1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * cros_ec_sensors_core - Common function for Chrome OS EC sensor driver.
4 *
5 * Copyright (C) 2016 Google, Inc
6 */
7
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/iio/buffer.h>
11 #include <linux/iio/common/cros_ec_sensors_core.h>
12 #include <linux/iio/iio.h>
13 #include <linux/iio/kfifo_buf.h>
14 #include <linux/iio/sysfs.h>
15 #include <linux/iio/trigger.h>
16 #include <linux/iio/trigger_consumer.h>
17 #include <linux/iio/triggered_buffer.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/platform_data/cros_ec_commands.h>
22 #include <linux/platform_data/cros_ec_proto.h>
23 #include <linux/platform_data/cros_ec_sensorhub.h>
24 #include <linux/platform_device.h>
25
26 #include "cros_ec_sensors_trace.h"
27
28 /*
29 * Hard coded to the first device to support sensor fifo. The EC has a 2048
30 * byte fifo and will trigger an interrupt when fifo is 2/3 full.
31 */
32 #define CROS_EC_FIFO_SIZE (2048 * 2 / 3)
33
cros_ec_get_host_cmd_version_mask(struct cros_ec_device * ec_dev,u16 cmd_offset,u16 cmd,u32 * mask)34 static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
35 u16 cmd_offset, u16 cmd, u32 *mask)
36 {
37 DEFINE_RAW_FLEX(struct cros_ec_command, buf, data,
38 MAX(sizeof(struct ec_response_get_cmd_versions),
39 sizeof(struct ec_params_get_cmd_versions)));
40 int ret;
41
42 buf->command = EC_CMD_GET_CMD_VERSIONS + cmd_offset;
43 buf->insize = sizeof(struct ec_response_get_cmd_versions);
44 buf->outsize = sizeof(struct ec_params_get_cmd_versions);
45 ((struct ec_params_get_cmd_versions *)buf->data)->cmd = cmd;
46
47 ret = cros_ec_cmd_xfer_status(ec_dev, buf);
48 if (ret >= 0)
49 *mask = ((struct ec_response_get_cmd_versions *)buf->data)->version_mask;
50 return ret;
51 }
52
get_default_min_max_freq(enum motionsensor_type type,u32 * min_freq,u32 * max_freq,u32 * max_fifo_events)53 static void get_default_min_max_freq(enum motionsensor_type type,
54 u32 *min_freq,
55 u32 *max_freq,
56 u32 *max_fifo_events)
57 {
58 /*
59 * We don't know fifo size, set to size previously used by older
60 * hardware.
61 */
62 *max_fifo_events = CROS_EC_FIFO_SIZE;
63
64 switch (type) {
65 case MOTIONSENSE_TYPE_ACCEL:
66 *min_freq = 12500;
67 *max_freq = 100000;
68 break;
69 case MOTIONSENSE_TYPE_GYRO:
70 *min_freq = 25000;
71 *max_freq = 100000;
72 break;
73 case MOTIONSENSE_TYPE_MAG:
74 *min_freq = 5000;
75 *max_freq = 25000;
76 break;
77 case MOTIONSENSE_TYPE_PROX:
78 case MOTIONSENSE_TYPE_LIGHT:
79 *min_freq = 100;
80 *max_freq = 50000;
81 break;
82 case MOTIONSENSE_TYPE_BARO:
83 *min_freq = 250;
84 *max_freq = 20000;
85 break;
86 case MOTIONSENSE_TYPE_ACTIVITY:
87 default:
88 *min_freq = 0;
89 *max_freq = 0;
90 break;
91 }
92 }
93
cros_ec_sensor_set_report_latency(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)94 static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
95 struct device_attribute *attr,
96 const char *buf, size_t len)
97 {
98 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
99 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
100 int integer, fract, ret;
101 int latency;
102
103 ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
104 if (ret)
105 return ret;
106
107 /* EC rate is in ms. */
108 latency = integer * 1000 + fract / 1000;
109
110 mutex_lock(&st->cmd_lock);
111 st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
112 st->param.ec_rate.data = min(U16_MAX, latency);
113 ret = cros_ec_motion_send_host_cmd(st, 0);
114 if (ret < 0) {
115 mutex_unlock(&st->cmd_lock);
116 return ret;
117 }
118
119 /*
120 * Flush samples currently in the FIFO, especially when the new latency
121 * is shorter than the old one: new timeout value is only considered when
122 * there is a new sample available. It can take a while for a slow
123 * sensor.
