x86/speculation/mds: Fix documentation typo
[linux/fpc-iii.git] / drivers / iio / pressure / zpa2326.c
blob91431454eb85de1c51cf88e477ab3d8378e4d007
1 /*
2 * Murata ZPA2326 pressure and temperature sensor IIO driver
4 * Copyright (c) 2016 Parrot S.A.
6 * Author: Gregor Boirie <gregor.boirie@parrot.com>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 as published by
10 * the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
18 /**
19 * DOC: ZPA2326 theory of operations
21 * This driver supports %INDIO_DIRECT_MODE and %INDIO_BUFFER_TRIGGERED IIO
22 * modes.
23 * A internal hardware trigger is also implemented to dispatch registered IIO
24 * trigger consumers upon "sample ready" interrupts.
26 * ZPA2326 hardware supports 2 sampling mode: one shot and continuous.
28 * A complete one shot sampling cycle gets device out of low power mode,
29 * performs pressure and temperature measurements, then automatically switches
30 * back to low power mode. It is meant for on demand sampling with optimal power
31 * saving at the cost of lower sampling rate and higher software overhead.
32 * This is a natural candidate for IIO read_raw hook implementation
33 * (%INDIO_DIRECT_MODE). It is also used for triggered buffering support to
34 * ensure explicit synchronization with external trigger events
35 * (%INDIO_BUFFER_TRIGGERED).
37 * The continuous mode works according to a periodic hardware measurement
38 * process continuously pushing samples into an internal hardware FIFO (for
39 * pressure samples only). Measurement cycle completion may be signaled by a
40 * "sample ready" interrupt.
41 * Typical software sequence of operations :
42 * - get device out of low power mode,
43 * - setup hardware sampling period,
44 * - at end of period, upon data ready interrupt: pop pressure samples out of
45 * hardware FIFO and fetch temperature sample
46 * - when no longer needed, stop sampling process by putting device into
47 * low power mode.
48 * This mode is used to implement %INDIO_BUFFER_TRIGGERED mode if device tree
49 * declares a valid interrupt line. In this case, the internal hardware trigger
50 * drives acquisition.
52 * Note that hardware sampling frequency is taken into account only when
53 * internal hardware trigger is attached as the highest sampling rate seems to
54 * be the most energy efficient.
56 * TODO:
57 * preset pressure threshold crossing / IIO events ;
58 * differential pressure sampling ;
59 * hardware samples averaging.
62 #include <linux/module.h>
63 #include <linux/kernel.h>
64 #include <linux/delay.h>
65 #include <linux/interrupt.h>
66 #include <linux/regulator/consumer.h>
67 #include <linux/pm_runtime.h>
68 #include <linux/regmap.h>
69 #include <linux/iio/iio.h>
70 #include <linux/iio/sysfs.h>
71 #include <linux/iio/buffer.h>
72 #include <linux/iio/trigger.h>
73 #include <linux/iio/trigger_consumer.h>
74 #include <linux/iio/triggered_buffer.h>
75 #include "zpa2326.h"
77 /* 200 ms should be enough for the longest conversion time in one-shot mode. */
78 #define ZPA2326_CONVERSION_JIFFIES (HZ / 5)
80 /* There should be a 1 ms delay (Tpup) after getting out of reset. */
81 #define ZPA2326_TPUP_USEC_MIN (1000)
82 #define ZPA2326_TPUP_USEC_MAX (2000)
84 /**
85 * struct zpa2326_frequency - Hardware sampling frequency descriptor
86 * @hz : Frequency in Hertz.
87 * @odr: Output Data Rate word as expected by %ZPA2326_CTRL_REG3_REG.
89 struct zpa2326_frequency {
90 int hz;
91 u16 odr;
95 * Keep these in strict ascending order: last array entry is expected to
96 * correspond to the highest sampling frequency.
98 static const struct zpa2326_frequency zpa2326_sampling_frequencies[] = {
99 { .hz = 1, .odr = 1 << ZPA2326_CTRL_REG3_ODR_SHIFT },
100 { .hz = 5, .odr = 5 << ZPA2326_CTRL_REG3_ODR_SHIFT },
101 { .hz = 11, .odr = 6 << ZPA2326_CTRL_REG3_ODR_SHIFT },
102 { .hz = 23, .odr = 7 << ZPA2326_CTRL_REG3_ODR_SHIFT },
105 /* Return the highest hardware sampling frequency available. */
106 static const struct zpa2326_frequency *zpa2326_highest_frequency(void)
108 return &zpa2326_sampling_frequencies[
109 ARRAY_SIZE(zpa2326_sampling_frequencies) - 1];
113 * struct zpa_private - Per-device internal private state
114 * @timestamp: Buffered samples ready datum.
115 * @regmap: Underlying I2C / SPI bus adapter used to abstract slave register
116 * accesses.
117 * @result: Allows sampling logic to get completion status of operations
118 * that interrupt handlers perform asynchronously.
119 * @data_ready: Interrupt handler uses this to wake user context up at sampling
120 * operation completion.
121 * @trigger: Optional hardware / interrupt driven trigger used to notify
122 * external devices a new sample is ready.
123 * @waken: Flag indicating whether or not device has just been powered on.
124 * @irq: Optional interrupt line: negative or zero if not declared into
125 * DT, in which case sampling logic keeps polling status register
126 * to detect completion.
127 * @frequency: Current hardware sampling frequency.
128 * @vref: Power / voltage reference.
129 * @vdd: Power supply.
