Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
[sfrench/cifs-2.6.git] / drivers / iio / adc / rcar-gyroadc.c
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
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
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
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
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
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
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
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", &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
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
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
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
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)
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
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");