1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Renesas R-Car GyroADC driver
4 *
5 * Copyright 2016 Marek Vasut <marek.vasut@gmail.com>
6 */
7
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/delay.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/io.h>
14 #include <linux/clk.h>
15 #include <linux/of.h>
16 #include <linux/of_irq.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/of_platform.h>
19 #include <linux/err.h>
20 #include <linux/pm_runtime.h>
21
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/trigger.h>
25
26 #define DRIVER_NAME "rcar-gyroadc"
27
28 /* GyroADC registers. */
29 #define RCAR_GYROADC_MODE_SELECT 0x00
30 #define RCAR_GYROADC_MODE_SELECT_1_MB88101A 0x0
31 #define RCAR_GYROADC_MODE_SELECT_2_ADCS7476 0x1
32 #define RCAR_GYROADC_MODE_SELECT_3_MAX1162 0x3
33
34 #define RCAR_GYROADC_START_STOP 0x04
35 #define RCAR_GYROADC_START_STOP_START BIT(0)
36
37 #define RCAR_GYROADC_CLOCK_LENGTH 0x08
38 #define RCAR_GYROADC_1_25MS_LENGTH 0x0c
39
40 #define RCAR_GYROADC_REALTIME_DATA(ch) (0x10 + ((ch) * 4))
41 #define RCAR_GYROADC_100MS_ADDED_DATA(ch) (0x30 + ((ch) * 4))
42 #define RCAR_GYROADC_10MS_AVG_DATA(ch) (0x50 + ((ch) * 4))
43
44 #define RCAR_GYROADC_FIFO_STATUS 0x70
45 #define RCAR_GYROADC_FIFO_STATUS_EMPTY(ch) BIT(0 + (4 * (ch)))
46 #define RCAR_GYROADC_FIFO_STATUS_FULL(ch) BIT(1 + (4 * (ch)))
47 #define RCAR_GYROADC_FIFO_STATUS_ERROR(ch) BIT(2 + (4 * (ch)))
48
49 #define RCAR_GYROADC_INTR 0x74
50 #define RCAR_GYROADC_INTR_INT BIT(0)
51
52 #define RCAR_GYROADC_INTENR 0x78
53 #define RCAR_GYROADC_INTENR_INTEN BIT(0)
54
55 #define RCAR_GYROADC_SAMPLE_RATE 800 /* Hz */
56
57 #define RCAR_GYROADC_RUNTIME_PM_DELAY_MS 2000
58
59 enum rcar_gyroadc_model {
60 RCAR_GYROADC_MODEL_DEFAULT,
61 RCAR_GYROADC_MODEL_R8A7792,
62 };
63
64 struct rcar_gyroadc {
65 struct device *dev;
66 void __iomem *regs;
67 struct clk *clk;
68 struct regulator *vref[8];
69 unsigned int num_channels;
70 enum rcar_gyroadc_model model;
71 unsigned int mode;
72 unsigned int sample_width;
73 };
74
rcar_gyroadc_hw_init(struct rcar_gyroadc * priv)75 static void rcar_gyroadc_hw_init(struct rcar_gyroadc *priv)
76 {
77 const unsigned long clk_mhz = clk_get_rate(priv->clk) / 1000000;
78 const unsigned long clk_mul =
79 (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) ? 10 : 5;
80 unsigned long clk_len = clk_mhz * clk_mul;
81
82 /*
83 * According to the R-Car Gen2 datasheet Rev. 1.01, Sept 08 2014,
84 * page 77-7, clock length must be even number. If it's odd number,
85 * add one.
86 */
87 if (clk_len & 1)
88 clk_len++;
89
90 /* Stop the GyroADC. */
91 writel(0, priv->regs + RCAR_GYROADC_START_STOP);
92
93 /* Disable IRQ on V2H. */
94 if (priv->model == RCAR_GYROADC_MODEL_R8A7792)
95 writel(0, priv->regs + RCAR_GYROADC_INTENR);
96
97 /* Set mode and timing. */
98 writel(priv->mode, priv->regs + RCAR_GYROADC_MODE_SELECT);
99 writel(clk_len, priv->regs + RCAR_GYROADC_CLOCK_LENGTH);
100 writel(clk_mhz * 1250, priv->regs + RCAR_GYROADC_1_25MS_LENGTH);
101 }
102
rcar_gyroadc_hw_start(struct rcar_gyroadc * priv)103 static void rcar_gyroadc_hw_start(struct rcar_gyroadc *priv)
104 {
105 /* Start sampling. */
106 writel(RCAR_GYROADC_START_STOP_START,
107 priv->regs + RCAR_GYROADC_START_STOP);
108
109 /*
110 * Wait for the first conversion to complete. This is longer than
111 * the 1.25 mS in the datasheet because 1.25 mS is not enough for
112 * the hardware to deliver the first sample and the hardware does
113 * then return zeroes instead of valid data.