124 */
125 st->param.cmd = MOTIONSENSE_CMD_FIFO_FLUSH;
126 ret = cros_ec_motion_send_host_cmd(st, 0);
127 mutex_unlock(&st->cmd_lock);
128 if (ret < 0)
129 return ret;
130
131 return len;
132 }
133
cros_ec_sensor_get_report_latency(struct device * dev,struct device_attribute * attr,char * buf)134 static ssize_t cros_ec_sensor_get_report_latency(struct device *dev,
135 struct device_attribute *attr,
136 char *buf)
137 {
138 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
139 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
140 int latency, ret;
141
142 mutex_lock(&st->cmd_lock);
143 st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
144 st->param.ec_rate.data = EC_MOTION_SENSE_NO_VALUE;
145
146 ret = cros_ec_motion_send_host_cmd(st, 0);
147 latency = st->resp->ec_rate.ret;
148 mutex_unlock(&st->cmd_lock);
149 if (ret < 0)
150 return ret;
151
152 return sprintf(buf, "%d.%06u\n",
153 latency / 1000,
154 (latency % 1000) * 1000);
155 }
156
157 static IIO_DEVICE_ATTR(hwfifo_timeout, 0644,
158 cros_ec_sensor_get_report_latency,
159 cros_ec_sensor_set_report_latency, 0);
160
hwfifo_watermark_max_show(struct device * dev,struct device_attribute * attr,char * buf)161 static ssize_t hwfifo_watermark_max_show(struct device *dev,
162 struct device_attribute *attr,
163 char *buf)
164 {
165 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
166 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
167
168 return sprintf(buf, "%d\n", st->fifo_max_event_count);
169 }
170
171 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
172
173 static const struct iio_dev_attr *cros_ec_sensor_fifo_attributes[] = {
174 &iio_dev_attr_hwfifo_timeout,
175 &iio_dev_attr_hwfifo_watermark_max,
176 NULL,
177 };
178
cros_ec_sensors_push_data(struct iio_dev * indio_dev,s16 * data,s64 timestamp)179 int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
180 s16 *data,
181 s64 timestamp)
182 {
183 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
184 s16 *out;
185 s64 delta;
186 unsigned int i;
187
188 /*
189 * Ignore samples if the buffer is not set: it is needed if the ODR is
190 * set but the buffer is not enabled yet.
191 *
192 * Note: iio_device_claim_buffer_mode() returns -EBUSY if the buffer
193 * is not enabled.
194 */
195 if (iio_device_claim_buffer_mode(indio_dev) < 0)
196 return 0;
197
198 out = (s16 *)st->samples;
199 iio_for_each_active_channel(indio_dev, i) {
200 *out = data[i];
201 out++;
202 }
203
204 if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
205 delta = iio_get_time_ns(indio_dev) - cros_ec_get_time_ns();
206 else
207 delta = 0;
208
209 iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
210 timestamp + delta);
211
212 iio_device_release_buffer_mode(indio_dev);
213 return 0;
214 }
215 EXPORT_SYMBOL_GPL(cros_ec_sensors_push_data);
216
cros_ec_sensors_core_clean(void * arg)217 static void cros_ec_sensors_core_clean(void *arg)
218 {
219 struct platform_device *pdev = (struct platform_device *)arg;
220 struct cros_ec_sensorhub *sensor_hub =
221 dev_get_drvdata(pdev->dev.parent);
222 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
223 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
224 u8 sensor_num = st->param.info.sensor_num;
225
226 cros_ec_sensorhub_unregister_push_data(sensor_hub, sensor_num);
227 }
228
229 /**
230 * cros_ec_sensors_core_init() - basic initialization of the core structure
231 * @pdev: platform device created for the sensor
232 * @indio_dev: iio device structure of the device
233 * @physical_device: true if the device refers to a physical device
234 * @trigger_capture: function pointer to call buffer is triggered,
235 * for backward compatibility.
