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 } else {
169 pm_runtime_mark_last_busy(dev);
170 return pm_runtime_put_autosuspend(dev);
171 }
172 }
173
rcar_gyroadc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)174 static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev,
175 struct iio_chan_spec const *chan,
176 int *val, int *val2, long mask)
177 {
178 struct rcar_gyroadc *priv = iio_priv(indio_dev);
179 struct regulator *consumer;
180 unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel);
181 unsigned int vref;
182 int ret;
183
184 /*
185 * MB88101 is special in that it has only single regulator for
186 * all four channels.
187 */
188 if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)
189 consumer = priv->vref[0];
190 else
191 consumer = priv->vref[chan->channel];
192
193 switch (mask) {
194 case IIO_CHAN_INFO_RAW:
195 if (chan->type != IIO_VOLTAGE)
196 return -EINVAL;
197
198 /* Channel not connected. */
199 if (!consumer)
200 return -EINVAL;
201
202 ret = iio_device_claim_direct_mode(indio_dev);
203 if (ret)
204 return ret;
205
206 ret = rcar_gyroadc_set_power(priv, true);
207 if (ret < 0) {
208 iio_device_release_direct_mode(indio_dev);
209 return ret;
210 }
211
212 *val = readl(priv->regs + datareg);
213 *val &= BIT(priv->sample_width) - 1;
214
215 ret = rcar_gyroadc_set_power(priv, false);
216 iio_device_release_direct_mode(indio_dev);
217 if (ret < 0)
218 return ret;
219
220 return IIO_VAL_INT;
221 case IIO_CHAN_INFO_SCALE:
222 /* Channel not connected. */
223 if (!consumer)
224 return -EINVAL;
225
226 vref = regulator_get_voltage(consumer);
227 *val = vref / 1000;
228 *val2 = 1 << priv->sample_width;
229
230 return IIO_VAL_FRACTIONAL;
231 case IIO_CHAN_INFO_SAMP_FREQ:
232 *val = RCAR_GYROADC_SAMPLE_RATE;
233
234 return IIO_VAL_INT;
235 default:
236 return -EINVAL;
237 }
238 }
239
rcar_gyroadc_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)240 static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev,
241 unsigned int reg, unsigned int writeval,
242 unsigned int *readval)
243 {
244 struct rcar_gyroadc *priv = iio_priv(indio_dev);
245 unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS;
246
247 if (readval == NULL)
248 return -EINVAL;
249
250 if (reg % 4)
251 return -EINVAL;
252
253 /* Handle the V2H case with extra interrupt block. */
254 if (priv->model == RCAR_GYROADC_MODEL_R8A7792)
255 maxreg = RCAR_GYROADC_INTENR;
256
257 if (reg > maxreg)
258 return -EINVAL;
259
260 *readval = readl(priv->regs + reg);
261
262 return 0;
263 }
264
265 static const struct iio_info rcar_gyroadc_iio_info = {
266 .read_raw = rcar_gyroadc_read_raw,
267 .debugfs_reg_access = rcar_gyroadc_reg_access,
268 };
269
270 static const struct of_device_id rcar_gyroadc_match[] = {
271 {
272 /* R-Car compatible GyroADC */
273 .compatible = "renesas,rcar-gyroadc",
274 .data = (void *)RCAR_GYROADC_MODEL_DEFAULT,
275 }, {
276 /* R-Car V2H specialty with interrupt registers. */
277 .compatible = "renesas,r8a7792-gyroadc",
278 .data = (void *)RCAR_GYROADC_MODEL_R8A7792,
279 }, {
280 /* sentinel */
281 }
282 };
283
284 MODULE_DEVICE_TABLE(of, rcar_gyroadc_match);
285
286 static const struct of_device_id rcar_gyroadc_child_match[] = {
287 /* Mode 1 ADCs */
288 {
289 .compatible = "fujitsu,mb88101a",
290 .data = (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A,
291 },
292 /* Mode 2 ADCs */
293 {
294 .compatible = "ti,adcs7476",
295 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
296 }, {
297 .compatible = "ti,adc121",
298 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
299 }, {
300 .compatible = "adi,ad7476",
301 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
302 },
303 /* Mode 3 ADCs */
304 {
305 .compatible = "maxim,max1162",
306 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
307 }, {
308 .compatible = "maxim,max11100",
309 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
310 },
311 { /* sentinel */ }
312 };
313
rcar_gyroadc_parse_subdevs(struct iio_dev * indio_dev)314 static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
315 {
316 const struct of_device_id *of_id;
317 const struct iio_chan_spec *channels;
318 struct rcar_gyroadc *priv = iio_priv(indio_dev);
319 struct device *dev = priv->dev;
320 struct device_node *np = dev->of_node;
321 struct device_node *child;
322 struct regulator *vref;
323 unsigned int reg;
324 unsigned int adcmode = -1, childmode;
325 unsigned int sample_width;
326 unsigned int num_channels;
327 int ret, first = 1;
328
329 for_each_child_of_node(np, child) {
330 of_id = of_match_node(rcar_gyroadc_child_match, child);
331 if (!of_id) {
332 dev_err(dev, "Ignoring unsupported ADC \"%pOFn\".",
333 child);
334 continue;
335 }
336
337 childmode = (uintptr_t)of_id->data;
338 switch (childmode) {
339 case RCAR_GYROADC_MODE_SELECT_1_MB88101A:
340 sample_width = 12;
341 channels = rcar_gyroadc_iio_channels_1;
342 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1);
343 break;
344 case RCAR_GYROADC_MODE_SELECT_2_ADCS7476:
345 sample_width = 15;
346 channels = rcar_gyroadc_iio_channels_2;
347 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2);
348 break;
349 case RCAR_GYROADC_MODE_SELECT_3_MAX1162:
350 sample_width = 16;
351 channels = rcar_gyroadc_iio_channels_3;
352 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3);
353 break;
354 default:
355 goto err_e_inval;
356 }
357
358 /*
359 * MB88101 is special in that it's only a single chip taking
360 * up all the CHS lines. Thus, the DT binding is also special
361 * and has no reg property. If we run into such ADC, handle
362 * it here.
