1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * This file is part the core part STM32 DFSDM driver
4 *
5 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
6 * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics.
7 */
8
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/iio/iio.h>
12 #include <linux/iio/sysfs.h>
13 #include <linux/interrupt.h>
14 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/pinctrl/consumer.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/regmap.h>
19 #include <linux/slab.h>
20
21 #include "stm32-dfsdm.h"
22
23 /**
24 * struct stm32_dfsdm_dev_data - DFSDM compatible configuration data
25 * @ipid: DFSDM identification number. Used only if hardware provides identification registers
26 * @num_filters: DFSDM number of filters. Unused if identification registers are available
27 * @num_channels: DFSDM number of channels. Unused if identification registers are available
28 * @regmap_cfg: SAI register map configuration pointer
29 */
30 struct stm32_dfsdm_dev_data {
31 u32 ipid;
32 unsigned int num_filters;
33 unsigned int num_channels;
34 const struct regmap_config *regmap_cfg;
35 };
36
37 #define STM32H7_DFSDM_NUM_FILTERS 4
38 #define STM32H7_DFSDM_NUM_CHANNELS 8
39
stm32_dfsdm_volatile_reg(struct device * dev,unsigned int reg)40 static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
41 {
42 if (reg < DFSDM_FILTER_BASE_ADR)
43 return false;
44
45 /*
46 * Mask is done on register to avoid to list registers of all
47 * filter instances.
48 */
49 switch (reg & DFSDM_FILTER_REG_MASK) {
50 case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK:
51 case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK:
52 case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK:
53 case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK:
54 return true;
55 }
56
57 return false;
58 }
59
60 static const struct regmap_config stm32h7_dfsdm_regmap_cfg = {
61 .reg_bits = 32,
62 .val_bits = 32,
63 .reg_stride = sizeof(u32),
64 .max_register = 0x2B8,
65 .volatile_reg = stm32_dfsdm_volatile_reg,
66 .fast_io = true,
67 };
68
69 static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = {
70 .num_filters = STM32H7_DFSDM_NUM_FILTERS,
71 .num_channels = STM32H7_DFSDM_NUM_CHANNELS,
72 .regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
73 };
74
75 static const struct regmap_config stm32mp1_dfsdm_regmap_cfg = {
76 .reg_bits = 32,
77 .val_bits = 32,
78 .reg_stride = sizeof(u32),
79 .max_register = 0x7fc,
80 .volatile_reg = stm32_dfsdm_volatile_reg,
81 .fast_io = true,
82 };
83
84 static const struct stm32_dfsdm_dev_data stm32mp1_dfsdm_data = {
85 .ipid = STM32MP15_IPIDR_NUMBER,
86 .regmap_cfg = &stm32mp1_dfsdm_regmap_cfg,
87 };
88
89 struct dfsdm_priv {
90 struct platform_device *pdev; /* platform device */
91
92 struct stm32_dfsdm dfsdm; /* common data exported for all instances */
93
94 unsigned int spi_clk_out_div; /* SPI clkout divider value */
95 atomic_t n_active_ch; /* number of current active channels */
96
97 struct clk *clk; /* DFSDM clock */
98 struct clk *aclk; /* audio clock */
99 };
100
to_stm32_dfsdm_priv(struct stm32_dfsdm * dfsdm)101 static inline struct dfsdm_priv *to_stm32_dfsdm_priv(struct stm32_dfsdm *dfsdm)
102 {
103 return container_of(dfsdm, struct dfsdm_priv, dfsdm);
104 }
105
stm32_dfsdm_clk_prepare_enable(struct stm32_dfsdm * dfsdm)106 static int stm32_dfsdm_clk_prepare_enable(struct stm32_dfsdm *dfsdm)
107 {
108 struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
109 int ret;
110
111 ret = clk_prepare_enable(priv->clk);
112 if (ret || !priv->aclk)
113 return ret;
114
115 ret = clk_prepare_enable(priv->aclk);
116 if (ret)
117 clk_disable_unprepare(priv->clk);
118
119 return ret;
120 }
121
stm32_dfsdm_clk_disable_unprepare(struct stm32_dfsdm * dfsdm)122 static void stm32_dfsdm_clk_disable_unprepare(struct stm32_dfsdm *dfsdm)
123 {
124 struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
125
126 clk_disable_unprepare(priv->aclk);
127 clk_disable_unprepare(priv->clk);
128 }
129
130 /**
131 * stm32_dfsdm_start_dfsdm - start global dfsdm interface.
132 *
133 * Enable interface if n_active_ch is not null.