131 struct zpa2326_private {
132 s64 timestamp;
133 struct regmap *regmap;
134 int result;
135 struct completion data_ready;
136 struct iio_trigger *trigger;
137 bool waken;
138 int irq;
139 const struct zpa2326_frequency *frequency;
140 struct regulator *vref;
141 struct regulator *vdd;
144 #define zpa2326_err(idev, fmt, ...) \
145 dev_err(idev->dev.parent, fmt "\n", ##__VA_ARGS__)
147 #define zpa2326_warn(idev, fmt, ...) \
148 dev_warn(idev->dev.parent, fmt "\n", ##__VA_ARGS__)
150 #define zpa2326_dbg(idev, fmt, ...) \
151 dev_dbg(idev->dev.parent, fmt "\n", ##__VA_ARGS__)
153 bool zpa2326_isreg_writeable(struct device *dev, unsigned int reg)
155 switch (reg) {
156 case ZPA2326_REF_P_XL_REG:
157 case ZPA2326_REF_P_L_REG:
158 case ZPA2326_REF_P_H_REG:
159 case ZPA2326_RES_CONF_REG:
160 case ZPA2326_CTRL_REG0_REG:
161 case ZPA2326_CTRL_REG1_REG:
162 case ZPA2326_CTRL_REG2_REG:
163 case ZPA2326_CTRL_REG3_REG:
164 case ZPA2326_THS_P_LOW_REG:
165 case ZPA2326_THS_P_HIGH_REG:
166 return true;
168 default:
169 return false;
172 EXPORT_SYMBOL_GPL(zpa2326_isreg_writeable);
174 bool zpa2326_isreg_readable(struct device *dev, unsigned int reg)
176 switch (reg) {
177 case ZPA2326_REF_P_XL_REG:
178 case ZPA2326_REF_P_L_REG:
179 case ZPA2326_REF_P_H_REG:
180 case ZPA2326_DEVICE_ID_REG:
181 case ZPA2326_RES_CONF_REG:
182 case ZPA2326_CTRL_REG0_REG:
183 case ZPA2326_CTRL_REG1_REG:
184 case ZPA2326_CTRL_REG2_REG:
185 case ZPA2326_CTRL_REG3_REG:
186 case ZPA2326_INT_SOURCE_REG:
187 case ZPA2326_THS_P_LOW_REG:
188 case ZPA2326_THS_P_HIGH_REG:
189 case ZPA2326_STATUS_REG:
190 case ZPA2326_PRESS_OUT_XL_REG:
191 case ZPA2326_PRESS_OUT_L_REG:
192 case ZPA2326_PRESS_OUT_H_REG:
193 case ZPA2326_TEMP_OUT_L_REG:
194 case ZPA2326_TEMP_OUT_H_REG:
195 return true;
197 default:
198 return false;
201 EXPORT_SYMBOL_GPL(zpa2326_isreg_readable);
203 bool zpa2326_isreg_precious(struct device *dev, unsigned int reg)
205 switch (reg) {
206 case ZPA2326_INT_SOURCE_REG:
207 case ZPA2326_PRESS_OUT_H_REG:
208 return true;
210 default:
211 return false;
214 EXPORT_SYMBOL_GPL(zpa2326_isreg_precious);
217 * zpa2326_enable_device() - Enable device, i.e. get out of low power mode.
218 * @indio_dev: The IIO device associated with the hardware to enable.
220 * Required to access complete register space and to perform any sampling
221 * or control operations.
223 * Return: Zero when successful, a negative error code otherwise.
225 static int zpa2326_enable_device(const struct iio_dev *indio_dev)
227 int err;
229 err = regmap_write(((struct zpa2326_private *)
230 iio_priv(indio_dev))->regmap,
231 ZPA2326_CTRL_REG0_REG, ZPA2326_CTRL_REG0_ENABLE);
232 if (err) {
233 zpa2326_err(indio_dev, "failed to enable device (%d)", err);
234 return err;
237 zpa2326_dbg(indio_dev, "enabled");
239 return 0;
243 * zpa2326_sleep() - Disable device, i.e. switch to low power mode.
244 * @indio_dev: The IIO device associated with the hardware to disable.
246 * Only %ZPA2326_DEVICE_ID_REG and %ZPA2326_CTRL_REG0_REG registers may be
247 * accessed once device is in the disabled state.
249 * Return: Zero when successful, a negative error code otherwise.
251 static int zpa2326_sleep(const struct iio_dev *indio_dev)
253 int err;
255 err = regmap_write(((struct zpa2326_private *)
256 iio_priv(indio_dev))->regmap,
257 ZPA2326_CTRL_REG0_REG, 0);
258 if (err) {
259 zpa2326_err(indio_dev, "failed to sleep (%d)", err);
260 return err;
263 zpa2326_dbg(indio_dev, "sleeping");
265 return 0;
269 * zpa2326_reset_device() - Reset device to default hardware state.
270 * @indio_dev: The IIO device associated with the hardware to reset.
272 * Disable sampling and empty hardware FIFO.
273 * Device must be enabled before reset, i.e. not in low power mode.
275 * Return: Zero when successful, a negative error code otherwise.
277 static int zpa2326_reset_device(const struct iio_dev *indio_dev)
279 int err;
281 err = regmap_write(((struct zpa2326_private *)
282 iio_priv(indio_dev))->regmap,
283 ZPA2326_CTRL_REG2_REG, ZPA2326_CTRL_REG2_SWRESET);
284 if (err) {
285 zpa2326_err(indio_dev, "failed to reset device (%d)", err);
286 return err;
289 usleep_range(ZPA2326_TPUP_USEC_MIN, ZPA2326_TPUP_USEC_MAX);
291 zpa2326_dbg(indio_dev, "reset");
293 return 0;
297 * zpa2326_start_oneshot() - Start a single sampling cycle, i.e. in one shot
298 * mode.
299 * @indio_dev: The IIO device associated with the sampling hardware.
301 * Device must have been previously enabled and configured for one shot mode.
302 * Device will be switched back to low power mode at end of cycle.
304 * Return: Zero when successful, a negative error code otherwise.
306 static int zpa2326_start_oneshot(const struct iio_dev *indio_dev)
308 int err;
310 err = regmap_write(((struct zpa2326_private *)
311 iio_priv(indio_dev))->regmap,
312 ZPA2326_CTRL_REG0_REG,
313 ZPA2326_CTRL_REG0_ENABLE |
314 ZPA2326_CTRL_REG0_ONE_SHOT);
315 if (err) {
316 zpa2326_err(indio_dev, "failed to start one shot cycle (%d)",
317 err);
318 return err;
321 zpa2326_dbg(indio_dev, "one shot cycle started");
323 return 0;
327 * zpa2326_power_on() - Power on device to allow subsequent configuration.
328 * @indio_dev: The IIO device associated with the sampling hardware.
329 * @private: Internal private state related to @indio_dev.
331 * Sampling will be disabled, preventing strange things from happening in our
332 * back. Hardware FIFO content will be cleared.
333 * When successful, device will be left in the enabled state to allow further
334 * configuration.
336 * Return: Zero when successful, a negative error code otherwise.
338 static int zpa2326_power_on(const struct iio_dev *indio_dev,
339 const struct zpa2326_private *private)
341 int err;
343 err = regulator_enable(private->vref);
344 if (err)
345 return err;
347 err = regulator_enable(private->vdd);
348 if (err)
349 goto vref;
351 zpa2326_dbg(indio_dev, "powered on");
353 err = zpa2326_enable_device(indio_dev);
354 if (err)
355 goto vdd;
357 err = zpa2326_reset_device(indio_dev);
358 if (err)
359 goto sleep;
361 return 0;
363 sleep:
364 zpa2326_sleep(indio_dev);
365 vdd:
366 regulator_disable(private->vdd);
367 vref:
368 regulator_disable(private->vref);
370 zpa2326_dbg(indio_dev, "powered off");
372 return err;
376 * zpa2326_power_off() - Power off device, i.e. disable attached power
377 * regulators.
378 * @indio_dev: The IIO device associated with the sampling hardware.
379 * @private: Internal private state related to @indio_dev.
381 * Return: Zero when successful, a negative error code otherwise.
383 static void zpa2326_power_off(const struct iio_dev *indio_dev,
384 const struct zpa2326_private *private)
386 regulator_disable(private->vdd);
387 regulator_disable(private->vref);
389 zpa2326_dbg(indio_dev, "powered off");
393 * zpa2326_config_oneshot() - Setup device for one shot / on demand mode.
