1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * 3-axis accelerometer driver for MXC4005XC Memsic sensor
4 *
5 * Copyright (c) 2014, Intel Corporation.
6 */
7
8 #include <linux/module.h>
9 #include <linux/i2c.h>
10 #include <linux/iio/iio.h>
11 #include <linux/acpi.h>
12 #include <linux/regmap.h>
13 #include <linux/iio/sysfs.h>
14 #include <linux/iio/trigger.h>
15 #include <linux/iio/buffer.h>
16 #include <linux/iio/triggered_buffer.h>
17 #include <linux/iio/trigger_consumer.h>
18
19 #define MXC4005_DRV_NAME "mxc4005"
20 #define MXC4005_IRQ_NAME "mxc4005_event"
21 #define MXC4005_REGMAP_NAME "mxc4005_regmap"
22
23 #define MXC4005_REG_XOUT_UPPER 0x03
24 #define MXC4005_REG_XOUT_LOWER 0x04
25 #define MXC4005_REG_YOUT_UPPER 0x05
26 #define MXC4005_REG_YOUT_LOWER 0x06
27 #define MXC4005_REG_ZOUT_UPPER 0x07
28 #define MXC4005_REG_ZOUT_LOWER 0x08
29
30 #define MXC4005_REG_INT_MASK1 0x0B
31 #define MXC4005_REG_INT_MASK1_BIT_DRDYE 0x01
32
33 #define MXC4005_REG_INT_CLR1 0x01
34 #define MXC4005_REG_INT_CLR1_BIT_DRDYC 0x01
35
36 #define MXC4005_REG_CONTROL 0x0D
37 #define MXC4005_REG_CONTROL_MASK_FSR GENMASK(6, 5)
38 #define MXC4005_CONTROL_FSR_SHIFT 5
39
40 #define MXC4005_REG_DEVICE_ID 0x0E
41
42 enum mxc4005_axis {
43 AXIS_X,
44 AXIS_Y,
45 AXIS_Z,
46 };
47
48 enum mxc4005_range {
49 MXC4005_RANGE_2G,
50 MXC4005_RANGE_4G,
51 MXC4005_RANGE_8G,
52 };
53
54 struct mxc4005_data {
55 struct device *dev;
56 struct mutex mutex;
57 struct regmap *regmap;
58 struct iio_trigger *dready_trig;
59 __be16 buffer[8];
60 bool trigger_enabled;
61 };
62
63 /*
64 * MXC4005 can operate in the following ranges:
65 * +/- 2G, 4G, 8G (the default +/-2G)
66 *
67 * (2 + 2) * 9.81 / (2^12 - 1) = 0.009582
68 * (4 + 4) * 9.81 / (2^12 - 1) = 0.019164
69 * (8 + 8) * 9.81 / (2^12 - 1) = 0.038329
70 */
71 static const struct {
72 u8 range;
73 int scale;
74 } mxc4005_scale_table[] = {
75 {MXC4005_RANGE_2G, 9582},
76 {MXC4005_RANGE_4G, 19164},
77 {MXC4005_RANGE_8G, 38329},
78 };
79
80
81 static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329");
82
83 static struct attribute *mxc4005_attributes[] = {
84 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
85 NULL,
86 };
87
88 static const struct attribute_group mxc4005_attrs_group = {
89 .attrs = mxc4005_attributes,
90 };
91
mxc4005_is_readable_reg(struct device * dev,unsigned int reg)92 static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
93 {
94 switch (reg) {
95 case MXC4005_REG_XOUT_UPPER:
96 case MXC4005_REG_XOUT_LOWER:
97 case MXC4005_REG_YOUT_UPPER:
98 case MXC4005_REG_YOUT_LOWER:
99 case MXC4005_REG_ZOUT_UPPER:
100 case MXC4005_REG_ZOUT_LOWER:
101 case MXC4005_REG_DEVICE_ID:
102 case MXC4005_REG_CONTROL:
103 return true;
104 default:
105 return false;
106 }
107 }
108
mxc4005_is_writeable_reg(struct device * dev,unsigned int reg)109 static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg)
110 {
111 switch (reg) {
112 case MXC4005_REG_INT_CLR1:
113 case MXC4005_REG_INT_MASK1:
114 case MXC4005_REG_CONTROL:
115 return true;
116 default:
117 return false;
118 }
119 }
120
121 static const struct regmap_config mxc4005_regmap_config = {
122 .name = MXC4005_REGMAP_NAME,
123
124 .reg_bits = 8,
125 .val_bits = 8,
126
127 .max_register = MXC4005_REG_DEVICE_ID,
128
129 .readable_reg = mxc4005_is_readable_reg,