236 *
237 * Return: 0 on success, -errno on failure.
238 */
cros_ec_sensors_core_init(struct platform_device * pdev,struct iio_dev * indio_dev,bool physical_device,cros_ec_sensors_capture_t trigger_capture)239 int cros_ec_sensors_core_init(struct platform_device *pdev,
240 struct iio_dev *indio_dev,
241 bool physical_device,
242 cros_ec_sensors_capture_t trigger_capture)
243 {
244 struct device *dev = &pdev->dev;
245 struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
246 struct cros_ec_sensorhub *sensor_hub = dev_get_drvdata(dev->parent);
247 struct cros_ec_dev *ec = sensor_hub->ec;
248 struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
249 u32 ver_mask, temp;
250 int frequencies[ARRAY_SIZE(state->frequencies) / 2] = { 0 };
251 int ret, i;
252
253 platform_set_drvdata(pdev, indio_dev);
254
255 state->ec = ec->ec_dev;
256 state->msg = devm_kzalloc(&pdev->dev, sizeof(*state->msg) +
257 max((u16)sizeof(struct ec_params_motion_sense),
258 state->ec->max_response), GFP_KERNEL);
259 if (!state->msg)
260 return -ENOMEM;
261
262 state->resp = (struct ec_response_motion_sense *)state->msg->data;
263
264 mutex_init(&state->cmd_lock);
265
266 ret = cros_ec_get_host_cmd_version_mask(state->ec,
267 ec->cmd_offset,
268 EC_CMD_MOTION_SENSE_CMD,
269 &ver_mask);
270 if (ret < 0)
271 return ret;
272
273 /* Set up the host command structure. */
274 state->msg->version = fls(ver_mask) - 1;
275 state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
276 state->msg->outsize = sizeof(struct ec_params_motion_sense);
277
278 indio_dev->name = pdev->name;
279
280 if (physical_device) {
281 enum motionsensor_location loc;
282
283 state->param.cmd = MOTIONSENSE_CMD_INFO;
284 state->param.info.sensor_num = sensor_platform->sensor_num;
285 ret = cros_ec_motion_send_host_cmd(state, 0);
286 if (ret) {
287 dev_warn(dev, "Can not access sensor info\n");
288 return ret;
289 }
290 state->type = state->resp->info.type;
291 loc = state->resp->info.location;
292 if (loc == MOTIONSENSE_LOC_BASE)
293 indio_dev->label = "accel-base";
294 else if (loc == MOTIONSENSE_LOC_LID)
295 indio_dev->label = "accel-display";
296 else if (loc == MOTIONSENSE_LOC_CAMERA)
297 indio_dev->label = "accel-camera";
298
299 /* Set sign vector, only used for backward compatibility. */
300 memset(state->sign, 1, CROS_EC_SENSOR_MAX_AXIS);
301
302 for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
303 state->calib[i].scale = MOTION_SENSE_DEFAULT_SCALE;
304
305 /* 0 is a correct value used to stop the device */
306 if (state->msg->version < 3) {
307 get_default_min_max_freq(state->resp->info.type,
308 &frequencies[1],
309 &frequencies[2],
310 &state->fifo_max_event_count);
311 } else {
312 if (state->resp->info_3.max_frequency == 0) {
313 get_default_min_max_freq(state->resp->info.type,
314 &frequencies[1],
315 &frequencies[2],
316 &temp);
317 } else {
318 frequencies[1] = state->resp->info_3.min_frequency;
319 frequencies[2] = state->resp->info_3.max_frequency;
320 }
321 state->fifo_max_event_count = state->resp->info_3.fifo_max_event_count;
322 }
323 for (i = 0; i < ARRAY_SIZE(frequencies); i++) {
324 state->frequencies[2 * i] = frequencies[i] / 1000;
325 state->frequencies[2 * i + 1] =
326 (frequencies[i] % 1000) * 1000;
327 }
328
329 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
330 /*
331 * Create a software buffer, feed by the EC FIFO.