394 * @indio_dev: The IIO device associated with the sampling hardware.
395 * @irq: Optional interrupt line the hardware uses to notify new data
396 * samples are ready. Negative or zero values indicate no interrupts
397 * are available, meaning polling is required.
399 * Output Data Rate is configured for the highest possible rate so that
400 * conversion time and power consumption are reduced to a minimum.
401 * Note that hardware internal averaging machinery (not implemented in this
402 * driver) is not applicable in this mode.
404 * Device must have been previously enabled before calling
405 * zpa2326_config_oneshot().
407 * Return: Zero when successful, a negative error code otherwise.
409 static int zpa2326_config_oneshot(const struct iio_dev *indio_dev,
410 int irq)
412 struct regmap *regs = ((struct zpa2326_private *)
413 iio_priv(indio_dev))->regmap;
414 const struct zpa2326_frequency *freq = zpa2326_highest_frequency();
415 int err;
417 /* Setup highest available Output Data Rate for one shot mode. */
418 err = regmap_write(regs, ZPA2326_CTRL_REG3_REG, freq->odr);
419 if (err)
420 return err;
422 if (irq > 0) {
423 /* Request interrupt when new sample is available. */
424 err = regmap_write(regs, ZPA2326_CTRL_REG1_REG,
425 (u8)~ZPA2326_CTRL_REG1_MASK_DATA_READY);
427 if (err) {
428 dev_err(indio_dev->dev.parent,
429 "failed to setup one shot mode (%d)", err);
430 return err;
434 zpa2326_dbg(indio_dev, "one shot mode setup @%dHz", freq->hz);
436 return 0;
440 * zpa2326_clear_fifo() - Clear remaining entries in hardware FIFO.
441 * @indio_dev: The IIO device associated with the sampling hardware.
442 * @min_count: Number of samples present within hardware FIFO.
444 * @min_count argument is a hint corresponding to the known minimum number of
445 * samples currently living in the FIFO. This allows to reduce the number of bus
446 * accesses by skipping status register read operation as long as we know for
447 * sure there are still entries left.
449 * Return: Zero when successful, a negative error code otherwise.
451 static int zpa2326_clear_fifo(const struct iio_dev *indio_dev,
452 unsigned int min_count)
454 struct regmap *regs = ((struct zpa2326_private *)
455 iio_priv(indio_dev))->regmap;
456 int err;
457 unsigned int val;
459 if (!min_count) {
461 * No hint: read status register to determine whether FIFO is
462 * empty or not.
464 err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
466 if (err < 0)
467 goto err;
469 if (val & ZPA2326_STATUS_FIFO_E)
470 /* Fifo is empty: nothing to trash. */
471 return 0;
474 /* Clear FIFO. */
475 do {
477 * A single fetch from pressure MSB register is enough to pop
478 * values out of FIFO.
480 err = regmap_read(regs, ZPA2326_PRESS_OUT_H_REG, &val);
481 if (err < 0)
482 goto err;
484 if (min_count) {
486 * We know for sure there are at least min_count entries
487 * left in FIFO. Skip status register read.
489 min_count--;
490 continue;
493 err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
494 if (err < 0)
495 goto err;
497 } while (!(val & ZPA2326_STATUS_FIFO_E));
499 zpa2326_dbg(indio_dev, "FIFO cleared");
501 return 0;
503 err:
504 zpa2326_err(indio_dev, "failed to clear FIFO (%d)", err);
506 return err;
510 * zpa2326_dequeue_pressure() - Retrieve the most recent pressure sample from
511 * hardware FIFO.
512 * @indio_dev: The IIO device associated with the sampling hardware.
513 * @pressure: Sampled pressure output.
515 * Note that ZPA2326 hardware FIFO stores pressure samples only.
517 * Return: Zero when successful, a negative error code otherwise.
519 static int zpa2326_dequeue_pressure(const struct iio_dev *indio_dev,
520 u32 *pressure)
522 struct regmap *regs = ((struct zpa2326_private *)
523 iio_priv(indio_dev))->regmap;
524 unsigned int val;
525 int err;
526 int cleared = -1;
528 err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
529 if (err < 0)
530 return err;
532 *pressure = 0;
534 if (val & ZPA2326_STATUS_P_OR) {
536 * Fifo overrun : first sample dequeued from FIFO is the
537 * newest.
539 zpa2326_warn(indio_dev, "FIFO overflow");
541 err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure,
543 if (err)
544 return err;
546 #define ZPA2326_FIFO_DEPTH (16U)
547 /* Hardware FIFO may hold no more than 16 pressure samples. */
548 return zpa2326_clear_fifo(indio_dev, ZPA2326_FIFO_DEPTH - 1);
552 * Fifo has not overflown : retrieve newest sample. We need to pop
553 * values out until FIFO is empty : last fetched pressure is the newest.
554 * In nominal cases, we should find a single queued sample only.
556 do {
557 err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure,
559 if (err)
560 return err;
562 err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
563 if (err < 0)
564 return err;
566 cleared++;
567 } while (!(val & ZPA2326_STATUS_FIFO_E));
569 if (cleared)
571 * Samples were pushed by hardware during previous rounds but we
572 * didn't consume them fast enough: inform user.
574 zpa2326_dbg(indio_dev, "cleared %d FIFO entries", cleared);
576 return 0;
580 * zpa2326_fill_sample_buffer() - Enqueue new channel samples to IIO buffer.
581 * @indio_dev: The IIO device associated with the sampling hardware.
582 * @private: Internal private state related to @indio_dev.
584 * Return: Zero when successful, a negative error code otherwise.
586 static int zpa2326_fill_sample_buffer(struct iio_dev *indio_dev,
587 const struct zpa2326_private *private)
589 struct {
590 u32 pressure;
591 u16 temperature;
592 u64 timestamp;
593 } sample;
594 int err;
596 if (test_bit(0, indio_dev->active_scan_mask)) {
597 /* Get current pressure from hardware FIFO. */
598 err = zpa2326_dequeue_pressure(indio_dev, &sample.pressure);
599 if (err) {
600 zpa2326_warn(indio_dev, "failed to fetch pressure (%d)",
601 err);
602 return err;
606 if (test_bit(1, indio_dev->active_scan_mask)) {
607 /* Get current temperature. */
608 err = regmap_bulk_read(private->regmap, ZPA2326_TEMP_OUT_L_REG,
609 &sample.temperature, 2);
610 if (err) {
611 zpa2326_warn(indio_dev,
612 "failed to fetch temperature (%d)", err);
613 return err;
618 * Now push samples using timestamp stored either :
619 * - by hardware interrupt handler if interrupt is available: see
620 * zpa2326_handle_irq(),
621 * - or oneshot completion polling machinery : see
622 * zpa2326_trigger_handler().
