Lines Matching +full:startup +full:- +full:sensor
1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * SRF04: ultrasonic sensor for distance measuring by using GPIOs
5 * Copyright (c) 2017 Andreas Klinger <ak@it-klinger.de>
8 * https://www.robot-electronics.co.uk/htm/srf04tech.htm
12 * +---+
14 * trig: --+ +------------------------------------------------------
16 * |<->|
19 * ultra +-+ +-+ +-+
21 * burst: ---------+ +-+ +-+ +-----------------------------------------
23 * ultra . +-+ +-+ +-+
25 * echo: ----------------------------------+ +-+ +-+ +----------------
27 * +------------------------+
29 * echo: -------------------+ +---------------
33 * |<---------------------->|
35 * --> one round trip of ultra sonic waves
85 if (gpiod_get_value(data->gpiod_echo)) { in srf04_handle_irq()
86 data->ts_rising = now; in srf04_handle_irq()
87 complete(&data->rising); in srf04_handle_irq()
89 data->ts_falling = now; in srf04_handle_irq()
90 complete(&data->falling); in srf04_handle_irq()
103 if (data->gpiod_power) { in srf04_read()
104 ret = pm_runtime_resume_and_get(data->dev); in srf04_read()
109 * just one read-echo-cycle can take place at a time in srf04_read()
112 mutex_lock(&data->lock); in srf04_read()
114 reinit_completion(&data->rising); in srf04_read()
115 reinit_completion(&data->falling); in srf04_read()
117 gpiod_set_value(data->gpiod_trig, 1); in srf04_read()
118 udelay(data->cfg->trigger_pulse_us); in srf04_read()
119 gpiod_set_value(data->gpiod_trig, 0); in srf04_read()
121 if (data->gpiod_power) { in srf04_read()
122 pm_runtime_mark_last_busy(data->dev); in srf04_read()
123 pm_runtime_put_autosuspend(data->dev); in srf04_read()
127 ret = wait_for_completion_killable_timeout(&data->rising, HZ/50); in srf04_read()
129 mutex_unlock(&data->lock); in srf04_read()
132 mutex_unlock(&data->lock); in srf04_read()
133 return -ETIMEDOUT; in srf04_read()
137 ret = wait_for_completion_killable_timeout(&data->falling, HZ/20); in srf04_read()
139 mutex_unlock(&data->lock); in srf04_read()
142 mutex_unlock(&data->lock); in srf04_read()
143 return -ETIMEDOUT; in srf04_read()
146 ktime_dt = ktime_sub(data->ts_falling, data->ts_rising); in srf04_read()
148 mutex_unlock(&data->lock); in srf04_read()
155 * another us sensor in srf04_read()
159 * time = ---------- = ------------ = 40438871 ns in srf04_read()
162 * using a minimum speed at -20 °C of 319 m/s in srf04_read()
165 return -EIO; in srf04_read()
181 * distance = ------ * ------- = ------------ in srf04_read()
201 if (channel->type != IIO_DISTANCE) in srf04_read_raw()
202 return -EINVAL; in srf04_read_raw()
220 return -EINVAL; in srf04_read_raw()
251 struct device *dev = &pdev->dev; in srf04_probe()
259 return -ENOMEM; in srf04_probe()
263 data->dev = dev; in srf04_probe()
264 data->cfg = of_match_device(of_srf04_match, dev)->data; in srf04_probe()
266 mutex_init(&data->lock); in srf04_probe()
267 init_completion(&data->rising); in srf04_probe()
268 init_completion(&data->falling); in srf04_probe()
270 data->gpiod_trig = devm_gpiod_get(dev, "trig", GPIOD_OUT_LOW); in srf04_probe()