130 .writeable_reg = mxc4005_is_writeable_reg,
131 };
132
mxc4005_read_xyz(struct mxc4005_data * data)133 static int mxc4005_read_xyz(struct mxc4005_data *data)
134 {
135 int ret;
136
137 ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
138 data->buffer, sizeof(data->buffer));
139 if (ret < 0) {
140 dev_err(data->dev, "failed to read axes\n");
141 return ret;
142 }
143
144 return 0;
145 }
146
mxc4005_read_axis(struct mxc4005_data * data,unsigned int addr)147 static int mxc4005_read_axis(struct mxc4005_data *data,
148 unsigned int addr)
149 {
150 __be16 reg;
151 int ret;
152
153 ret = regmap_bulk_read(data->regmap, addr, ®, sizeof(reg));
154 if (ret < 0) {
155 dev_err(data->dev, "failed to read reg %02x\n", addr);
156 return ret;
157 }
158
159 return be16_to_cpu(reg);
160 }
161
mxc4005_read_scale(struct mxc4005_data * data)162 static int mxc4005_read_scale(struct mxc4005_data *data)
163 {
164 unsigned int reg;
165 int ret;
166 int i;
167
168 ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, ®);
169 if (ret < 0) {
170 dev_err(data->dev, "failed to read reg_control\n");
171 return ret;
172 }
173
174 i = reg >> MXC4005_CONTROL_FSR_SHIFT;
175
176 if (i < 0 || i >= ARRAY_SIZE(mxc4005_scale_table))
177 return -EINVAL;
178
179 return mxc4005_scale_table[i].scale;
180 }
181
mxc4005_set_scale(struct mxc4005_data * data,int val)182 static int mxc4005_set_scale(struct mxc4005_data *data, int val)
183 {
184 unsigned int reg;
185 int i;
186 int ret;
187
188 for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) {
189 if (mxc4005_scale_table[i].scale == val) {
190 reg = i << MXC4005_CONTROL_FSR_SHIFT;
191 ret = regmap_update_bits(data->regmap,
192 MXC4005_REG_CONTROL,
193 MXC4005_REG_CONTROL_MASK_FSR,
194 reg);
195 if (ret < 0)
196 dev_err(data->dev,
197 "failed to write reg_control\n");
198 return ret;
199 }
200 }
201
202 return -EINVAL;
203 }
204
mxc4005_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)205 static int mxc4005_read_raw(struct iio_dev *indio_dev,
206 struct iio_chan_spec const *chan,
207 int *val, int *val2, long mask)
208 {
209 struct mxc4005_data *data = iio_priv(indio_dev);
210 int ret;
211
212 switch (mask) {
213 case IIO_CHAN_INFO_RAW:
214 switch (chan->type) {
215 case IIO_ACCEL:
216 if (iio_buffer_enabled(indio_dev))
217 return -EBUSY;
218
219 ret = mxc4005_read_axis(data, chan->address);
220 if (ret < 0)
221 return ret;
222 *val = sign_extend32(ret >> chan->scan_type.shift,
223 chan->scan_type.realbits - 1);
224 return IIO_VAL_INT;
225 default:
226 return -EINVAL;
227 }
228 case IIO_CHAN_INFO_SCALE:
229 ret = mxc4005_read_scale(data);
230 if (ret < 0)
231 return ret;
232
233 *val = 0;
234 *val2 = ret;
235 return IIO_VAL_INT_PLUS_MICRO;
236 default:
237 return -EINVAL;
238 }
239 }
240
mxc4005_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)241 static int mxc4005_write_raw(struct iio_dev *indio_dev,
242 struct iio_chan_spec const *chan,
243 int val, int val2, long mask)
244 {
245 struct mxc4005_data *data = iio_priv(indio_dev);
246
247 switch (mask) {
248 case IIO_CHAN_INFO_SCALE:
249 if (val != 0)
250 return -EINVAL;
251
252 return mxc4005_set_scale(data, val2);
253 default:
254 return -EINVAL;
255 }
256 }
257
258 static const struct iio_info mxc4005_info = {