624 zpa2326_dbg(indio_dev, "filling raw samples buffer");
626 iio_push_to_buffers_with_timestamp(indio_dev, &sample,
627 private->timestamp);
629 return 0;
632 #ifdef CONFIG_PM
633 static int zpa2326_runtime_suspend(struct device *parent)
635 const struct iio_dev *indio_dev = dev_get_drvdata(parent);
637 if (pm_runtime_autosuspend_expiration(parent))
638 /* Userspace changed autosuspend delay. */
639 return -EAGAIN;
641 zpa2326_power_off(indio_dev, iio_priv(indio_dev));
643 return 0;
646 static int zpa2326_runtime_resume(struct device *parent)
648 const struct iio_dev *indio_dev = dev_get_drvdata(parent);
650 return zpa2326_power_on(indio_dev, iio_priv(indio_dev));
653 const struct dev_pm_ops zpa2326_pm_ops = {
654 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
655 pm_runtime_force_resume)
656 SET_RUNTIME_PM_OPS(zpa2326_runtime_suspend, zpa2326_runtime_resume,
657 NULL)
659 EXPORT_SYMBOL_GPL(zpa2326_pm_ops);
662 * zpa2326_resume() - Request the PM layer to power supply the device.
663 * @indio_dev: The IIO device associated with the sampling hardware.
665 * Return:
666 * < 0 - a negative error code meaning failure ;
667 * 0 - success, device has just been powered up ;
668 * 1 - success, device was already powered.
670 static int zpa2326_resume(const struct iio_dev *indio_dev)
672 int err;
674 err = pm_runtime_get_sync(indio_dev->dev.parent);
675 if (err < 0)
676 return err;
678 if (err > 0) {
680 * Device was already power supplied: get it out of low power
681 * mode and inform caller.
683 zpa2326_enable_device(indio_dev);
684 return 1;
687 /* Inform caller device has just been brought back to life. */
688 return 0;
692 * zpa2326_suspend() - Schedule a power down using autosuspend feature of PM
693 * layer.
694 * @indio_dev: The IIO device associated with the sampling hardware.
696 * Device is switched to low power mode at first to save power even when
697 * attached regulator is a "dummy" one.
699 static void zpa2326_suspend(struct iio_dev *indio_dev)
701 struct device *parent = indio_dev->dev.parent;
703 zpa2326_sleep(indio_dev);
705 pm_runtime_mark_last_busy(parent);
706 pm_runtime_put_autosuspend(parent);
709 static void zpa2326_init_runtime(struct device *parent)
711 pm_runtime_get_noresume(parent);
712 pm_runtime_set_active(parent);
713 pm_runtime_enable(parent);
714 pm_runtime_set_autosuspend_delay(parent, 1000);
715 pm_runtime_use_autosuspend(parent);
716 pm_runtime_mark_last_busy(parent);
717 pm_runtime_put_autosuspend(parent);
720 static void zpa2326_fini_runtime(struct device *parent)
722 pm_runtime_disable(parent);
723 pm_runtime_set_suspended(parent);
725 #else /* !CONFIG_PM */
726 static int zpa2326_resume(const struct iio_dev *indio_dev)
728 zpa2326_enable_device(indio_dev);
730 return 0;
733 static void zpa2326_suspend(struct iio_dev *indio_dev)
735 zpa2326_sleep(indio_dev);
738 #define zpa2326_init_runtime(_parent)
739 #define zpa2326_fini_runtime(_parent)
740 #endif /* !CONFIG_PM */
743 * zpa2326_handle_irq() - Process hardware interrupts.
744 * @irq: Interrupt line the hardware uses to notify new data has arrived.
745 * @data: The IIO device associated with the sampling hardware.
747 * Timestamp buffered samples as soon as possible then schedule threaded bottom
748 * half.
750 * Return: Always successful.
752 static irqreturn_t zpa2326_handle_irq(int irq, void *data)
754 struct iio_dev *indio_dev = data;
756 if (iio_buffer_enabled(indio_dev)) {
757 /* Timestamping needed for buffered sampling only. */
758 ((struct zpa2326_private *)
759 iio_priv(indio_dev))->timestamp = iio_get_time_ns(indio_dev);
762 return IRQ_WAKE_THREAD;
766 * zpa2326_handle_threaded_irq() - Interrupt bottom-half handler.
767 * @irq: Interrupt line the hardware uses to notify new data has arrived.
768 * @data: The IIO device associated with the sampling hardware.
770 * Mainly ensures interrupt is caused by a real "new sample available"
771 * condition. This relies upon the ability to perform blocking / sleeping bus
772 * accesses to slave's registers. This is why zpa2326_handle_threaded_irq() is
773 * called from within a thread, i.e. not called from hard interrupt context.
775 * When device is using its own internal hardware trigger in continuous sampling
776 * mode, data are available into hardware FIFO once interrupt has occurred. All
777 * we have to do is to dispatch the trigger, which in turn will fetch data and
778 * fill IIO buffer.
780 * When not using its own internal hardware trigger, the device has been
781 * configured in one-shot mode either by an external trigger or the IIO read_raw
782 * hook. This means one of the latter is currently waiting for sampling
783 * completion, in which case we must simply wake it up.
785 * See zpa2326_trigger_handler().
787 * Return:
788 * %IRQ_NONE - no consistent interrupt happened ;
789 * %IRQ_HANDLED - there was new samples available.
791 static irqreturn_t zpa2326_handle_threaded_irq(int irq, void *data)
793 struct iio_dev *indio_dev = data;
794 struct zpa2326_private *priv = iio_priv(indio_dev);
795 unsigned int val;
796 bool cont;
797 irqreturn_t ret = IRQ_NONE;
800 * Are we using our own internal trigger in triggered buffer mode, i.e.,
801 * currently working in continuous sampling mode ?
803 cont = (iio_buffer_enabled(indio_dev) &&
804 iio_trigger_using_own(indio_dev));
807 * Device works according to a level interrupt scheme: reading interrupt
808 * status de-asserts interrupt line.
810 priv->result = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);
811 if (priv->result < 0) {
812 if (cont)
813 return IRQ_NONE;
815 goto complete;
818 /* Data ready is the only interrupt source we requested. */
819 if (!(val & ZPA2326_INT_SOURCE_DATA_READY)) {
821 * Interrupt happened but no new sample available: likely caused
822 * by spurious interrupts, in which case, returning IRQ_NONE
823 * allows to benefit from the generic spurious interrupts
824 * handling.
826 zpa2326_warn(indio_dev, "unexpected interrupt status %02x",
827 val);
829 if (cont)
830 return IRQ_NONE;
832 priv->result = -ENODATA;
833 goto complete;
836 /* New sample available: dispatch internal trigger consumers. */
837 iio_trigger_poll_chained(priv->trigger);
839 if (cont)
841 * Internal hardware trigger has been scheduled above : it will
842 * fetch data on its own.
844 return IRQ_HANDLED;
846 ret = IRQ_HANDLED;
848 complete:
850 * Wake up direct or externaly triggered buffer mode waiters: see
851 * zpa2326_sample_oneshot() and zpa2326_trigger_handler().