134 * @dfsdm: Handle used to retrieve dfsdm context.
135 */
stm32_dfsdm_start_dfsdm(struct stm32_dfsdm * dfsdm)136 int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
137 {
138 struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
139 struct device *dev = &priv->pdev->dev;
140 unsigned int clk_div = priv->spi_clk_out_div, clk_src;
141 int ret;
142
143 if (atomic_inc_return(&priv->n_active_ch) == 1) {
144 ret = pm_runtime_resume_and_get(dev);
145 if (ret < 0)
146 goto error_ret;
147
148 /* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */
149 clk_src = priv->aclk ? 1 : 0;
150 ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
151 DFSDM_CHCFGR1_CKOUTSRC_MASK,
152 DFSDM_CHCFGR1_CKOUTSRC(clk_src));
153 if (ret < 0)
154 goto pm_put;
155
156 /* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */
157 ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
158 DFSDM_CHCFGR1_CKOUTDIV_MASK,
159 DFSDM_CHCFGR1_CKOUTDIV(clk_div));
160 if (ret < 0)
161 goto pm_put;
162
163 /* Global enable of DFSDM interface */
164 ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
165 DFSDM_CHCFGR1_DFSDMEN_MASK,
166 DFSDM_CHCFGR1_DFSDMEN(1));
167 if (ret < 0)
168 goto pm_put;
169 }
170
171 dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
172 atomic_read(&priv->n_active_ch));
173
174 return 0;
175
176 pm_put:
177 pm_runtime_put_sync(dev);
178 error_ret:
179 atomic_dec(&priv->n_active_ch);
180
181 return ret;
182 }
183 EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);
184
185 /**
186 * stm32_dfsdm_stop_dfsdm - stop global DFSDM interface.
187 *
188 * Disable interface if n_active_ch is null
189 * @dfsdm: Handle used to retrieve dfsdm context.
190 */
stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm * dfsdm)191 int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
192 {
193 struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
194 int ret;
195
196 if (atomic_dec_and_test(&priv->n_active_ch)) {
197 /* Global disable of DFSDM interface */
198 ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
199 DFSDM_CHCFGR1_DFSDMEN_MASK,
200 DFSDM_CHCFGR1_DFSDMEN(0));
201 if (ret < 0)
202 return ret;
203
204 /* Stop SPI CLKOUT */
205 ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
206 DFSDM_CHCFGR1_CKOUTDIV_MASK,
207 DFSDM_CHCFGR1_CKOUTDIV(0));
208 if (ret < 0)
209 return ret;
210
211 pm_runtime_put_sync(&priv->pdev->dev);
212 }
213 dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
214 atomic_read(&priv->n_active_ch));
215
216 return 0;
217 }
218 EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm);
219
stm32_dfsdm_parse_of(struct platform_device * pdev,struct dfsdm_priv * priv)220 static int stm32_dfsdm_parse_of(struct platform_device *pdev,
221 struct dfsdm_priv *priv)
222 {
223 struct device_node *node = pdev->dev.of_node;
224 struct resource *res;
225 unsigned long clk_freq, divider;
226 unsigned int spi_freq, rem;
227 int ret;
228
229 if (!node)
230 return -EINVAL;
231
232 priv->dfsdm.base = devm_platform_get_and_ioremap_resource(pdev, 0,
233 &res);
234 if (IS_ERR(priv->dfsdm.base))
235 return PTR_ERR(priv->dfsdm.base);
236
237 priv->dfsdm.phys_base = res->start;
238
239 /*
240 * "dfsdm" clock is mandatory for DFSDM peripheral clocking.
241 * "dfsdm" or "audio" clocks can be used as source clock for
242 * the SPI clock out signal and internal processing, depending
243 * on use case.
