1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
30  * GPIOTHS - Temp/Humidity sensor over GPIO.
32  * This is driver for Temperature & Humidity sensor which provides digital
33  * output over single-wire protocol from embedded 8-bit microcontroller.
34  * Note that it uses a custom single-wire protocol, it is not 1-wire(tm).
37  *   DHT11:  Temp   0c to 50c +-2.0c, Humidity 20% to  90% +-5%
38  *   DHT12:  Temp -20c to 60c +-0.5c, Humidity 20% to  95% +-5%
39  *   DHT21:  Temp -40c to 80c +-0.3c, Humidity  0% to 100% +-3%
40  *   DHT22:  Temp -40c to 80c +-0.3c, Humidity  0% to 100% +-2%
44  * Temp/Humidity sensor can't be discovered automatically, please specify hints
109 	    ofw_bus_search_compatible(dev, compat_data)->ocd_data)  in gpioths_probe()
113 	device_set_desc(dev, "DHT11/DHT22 Temperature and Humidity Sensor");  in gpioths_probe()
125 		gpio_pin_is_active(sc->pin, &cur_level);  in gpioths_dht_timeuntil()
148 	gpio_pin_setflags(sc->pin, GPIO_PIN_OUTPUT);  in gpioths_dht_initread()
149 	gpio_pin_set_active(sc->pin, false);  in gpioths_dht_initread()
151 	gpio_pin_set_active(sc->pin, true);  in gpioths_dht_initread()
152 	gpio_pin_setflags(sc->pin, GPIO_PIN_INPUT);  in gpioths_dht_initread()
168 		device_printf(sc->dev, "err(START) = %d\n", err);  in gpioths_dht_readbytes()
172 	/* reading - 41 cycles */  in gpioths_dht_readbytes()
176 			device_printf(sc->dev, "err(CAL, %d) = %d\n", i, err);  in gpioths_dht_readbytes()
181 			device_printf(sc->dev, "err(INTERVAL, %d) = %d\n", i, err);  in gpioths_dht_readbytes()
191 	avglen = avglen / (GPIOTHS_DHT_CYCLES - 1);  in gpioths_dht_readbytes()
220 		device_printf(sc->dev, "%d: %d %d\n", i, calibrations[i],  in gpioths_dht_readbytes()
223 	device_printf(sc->dev, "len=%d, data=%x, crc=%x/%x\n", avglen, value, crc,  in gpioths_dht_readbytes()
229 		err = -1;  in gpioths_dht_readbytes()
237 	 *  - DHT11: 0HHHHHHH 00000000 00TTTTTT 00000000  in gpioths_dht_readbytes()
238 	 *  - DHT12: 0HHHHHHH 0000hhhh 00TTTTTT s000tttt  in gpioths_dht_readbytes()
243 	 *  - DHT21: 000000HH HHHHHHHH s00000TT TTTTTTTT  in gpioths_dht_readbytes()
244 	 *  - DHT22: 000000HH HHHHHHHH s00000TT TTTTTTTT  in gpioths_dht_readbytes()
250 	 * humidity.  A DHT21/22 cannot report a value greater than 3 in  in gpioths_dht_readbytes()
251 	 * the upper bits of its 16-bit humidity.  A DHT11/12 should not report  in gpioths_dht_readbytes()
255 	 * DHT11/12 (that would be a humidity over 256% on a DHT21/22).  in gpioths_dht_readbytes()
262 		negmul = (value & 0x80) ? -1 : 1;  in gpioths_dht_readbytes()
263 		sc->temp = DK_OFFSET + (negmul * (tmphi * 10 + tmplo));  in gpioths_dht_readbytes()
264 		sc->hum = (value >> 24) & 0x7f;  in gpioths_dht_readbytes()
267 		negmul = (value & 0x8000) ? -1 : 1;  in gpioths_dht_readbytes()
268 		sc->temp = DK_OFFSET + (negmul * (value & 0x03ff));  in gpioths_dht_readbytes()
269 		sc->hum = ((value >> 16) & 0x03ff) / 10;  in gpioths_dht_readbytes()
272 	sc->fails = 0;  in gpioths_dht_readbytes()
276 	device_printf(dev, "fails=%d, temp=%d, hum=%d\n", sc->fails,  in gpioths_dht_readbytes()
277 	    sc->temp, sc->hum);  in gpioths_dht_readbytes()
282 	sc->fails++;  in gpioths_dht_readbytes()
294 	if (!sc->detaching)  in gpioths_poll()
295 		taskqueue_enqueue_timeout_sbt(taskqueue_thread, &sc->task,  in gpioths_poll()
311 	sc->dev = dev;  in gpioths_attach()
313 	TIMEOUT_TASK_INIT(taskqueue_thread, &sc->task, 0, gpioths_poll, sc);  in gpioths_attach()
316 	/* Try to configure our pin from fdt data on fdt-based systems. */  in gpioths_attach()
318 	    &sc->pin);  in gpioths_attach()
325 	 * on fdt-based systems).  in gpioths_attach()
329 		err = gpio_pin_get_by_child_index(dev, PIN_IDX, &sc->pin);  in gpioths_attach()
333 		device_printf(sc->dev,  in gpioths_attach()
343 	err = gpio_pin_setflags(sc->pin, GPIO_PIN_OUTPUT);  in gpioths_attach()
348 	err = gpio_pin_set_active(sc->pin, true);  in gpioths_attach()
353 	err = gpio_pin_setflags(sc->pin, GPIO_PIN_INPUT);  in gpioths_attach()
369 	    &sc->temp, 0, sysctl_handle_int, "IK", "temperature", NULL);  in gpioths_attach()
371 	SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "humidity",  in gpioths_attach()
372 	    CTLFLAG_RD, &sc->hum, 0, "relative humidity(%)");  in gpioths_attach()
375 	    CTLFLAG_RD, &sc->fails, 0,  in gpioths_attach()
387 	gpio_pin_release(sc->pin);  in gpioths_detach()
388 	sc->detaching = true;  in gpioths_detach()
389 	while (taskqueue_cancel_timeout(taskqueue_thread, &sc->task, NULL) != 0)  in gpioths_detach()
390 		taskqueue_drain_timeout(taskqueue_thread, &sc->task);  in gpioths_detach()