1 // SPDX-License-Identifier: GPL-2.0-only
18  * ZPA2326 hardware supports 2 sampling mode: one shot and continuous.
20  * A complete one shot sampling cycle gets device out of low power mode,
34  * - get device out of low power mode,
35  * - setup hardware sampling period,
36  * - at end of period, upon data ready interrupt: pop pressure samples out of
38  * - when no longer needed, stop sampling process by putting device into
70 /* 200 ms should be enough for the longest conversion time in one-shot mode. */
78  * struct zpa2326_frequency - Hardware sampling frequency descriptor
102 		ARRAY_SIZE(zpa2326_sampling_frequencies) - 1];  in zpa2326_highest_frequency()
106  * struct zpa2326_private - Per-device internal private state
138 	dev_err(idev->dev.parent, fmt "\n", ##__VA_ARGS__)
141 	dev_warn(idev->dev.parent, fmt "\n", ##__VA_ARGS__)
144 	dev_dbg(idev->dev.parent, fmt "\n", ##__VA_ARGS__)
210  * zpa2326_enable_device() - Enable device, i.e. get out of low power mode.
223 			    iio_priv(indio_dev))->regmap,  in zpa2326_enable_device()
236  * zpa2326_sleep() - Disable device, i.e. switch to low power mode.
249 			    iio_priv(indio_dev))->regmap,  in zpa2326_sleep()
262  * zpa2326_reset_device() - Reset device to default hardware state.
275 			    iio_priv(indio_dev))->regmap,  in zpa2326_reset_device()
290  * zpa2326_start_oneshot() - Start a single sampling cycle, i.e. in one shot
294  * Device must have been previously enabled and configured for one shot mode.
304 			    iio_priv(indio_dev))->regmap,  in zpa2326_start_oneshot()
309 		zpa2326_err(indio_dev, "failed to start one shot cycle (%d)",  in zpa2326_start_oneshot()
314 	zpa2326_dbg(indio_dev, "one shot cycle started");  in zpa2326_start_oneshot()
320  * zpa2326_power_on() - Power on device to allow subsequent configuration.
336 	err = regulator_enable(private->vref);  in zpa2326_power_on()
340 	err = regulator_enable(private->vdd);  in zpa2326_power_on()
359 	regulator_disable(private->vdd);  in zpa2326_power_on()
361 	regulator_disable(private->vref);  in zpa2326_power_on()
369  * zpa2326_power_off() - Power off device, i.e. disable attached power
379 	regulator_disable(private->vdd);  in zpa2326_power_off()
380 	regulator_disable(private->vref);  in zpa2326_power_off()
386  * zpa2326_config_oneshot() - Setup device for one shot / on demand mode.
406 						iio_priv(indio_dev))->regmap;  in zpa2326_config_oneshot()
410 	/* Setup highest available Output Data Rate for one shot mode. */  in zpa2326_config_oneshot()
411 	err = regmap_write(regs, ZPA2326_CTRL_REG3_REG, freq->odr);  in zpa2326_config_oneshot()
421 			dev_err(indio_dev->dev.parent,  in zpa2326_config_oneshot()
422 				"failed to setup one shot mode (%d)", err);  in zpa2326_config_oneshot()
427 	zpa2326_dbg(indio_dev, "one shot mode setup @%dHz", freq->hz);  in zpa2326_config_oneshot()
433  * zpa2326_clear_fifo() - Clear remaining entries in hardware FIFO.
448 			       iio_priv(indio_dev))->regmap;  in zpa2326_clear_fifo()
482 			min_count--;  in zpa2326_clear_fifo()
503  * zpa2326_dequeue_pressure() - Retrieve the most recent pressure sample from
516 			       iio_priv(indio_dev))->regmap;  in zpa2326_dequeue_pressure()
519 	int            cleared = -1;  in zpa2326_dequeue_pressure()
541 		return zpa2326_clear_fifo(indio_dev, ZPA2326_FIFO_DEPTH - 1);  in zpa2326_dequeue_pressure()
573  * zpa2326_fill_sample_buffer() - Enqueue new channel samples to IIO buffer.
589 	if (test_bit(0, indio_dev->active_scan_mask)) {  in zpa2326_fill_sample_buffer()
599 	if (test_bit(1, indio_dev->active_scan_mask)) {  in zpa2326_fill_sample_buffer()
601 		err = regmap_bulk_read(private->regmap, ZPA2326_TEMP_OUT_L_REG,  in zpa2326_fill_sample_buffer()
612 	 *   - by hardware interrupt handler if interrupt is available: see  in zpa2326_fill_sample_buffer()
614 	 *   - or oneshot completion polling machinery : see  in zpa2326_fill_sample_buffer()
620 					   private->timestamp);  in zpa2326_fill_sample_buffer()
632 		return -EAGAIN;  in zpa2326_runtime_suspend()
655  * zpa2326_resume() - Request the PM layer to power supply the device.
659  *  < 0 - a negative error code meaning failure ;
660  *    0 - success, device has just been powered up ;
661  *    1 - success, device was already powered.
