed by alsa fw.
270 * These pins are managed in suspend/resume callbacks.
271 */
stm32_sai_suspend(struct device * dev)272 static int stm32_sai_suspend(struct device *dev)
273 {
274 struct stm32_sai_data *sai = dev_get_drvdata(dev);
275 int ret;
276
277 ret = stm32_sai_pclk_enable(dev);
278 if (ret)
279 return ret;
280
281 sai->gcr = readl_relaxed(sai->base);
282 stm32_sai_pclk_disable(dev);
283
284 return pinctrl_pm_select_sleep_state(dev);
285 }
286
stm32_sai_resume(struct device * dev)287 static int stm32_sai_resume(struct device *dev)
288 {
289 struct stm32_sai_data *sai = dev_get_drvdata(dev);
290 int ret;
291
292 ret = stm32_sai_pclk_enable(dev);
293 if (ret)
294 return ret;
295
296 writel_relaxed(sai->gcr, sai->base);
297 stm32_sai_pclk_disable(dev);
298
299 return pinctrl_pm_select_default_state(dev);
300 }
301
302 static const struct dev_pm_ops stm32_sai_pm_ops = {
303 SYSTEM_SLEEP_PM_OPS(stm32_sai_suspend, stm32_sai_resume)
304 };
305
306 MODULE_DEVICE_TABLE(of, stm32_sai_ids);
307
308 static struct platform_driver stm32_sai_driver = {
309 .driver = {
310 .name = "st,stm32-sai",
311 .of_match_table = stm32_sai_ids,
312 .pm = pm_ptr(&stm32_sai_pm_ops),
313 },
314 .probe = stm32_sai_probe,
315 };
316
317 module_platform_driver(stm32_sai_driver);
318
319 MODULE_DESCRIPTION("STM32 Soc SAI Interface");
320 MODULE_AUTHOR("Olivier Moysan <olivier.moysan@st.com>");
321 MODULE_ALIAS("platform:st,stm32-sai");
322 MODULE_LICENSE("GPL v2");
323