363 */
364 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
365 reg = 0;
366 } else {
367 ret = of_property_read_u32(child, "reg", ®);
368 if (ret) {
369 dev_err(dev,
370 "Failed to get child reg property of ADC \"%pOFn\".\n",
371 child);
372 goto err_of_node_put;
373 }
374
375 /* Channel number is too high. */
376 if (reg >= num_channels) {
377 dev_err(dev,
378 "Only %i channels supported with %pOFn, but reg = <%i>.\n",
379 num_channels, child, reg);
380 goto err_e_inval;
381 }
382 }
383
384 /* Child node selected different mode than the rest. */
385 if (!first && (adcmode != childmode)) {
386 dev_err(dev,
387 "Channel %i uses different ADC mode than the rest.\n",
388 reg);
389 goto err_e_inval;
390 }
391
392 /* Channel is valid, grab the regulator. */
393 dev->of_node = child;
394 vref = devm_regulator_get(dev, "vref");
395 dev->of_node = np;
396 if (IS_ERR(vref)) {
397 dev_dbg(dev, "Channel %i 'vref' supply not connected.\n",
398 reg);
399 ret = PTR_ERR(vref);
400 goto err_of_node_put;
401 }
402
403 priv->vref[reg] = vref;
404
405 if (!first)
406 continue;
407
408 /* First child node which passed sanity tests. */
409 adcmode = childmode;
410 first = 0;
411
412 priv->num_channels = num_channels;
413 priv->mode = childmode;
414 priv->sample_width = sample_width;
415
416 indio_dev->channels = channels;
417 indio_dev->num_channels = num_channels;
418
419 /*
420 * MB88101 is special and we only have one such device
421 * attached to the GyroADC at a time, so if we found it,
422 * we can stop parsing here.
423 */
424 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
425 of_node_put(child);
426 break;
427 }
428 }
429
430 if (first) {
431 dev_err(dev, "No valid ADC channels found, aborting.\n");
432 return -EINVAL;
433 }
434
435 return 0;
436
437 err_e_inval:
438 ret = -EINVAL;
439 err_of_node_put:
440 of_node_put(child);
441 return ret;
442 }
443
rcar_gyroadc_deinit_supplies(struct iio_dev * indio_dev)444 static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev)
445 {
446 struct rcar_gyroadc *priv = iio_priv(indio_dev);
447 unsigned int i;
448
449 for (i = 0; i < priv->num_channels; i++) {
450 if (!priv->vref[i])
451 continue;
452
453 regulator_disable(priv->vref[i]);
454 }
455 }
456
rcar_gyroadc_init_supplies(struct iio_dev * indio_dev)457 static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev)
458 {
459 struct rcar_gyroadc *priv = iio_priv(indio_dev);
460 struct device *dev = priv->dev;
461 unsigned int i;
462 int ret;
463
464 for (i = 0; i < priv->num_channels; i++) {
465 if (!priv->vref[i])
466 continue;
467
468 ret = regulator_enable(priv->vref[i]);
469 if (ret) {
470 dev_err(dev, "Failed to enable regulator %i (ret=%i)\n",
471 i, ret);
472 goto err;
473 }
474 }
475
476 return 0;
477
478 err:
479 rcar_gyroadc_deinit_supplies(indio_dev);
480 return ret;
481 }
482
rcar_gyroadc_probe(struct platform_device * pdev)483 static int rcar_gyroadc_probe(struct platform_device *pdev)
484 {
485 struct device *dev = &pdev->dev;
486 struct rcar_gyroadc *priv;
487 struct iio_dev *indio_dev;
488 int ret;
489
490 indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
491 if (!indio_dev)
492 return -ENOMEM;
493
494 priv = iio_priv(indio_dev);
495 priv->dev = dev;
496
497 priv->regs = devm_platform_ioremap_resource(pdev, 0);