114 */
115 mdelay(3);
116 }
117
rcar_gyroadc_hw_stop(struct rcar_gyroadc * priv)118 static void rcar_gyroadc_hw_stop(struct rcar_gyroadc *priv)
119 {
120 /* Stop the GyroADC. */
121 writel(0, priv->regs + RCAR_GYROADC_START_STOP);
122 }
123
124 #define RCAR_GYROADC_CHAN(_idx) { \
125 .type = IIO_VOLTAGE, \
126 .indexed = 1, \
127 .channel = (_idx), \
128 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
129 BIT(IIO_CHAN_INFO_SCALE), \
130 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
131 }
132
133 static const struct iio_chan_spec rcar_gyroadc_iio_channels_1[] = {
134 RCAR_GYROADC_CHAN(0),
135 RCAR_GYROADC_CHAN(1),
136 RCAR_GYROADC_CHAN(2),
137 RCAR_GYROADC_CHAN(3),
138 };
139
140 static const struct iio_chan_spec rcar_gyroadc_iio_channels_2[] = {
141 RCAR_GYROADC_CHAN(0),
142 RCAR_GYROADC_CHAN(1),
143 RCAR_GYROADC_CHAN(2),
144 RCAR_GYROADC_CHAN(3),
145 RCAR_GYROADC_CHAN(4),
146 RCAR_GYROADC_CHAN(5),
147 RCAR_GYROADC_CHAN(6),
148 RCAR_GYROADC_CHAN(7),
149 };
150
151 static const struct iio_chan_spec rcar_gyroadc_iio_channels_3[] = {
152 RCAR_GYROADC_CHAN(0),
153 RCAR_GYROADC_CHAN(1),
154 RCAR_GYROADC_CHAN(2),
155 RCAR_GYROADC_CHAN(3),
156 RCAR_GYROADC_CHAN(4),
157 RCAR_GYROADC_CHAN(5),
158 RCAR_GYROADC_CHAN(6),
159 RCAR_GYROADC_CHAN(7),
160 };
161
rcar_gyroadc_set_power(struct rcar_gyroadc * priv,bool on)162 static int rcar_gyroadc_set_power(struct rcar_gyroadc *priv, bool on)
163 {
164 struct device *dev = priv->dev;
165
166 if (on)
167 return pm_runtime_resume_and_get(dev);
168
169 return pm_runtime_put_autosuspend(dev);
170 }
171
rcar_gyroadc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)172 static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev,
173 struct iio_chan_spec const *chan,
174 int *val, int *val2, long mask)
175 {
176 struct rcar_gyroadc *priv = iio_priv(indio_dev);
177 struct regulator *consumer;
178 unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel);
179 unsigned int vref;
180 int ret;
181
182 /*
183 * MB88101 is special in that it has only single regulator for
184 * all four channels.