667 	err = pm_runtime_get_sync(indio_dev->dev.parent);  in zpa2326_resume()
669 		pm_runtime_put(indio_dev->dev.parent);  in zpa2326_resume()
687  * zpa2326_suspend() - Schedule a power down using autosuspend feature of PM
692  * attached regulator is a "dummy" one.
696 	struct device *parent = indio_dev->dev.parent;  in zpa2326_suspend()
738  * zpa2326_handle_irq() - Process hardware interrupts.
754 		 iio_priv(indio_dev))->timestamp = iio_get_time_ns(indio_dev);  in zpa2326_handle_irq()
761  * zpa2326_handle_threaded_irq() - Interrupt bottom-half handler.
776  * configured in one-shot mode either by an external trigger or the IIO read_raw
777  * hook. This means one of the latter is currently waiting for sampling
783  *   %IRQ_NONE - no consistent interrupt happened ;
784  *   %IRQ_HANDLED - there was new samples available.
803 	 * status de-asserts interrupt line.  in zpa2326_handle_threaded_irq()
805 	priv->result = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);  in zpa2326_handle_threaded_irq()
806 	if (priv->result < 0) {  in zpa2326_handle_threaded_irq()
827 		priv->result = -ENODATA;  in zpa2326_handle_threaded_irq()
832 	iio_trigger_poll_nested(priv->trigger);  in zpa2326_handle_threaded_irq()
848 	complete(&priv->data_ready);  in zpa2326_handle_threaded_irq()
854  * zpa2326_wait_oneshot_completion() - Wait for oneshot data ready interrupt.
866 	zpa2326_dbg(indio_dev, "waiting for one shot completion interrupt");  in zpa2326_wait_oneshot_completion()
869 		&private->data_ready, ZPA2326_CONVERSION_JIFFIES);  in zpa2326_wait_oneshot_completion()
875 		return private->result;  in zpa2326_wait_oneshot_completion()
878 	regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val);  in zpa2326_wait_oneshot_completion()
882 		zpa2326_warn(indio_dev, "no one shot interrupt occurred (%ld)",  in zpa2326_wait_oneshot_completion()
884 		return -ETIME;  in zpa2326_wait_oneshot_completion()
887 	zpa2326_warn(indio_dev, "wait for one shot interrupt cancelled");  in zpa2326_wait_oneshot_completion()
888 	return -ERESTARTSYS;  in zpa2326_wait_oneshot_completion()
898 	private->irq = irq;  in zpa2326_init_managed_irq()
909 	init_completion(&private->data_ready);  in zpa2326_init_managed_irq()
928  * zpa2326_poll_oneshot_completion() - Actively poll for one shot data ready.
940 			       iio_priv(indio_dev))->regmap;  in zpa2326_poll_oneshot_completion()
944 	zpa2326_dbg(indio_dev, "polling for one shot completion");  in zpa2326_poll_oneshot_completion()
947 	 * At least, 100 ms is needed for the device to complete its one-shot  in zpa2326_poll_oneshot_completion()
951 		return -ERESTARTSYS;  in zpa2326_poll_oneshot_completion()
960 			/* One-shot bit self clears at conversion end. */  in zpa2326_poll_oneshot_completion()
965 			err = -ETIME;  in zpa2326_poll_oneshot_completion()
983 		err = -ENODATA;  in zpa2326_poll_oneshot_completion()
990 	zpa2326_warn(indio_dev, "failed to poll one shot completion (%d)", err);  in zpa2326_poll_oneshot_completion()
996  * zpa2326_fetch_raw_sample() - Retrieve a raw sample and convert it to CPU
1009 			       iio_priv(indio_dev))->regmap;  in zpa2326_fetch_raw_sample()
1038 		/* Temperature is a 16 bits wide little-endian signed int. */  in zpa2326_fetch_raw_sample()
1044 		return -EINVAL;  in zpa2326_fetch_raw_sample()
1049  * zpa2326_sample_oneshot() - Perform a complete one shot sampling cycle.
1096 		ret = zpa2326_config_oneshot(indio_dev, priv->irq);  in zpa2326_sample_oneshot()
1107 	if (priv->irq > 0)  in zpa2326_sample_oneshot()
1127  * zpa2326_trigger_handler() - Perform an IIO buffered sampling round in one
1128  *                             shot mode.
1133  * Bottom-half handler called by the IIO trigger to which our device is
1150  *   %IRQ_NONE - no consistent interrupt happened ;
1151  *   %IRQ_HANDLED - there was new samples available.
1156 					     data)->indio_dev;  in zpa2326_trigger_handler()
1168 		/* On demand sampling : start a one shot cycle. */  in zpa2326_trigger_handler()
1173 		if (priv->irq <= 0) {  in zpa2326_trigger_handler()
1179 			priv->timestamp = iio_get_time_ns(indio_dev);  in zpa2326_trigger_handler()
1196 	iio_trigger_notify_done(indio_dev->trig);  in zpa2326_trigger_handler()
1202  * zpa2326_preenable_buffer() - Prepare device for configuring triggered
1221 	 iio_priv(indio_dev))->waken = iio_priv(indio_dev);  in zpa2326_preenable_buffer()
1227  * zpa2326_postenable_buffer() - Configure device for triggered sampling.