244 */
245 priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
246 if (IS_ERR(priv->clk))
247 return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
248 "Failed to get clock\n");
249
250 priv->aclk = devm_clk_get(&pdev->dev, "audio");
251 if (IS_ERR(priv->aclk))
252 priv->aclk = NULL;
253
254 if (priv->aclk)
255 clk_freq = clk_get_rate(priv->aclk);
256 else
257 clk_freq = clk_get_rate(priv->clk);
258
259 /* SPI clock out frequency */
260 ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
261 &spi_freq);
262 if (ret < 0) {
263 /* No SPI master mode */
264 return 0;
265 }
266
267 divider = div_u64_rem(clk_freq, spi_freq, &rem);
268 /* Round up divider when ckout isn't precise, not to exceed spi_freq */
269 if (rem)
270 divider++;
271
272 /* programmable divider is in range of [2:256] */
273 if (divider < 2 || divider > 256) {
274 dev_err(&pdev->dev, "spi-max-frequency not achievable\n");
275 return -EINVAL;
276 }
277
278 /* SPI clock output divider is: divider = CKOUTDIV + 1 */
279 priv->spi_clk_out_div = divider - 1;
280 priv->dfsdm.spi_master_freq = clk_freq / (priv->spi_clk_out_div + 1);
281
282 if (rem) {
283 dev_warn(&pdev->dev, "SPI clock not accurate\n");
284 dev_warn(&pdev->dev, "%ld = %d * %d + %d\n",
285 clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem);
286 }
287
288 return 0;
289 };
290
291 static const struct of_device_id stm32_dfsdm_of_match[] = {
292 {
293 .compatible = "st,stm32h7-dfsdm",
294 .data = &stm32h7_dfsdm_data,
295 },
296 {
297 .compatible = "st,stm32mp1-dfsdm",
298 .data = &stm32mp1_dfsdm_data,
299 },
300 {}
301 };
302 MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);
303
stm32_dfsdm_probe_identification(struct platform_device * pdev,struct dfsdm_priv * priv,const struct stm32_dfsdm_dev_data * dev_data)304 static int stm32_dfsdm_probe_identification(struct platform_device *pdev,
305 struct dfsdm_priv *priv,
306 const struct stm32_dfsdm_dev_data *dev_data)
307 {
308 struct device_node *np = pdev->dev.of_node;
309 struct device_node *child;
310 struct stm32_dfsdm *dfsdm = &priv->dfsdm;
311 const char *compat;
312 int ret, count = 0;
313 u32 id, val;
314
315 if (!dev_data->ipid) {
316 dfsdm->num_fls = dev_data->num_filters;
317 dfsdm->num_chs = dev_data->num_channels;
318 return 0;
319 }
320
321 ret = regmap_read(dfsdm->regmap, DFSDM_IPIDR, &id);
322 if (ret)
323 return ret;
324
325 if (id != dev_data->ipid) {
326 dev_err(&pdev->dev, "Unexpected IP version: 0x%x", id);
327 return -EINVAL;
328 }
329
330 for_each_child_of_node(np, child) {
331 ret = of_property_read_string(child, "compatible", &compat);
332 if (ret)
333 continue;
334 /* Count only child nodes with dfsdm compatible */
335 if (strstr(compat, "dfsdm"))
336 count++;
337 }
338
339 ret = regmap_read(dfsdm->regmap, DFSDM_HWCFGR, &val);
340 if (ret)
341 return ret;
342
343 dfsdm->num_fls = FIELD_GET(DFSDM_HWCFGR_NBF_MASK, val);
344 dfsdm->num_chs = FIELD_GET(DFSDM_HWCFGR_NBT_MASK, val);
345
346 if (count > dfsdm->num_fls) {
347 dev_err(&pdev->dev, "Unexpected child number: %d", count);
348 return -EINVAL;
349 }
350
351 ret = regmap_read(dfsdm->regmap, DFSDM_VERR, &val);
352 if (ret)
353 return ret;
354
355 dev_dbg(&pdev->dev, "DFSDM version: %lu.%lu. %d channels/%d filters\n",
356 FIELD_GET(DFSDM_VERR_MAJREV_MASK, val),
357 FIELD_GET(DFSDM_VERR_MINREV_MASK, val),
358 dfsdm->num_chs, dfsdm->num_fls);
359
360 return 0;
361 }
362
stm32_dfsdm_probe(struct platform_device * pdev)363 static int stm32_dfsdm_probe(struct platform_device *pdev)
364 {
365 struct dfsdm_priv *priv;
366 const struct stm32_dfsdm_dev_data *dev_data;
367 struct stm32_dfsdm *dfsdm;
368 int ret;
369
370 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
371 if (!priv)
372 return -ENOMEM;
373
374 priv->pdev = pdev;
375
376 dev_data = of_device_get_match_data(&pdev->dev);
377
378 dfsdm = &priv->dfsdm;
379
380 ret = stm32_dfsdm_parse_of(pdev, priv);
381 if (ret < 0)
382 return ret;
383