185 */
186 if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)
187 consumer = priv->vref[0];
188 else
189 consumer = priv->vref[chan->channel];
190
191 switch (mask) {
192 case IIO_CHAN_INFO_RAW:
193 if (chan->type != IIO_VOLTAGE)
194 return -EINVAL;
195
196 /* Channel not connected. */
197 if (!consumer)
198 return -EINVAL;
199
200 if (!iio_device_claim_direct(indio_dev))
201 return -EBUSY;
202
203 ret = rcar_gyroadc_set_power(priv, true);
204 if (ret < 0) {
205 iio_device_release_direct(indio_dev);
206 return ret;
207 }
208
209 *val = readl(priv->regs + datareg);
210 *val &= BIT(priv->sample_width) - 1;
211
212 ret = rcar_gyroadc_set_power(priv, false);
213 iio_device_release_direct(indio_dev);
214 if (ret < 0)
215 return ret;
216
217 return IIO_VAL_INT;
218 case IIO_CHAN_INFO_SCALE:
219 /* Channel not connected. */
220 if (!consumer)
221 return -EINVAL;
222
223 vref = regulator_get_voltage(consumer);
224 *val = vref / 1000;
225 *val2 = 1 << priv->sample_width;
226
227 return IIO_VAL_FRACTIONAL;
228 case IIO_CHAN_INFO_SAMP_FREQ:
229 *val = RCAR_GYROADC_SAMPLE_RATE;
230
231 return IIO_VAL_INT;
232 default:
233 return -EINVAL;
234 }
235 }
236
rcar_gyroadc_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)237 static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev,
238 unsigned int reg, unsigned int writeval,
239 unsigned int *readval)
240 {
241 struct rcar_gyroadc *priv = iio_priv(indio_dev);
242 unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS;
243
244 if (readval == NULL)
245 return -EINVAL;
246
247 if (reg % 4)
248 return -EINVAL;
249
250 /* Handle the V2H case with extra interrupt block. */
251 if (priv->model == RCAR_GYROADC_MODEL_R8A7792)
252 maxreg = RCAR_GYROADC_INTENR;
253
254 if (reg > maxreg)
255 return -EINVAL;
256
257 *readval = readl(priv->regs + reg);
258
259 return 0;
260 }
261
262 static const struct iio_info rcar_gyroadc_iio_info = {
263 .read_raw = rcar_gyroadc_read_raw,
264 .debugfs_reg_access = rcar_gyroadc_reg_access,
265 };
266
267 static const struct of_device_id rcar_gyroadc_match[] = {
268 {
269 /* R-Car compatible GyroADC */
270 .compatible = "renesas,rcar-gyroadc",
271 .data = (void *)RCAR_GYROADC_MODEL_DEFAULT,
272 }, {
273 /* R-Car V2H specialty with interrupt registers. */
274 .compatible = "renesas,r8a7792-gyroadc",
275 .data = (void *)RCAR_GYROADC_MODEL_R8A7792,
276 }, {
277 /* sentinel */
278 }
279 };
280
281 MODULE_DEVICE_TABLE(of, rcar_gyroadc_match);
282
283 static const struct of_device_id rcar_gyroadc_child_match[] __maybe_unused = {
284 /* Mode 1 ADCs */
285 {
286 .compatible = "fujitsu,mb88101a",
287 .data = (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A,
288 },
289 /* Mode 2 ADCs */
290 {
291 .compatible = "ti,adcs7476",
292 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
293 }, {
294 .compatible = "ti,adc121",
295 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
296 }, {
297 .compatible = "adi,ad7476",
298 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
299 },
300 /* Mode 3 ADCs */
301 {
302 .compatible = "maxim,max1162",
303 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
304 }, {
305 .compatible = "maxim,max11100",
306 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
307 },
308 { }
309 };
310
rcar_gyroadc_parse_subdevs(struct iio_dev * indio_dev)311 static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
312 {
313 const struct of_device_id *of_id;
314 const struct iio_chan_spec *channels;
315 struct rcar_gyroadc *priv = iio_priv(indio_dev);
316 struct device *dev = priv->dev;
317 struct device_node *np = dev->of_node;
318 struct regulator *vref;
319 unsigned int reg;
320 unsigned int adcmode = -1, childmode;
321 unsigned int sample_width;
322 unsigned int num_channels;
323 int ret, first = 1;
324
325 for_each_available_child_of_node_scoped(np, child) {
326 of_id = of_match_node(rcar_gyroadc_child_match, child);
327 if (!of_id) {
328 dev_err(dev, "Ignoring unsupported ADC \"%pOFn\".",
329 child);
330 continue;
331 }
332
333 childmode = (uintptr_t)of_id->data;
334 switch (childmode) {
335 case RCAR_GYROADC_MODE_SELECT_1_MB88101A:
336 sample_width = 12;
337 channels = rcar_gyroadc_iio_channels_1;
338 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1);
339 break;
340 case RCAR_GYROADC_MODE_SELECT_2_ADCS7476:
341 sample_width = 15;
342 channels = rcar_gyroadc_iio_channels_2;
343 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2);
344 break;
345 case RCAR_GYROADC_MODE_SELECT_3_MAX1162:
346 sample_width = 16;
347 channels = rcar_gyroadc_iio_channels_3;
348 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3);
349 break;
350 default:
351 return -EINVAL;
352 }
353
354 /*
355 * MB88101 is special in that it's only a single chip taking
356 * up all the CHS lines. Thus, the DT binding is also special
357 * and has no reg property. If we run into such ADC, handle
358 * it here.