332 * We can not use trigger here, as events are generated
333 * as soon as sample_frequency is set.
334 */
335 ret = devm_iio_kfifo_buffer_setup_ext(dev, indio_dev, NULL,
336 cros_ec_sensor_fifo_attributes);
337 if (ret)
338 return ret;
339
340 /* Timestamp coming from FIFO are in ns since boot. */
341 ret = iio_device_set_clock(indio_dev, CLOCK_BOOTTIME);
342 if (ret)
343 return ret;
344
345 } else {
346 /*
347 * The only way to get samples in buffer is to set a
348 * software trigger (systrig, hrtimer).
349 */
350 ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
351 NULL, trigger_capture, NULL);
352 if (ret)
353 return ret;
354 }
355 }
356
357 return 0;
358 }
359 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);
360
361 /**
362 * cros_ec_sensors_core_register() - Register callback to FIFO and IIO when
363 * sensor is ready.
364 * It must be called at the end of the sensor probe routine.
365 * @dev: device created for the sensor
366 * @indio_dev: iio device structure of the device
367 * @push_data: function to call when cros_ec_sensorhub receives
368 * a sample for that sensor.
369 *
370 * Return: 0 on success, -errno on failure.
371 */
cros_ec_sensors_core_register(struct device * dev,struct iio_dev * indio_dev,cros_ec_sensorhub_push_data_cb_t push_data)372 int cros_ec_sensors_core_register(struct device *dev,
373 struct iio_dev *indio_dev,
374 cros_ec_sensorhub_push_data_cb_t push_data)
375 {
376 struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
377 struct cros_ec_sensorhub *sensor_hub = dev_get_drvdata(dev->parent);
378 struct platform_device *pdev = to_platform_device(dev);
379 struct cros_ec_dev *ec = sensor_hub->ec;
380 int ret;
381
382 ret = devm_iio_device_register(dev, indio_dev);
383 if (ret)
384 return ret;
385
386 if (!push_data ||
387 !cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
388 return 0;
389
390 ret = cros_ec_sensorhub_register_push_data(
391 sensor_hub, sensor_platform->sensor_num,
392 indio_dev, push_data);
393 if (ret)
394 return ret;
395
396 return devm_add_action_or_reset(
397 dev, cros_ec_sensors_core_clean, pdev);
398 }
399 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_register);
400
401 /**
402 * cros_ec_motion_send_host_cmd() - send motion sense host command
403 * @state: pointer to state information for device
404 * @opt_length: optional length to reduce the response size, useful on the data
405 * path. Otherwise, the maximal allowed response size is used
406 *
407 * When called, the sub-command is assumed to be set in param->cmd.
408 *
409 * Return: 0 on success, -errno on failure.