271 if (IS_ERR(data->gpiod_trig)) { in srf04_probe()
272 dev_err(dev, "failed to get trig-gpios: err=%ld\n", in srf04_probe()
273 PTR_ERR(data->gpiod_trig)); in srf04_probe()
274 return PTR_ERR(data->gpiod_trig); in srf04_probe()
277 data->gpiod_echo = devm_gpiod_get(dev, "echo", GPIOD_IN); in srf04_probe()
278 if (IS_ERR(data->gpiod_echo)) { in srf04_probe()
279 dev_err(dev, "failed to get echo-gpios: err=%ld\n", in srf04_probe()
280 PTR_ERR(data->gpiod_echo)); in srf04_probe()
281 return PTR_ERR(data->gpiod_echo); in srf04_probe()
284 data->gpiod_power = devm_gpiod_get_optional(dev, "power", in srf04_probe()
286 if (IS_ERR(data->gpiod_power)) { in srf04_probe()
287 dev_err(dev, "failed to get power-gpios: err=%ld\n", in srf04_probe()
288 PTR_ERR(data->gpiod_power)); in srf04_probe()
289 return PTR_ERR(data->gpiod_power); in srf04_probe()
291 if (data->gpiod_power) { in srf04_probe()
293 if (of_property_read_u32(dev->of_node, "startup-time-ms", in srf04_probe()
294 &data->startup_time_ms)) in srf04_probe()
295 data->startup_time_ms = 100; in srf04_probe()
296 dev_dbg(dev, "using power gpio: startup-time-ms=%d\n", in srf04_probe()
297 data->startup_time_ms); in srf04_probe()
300 if (gpiod_cansleep(data->gpiod_echo)) { in srf04_probe()
301 dev_err(data->dev, "cansleep-GPIOs not supported\n"); in srf04_probe()
302 return -ENODEV; in srf04_probe()
305 data->irqnr = gpiod_to_irq(data->gpiod_echo); in srf04_probe()
306 if (data->irqnr < 0) { in srf04_probe()
307 dev_err(data->dev, "gpiod_to_irq: %d\n", data->irqnr); in srf04_probe()
308 return data->irqnr; in srf04_probe()
311 ret = devm_request_irq(dev, data->irqnr, srf04_handle_irq, in srf04_probe()
313 pdev->name, indio_dev); in srf04_probe()
315 dev_err(data->dev, "request_irq: %d\n", ret); in srf04_probe()
321 indio_dev->name = "srf04"; in srf04_probe()
322 indio_dev->info = &srf04_iio_info; in srf04_probe()
323 indio_dev->modes = INDIO_DIRECT_MODE; in srf04_probe()
324 indio_dev->channels = srf04_chan_spec; in srf04_probe()
325 indio_dev->num_channels = ARRAY_SIZE(srf04_chan_spec); in srf04_probe()
329 dev_err(data->dev, "iio_device_register: %d\n", ret); in srf04_probe()
333 if (data->gpiod_power) { in srf04_probe()
334 pm_runtime_set_autosuspend_delay(data->dev, 1000); in srf04_probe()
335 pm_runtime_use_autosuspend(data->dev); in srf04_probe()
337 ret = pm_runtime_set_active(data->dev); in srf04_probe()
339 dev_err(data->dev, "pm_runtime_set_active: %d\n", ret); in srf04_probe()
343 pm_runtime_enable(data->dev); in srf04_probe()
344 pm_runtime_idle(data->dev); in srf04_probe()
357 if (data->gpiod_power) { in srf04_remove()
358 pm_runtime_disable(data->dev); in srf04_remove()
359 pm_runtime_set_suspended(data->dev); in srf04_remove()
372 gpiod_set_value(data->gpiod_power, 0); in srf04_pm_runtime_suspend()
384 gpiod_set_value(data->gpiod_power, 1); in srf04_pm_runtime_resume()
385 msleep(data->startup_time_ms); in srf04_pm_runtime_resume()
399 .name = "srf04-gpio",
407 MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");
408 MODULE_DESCRIPTION("SRF04 ultrasonic sensor for distance measuring using GPIOs");