359 */
360 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
361 reg = 0;
362 } else {
363 ret = of_property_read_u32(child, "reg", ®);
364 if (ret) {
365 dev_err(dev,
366 "Failed to get child reg property of ADC \"%pOFn\".\n",
367 child);
368 return ret;
369 }
370
371 /* Channel number is too high. */
372 if (reg >= num_channels) {
373 dev_err(dev,
374 "Only %i channels supported with %pOFn, but reg = <%i>.\n",
375 num_channels, child, reg);
376 return -EINVAL;
377 }
378 }
379
380 /* Child node selected different mode than the rest. */
381 if (!first && (adcmode != childmode)) {
382 dev_err(dev,
383 "Channel %i uses different ADC mode than the rest.\n",
384 reg);
385 return -EINVAL;
386 }
387
388 /* Channel is valid, grab the regulator. */
389 dev->of_node = child;
390 vref = devm_regulator_get(dev, "vref");
391 dev->of_node = np;
392 if (IS_ERR(vref)) {
393 dev_dbg(dev, "Channel %i 'vref' supply not connected.\n",
394 reg);
395 return PTR_ERR(vref);
396 }
397
398 priv->vref[reg] = vref;
399
400 if (!first)
401 continue;
402
403 /* First child node which passed sanity tests. */
404 adcmode = childmode;
405 first = 0;
406
407 priv->num_channels = num_channels;
408 priv->mode = childmode;
409 priv->sample_width = sample_width;
410
411 indio_dev->channels = channels;
412 indio_dev->num_channels = num_channels;
413
414 /*
415 * MB88101 is special and we only have one such device
416 * attached to the GyroADC at a time, so if we found it,
417 * we can stop parsing here.
418 */
419 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
420 break;
421 }
422 }
423
424 if (first) {
425 dev_err(dev, "No valid ADC channels found, aborting.\n");
426 return -EINVAL;
427 }
428
429 return 0;
430 }
431
rcar_gyroadc_deinit_supplies(struct iio_dev * indio_dev)432 static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev)
433 {
434 struct rcar_gyroadc *priv = iio_priv(indio_dev);
435 unsigned int i;
436
437 for (i = 0; i < priv->num_channels; i++) {
438 if (!priv->vref[i])
439 continue;
440
441 regulator_disable(priv->vref[i]);
442 }
443 }
444
rcar_gyroadc_init_supplies(struct iio_dev * indio_dev)445 static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev)
446 {
447 struct rcar_gyroadc *priv = iio_priv(indio_dev);
448 struct device *dev = priv->dev;
449 unsigned int i;
450 int ret;
451
452 for (i = 0; i < priv->num_channels; i++) {
453 if (!priv->vref[i])
454 continue;
455
456 ret = regulator_enable(priv->vref[i]);
457 if (ret) {
458 dev_err(dev, "Failed to enable regulator %i (ret=%i)\n",
459 i, ret);
460 goto err;
461 }
462 }
463
464 return 0;
465
466 err:
467 rcar_gyroadc_deinit_supplies(indio_dev);
468 return ret;
469 }
470
rcar_gyroadc_probe(struct platform_device * pdev)471 static int rcar_gyroadc_probe(struct platform_device *pdev)
472 {
473 struct device *dev = &pdev->dev;
474 struct rcar_gyroadc *priv;
475 struct iio_dev *indio_dev;
476 int ret;
477
478 indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
479 if (!indio_dev)
480 return -ENOMEM;
481
482 priv = iio_priv(indio_dev);
483 priv->dev = dev;
484
485 priv->regs = devm_platform_ioremap_resource(pdev, 0);
486 if (IS_ERR(priv->regs))
487 return PTR_ERR(priv->regs);
488