410 */
cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state * state,u16 opt_length)411 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *state,
412 u16 opt_length)
413 {
414 struct ec_response_motion_sense *resp = (struct ec_response_motion_sense *)state->msg->data;
415 int ret;
416
417 if (opt_length)
418 state->msg->insize = min(opt_length, state->ec->max_response);
419 else
420 state->msg->insize = state->ec->max_response;
421
422 memcpy(state->msg->data, &state->param, sizeof(state->param));
423
424 ret = cros_ec_cmd_xfer_status(state->ec, state->msg);
425 trace_cros_ec_motion_host_cmd(&state->param, resp, ret);
426 if (ret < 0)
427 return ret;
428
429 if (ret && state->resp != resp)
430 memcpy(state->resp, resp, ret);
431
432 return 0;
433 }
434 EXPORT_SYMBOL_GPL(cros_ec_motion_send_host_cmd);
435
cros_ec_sensors_calibrate(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)436 static ssize_t cros_ec_sensors_calibrate(struct iio_dev *indio_dev,
437 uintptr_t private, const struct iio_chan_spec *chan,
438 const char *buf, size_t len)
439 {
440 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
441 int ret, i;
442 bool calibrate;
443
444 ret = kstrtobool(buf, &calibrate);
445 if (ret < 0)
446 return ret;
447 if (!calibrate)
448 return -EINVAL;
449
450 mutex_lock(&st->cmd_lock);
451 st->param.cmd = MOTIONSENSE_CMD_PERFORM_CALIB;
452 ret = cros_ec_motion_send_host_cmd(st, 0);
453 if (ret != 0) {
454 dev_warn(&indio_dev->dev, "Unable to calibrate sensor\n");
455 } else {
456 /* Save values */
457 for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
458 st->calib[i].offset = st->resp->perform_calib.offset[i];
459 }
460 mutex_unlock(&st->cmd_lock);
461
462 return ret ? ret : len;
463 }
464
cros_ec_sensors_id(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)465 static ssize_t cros_ec_sensors_id(struct iio_dev *indio_dev,
466 uintptr_t private,
467 const struct iio_chan_spec *chan, char *buf)
468 {
469 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
470
471 return snprintf(buf, PAGE_SIZE, "%d\n", st->param.info.sensor_num);
472 }
473
474 const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
475 {
476 .name = "calibrate",
477 .shared = IIO_SHARED_BY_ALL,
478 .write = cros_ec_sensors_calibrate
479 },
480 {
481 .name = "id",
482 .shared = IIO_SHARED_BY_ALL,
483 .read = cros_ec_sensors_id
484 },
485 { }
486 };
487 EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info);
488
489 /**
490 * cros_ec_sensors_idx_to_reg - convert index into offset in shared memory
491 * @st: pointer to state information for device
492 * @idx: sensor index (should be element of enum sensor_index)
493 *
494 * Return: address to read at
495 */
cros_ec_sensors_idx_to_reg(struct cros_ec_sensors_core_state * st,unsigned int idx)496 static unsigned int cros_ec_sensors_idx_to_reg(
497 struct cros_ec_sensors_core_state *st,
498 unsigned int idx)
499 {
500 /*
501 * When using LPC interface, only space for 2 Accel and one Gyro.
502 * First halfword of MOTIONSENSE_TYPE_ACCEL is used by angle.
503 */
504 if (st->type == MOTIONSENSE_TYPE_ACCEL)
505 return EC_MEMMAP_ACC_DATA + sizeof(u16) *
506 (1 + idx + st->param.info.sensor_num *
507 CROS_EC_SENSOR_MAX_AXIS);
508
509 return EC_MEMMAP_GYRO_DATA + sizeof(u16) * idx;
510 }
511
cros_ec_sensors_cmd_read_u8(struct cros_ec_device * ec,unsigned int offset,u8 * dest)512 static int cros_ec_sensors_cmd_read_u8(struct cros_ec_device *ec,
513 unsigned int offset, u8 *dest)
514 {
515 return ec->cmd_readmem(ec, offset, 1, dest);
516 }
517
cros_ec_sensors_cmd_read_u16(struct cros_ec_device * ec,unsigned int offset,u16 * dest)518 static int cros_ec_sensors_cmd_read_u16(struct cros_ec_device *ec,
519 unsigned int offset, u16 *dest)
520 {
521 __le16 tmp;
522 int ret = ec->cmd_readmem(ec, offset, 2, &tmp);
523
524 if (ret >= 0)
525 *dest = le16_to_cpu(tmp);
526
527 return ret;
528 }
529
530 /**
531 * cros_ec_sensors_read_until_not_busy() - read until is not busy
532 *
533 * @st: pointer to state information for device
534 *
535 * Read from EC status byte until it reads not busy.