384 dfsdm->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dfsdm",
385 dfsdm->base,
386 dev_data->regmap_cfg);
387 if (IS_ERR(dfsdm->regmap)) {
388 ret = PTR_ERR(dfsdm->regmap);
389 dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n",
390 __func__, ret);
391 return ret;
392 }
393
394 ret = stm32_dfsdm_probe_identification(pdev, priv, dev_data);
395 if (ret < 0)
396 return ret;
397
398 dfsdm->fl_list = devm_kcalloc(&pdev->dev, dfsdm->num_fls,
399 sizeof(*dfsdm->fl_list), GFP_KERNEL);
400 if (!dfsdm->fl_list)
401 return -ENOMEM;
402
403 dfsdm->ch_list = devm_kcalloc(&pdev->dev, dfsdm->num_chs,
404 sizeof(*dfsdm->ch_list), GFP_KERNEL);
405 if (!dfsdm->ch_list)
406 return -ENOMEM;
407
408 platform_set_drvdata(pdev, dfsdm);
409
410 ret = stm32_dfsdm_clk_prepare_enable(dfsdm);
411 if (ret) {
412 dev_err(&pdev->dev, "Failed to start clock\n");
413 return ret;
414 }
415
416 pm_runtime_get_noresume(&pdev->dev);
417 pm_runtime_set_active(&pdev->dev);
418 pm_runtime_enable(&pdev->dev);
419
420 ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
421 if (ret)
422 goto pm_put;
423
424 pm_runtime_put(&pdev->dev);
425
426 return 0;
427
428 pm_put:
429 pm_runtime_disable(&pdev->dev);
430 pm_runtime_set_suspended(&pdev->dev);
431 pm_runtime_put_noidle(&pdev->dev);
432 stm32_dfsdm_clk_disable_unprepare(dfsdm);
433
434 return ret;
435 }
436
stm32_dfsdm_core_remove(struct platform_device * pdev)437 static int stm32_dfsdm_core_remove(struct platform_device *pdev)
438 {
439 struct stm32_dfsdm *dfsdm = platform_get_drvdata(pdev);
440
441 pm_runtime_get_sync(&pdev->dev);
442 of_platform_depopulate(&pdev->dev);
443 pm_runtime_disable(&pdev->dev);
444 pm_runtime_set_suspended(&pdev->dev);
445 pm_runtime_put_noidle(&pdev->dev);
446 stm32_dfsdm_clk_disable_unprepare(dfsdm);
447
448 return 0;
449 }
450
stm32_dfsdm_core_suspend(struct device * dev)451 static int stm32_dfsdm_core_suspend(struct device *dev)
452 {
453 struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
454 struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
455 int ret;
456
457 ret = pm_runtime_force_suspend(dev);
458 if (ret)
459 return ret;
460
461 /* Balance devm_regmap_init_mmio_clk() clk_prepare() */
462 clk_unprepare(priv->clk);
463
464 return pinctrl_pm_select_sleep_state(dev);
465 }
466
stm32_dfsdm_core_resume(struct device * dev)467 static int stm32_dfsdm_core_resume(struct device *dev)
468 {
469 struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
470 struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
471 int ret;
472
473 ret = pinctrl_pm_select_default_state(dev);
474 if (ret)
475 return ret;
476
477 ret = clk_prepare(priv->clk);
478 if (ret)
479 return ret;
480
481 return pm_runtime_force_resume(dev);
482 }
483
stm32_dfsdm_core_runtime_suspend(struct device * dev)484 static int stm32_dfsdm_core_runtime_suspend(struct device *dev)
485 {
486 struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
487
488 stm32_dfsdm_clk_disable_unprepare(dfsdm);
489
490 return 0;
491 }
492
stm32_dfsdm_core_runtime_resume(struct device * dev)493 static int stm32_dfsdm_core_runtime_resume(struct device *dev)
494 {
495 struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
496
497 return stm32_dfsdm_clk_prepare_enable(dfsdm);
498 }
499
500 static const struct dev_pm_ops stm32_dfsdm_core_pm_ops = {
501 SYSTEM_SLEEP_PM_OPS(stm32_dfsdm_core_suspend, stm32_dfsdm_core_resume)
502 RUNTIME_PM_OPS(stm32_dfsdm_core_runtime_suspend,
503 stm32_dfsdm_core_runtime_resume,
504 NULL)
505 };
506
507 static struct platform_driver stm32_dfsdm_driver = {
508 .probe = stm32_dfsdm_probe,
509 .remove = stm32_dfsdm_core_remove,
510 .driver = {
511 .name = "stm32-dfsdm",
512 .of_match_table = stm32_dfsdm_of_match,
513 .pm = pm_ptr(&stm32_dfsdm_core_pm_ops),
514 },
515 };
516
517 module_platform_driver(stm32_dfsdm_driver);
518
519 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
520 MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver");
521 MODULE_LICENSE("GPL v2");
522