853 complete(&priv->data_ready);
855 return ret;
859 * zpa2326_wait_oneshot_completion() - Wait for oneshot data ready interrupt.
860 * @indio_dev: The IIO device associated with the sampling hardware.
861 * @private: Internal private state related to @indio_dev.
863 * Return: Zero when successful, a negative error code otherwise.
865 static int zpa2326_wait_oneshot_completion(const struct iio_dev *indio_dev,
866 struct zpa2326_private *private)
868 unsigned int val;
869 long timeout;
871 zpa2326_dbg(indio_dev, "waiting for one shot completion interrupt");
873 timeout = wait_for_completion_interruptible_timeout(
874 &private->data_ready, ZPA2326_CONVERSION_JIFFIES);
875 if (timeout > 0)
877 * Interrupt handler completed before timeout: return operation
878 * status.
880 return private->result;
882 /* Clear all interrupts just to be sure. */
883 regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val);
885 if (!timeout) {
886 /* Timed out. */
887 zpa2326_warn(indio_dev, "no one shot interrupt occurred (%ld)",
888 timeout);
889 return -ETIME;
892 zpa2326_warn(indio_dev, "wait for one shot interrupt cancelled");
893 return -ERESTARTSYS;
896 static int zpa2326_init_managed_irq(struct device *parent,
897 struct iio_dev *indio_dev,
898 struct zpa2326_private *private,
899 int irq)
901 int err;
903 private->irq = irq;
905 if (irq <= 0) {
907 * Platform declared no interrupt line: device will be polled
908 * for data availability.
910 dev_info(parent, "no interrupt found, running in polling mode");
911 return 0;
914 init_completion(&private->data_ready);
916 /* Request handler to be scheduled into threaded interrupt context. */
917 err = devm_request_threaded_irq(parent, irq, zpa2326_handle_irq,
918 zpa2326_handle_threaded_irq,
919 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
920 dev_name(parent), indio_dev);
921 if (err) {
922 dev_err(parent, "failed to request interrupt %d (%d)", irq,
923 err);
924 return err;
927 dev_info(parent, "using interrupt %d", irq);
929 return 0;
933 * zpa2326_poll_oneshot_completion() - Actively poll for one shot data ready.
934 * @indio_dev: The IIO device associated with the sampling hardware.
936 * Loop over registers content to detect end of sampling cycle. Used when DT
937 * declared no valid interrupt lines.
939 * Return: Zero when successful, a negative error code otherwise.
941 static int zpa2326_poll_oneshot_completion(const struct iio_dev *indio_dev)
943 unsigned long tmout = jiffies + ZPA2326_CONVERSION_JIFFIES;
944 struct regmap *regs = ((struct zpa2326_private *)
945 iio_priv(indio_dev))->regmap;
946 unsigned int val;
947 int err;
949 zpa2326_dbg(indio_dev, "polling for one shot completion");
952 * At least, 100 ms is needed for the device to complete its one-shot
953 * cycle.
955 if (msleep_interruptible(100))
956 return -ERESTARTSYS;
958 /* Poll for conversion completion in hardware. */
959 while (true) {
960 err = regmap_read(regs, ZPA2326_CTRL_REG0_REG, &val);
961 if (err < 0)
962 goto err;
964 if (!(val & ZPA2326_CTRL_REG0_ONE_SHOT))
965 /* One-shot bit self clears at conversion end. */
966 break;
968 if (time_after(jiffies, tmout)) {
969 /* Prevent from waiting forever : let's time out. */
970 err = -ETIME;
971 goto err;
974 usleep_range(10000, 20000);
978 * In oneshot mode, pressure sample availability guarantees that
979 * temperature conversion has also completed : just check pressure
980 * status bit to keep things simple.
982 err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
983 if (err < 0)
984 goto err;
986 if (!(val & ZPA2326_STATUS_P_DA)) {
987 /* No sample available. */
988 err = -ENODATA;
989 goto err;
992 return 0;
994 err:
995 zpa2326_warn(indio_dev, "failed to poll one shot completion (%d)", err);
997 return err;
1001 * zpa2326_fetch_raw_sample() - Retrieve a raw sample and convert it to CPU
1002 * endianness.
1003 * @indio_dev: The IIO device associated with the sampling hardware.
1004 * @type: Type of measurement / channel to fetch from.
1005 * @value: Sample output.
1007 * Return: Zero when successful, a negative error code otherwise.
1009 static int zpa2326_fetch_raw_sample(const struct iio_dev *indio_dev,
1010 enum iio_chan_type type,
1011 int *value)
1013 struct regmap *regs = ((struct zpa2326_private *)
1014 iio_priv(indio_dev))->regmap;
1015 int err;
1017 switch (type) {
1018 case IIO_PRESSURE:
1019 zpa2326_dbg(indio_dev, "fetching raw pressure sample");
1021 err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, value,
1023 if (err) {
1024 zpa2326_warn(indio_dev, "failed to fetch pressure (%d)",
1025 err);
1026 return err;
1029 /* Pressure is a 24 bits wide little-endian unsigned int. */
1030 *value = (((u8 *)value)[2] << 16) | (((u8 *)value)[1] << 8) |
1031 ((u8 *)value)[0];
1033 return IIO_VAL_INT;
1035 case IIO_TEMP:
1036 zpa2326_dbg(indio_dev, "fetching raw temperature sample");
1038 err = regmap_bulk_read(regs, ZPA2326_TEMP_OUT_L_REG, value, 2);
1039 if (err) {
1040 zpa2326_warn(indio_dev,
1041 "failed to fetch temperature (%d)", err);
1042 return err;
1045 /* Temperature is a 16 bits wide little-endian signed int. */
1046 *value = (int)le16_to_cpup((__le16 *)value);
1048 return IIO_VAL_INT;
1050 default:
1051 return -EINVAL;
1056 * zpa2326_sample_oneshot() - Perform a complete one shot sampling cycle.
1057 * @indio_dev: The IIO device associated with the sampling hardware.
1058 * @type: Type of measurement / channel to fetch from.
1059 * @value: Sample output.
1061 * Return: Zero when successful, a negative error code otherwise.
1063 static int zpa2326_sample_oneshot(struct iio_dev *indio_dev,
1064 enum iio_chan_type type,
1065 int *value)
1067 int ret;
1068 struct zpa2326_private *priv;
1070 ret = iio_device_claim_direct_mode(indio_dev);
1071 if (ret)
1072 return ret;
1074 ret = zpa2326_resume(indio_dev);
1075 if (ret < 0)
1076 goto release;
1078 priv = iio_priv(indio_dev);
1080 if (ret > 0) {
1082 * We were already power supplied. Just clear hardware FIFO to
1083 * get rid of samples acquired during previous rounds (if any).
1084 * Sampling operation always generates both temperature and
1085 * pressure samples. The latter are always enqueued into
1086 * hardware FIFO. This may lead to situations were pressure
1087 * samples still sit into FIFO when previous cycle(s) fetched
1088 * temperature data only.