536 * Return: 8-bit status if ok, -errno on failure.
537 */
cros_ec_sensors_read_until_not_busy(struct cros_ec_sensors_core_state * st)538 static int cros_ec_sensors_read_until_not_busy(
539 struct cros_ec_sensors_core_state *st)
540 {
541 struct cros_ec_device *ec = st->ec;
542 u8 status;
543 int ret, attempts = 0;
544
545 ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
546 if (ret < 0)
547 return ret;
548
549 while (status & EC_MEMMAP_ACC_STATUS_BUSY_BIT) {
550 /* Give up after enough attempts, return error. */
551 if (attempts++ >= 50)
552 return -EIO;
553
554 /* Small delay every so often. */
555 if (attempts % 5 == 0)
556 msleep(25);
557
558 ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
559 &status);
560 if (ret < 0)
561 return ret;
562 }
563
564 return status;
565 }
566
567 /**
568 * cros_ec_sensors_read_data_unsafe() - read acceleration data from EC shared memory
569 * @indio_dev: pointer to IIO device
570 * @scan_mask: bitmap of the sensor indices to scan
571 * @data: location to store data
572 *
573 * This is the unsafe function for reading the EC data. It does not guarantee
574 * that the EC will not modify the data as it is being read in.
575 *
576 * Return: 0 on success, -errno on failure.
577 */
cros_ec_sensors_read_data_unsafe(struct iio_dev * indio_dev,unsigned long scan_mask,s16 * data)578 static int cros_ec_sensors_read_data_unsafe(struct iio_dev *indio_dev,
579 unsigned long scan_mask, s16 *data)
580 {
581 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
582 struct cros_ec_device *ec = st->ec;
583 unsigned int i;
584 int ret;
585
586 /* Read all sensors enabled in scan_mask. Each value is 2 bytes. */
587 for_each_set_bit(i, &scan_mask, iio_get_masklength(indio_dev)) {
588 ret = cros_ec_sensors_cmd_read_u16(ec,
589 cros_ec_sensors_idx_to_reg(st, i),
590 data);
591 if (ret < 0)
592 return ret;
593
594 *data *= st->sign[i];
595 data++;
596 }
597
598 return 0;
599 }
600
601 /**
602 * cros_ec_sensors_read_lpc() - read acceleration data from EC shared memory.
603 * @indio_dev: pointer to IIO device.
604 * @scan_mask: bitmap of the sensor indices to scan.
605 * @data: location to store data.
606 *
607 * Note: this is the safe function for reading the EC data. It guarantees
608 * that the data sampled was not modified by the EC while being read.
609 *
610 * Return: 0 on success, -errno on failure.
611 */
cros_ec_sensors_read_lpc(struct iio_dev * indio_dev,unsigned long scan_mask,s16 * data)612 int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev,
613 unsigned long scan_mask, s16 *data)
614 {
615 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
616 struct cros_ec_device *ec = st->ec;
617 u8 samp_id = 0xff, status = 0;
618 int ret, attempts = 0;
619
620 /*
621 * Continually read all data from EC until the status byte after
622 * all reads reflects that the EC is not busy and the sample id
623 * matches the sample id from before all reads. This guarantees
624 * that data read in was not modified by the EC while reading.
625 */
626 while ((status & (EC_MEMMAP_ACC_STATUS_BUSY_BIT |
627 EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK)) != samp_id) {
628 /* If we have tried to read too many times, return error. */
629 if (attempts++ >= 5)
630 return -EIO;
631
632 /* Read status byte until EC is not busy. */
633 ret = cros_ec_sensors_read_until_not_busy(st);
634 if (ret < 0)
635 return ret;
636
637 /*
638 * Store the current sample id so that we can compare to the
639 * sample id after reading the data.
