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 int ret;
166
167 if (on) {
168 ret = pm_runtime_get_sync(dev);
169 if (ret < 0)
170 pm_runtime_put_noidle(dev);
171 } else {
172 pm_runtime_mark_last_busy(dev);
173 ret = pm_runtime_put_autosuspend(dev);
174 }
175
176 return ret;
177 }
178
rcar_gyroadc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)179 static int rcar_gyroadc_read_raw(struct iio_dev *indio_dev,
180 struct iio_chan_spec const *chan,
181 int *val, int *val2, long mask)
182 {
183 struct rcar_gyroadc *priv = iio_priv(indio_dev);
184 struct regulator *consumer;
185 unsigned int datareg = RCAR_GYROADC_REALTIME_DATA(chan->channel);
186 unsigned int vref;
187 int ret;
188
189 /*
190 * MB88101 is special in that it has only single regulator for
191 * all four channels.
192 */
193 if (priv->mode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)
194 consumer = priv->vref[0];
195 else
196 consumer = priv->vref[chan->channel];
197
198 switch (mask) {
199 case IIO_CHAN_INFO_RAW:
200 if (chan->type != IIO_VOLTAGE)
201 return -EINVAL;
202
203 /* Channel not connected. */
204 if (!consumer)
205 return -EINVAL;
206
207 ret = iio_device_claim_direct_mode(indio_dev);
208 if (ret)
209 return ret;
210
211 ret = rcar_gyroadc_set_power(priv, true);
212 if (ret < 0) {
213 iio_device_release_direct_mode(indio_dev);
214 return ret;
215 }
216
217 *val = readl(priv->regs + datareg);
218 *val &= BIT(priv->sample_width) - 1;
219
220 ret = rcar_gyroadc_set_power(priv, false);
221 iio_device_release_direct_mode(indio_dev);
222 if (ret < 0)
223 return ret;
224
225 return IIO_VAL_INT;
226 case IIO_CHAN_INFO_SCALE:
227 /* Channel not connected. */
228 if (!consumer)
229 return -EINVAL;
230
231 vref = regulator_get_voltage(consumer);
232 *val = vref / 1000;
233 *val2 = 1 << priv->sample_width;
234
235 return IIO_VAL_FRACTIONAL;
236 case IIO_CHAN_INFO_SAMP_FREQ:
237 *val = RCAR_GYROADC_SAMPLE_RATE;
238
239 return IIO_VAL_INT;
240 default:
241 return -EINVAL;
242 }
243 }
244
rcar_gyroadc_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)245 static int rcar_gyroadc_reg_access(struct iio_dev *indio_dev,
246 unsigned int reg, unsigned int writeval,
247 unsigned int *readval)
248 {
249 struct rcar_gyroadc *priv = iio_priv(indio_dev);
250 unsigned int maxreg = RCAR_GYROADC_FIFO_STATUS;
251
252 if (readval == NULL)
253 return -EINVAL;
254
255 if (reg % 4)
256 return -EINVAL;
257
258 /* Handle the V2H case with extra interrupt block. */
259 if (priv->model == RCAR_GYROADC_MODEL_R8A7792)
260 maxreg = RCAR_GYROADC_INTENR;
261
262 if (reg > maxreg)
263 return -EINVAL;
264
265 *readval = readl(priv->regs + reg);
266
267 return 0;
268 }
269
270 static const struct iio_info rcar_gyroadc_iio_info = {
271 .read_raw = rcar_gyroadc_read_raw,
272 .debugfs_reg_access = rcar_gyroadc_reg_access,
273 };
274
275 static const struct of_device_id rcar_gyroadc_match[] = {
276 {
277 /* R-Car compatible GyroADC */
278 .compatible = "renesas,rcar-gyroadc",
279 .data = (void *)RCAR_GYROADC_MODEL_DEFAULT,
280 }, {
281 /* R-Car V2H specialty with interrupt registers. */
282 .compatible = "renesas,r8a7792-gyroadc",
283 .data = (void *)RCAR_GYROADC_MODEL_R8A7792,
284 }, {
285 /* sentinel */
286 }
287 };
288
289 MODULE_DEVICE_TABLE(of, rcar_gyroadc_match);
290
291 static const struct of_device_id rcar_gyroadc_child_match[] = {
292 /* Mode 1 ADCs */
293 {
294 .compatible = "fujitsu,mb88101a",
295 .data = (void *)RCAR_GYROADC_MODE_SELECT_1_MB88101A,
296 },
297 /* Mode 2 ADCs */
298 {
299 .compatible = "ti,adcs7476",
300 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