1089 * Hence, we need to clear hardware FIFO content to prevent from
1090 * getting outdated values at the end of current cycle.
1092 if (type == IIO_PRESSURE) {
1093 ret = zpa2326_clear_fifo(indio_dev, 0);
1094 if (ret)
1095 goto suspend;
1097 } else {
1099 * We have just been power supplied, i.e. device is in default
1100 * "out of reset" state, meaning we need to reconfigure it
1101 * entirely.
1103 ret = zpa2326_config_oneshot(indio_dev, priv->irq);
1104 if (ret)
1105 goto suspend;
1108 /* Start a sampling cycle in oneshot mode. */
1109 ret = zpa2326_start_oneshot(indio_dev);
1110 if (ret)
1111 goto suspend;
1113 /* Wait for sampling cycle to complete. */
1114 if (priv->irq > 0)
1115 ret = zpa2326_wait_oneshot_completion(indio_dev, priv);
1116 else
1117 ret = zpa2326_poll_oneshot_completion(indio_dev);
1119 if (ret)
1120 goto suspend;
1122 /* Retrieve raw sample value and convert it to CPU endianness. */
1123 ret = zpa2326_fetch_raw_sample(indio_dev, type, value);
1125 suspend:
1126 zpa2326_suspend(indio_dev);
1127 release:
1128 iio_device_release_direct_mode(indio_dev);
1130 return ret;
1134 * zpa2326_trigger_handler() - Perform an IIO buffered sampling round in one
1135 * shot mode.
1136 * @irq: The software interrupt assigned to @data
1137 * @data: The IIO poll function dispatched by external trigger our device is
1138 * attached to.
1140 * Bottom-half handler called by the IIO trigger to which our device is
1141 * currently attached. Allows us to synchronize this device buffered sampling
1142 * either with external events (such as timer expiration, external device sample
1143 * ready, etc...) or with its own interrupt (internal hardware trigger).
1145 * When using an external trigger, basically run the same sequence of operations
1146 * as for zpa2326_sample_oneshot() with the following hereafter. Hardware FIFO
1147 * is not cleared since already done at buffering enable time and samples
1148 * dequeueing always retrieves the most recent value.
1150 * Otherwise, when internal hardware trigger has dispatched us, just fetch data
1151 * from hardware FIFO.
1153 * Fetched data will pushed unprocessed to IIO buffer since samples conversion
1154 * is delegated to userspace in buffered mode (endianness, etc...).
1156 * Return:
1157 * %IRQ_NONE - no consistent interrupt happened ;
1158 * %IRQ_HANDLED - there was new samples available.
1160 static irqreturn_t zpa2326_trigger_handler(int irq, void *data)
1162 struct iio_dev *indio_dev = ((struct iio_poll_func *)
1163 data)->indio_dev;
1164 struct zpa2326_private *priv = iio_priv(indio_dev);
1165 bool cont;
1168 * We have been dispatched, meaning we are in triggered buffer mode.
1169 * Using our own internal trigger implies we are currently in continuous
1170 * hardware sampling mode.
1172 cont = iio_trigger_using_own(indio_dev);
1174 if (!cont) {
1175 /* On demand sampling : start a one shot cycle. */
1176 if (zpa2326_start_oneshot(indio_dev))
1177 goto out;
1179 /* Wait for sampling cycle to complete. */
1180 if (priv->irq <= 0) {
1181 /* No interrupt available: poll for completion. */
1182 if (zpa2326_poll_oneshot_completion(indio_dev))
1183 goto out;
1185 /* Only timestamp sample once it is ready. */
1186 priv->timestamp = iio_get_time_ns(indio_dev);
1187 } else {
1188 /* Interrupt handlers will timestamp for us. */
1189 if (zpa2326_wait_oneshot_completion(indio_dev, priv))
1190 goto out;
1194 /* Enqueue to IIO buffer / userspace. */
1195 zpa2326_fill_sample_buffer(indio_dev, priv);
1197 out:
1198 if (!cont)
1199 /* Don't switch to low power if sampling continuously. */
1200 zpa2326_sleep(indio_dev);
1202 /* Inform attached trigger we are done. */
1203 iio_trigger_notify_done(indio_dev->trig);
1205 return IRQ_HANDLED;
1209 * zpa2326_preenable_buffer() - Prepare device for configuring triggered
1210 * sampling
1211 * modes.
1212 * @indio_dev: The IIO device associated with the sampling hardware.
1214 * Basically power up device.
1215 * Called with IIO device's lock held.
1217 * Return: Zero when successful, a negative error code otherwise.
1219 static int zpa2326_preenable_buffer(struct iio_dev *indio_dev)
1221 int ret = zpa2326_resume(indio_dev);
1223 if (ret < 0)
1224 return ret;
1226 /* Tell zpa2326_postenable_buffer() if we have just been powered on. */
1227 ((struct zpa2326_private *)
1228 iio_priv(indio_dev))->waken = iio_priv(indio_dev);
1230 return 0;
1234 * zpa2326_postenable_buffer() - Configure device for triggered sampling.
1235 * @indio_dev: The IIO device associated with the sampling hardware.
1237 * Basically setup one-shot mode if plugging external trigger.
1238 * Otherwise, let internal trigger configure continuous sampling :
1239 * see zpa2326_set_trigger_state().
1241 * If an error is returned, IIO layer will call our postdisable hook for us,
1242 * i.e. no need to explicitly power device off here.
1243 * Called with IIO device's lock held.
1245 * Called with IIO device's lock held.
1247 * Return: Zero when successful, a negative error code otherwise.
1249 static int zpa2326_postenable_buffer(struct iio_dev *indio_dev)
1251 const struct zpa2326_private *priv = iio_priv(indio_dev);
1252 int err;
1254 if (!priv->waken) {
1256 * We were already power supplied. Just clear hardware FIFO to
1257 * get rid of samples acquired during previous rounds (if any).
1259 err = zpa2326_clear_fifo(indio_dev, 0);
1260 if (err)
1261 goto err;
1264 if (!iio_trigger_using_own(indio_dev) && priv->waken) {
1266 * We are using an external trigger and we have just been
1267 * powered up: reconfigure one-shot mode.
1269 err = zpa2326_config_oneshot(indio_dev, priv->irq);
1270 if (err)
1271 goto err;
1274 /* Plug our own trigger event handler. */
1275 err = iio_triggered_buffer_postenable(indio_dev);
1276 if (err)
1277 goto err;
1279 return 0;
1281 err:
1282 zpa2326_err(indio_dev, "failed to enable buffering (%d)", err);
1284 return err;
1287 static int zpa2326_postdisable_buffer(struct iio_dev *indio_dev)
1289 zpa2326_suspend(indio_dev);
1291 return 0;
1294 static const struct iio_buffer_setup_ops zpa2326_buffer_setup_ops = {
1295 .preenable = zpa2326_preenable_buffer,
1296 .postenable = zpa2326_postenable_buffer,
1297 .predisable = iio_triggered_buffer_predisable,
1298 .postdisable = zpa2326_postdisable_buffer
1302 * zpa2326_set_trigger_state() - Start / stop continuous sampling.