640 */
641 samp_id = ret & EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK;
642
643 /* Read all EC data, format it, and store it into data. */
644 ret = cros_ec_sensors_read_data_unsafe(indio_dev, scan_mask,
645 data);
646 if (ret < 0)
647 return ret;
648
649 /* Read status byte. */
650 ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
651 &status);
652 if (ret < 0)
653 return ret;
654 }
655
656 return 0;
657 }
658 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_lpc);
659
660 /**
661 * cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol
662 * @indio_dev: pointer to IIO device
663 * @scan_mask: bitmap of the sensor indices to scan
664 * @data: location to store data
665 *
666 * Return: 0 on success, -errno on failure.
667 */
cros_ec_sensors_read_cmd(struct iio_dev * indio_dev,unsigned long scan_mask,s16 * data)668 int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
669 unsigned long scan_mask, s16 *data)
670 {
671 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
672 int ret;
673 unsigned int i;
674
675 /* Read all sensor data through a command. */
676 st->param.cmd = MOTIONSENSE_CMD_DATA;
677 ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->data));
678 if (ret != 0) {
679 dev_warn(&indio_dev->dev, "Unable to read sensor data\n");
680 return ret;
681 }
682
683 for_each_set_bit(i, &scan_mask, iio_get_masklength(indio_dev)) {
684 *data = st->resp->data.data[i];
685 data++;
686 }
687
688 return 0;
689 }
690 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_cmd);
691
692 /**
693 * cros_ec_sensors_capture() - the trigger handler function
694 * @irq: the interrupt number.
695 * @p: a pointer to the poll function.
696 *
697 * On a trigger event occurring, if the pollfunc is attached then this
698 * handler is called as a threaded interrupt (and hence may sleep). It
699 * is responsible for grabbing data from the device and pushing it into
700 * the associated buffer.
701 *
702 * Return: IRQ_HANDLED
703 */
cros_ec_sensors_capture(int irq,void * p)704 irqreturn_t cros_ec_sensors_capture(int irq, void *p)
705 {
706 struct iio_poll_func *pf = p;
707 struct iio_dev *indio_dev = pf->indio_dev;
708 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
709 int ret;
710
711 mutex_lock(&st->cmd_lock);
712
713 /* Clear capture data. */
714 memset(st->samples, 0, indio_dev->scan_bytes);
715
716 /* Read data based on which channels are enabled in scan mask. */
717 ret = st->read_ec_sensors_data(indio_dev,
718 *(indio_dev->active_scan_mask),
719 (s16 *)st->samples);
720 if (ret < 0)
721 goto done;
722
723 iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
724 iio_get_time_ns(indio_dev));
725
726 done:
727 /*
728 * Tell the core we are done with this trigger and ready for the
729 * next one.