301 }, {
302 .compatible = "ti,adc121",
303 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
304 }, {
305 .compatible = "adi,ad7476",
306 .data = (void *)RCAR_GYROADC_MODE_SELECT_2_ADCS7476,
307 },
308 /* Mode 3 ADCs */
309 {
310 .compatible = "maxim,max1162",
311 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
312 }, {
313 .compatible = "maxim,max11100",
314 .data = (void *)RCAR_GYROADC_MODE_SELECT_3_MAX1162,
315 },
316 { /* sentinel */ }
317 };
318
rcar_gyroadc_parse_subdevs(struct iio_dev * indio_dev)319 static int rcar_gyroadc_parse_subdevs(struct iio_dev *indio_dev)
320 {
321 const struct of_device_id *of_id;
322 const struct iio_chan_spec *channels;
323 struct rcar_gyroadc *priv = iio_priv(indio_dev);
324 struct device *dev = priv->dev;
325 struct device_node *np = dev->of_node;
326 struct device_node *child;
327 struct regulator *vref;
328 unsigned int reg;
329 unsigned int adcmode = -1, childmode;
330 unsigned int sample_width;
331 unsigned int num_channels;
332 int ret, first = 1;
333
334 for_each_child_of_node(np, child) {
335 of_id = of_match_node(rcar_gyroadc_child_match, child);
336 if (!of_id) {
337 dev_err(dev, "Ignoring unsupported ADC \"%pOFn\".",
338 child);
339 continue;
340 }
341
342 childmode = (uintptr_t)of_id->data;
343 switch (childmode) {
344 case RCAR_GYROADC_MODE_SELECT_1_MB88101A:
345 sample_width = 12;
346 channels = rcar_gyroadc_iio_channels_1;
347 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_1);
348 break;
349 case RCAR_GYROADC_MODE_SELECT_2_ADCS7476:
350 sample_width = 15;
351 channels = rcar_gyroadc_iio_channels_2;
352 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_2);
353 break;
354 case RCAR_GYROADC_MODE_SELECT_3_MAX1162:
355 sample_width = 16;
356 channels = rcar_gyroadc_iio_channels_3;
357 num_channels = ARRAY_SIZE(rcar_gyroadc_iio_channels_3);
358 break;
359 default:
360 return -EINVAL;
361 }
362
363 /*
364 * MB88101 is special in that it's only a single chip taking
365 * up all the CHS lines. Thus, the DT binding is also special
366 * and has no reg property. If we run into such ADC, handle
367 * it here.
368 */
369 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A) {
370 reg = 0;
371 } else {
372 ret = of_property_read_u32(child, "reg", ®);
373 if (ret) {
374 dev_err(dev,
375 "Failed to get child reg property of ADC \"%pOFn\".\n",
376 child);
377 return ret;
378 }
379
380 /* Channel number is too high. */
381 if (reg >= num_channels) {
382 dev_err(dev,
383 "Only %i channels supported with %pOFn, but reg = <%i>.\n",
384 num_channels, child, reg);
385 return -EINVAL;
386 }
387 }
388
389 /* Child node selected different mode than the rest. */
390 if (!first && (adcmode != childmode)) {
391 dev_err(dev,
392 "Channel %i uses different ADC mode than the rest.\n",
393 reg);
394 return -EINVAL;
395 }
396
397 /* Channel is valid, grab the regulator. */
398 dev->of_node = child;
399 vref = devm_regulator_get(dev, "vref");
400 dev->of_node = np;
401 if (IS_ERR(vref)) {
402 dev_dbg(dev, "Channel %i 'vref' supply not connected.\n",
403 reg);
404 return PTR_ERR(vref);
405 }
406
407 priv->vref[reg] = vref;
408
409 if (!first)
410 continue;
411
412 /* First child node which passed sanity tests. */
413 adcmode = childmode;
414 first = 0;
415
416 priv->num_channels = num_channels;
417 priv->mode = childmode;
418 priv->sample_width = sample_width;
419
420 indio_dev->channels = channels;
421 indio_dev->num_channels = num_channels;
422
423 /*
424 * MB88101 is special and we only have one such device
425 * attached to the GyroADC at a time, so if we found it,
426 * we can stop parsing here.