259 .read_raw = mxc4005_read_raw,
260 .write_raw = mxc4005_write_raw,
261 .attrs = &mxc4005_attrs_group,
262 };
263
264 static const unsigned long mxc4005_scan_masks[] = {
265 BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
266 0
267 };
268
269 #define MXC4005_CHANNEL(_axis, _addr) { \
270 .type = IIO_ACCEL, \
271 .modified = 1, \
272 .channel2 = IIO_MOD_##_axis, \
273 .address = _addr, \
274 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
275 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
276 .scan_index = AXIS_##_axis, \
277 .scan_type = { \
278 .sign = 's', \
279 .realbits = 12, \
280 .storagebits = 16, \
281 .shift = 4, \
282 .endianness = IIO_BE, \
283 }, \
284 }
285
286 static const struct iio_chan_spec mxc4005_channels[] = {
287 MXC4005_CHANNEL(X, MXC4005_REG_XOUT_UPPER),
288 MXC4005_CHANNEL(Y, MXC4005_REG_YOUT_UPPER),
289 MXC4005_CHANNEL(Z, MXC4005_REG_ZOUT_UPPER),
290 IIO_CHAN_SOFT_TIMESTAMP(3),
291 };
292
mxc4005_trigger_handler(int irq,void * private)293 static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
294 {
295 struct iio_poll_func *pf = private;
296 struct iio_dev *indio_dev = pf->indio_dev;
297 struct mxc4005_data *data = iio_priv(indio_dev);
298 int ret;
299
300 ret = mxc4005_read_xyz(data);
301 if (ret < 0)
302 goto err;
303
304 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
305 pf->timestamp);
306
307 err:
308 iio_trigger_notify_done(indio_dev->trig);
309
310 return IRQ_HANDLED;
311 }
312
mxc4005_clr_intr(struct mxc4005_data * data)313 static void mxc4005_clr_intr(struct mxc4005_data *data)
314 {
315 int ret;
316
317 /* clear interrupt */
318 ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
319 MXC4005_REG_INT_CLR1_BIT_DRDYC);
320 if (ret < 0)
321 dev_err(data->dev, "failed to write to reg_int_clr1\n");
322 }
323
mxc4005_set_trigger_state(struct iio_trigger * trig,bool state)324 static int mxc4005_set_trigger_state(struct iio_trigger *trig,
325 bool state)
326 {
327 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
328 struct mxc4005_data *data = iio_priv(indio_dev);
329 int ret;
330
331 mutex_lock(&data->mutex);
332 if (state) {
333 ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1,
334 MXC4005_REG_INT_MASK1_BIT_DRDYE);
335 } else {
336 ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1,
337 ~MXC4005_REG_INT_MASK1_BIT_DRDYE);
338 }
339
340 if (ret < 0) {
341 mutex_unlock(&data->mutex);
342 dev_err(data->dev, "failed to update reg_int_mask1");
343 return ret;
344 }
345
346 data->trigger_enabled = state;
347 mutex_unlock(&data->mutex);
348
349 return 0;
350 }
351
mxc4005_trigger_reen(struct iio_trigger * trig)352 static void mxc4005_trigger_reen(struct iio_trigger *trig)
353 {
354 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
355 struct mxc4005_data *data = iio_priv(indio_dev);
356
357 if (!data->dready_trig)
358 return;
359
360 mxc4005_clr_intr(data);
361 }
362
363 static const struct iio_trigger_ops mxc4005_trigger_ops = {
364 .set_trigger_state = mxc4005_set_trigger_state,
365 .reenable = mxc4005_trigger_reen,
366 };
367
mxc4005_chip_init(struct mxc4005_data * data)368 static int mxc4005_chip_init(struct mxc4005_data *data)
369 {
370 int ret;
371 unsigned int reg;
372
373 ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, ®);
374 if (ret < 0) {