730 */
731 iio_trigger_notify_done(indio_dev->trig);
732
733 mutex_unlock(&st->cmd_lock);
734
735 return IRQ_HANDLED;
736 }
737 EXPORT_SYMBOL_GPL(cros_ec_sensors_capture);
738
739 /**
740 * cros_ec_sensors_core_read() - function to request a value from the sensor
741 * @st: pointer to state information for device
742 * @chan: channel specification structure table
743 * @val: will contain one element making up the returned value
744 * @val2: will contain another element making up the returned value
745 * @mask: specifies which values to be requested
746 *
747 * Return: the type of value returned by the device
748 */
cros_ec_sensors_core_read(struct cros_ec_sensors_core_state * st,struct iio_chan_spec const * chan,int * val,int * val2,long mask)749 int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
750 struct iio_chan_spec const *chan,
751 int *val, int *val2, long mask)
752 {
753 int ret, frequency;
754
755 switch (mask) {
756 case IIO_CHAN_INFO_SAMP_FREQ:
757 st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
758 st->param.sensor_odr.data =
759 EC_MOTION_SENSE_NO_VALUE;
760
761 ret = cros_ec_motion_send_host_cmd(st, 0);
762 if (ret)
763 break;
764
765 frequency = st->resp->sensor_odr.ret;
766 *val = frequency / 1000;
767 *val2 = (frequency % 1000) * 1000;
768 ret = IIO_VAL_INT_PLUS_MICRO;
769 break;
770 default:
771 ret = -EINVAL;
772 break;
773 }
774
775 return ret;
776 }
777 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);
778
779 /**
780 * cros_ec_sensors_core_read_avail() - get available values
781 * @indio_dev: pointer to state information for device
782 * @chan: channel specification structure table
783 * @vals: list of available values
784 * @type: type of data returned
785 * @length: number of data returned in the array
786 * @mask: specifies which values to be requested
787 *
788 * Return: an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST
789 */
cros_ec_sensors_core_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)790 int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
791 struct iio_chan_spec const *chan,
792 const int **vals,
793 int *type,
794 int *length,
795 long mask)
796 {
797 struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
798
799 switch (mask) {
800 case IIO_CHAN_INFO_SAMP_FREQ:
801 *length = ARRAY_SIZE(state->frequencies);
802 *vals = (const int *)&state->frequencies;
803 *type = IIO_VAL_INT_PLUS_MICRO;
804 return IIO_AVAIL_LIST;
805 }
806
807 return -EINVAL;
808 }
809 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read_avail);
810
811 /**
812 * cros_ec_sensors_core_write() - function to write a value to the sensor
813 * @st: pointer to state information for device
814 * @chan: channel specification structure table
815 * @val: first part of value to write
816 * @val2: second part of value to write
817 * @mask: specifies which values to write
818 *
819 * Return: the type of value returned by the device
820 */
cros_ec_sensors_core_write(struct cros_ec_sensors_core_state * st,struct iio_chan_spec const * chan,int val,int val2,long mask)821 int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
822 struct iio_chan_spec const *chan,
823 int val, int val2, long mask)
824 {
825 int ret, frequency;
826
827 switch (mask) {
828 case IIO_CHAN_INFO_SAMP_FREQ:
829 frequency = val * 1000 + val2 / 1000;
830 st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
831 st->param.sensor_odr.data = frequency;
832
833 /* Always roundup, so caller gets at least what it asks for. */
834 st->param.sensor_odr.roundup = 1;
835
836 ret = cros_ec_motion_send_host_cmd(st, 0);
837 if (ret)
838 break;
839
840 /* Flush the FIFO when a sensor is stopped.
841 * If the FIFO has just been emptied, pending samples will be
842 * stuck until new samples are available. It will not happen
843 * when all the sensors are stopped.
844 */
845 if (frequency == 0) {
846 st->param.cmd = MOTIONSENSE_CMD_FIFO_FLUSH;
847 ret = cros_ec_motion_send_host_cmd(st, 0);
848 }
849 break;
850 default:
851 ret = -EINVAL;
852 break;
853 }
854 return ret;
855 }
856 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);
857
cros_ec_sensors_resume(struct device * dev)858 static int __maybe_unused cros_ec_sensors_resume(struct device *dev)
859 {
860 struct iio_dev *indio_dev = dev_get_drvdata(dev);
861 struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
862 int ret = 0;
863
864 if (st->range_updated) {
865 mutex_lock(&st->cmd_lock);
866 st->param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
867 st->param.sensor_range.data = st->curr_range;
868 st->param.sensor_range.roundup = 1;
869 ret = cros_ec_motion_send_host_cmd(st, 0);
870 mutex_unlock(&st->cmd_lock);
871 }
872 return ret;
873 }
874
875 SIMPLE_DEV_PM_OPS(cros_ec_sensors_pm_ops, NULL, cros_ec_sensors_resume);
876 EXPORT_SYMBOL_GPL(cros_ec_sensors_pm_ops);
877
878 MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
879 MODULE_LICENSE("GPL v2");
880