1230  * Basically setup one-shot mode if plugging external trigger.
1247 	if (!priv->waken) {  in zpa2326_postenable_buffer()
1260 	if (!iio_trigger_using_own(indio_dev) && priv->waken) {  in zpa2326_postenable_buffer()
1263 		 * powered up: reconfigure one-shot mode.  in zpa2326_postenable_buffer()
1265 		err = zpa2326_config_oneshot(indio_dev, priv->irq);  in zpa2326_postenable_buffer()
1290  * zpa2326_set_trigger_state() - Start / stop continuous sampling.
1304 							trig->dev.parent);  in zpa2326_set_trigger_state()
1321 		 * required to, i.e. by restoring back to default one shot mode.  in zpa2326_set_trigger_state()
1323 		disable_irq(priv->irq);  in zpa2326_set_trigger_state()
1327 		 * one shot / direct sampling operations.  in zpa2326_set_trigger_state()
1329 		err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,  in zpa2326_set_trigger_state()
1330 				   zpa2326_highest_frequency()->odr);  in zpa2326_set_trigger_state()
1339 		err = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);  in zpa2326_set_trigger_state()
1344 		 * Re-enable interrupts only if we can guarantee the device will  in zpa2326_set_trigger_state()
1348 		enable_irq(priv->irq);  in zpa2326_set_trigger_state()
1357 		if (priv->waken) {  in zpa2326_set_trigger_state()
1359 			err = regmap_write(priv->regmap, ZPA2326_CTRL_REG1_REG,  in zpa2326_set_trigger_state()
1367 		err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,  in zpa2326_set_trigger_state()
1369 				   priv->frequency->odr);  in zpa2326_set_trigger_state()
1374 			    priv->frequency->hz);  in zpa2326_set_trigger_state()
1385  * zpa2326_init_managed_trigger() - Create interrupt driven / hardware trigger
1410 	trigger = devm_iio_trigger_alloc(parent, "%s-dev%d",  in zpa2326_init_managed_trigger()
1411 					 indio_dev->name,  in zpa2326_init_managed_trigger()
1414 		return -ENOMEM;  in zpa2326_init_managed_trigger()
1417 	trigger->ops = &zpa2326_trigger_ops;  in zpa2326_init_managed_trigger()
1419 	private->trigger = trigger;  in zpa2326_init_managed_trigger()
1432 	return ((struct zpa2326_private *)iio_priv(indio_dev))->frequency->hz;  in zpa2326_get_frequency()
1446 		return -EINVAL;  in zpa2326_set_frequency()
1453 	priv->frequency = &zpa2326_sampling_frequencies[freq];  in zpa2326_set_frequency()
1480 		return zpa2326_sample_oneshot(indio_dev, chan->type, val);  in zpa2326_read_raw()
1483 		switch (chan->type) {  in zpa2326_read_raw()
1496 			 *     Temp[degC] = Tempcode * 0.00649 - 176.83  in zpa2326_read_raw()
1500 			 * Hence, to produce a temperature in milli-degrees  in zpa2326_read_raw()
1505 			 *     Offset = -176.83 / 0.00649  in zpa2326_read_raw()
1513 			return -EINVAL;  in zpa2326_read_raw()
1517 		switch (chan->type) {  in zpa2326_read_raw()
1519 			*val = -17683000;  in zpa2326_read_raw()
1524 			return -EINVAL;  in zpa2326_read_raw()
1532 		return -EINVAL;  in zpa2326_read_raw()
1543 		return -EINVAL;  in zpa2326_write_raw()
1598 	indio_dev->modes = INDIO_DIRECT_MODE;  in zpa2326_create_managed_iiodev()
1599 	indio_dev->channels = zpa2326_channels;  in zpa2326_create_managed_iiodev()
1600 	indio_dev->num_channels = ARRAY_SIZE(zpa2326_channels);  in zpa2326_create_managed_iiodev()
1601 	indio_dev->name = name;  in zpa2326_create_managed_iiodev()
1602 	indio_dev->info = &zpa2326_info;  in zpa2326_create_managed_iiodev()
1620 		return -ENOMEM;  in zpa2326_probe()
1624 	priv->vref = devm_regulator_get(parent, "vref");  in zpa2326_probe()
1625 	if (IS_ERR(priv->vref))  in zpa2326_probe()
1626 		return PTR_ERR(priv->vref);  in zpa2326_probe()
1628 	priv->vdd = devm_regulator_get(parent, "vdd");  in zpa2326_probe()
1629 	if (IS_ERR(priv->vdd))  in zpa2326_probe()
1630 		return PTR_ERR(priv->vdd);  in zpa2326_probe()
1633 	priv->frequency = zpa2326_highest_frequency();  in zpa2326_probe()
1640 	priv->regmap = regmap;  in zpa2326_probe()
1668 		err = -ENODEV;  in zpa2326_probe()
1708 	zpa2326_fini_runtime(indio_dev->dev.parent);  in zpa2326_remove()