375 dev_err(data->dev, "failed to read chip id\n");
376 return ret;
377 }
378
379 dev_dbg(data->dev, "MXC4005 chip id %02x\n", reg);
380
381 return 0;
382 }
383
mxc4005_probe(struct i2c_client * client,const struct i2c_device_id * id)384 static int mxc4005_probe(struct i2c_client *client,
385 const struct i2c_device_id *id)
386 {
387 struct mxc4005_data *data;
388 struct iio_dev *indio_dev;
389 struct regmap *regmap;
390 int ret;
391
392 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
393 if (!indio_dev)
394 return -ENOMEM;
395
396 regmap = devm_regmap_init_i2c(client, &mxc4005_regmap_config);
397 if (IS_ERR(regmap)) {
398 dev_err(&client->dev, "failed to initialize regmap\n");
399 return PTR_ERR(regmap);
400 }
401
402 data = iio_priv(indio_dev);
403 i2c_set_clientdata(client, indio_dev);
404 data->dev = &client->dev;
405 data->regmap = regmap;
406
407 ret = mxc4005_chip_init(data);
408 if (ret < 0) {
409 dev_err(&client->dev, "failed to initialize chip\n");
410 return ret;
411 }
412
413 mutex_init(&data->mutex);
414
415 indio_dev->channels = mxc4005_channels;
416 indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels);
417 indio_dev->available_scan_masks = mxc4005_scan_masks;
418 indio_dev->name = MXC4005_DRV_NAME;
419 indio_dev->modes = INDIO_DIRECT_MODE;
420 indio_dev->info = &mxc4005_info;
421
422 ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
423 iio_pollfunc_store_time,
424 mxc4005_trigger_handler,
425 NULL);
426 if (ret < 0) {
427 dev_err(&client->dev,
428 "failed to setup iio triggered buffer\n");
429 return ret;
430 }
431
432 if (client->irq > 0) {
433 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
434 "%s-dev%d",
435 indio_dev->name,
436 indio_dev->id);
437 if (!data->dready_trig)
438 return -ENOMEM;
439
440 ret = devm_request_threaded_irq(&client->dev, client->irq,
441 iio_trigger_generic_data_rdy_poll,
442 NULL,
443 IRQF_TRIGGER_FALLING |
444 IRQF_ONESHOT,
445 MXC4005_IRQ_NAME,
446 data->dready_trig);
447 if (ret) {
448 dev_err(&client->dev,
449 "failed to init threaded irq\n");
450 return ret;
451 }
452
453 data->dready_trig->ops = &mxc4005_trigger_ops;
454 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
455 indio_dev->trig = data->dready_trig;
456 iio_trigger_get(indio_dev->trig);
457 ret = devm_iio_trigger_register(&client->dev,
458 data->dready_trig);
459 if (ret) {
460 dev_err(&client->dev,
461 "failed to register trigger\n");
462 return ret;
463 }
464 }
465
466 return devm_iio_device_register(&client->dev, indio_dev);
467 }
468
469 static const struct acpi_device_id mxc4005_acpi_match[] = {
470 {"MXC4005", 0},
471 {"MXC6655", 0},
472 { },
473 };
474 MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match);
475
476 static const struct i2c_device_id mxc4005_id[] = {
477 {"mxc4005", 0},
478 {"mxc6655", 0},
479 { },
480 };
481 MODULE_DEVICE_TABLE(i2c, mxc4005_id);
482
483 static struct i2c_driver mxc4005_driver = {
484 .driver = {
485 .name = MXC4005_DRV_NAME,
486 .acpi_match_table = ACPI_PTR(mxc4005_acpi_match),
487 },
488 .probe = mxc4005_probe,
489 .id_table = mxc4005_id,
490 };
491
492 module_i2c_driver(mxc4005_driver);
493
494 MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
495 MODULE_LICENSE("GPL v2");
496 MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver");
497