427 */
428 if (childmode == RCAR_GYROADC_MODE_SELECT_1_MB88101A)
429 break;
430 }
431
432 if (first) {
433 dev_err(dev, "No valid ADC channels found, aborting.\n");
434 return -EINVAL;
435 }
436
437 return 0;
438 }
439
rcar_gyroadc_deinit_supplies(struct iio_dev * indio_dev)440 static void rcar_gyroadc_deinit_supplies(struct iio_dev *indio_dev)
441 {
442 struct rcar_gyroadc *priv = iio_priv(indio_dev);
443 unsigned int i;
444
445 for (i = 0; i < priv->num_channels; i++) {
446 if (!priv->vref[i])
447 continue;
448
449 regulator_disable(priv->vref[i]);
450 }
451 }
452
rcar_gyroadc_init_supplies(struct iio_dev * indio_dev)453 static int rcar_gyroadc_init_supplies(struct iio_dev *indio_dev)
454 {
455 struct rcar_gyroadc *priv = iio_priv(indio_dev);
456 struct device *dev = priv->dev;
457 unsigned int i;
458 int ret;
459
460 for (i = 0; i < priv->num_channels; i++) {
461 if (!priv->vref[i])
462 continue;
463
464 ret = regulator_enable(priv->vref[i]);
465 if (ret) {
466 dev_err(dev, "Failed to enable regulator %i (ret=%i)\n",
467 i, ret);
468 goto err;
469 }
470 }
471
472 return 0;
473
474 err:
475 rcar_gyroadc_deinit_supplies(indio_dev);
476 return ret;
477 }
478
rcar_gyroadc_probe(struct platform_device * pdev)479 static int rcar_gyroadc_probe(struct platform_device *pdev)
480 {
481 struct device *dev = &pdev->dev;
482 struct rcar_gyroadc *priv;
483 struct iio_dev *indio_dev;
484 struct resource *mem;
485 int ret;
486
487 indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
488 if (!indio_dev)
489 return -ENOMEM;
490
491 priv = iio_priv(indio_dev);
492 priv->dev = dev;
493
494 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
495 priv->regs = devm_ioremap_resource(dev, mem);
496 if (IS_ERR(priv->regs))
497 return PTR_ERR(priv->regs);
498
499 priv->clk = devm_clk_get(dev, "fck");
500 if (IS_ERR(priv->clk)) {
501 ret = PTR_ERR(priv->clk);
502 if (ret != -EPROBE_DEFER)
503 dev_err(dev, "Failed to get IF clock (ret=%i)\n", ret);
504 return ret;
505 }
506
507 ret = rcar_gyroadc_parse_subdevs(indio_dev);
508 if (ret)
509 return ret;
510
511 ret = rcar_gyroadc_init_supplies(indio_dev);
512 if (ret)
513 return ret;
514
515 priv->model = (enum rcar_gyroadc_model)
516 of_device_get_match_data(&pdev->dev);
517
518 platform_set_drvdata(pdev, indio_dev);
519
520 indio_dev->name = DRIVER_NAME;
521 indio_dev->dev.parent = dev;
522 indio_dev->dev.of_node = pdev->dev.of_node;
523 indio_dev->info = &rcar_gyroadc_iio_info;
524 indio_dev->modes = INDIO_DIRECT_MODE;
525
526 ret = clk_prepare_enable(priv->clk);
527 if (ret) {
528 dev_err(dev, "Could not prepare or enable the IF clock.\n");
529 goto err_clk_if_enable;
530 }
531
532 pm_runtime_set_autosuspend_delay(dev, RCAR_GYROADC_RUNTIME_PM_DELAY_MS);
533 pm_runtime_use_autosuspend(dev);
534 pm_runtime_enable(dev);
535
536 pm_runtime_get_sync(dev);
537 rcar_gyroadc_hw_init(priv);
538 rcar_gyroadc_hw_start(priv);
539
540 ret = iio_device_register(indio_dev);
541 if (ret) {
542 dev_err(dev, "Couldn't register IIO device.\n");
543 goto err_iio_device_register;
544 }
545
546 pm_runtime_put_sync(dev);
547
548 return 0;
549
550 err_iio_device_register:
551 rcar_gyroadc_hw_stop(priv);
552 pm_runtime_put_sync(dev);
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
580 #if defined(CONFIG_PM)
rcar_gyroadc_suspend(struct device * dev)581 static int rcar_gyroadc_suspend(struct device *dev)
582 {
583 struct iio_dev *indio_dev = dev_get_drvdata(dev);
584 struct rcar_gyroadc *priv = iio_priv(indio_dev);
585
586 rcar_gyroadc_hw_stop(priv);
587
588 return 0;
589 }
590
rcar_gyroadc_resume(struct device * dev)591 static int rcar_gyroadc_resume(struct device *dev)
592 {
593 struct iio_dev *indio_dev = dev_get_drvdata(dev);
594 struct rcar_gyroadc *priv = iio_priv(indio_dev);
595
596 rcar_gyroadc_hw_start(priv);
597
598 return 0;
599 }
600 #endif
601
602 static const struct dev_pm_ops rcar_gyroadc_pm_ops = {
603 SET_RUNTIME_PM_OPS(rcar_gyroadc_suspend, rcar_gyroadc_resume, NULL)
604 };
605
606 static struct platform_driver rcar_gyroadc_driver = {
607 .probe = rcar_gyroadc_probe,
608 .remove = rcar_gyroadc_remove,
609 .driver = {
610 .name = DRIVER_NAME,
611 .of_match_table = rcar_gyroadc_match,
612 .pm = &rcar_gyroadc_pm_ops,
613 },
614 };
615
616 module_platform_driver(rcar_gyroadc_driver);
617
618 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
619 MODULE_DESCRIPTION("Renesas R-Car GyroADC driver");
620 MODULE_LICENSE("GPL");
621