1303 * @trig: The trigger being attached to IIO device associated with the sampling
1304 * hardware.
1305 * @state: Tell whether to start (true) or stop (false)
1307 * Basically enable / disable hardware continuous sampling mode.
1309 * Called with IIO device's lock held at postenable() or predisable() time.
1311 * Return: Zero when successful, a negative error code otherwise.
1313 static int zpa2326_set_trigger_state(struct iio_trigger *trig, bool state)
1315 const struct iio_dev *indio_dev = dev_get_drvdata(
1316 trig->dev.parent);
1317 const struct zpa2326_private *priv = iio_priv(indio_dev);
1318 int err;
1320 if (!state) {
1322 * Switch trigger off : in case of failure, interrupt is left
1323 * disabled in order to prevent handler from accessing released
1324 * resources.
1326 unsigned int val;
1329 * As device is working in continuous mode, handlers may be
1330 * accessing resources we are currently freeing...
1331 * Prevent this by disabling interrupt handlers and ensure
1332 * the device will generate no more interrupts unless explicitly
1333 * required to, i.e. by restoring back to default one shot mode.
1335 disable_irq(priv->irq);
1338 * Disable continuous sampling mode to restore settings for
1339 * one shot / direct sampling operations.
1341 err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,
1342 zpa2326_highest_frequency()->odr);
1343 if (err)
1344 return err;
1347 * Now that device won't generate interrupts on its own,
1348 * acknowledge any currently active interrupts (may happen on
1349 * rare occasions while stopping continuous mode).
1351 err = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);
1352 if (err < 0)
1353 return err;
1356 * Re-enable interrupts only if we can guarantee the device will
1357 * generate no more interrupts to prevent handlers from
1358 * accessing released resources.
1360 enable_irq(priv->irq);
1362 zpa2326_dbg(indio_dev, "continuous mode stopped");
1363 } else {
1365 * Switch trigger on : start continuous sampling at required
1366 * frequency.
1369 if (priv->waken) {
1370 /* Enable interrupt if getting out of reset. */
1371 err = regmap_write(priv->regmap, ZPA2326_CTRL_REG1_REG,
1372 (u8)
1373 ~ZPA2326_CTRL_REG1_MASK_DATA_READY);
1374 if (err)
1375 return err;
1378 /* Enable continuous sampling at specified frequency. */
1379 err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,
1380 ZPA2326_CTRL_REG3_ENABLE_MEAS |
1381 priv->frequency->odr);
1382 if (err)
1383 return err;
1385 zpa2326_dbg(indio_dev, "continuous mode setup @%dHz",
1386 priv->frequency->hz);
1389 return 0;
1392 static const struct iio_trigger_ops zpa2326_trigger_ops = {
1393 .owner = THIS_MODULE,
1394 .set_trigger_state = zpa2326_set_trigger_state,
1398 * zpa2326_init_trigger() - Create an interrupt driven / hardware trigger
1399 * allowing to notify external devices a new sample is
1400 * ready.
1401 * @parent: Hardware sampling device @indio_dev is a child of.
1402 * @indio_dev: The IIO device associated with the sampling hardware.
1403 * @private: Internal private state related to @indio_dev.
1404 * @irq: Optional interrupt line the hardware uses to notify new data
1405 * samples are ready. Negative or zero values indicate no interrupts
1406 * are available, meaning polling is required.
1408 * Only relevant when DT declares a valid interrupt line.
1410 * Return: Zero when successful, a negative error code otherwise.
1412 static int zpa2326_init_managed_trigger(struct device *parent,
1413 struct iio_dev *indio_dev,
1414 struct zpa2326_private *private,
1415 int irq)
1417 struct iio_trigger *trigger;
1418 int ret;
1420 if (irq <= 0)
1421 return 0;
1423 trigger = devm_iio_trigger_alloc(parent, "%s-dev%d",
1424 indio_dev->name, indio_dev->id);
1425 if (!trigger)
1426 return -ENOMEM;
1428 /* Basic setup. */
1429 trigger->dev.parent = parent;
1430 trigger->ops = &zpa2326_trigger_ops;
1432 private->trigger = trigger;
1434 /* Register to triggers space. */
1435 ret = devm_iio_trigger_register(parent, trigger);
1436 if (ret)
1437 dev_err(parent, "failed to register hardware trigger (%d)",
1438 ret);
1440 return ret;
1443 static int zpa2326_get_frequency(const struct iio_dev *indio_dev)
1445 return ((struct zpa2326_private *)iio_priv(indio_dev))->frequency->hz;
1448 static int zpa2326_set_frequency(struct iio_dev *indio_dev, int hz)
1450 struct zpa2326_private *priv = iio_priv(indio_dev);
1451 int freq;
1452 int err;
1454 /* Check if requested frequency is supported. */
1455 for (freq = 0; freq < ARRAY_SIZE(zpa2326_sampling_frequencies); freq++)
1456 if (zpa2326_sampling_frequencies[freq].hz == hz)
1457 break;
1458 if (freq == ARRAY_SIZE(zpa2326_sampling_frequencies))
1459 return -EINVAL;
1461 /* Don't allow changing frequency if buffered sampling is ongoing. */
1462 err = iio_device_claim_direct_mode(indio_dev);
1463 if (err)
1464 return err;
1466 priv->frequency = &zpa2326_sampling_frequencies[freq];
1468 iio_device_release_direct_mode(indio_dev);
1470 return 0;
1473 /* Expose supported hardware sampling frequencies (Hz) through sysfs. */
1474 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1 5 11 23");
1476 static struct attribute *zpa2326_attributes[] = {
1477 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
1478 NULL
1481 static const struct attribute_group zpa2326_attribute_group = {
1482 .attrs = zpa2326_attributes,
1485 static int zpa2326_read_raw(struct iio_dev *indio_dev,
1486 struct iio_chan_spec const *chan,
1487 int *val,
1488 int *val2,
1489 long mask)
1491 switch (mask) {
1492 case IIO_CHAN_INFO_RAW:
1493 return zpa2326_sample_oneshot(indio_dev, chan->type, val);
1495 case IIO_CHAN_INFO_SCALE:
1496 switch (chan->type) {
1497 case IIO_PRESSURE:
1499 * Pressure resolution is 1/64 Pascal. Scale to kPascal
1500 * as required by IIO ABI.
1502 *val = 1;
1503 *val2 = 64000;
1504 return IIO_VAL_FRACTIONAL;
1506 case IIO_TEMP:
1508 * Temperature follows the equation:
1509 * Temp[degC] = Tempcode * 0.00649 - 176.83
1510 * where:
1511 * Tempcode is composed the raw sampled 16 bits.