489 priv->clk = devm_clk_get(dev, "fck");
490 if (IS_ERR(priv->clk))
491 return dev_err_probe(dev, PTR_ERR(priv->clk),
492 "Failed to get IF clock\n");
493
494 ret = rcar_gyroadc_parse_subdevs(indio_dev);
495 if (ret)
496 return ret;
497
498 ret = rcar_gyroadc_init_supplies(indio_dev);
499 if (ret)
500 return ret;
501
502 priv->model = (uintptr_t)of_device_get_match_data(&pdev->dev);
503
504 platform_set_drvdata(pdev, indio_dev);
505
506 indio_dev->name = DRIVER_NAME;
507 indio_dev->info = &rcar_gyroadc_iio_info;
508 indio_dev->modes = INDIO_DIRECT_MODE;
509
510 ret = clk_prepare_enable(priv->clk);
511 if (ret) {
512 dev_err(dev, "Could not prepare or enable the IF clock.\n");
513 goto err_clk_if_enable;
514 }
515
516 pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS);
517 pm_runtime_use_autosuspend(dev);
518 pm_runtime_enable(dev);
519
520 ret = pm_runtime_resume_and_get(dev);
521 if (ret)
522 goto err_power_up;
523
524 rcar_gyroadc_hw_init(priv);
525 rcar_gyroadc_hw_start(priv);
526
527 ret = iio_device_register(indio_dev);
528 if (ret) {
529 dev_err(dev, "Couldn't register IIO device.\n");
530 goto err_iio_device_register;
531 }
532
533 pm_runtime_put_sync(dev);
534
535 return 0;
536
537 err_iio_device_register:
538 rcar_gyroadc_hw_stop(priv);
539 pm_runtime_put_sync(dev);
540 err_power_up:
541 pm_runtime_disable(dev);
542 pm_runtime_set_suspended(dev);
543 clk_disable_unprepare(priv->clk);
544 err_clk_if_enable:
545 rcar_gyroadc_deinit_supplies(indio_dev);
546
547 return ret;
548 }
549
rcar_gyroadc_remove(struct platform_device * pdev)550 static void rcar_gyroadc_remove(struct platform_device *pdev)
551 {
552 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
553 struct rcar_gyroadc *priv = iio_priv(indio_dev);
554 struct device *dev = priv->dev;
555
556 iio_device_unregister(indio_dev);
557 pm_runtime_get_sync(dev);
558 rcar_gyroadc_hw_stop(priv);
559 pm_runtime_put_sync(dev);
560 pm_runtime_disable(dev);
561 pm_runtime_set_suspended(dev);
562 clk_disable_unprepare(priv->clk);
563 rcar_gyroadc_deinit_supplies(indio_dev);
564 }
565
rcar_gyroadc_suspend(struct device * dev)566 static int rcar_gyroadc_suspend(struct device *dev)
567 {
568 struct iio_dev *indio_dev = dev_get_drvdata(dev);
569 struct rcar_gyroadc *priv = iio_priv(indio_dev);
570
571 rcar_gyroadc_hw_stop(priv);
572
573 return 0;
574 }
575
rcar_gyroadc_resume(struct device * dev)576 static int rcar_gyroadc_resume(struct device *dev)
577 {
578 struct iio_dev *indio_dev = dev_get_drvdata(dev);
579 struct rcar_gyroadc *priv = iio_priv(indio_dev);
580
581 rcar_gyroadc_hw_start(priv);
582
583 return 0;
584 }
585
586 static const struct dev_pm_ops rcar_gyroadc_pm_ops = {
587 RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL)
588 };
589
590 static struct platform_driver rcar_gyroadc_driver = {
591 .probe = rcar_gyroadc_probe,
592 .remove = rcar_gyroadc_remove,
593 .driver = {
594 .name = DRIVER_NAME,
595 .of_match_table = rcar_gyroadc_match,
596 .pm = pm_ptr(&rcar_gyroadc_pm_ops),
597 },
598 };
599
600 module_platform_driver(rcar_gyroadc_driver);
601
602 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
603 MODULE_DESCRIPTION("Renesas R-Car GyroADC driver");
604 MODULE_LICENSE("GPL");
605