498 if (IS_ERR(priv->regs))
499 return PTR_ERR(priv->regs);
500
501 priv->clk = devm_clk_get(dev, "fck");
502 if (IS_ERR(priv->clk))
503 return dev_err_probe(dev, PTR_ERR(priv->clk),
504 "Failed to get IF clock\n");
505
506 ret = rcar_gyroadc_parse_subdevs(indio_dev);
507 if (ret)
508 return ret;
509
510 ret = rcar_gyroadc_init_supplies(indio_dev);
511 if (ret)
512 return ret;
513
514 priv->model = (uintptr_t)of_device_get_match_data(&pdev->dev);
515
516 platform_set_drvdata(pdev, indio_dev);
517
518 indio_dev->name = DRIVER_NAME;
519 indio_dev->info = &rcar_gyroadc_iio_info;
520 indio_dev->modes = INDIO_DIRECT_MODE;
521
522 ret = clk_prepare_enable(priv->clk);
523 if (ret) {
524 dev_err(dev, "Could not prepare or enable the IF clock.\n");
525 goto err_clk_if_enable;
526 }
527
528 pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS);
529 pm_runtime_use_autosuspend(dev);
530 pm_runtime_enable(dev);
531
532 ret = pm_runtime_resume_and_get(dev);
533 if (ret)
534 goto err_power_up;
535
536 rcar_gyroadc_hw_init(priv);
537 rcar_gyroadc_hw_start(priv);
538
539 ret = iio_device_register(indio_dev);
540 if (ret) {
541 dev_err(dev, "Couldn't register IIO device.\n");
542 goto err_iio_device_register;
543 }
544
545 pm_runtime_put_sync(dev);
546
547 return 0;
548
549 err_iio_device_register:
550 rcar_gyroadc_hw_stop(priv);
551 pm_runtime_put_sync(dev);
552 err_power_up:
553 pm_runtime_disable(dev);
554 pm_runtime_set_suspended(dev);
555 clk_disable_unprepare(priv->clk);
556 err_clk_if_enable:
557 rcar_gyroadc_deinit_supplies(indio_dev);
558
559 return ret;
560 }
561
rcar_gyroadc_remove(struct platform_device * pdev)562 static int rcar_gyroadc_remove(struct platform_device *pdev)
563 {
564 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
565 struct rcar_gyroadc *priv = iio_priv(indio_dev);
566 struct device *dev = priv->dev;
567
568 iio_device_unregister(indio_dev);
569 pm_runtime_get_sync(dev);
570 rcar_gyroadc_hw_stop(priv);
571 pm_runtime_put_sync(dev);
572 pm_runtime_disable(dev);
573 pm_runtime_set_suspended(dev);
574 clk_disable_unprepare(priv->clk);
575 rcar_gyroadc_deinit_supplies(indio_dev);
576
577 return 0;
578 }
579
rcar_gyroadc_suspend(struct device * dev)580 static int rcar_gyroadc_suspend(struct device *dev)
581 {
582 struct iio_dev *indio_dev = dev_get_drvdata(dev);
583 struct rcar_gyroadc *priv = iio_priv(indio_dev);
584
585 rcar_gyroadc_hw_stop(priv);
586
587 return 0;
588 }
589
rcar_gyroadc_resume(struct device * dev)590 static int rcar_gyroadc_resume(struct device *dev)
591 {
592 struct iio_dev *indio_dev = dev_get_drvdata(dev);
593 struct rcar_gyroadc *priv = iio_priv(indio_dev);
594
595 rcar_gyroadc_hw_start(priv);
596
597 return 0;
598 }
599
600 static const struct dev_pm_ops rcar_gyroadc_pm_ops = {
601 RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL)
602 };
603
604 static struct platform_driver rcar_gyroadc_driver = {
605 .probe = rcar_gyroadc_probe,
606 .remove = rcar_gyroadc_remove,
607 .driver = {
608 .name = DRIVER_NAME,
609 .of_match_table = rcar_gyroadc_match,
610 .pm = pm_ptr(&rcar_gyroadc_pm_ops),
611 },
612 };
613
614 module_platform_driver(rcar_gyroadc_driver);
615
616 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
617 MODULE_DESCRIPTION("Renesas R-Car GyroADC driver");
618 MODULE_LICENSE("GPL");
619