1513 * Hence, to produce a temperature in milli-degrees
1514 * Celsius according to IIO ABI, we need to apply the
1515 * following equation to raw samples:
1516 * Temp[milli degC] = (Tempcode + Offset) * Scale
1517 * where:
1518 * Offset = -176.83 / 0.00649
1519 * Scale = 0.00649 * 1000
1521 *val = 6;
1522 *val2 = 490000;
1523 return IIO_VAL_INT_PLUS_MICRO;
1525 default:
1526 return -EINVAL;
1529 case IIO_CHAN_INFO_OFFSET:
1530 switch (chan->type) {
1531 case IIO_TEMP:
1532 *val = -17683000;
1533 *val2 = 649;
1534 return IIO_VAL_FRACTIONAL;
1536 default:
1537 return -EINVAL;
1540 case IIO_CHAN_INFO_SAMP_FREQ:
1541 *val = zpa2326_get_frequency(indio_dev);
1542 return IIO_VAL_INT;
1544 default:
1545 return -EINVAL;
1549 static int zpa2326_write_raw(struct iio_dev *indio_dev,
1550 const struct iio_chan_spec *chan,
1551 int val,
1552 int val2,
1553 long mask)
1555 if ((mask != IIO_CHAN_INFO_SAMP_FREQ) || val2)
1556 return -EINVAL;
1558 return zpa2326_set_frequency(indio_dev, val);
1561 static const struct iio_chan_spec zpa2326_channels[] = {
1562 [0] = {
1563 .type = IIO_PRESSURE,
1564 .scan_index = 0,
1565 .scan_type = {
1566 .sign = 'u',
1567 .realbits = 24,
1568 .storagebits = 32,
1569 .endianness = IIO_LE,
1571 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
1572 BIT(IIO_CHAN_INFO_SCALE),
1573 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
1575 [1] = {
1576 .type = IIO_TEMP,
1577 .scan_index = 1,
1578 .scan_type = {
1579 .sign = 's',
1580 .realbits = 16,
1581 .storagebits = 16,
1582 .endianness = IIO_LE,
1584 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
1585 BIT(IIO_CHAN_INFO_SCALE) |
1586 BIT(IIO_CHAN_INFO_OFFSET),
1587 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
1589 [2] = IIO_CHAN_SOFT_TIMESTAMP(2),
1592 static const struct iio_info zpa2326_info = {
1593 .driver_module = THIS_MODULE,
1594 .attrs = &zpa2326_attribute_group,
1595 .read_raw = zpa2326_read_raw,
1596 .write_raw = zpa2326_write_raw,
1599 static struct iio_dev *zpa2326_create_managed_iiodev(struct device *device,
1600 const char *name,
1601 struct regmap *regmap)
1603 struct iio_dev *indio_dev;
1605 /* Allocate space to hold IIO device internal state. */
1606 indio_dev = devm_iio_device_alloc(device,
1607 sizeof(struct zpa2326_private));
1608 if (!indio_dev)
1609 return NULL;
1611 /* Setup for userspace synchronous on demand sampling. */
1612 indio_dev->modes = INDIO_DIRECT_MODE;
1613 indio_dev->dev.parent = device;
1614 indio_dev->channels = zpa2326_channels;
1615 indio_dev->num_channels = ARRAY_SIZE(zpa2326_channels);
1616 indio_dev->name = name;
1617 indio_dev->info = &zpa2326_info;
1619 return indio_dev;
1622 int zpa2326_probe(struct device *parent,
1623 const char *name,
1624 int irq,
1625 unsigned int hwid,
1626 struct regmap *regmap)
1628 struct iio_dev *indio_dev;
1629 struct zpa2326_private *priv;
1630 int err;
1631 unsigned int id;
1633 indio_dev = zpa2326_create_managed_iiodev(parent, name, regmap);
1634 if (!indio_dev)
1635 return -ENOMEM;
1637 priv = iio_priv(indio_dev);
1639 priv->vref = devm_regulator_get(parent, "vref");
1640 if (IS_ERR(priv->vref))
1641 return PTR_ERR(priv->vref);
1643 priv->vdd = devm_regulator_get(parent, "vdd");
1644 if (IS_ERR(priv->vdd))
1645 return PTR_ERR(priv->vdd);
1647 /* Set default hardware sampling frequency to highest rate supported. */
1648 priv->frequency = zpa2326_highest_frequency();
1651 * Plug device's underlying bus abstraction : this MUST be set before
1652 * registering interrupt handlers since an interrupt might happen if
1653 * power up sequence is not properly applied.
1655 priv->regmap = regmap;
1657 err = devm_iio_triggered_buffer_setup(parent, indio_dev, NULL,
1658 zpa2326_trigger_handler,
1659 &zpa2326_buffer_setup_ops);
1660 if (err)
1661 return err;
1663 err = zpa2326_init_managed_trigger(parent, indio_dev, priv, irq);
1664 if (err)
1665 return err;
1667 err = zpa2326_init_managed_irq(parent, indio_dev, priv, irq);
1668 if (err)
1669 return err;
1671 /* Power up to check device ID and perform initial hardware setup. */
1672 err = zpa2326_power_on(indio_dev, priv);
1673 if (err)
1674 return err;
1676 /* Read id register to check we are talking to the right slave. */
1677 err = regmap_read(regmap, ZPA2326_DEVICE_ID_REG, &id);
1678 if (err)
1679 goto sleep;
1681 if (id != hwid) {
1682 dev_err(parent, "found device with unexpected id %02x", id);
1683 err = -ENODEV;
1684 goto sleep;
1687 err = zpa2326_config_oneshot(indio_dev, irq);
1688 if (err)
1689 goto sleep;
1691 /* Setup done : go sleeping. Device will be awaken upon user request. */
1692 err = zpa2326_sleep(indio_dev);
1693 if (err)
1694 goto poweroff;
1696 dev_set_drvdata(parent, indio_dev);
1698 zpa2326_init_runtime(parent);
1700 err = iio_device_register(indio_dev);
1701 if (err) {
1702 zpa2326_fini_runtime(parent);
1703 goto poweroff;
1706 return 0;
1708 sleep:
1709 /* Put to sleep just in case power regulators are "dummy" ones. */
1710 zpa2326_sleep(indio_dev);
1711 poweroff:
1712 zpa2326_power_off(indio_dev, priv);
1714 return err;
1716 EXPORT_SYMBOL_GPL(zpa2326_probe);
1718 void zpa2326_remove(const struct device *parent)
1720 struct iio_dev *indio_dev = dev_get_drvdata(parent);
1722 iio_device_unregister(indio_dev);
1723 zpa2326_fini_runtime(indio_dev->dev.parent);
1724 zpa2326_sleep(indio_dev);
1725 zpa2326_power_off(indio_dev, iio_priv(indio_dev));
1727 EXPORT_SYMBOL_GPL(zpa2326_remove);
1729 MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
1730 MODULE_DESCRIPTION("Core driver for Murata ZPA2326 pressure sensor");
1731 MODULE_LICENSE("GPL v2");