Lines Matching +full:conversion +full:- +full:start +full:- +full:gpios
2 * sht15.c - support for the SHT15 Temperature and Humidity Sensor
4 * Portions Copyright (c) 2010-2012 Savoir-faire Linux Inc.
24 #include <linux/hwmon-sysfs.h>
68 * struct sht15_temppair - elements of voltage dependent temp calc
77 /* Table 9 from datasheet - relates temperature calculation to supply voltage */
79 { 2500000, -39400 },
80 { 3000000, -39600 },
81 { 3500000, -39700 },
82 { 4000000, -39800 },
83 { 5000000, -40100 },
123 * struct sht15_data - device instance specific data
134 * @measurements_valid: are the current stored measures valid (start condition).
135 * @status_valid: is the current stored status valid (start condition).
179 * sht15_crc8() - compute crc8
190 u8 crc = bitrev8(data->val_status & 0x0F); in sht15_crc8()
192 while (len--) { in sht15_crc8()
201 * sht15_connection_reset() - reset the comms interface
210 err = gpiod_direction_output(data->data, 1); in sht15_connection_reset()
214 gpiod_set_value(data->sck, 0); in sht15_connection_reset()
217 gpiod_set_value(data->sck, 1); in sht15_connection_reset()
219 gpiod_set_value(data->sck, 0); in sht15_connection_reset()
226 * sht15_send_bit() - send an individual bit to the device
232 gpiod_set_value(data->data, val); in sht15_send_bit()
234 gpiod_set_value(data->sck, 1); in sht15_send_bit()
236 gpiod_set_value(data->sck, 0); in sht15_send_bit()
241 * sht15_transmission_start() - specific sequence for new transmission
253 err = gpiod_direction_output(data->data, 1); in sht15_transmission_start()
257 gpiod_set_value(data->sck, 0); in sht15_transmission_start()
259 gpiod_set_value(data->sck, 1); in sht15_transmission_start()
261 gpiod_set_value(data->data, 0); in sht15_transmission_start()
263 gpiod_set_value(data->sck, 0); in sht15_transmission_start()
265 gpiod_set_value(data->sck, 1); in sht15_transmission_start()
267 gpiod_set_value(data->data, 1); in sht15_transmission_start()
269 gpiod_set_value(data->sck, 0); in sht15_transmission_start()
275 * sht15_send_byte() - send a single byte to the device
290 * sht15_wait_for_response() - checks for ack from device
297 err = gpiod_direction_input(data->data); in sht15_wait_for_response()
300 gpiod_set_value(data->sck, 1); in sht15_wait_for_response()
302 if (gpiod_get_value(data->data)) { in sht15_wait_for_response()
303 gpiod_set_value(data->sck, 0); in sht15_wait_for_response()
304 dev_err(data->dev, "Command not acknowledged\n"); in sht15_wait_for_response()
308 return -EIO; in sht15_wait_for_response()
310 gpiod_set_value(data->sck, 0); in sht15_wait_for_response()
316 * sht15_send_cmd() - Sends a command to the device.
335 * sht15_soft_reset() - send a soft reset command
349 data->val_status = 0; in sht15_soft_reset()
355 * sht15_ack() - send a ack
365 err = gpiod_direction_output(data->data, 0); in sht15_ack()
369 gpiod_set_value(data->sck, 1); in sht15_ack()
371 gpiod_set_value(data->sck, 0); in sht15_ack()
373 gpiod_set_value(data->data, 1); in sht15_ack()
375 return gpiod_direction_input(data->data); in sht15_ack()
379 * sht15_end_transmission() - notify device of end of transmission
388 err = gpiod_direction_output(data->data, 1); in sht15_end_transmission()
392 gpiod_set_value(data->sck, 1); in sht15_end_transmission()
394 gpiod_set_value(data->sck, 0); in sht15_end_transmission()
400 * sht15_read_byte() - Read a byte back from the device
410 gpiod_set_value(data->sck, 1); in sht15_read_byte()
412 byte |= !!gpiod_get_value(data->data); in sht15_read_byte()
413 gpiod_set_value(data->sck, 0); in sht15_read_byte()
420 * sht15_send_status() - write the status register byte
433 err = gpiod_direction_output(data->data, 1); in sht15_send_status()
442 data->val_status = status; in sht15_send_status()
447 * sht15_update_status() - get updated status register from device if too old
461 mutex_lock(&data->read_lock); in sht15_update_status()
462 if (time_after(jiffies, data->last_status + timeout) in sht15_update_status()
463 || !data->status_valid) { in sht15_update_status()
469 if (data->checksumming) { in sht15_update_status()
474 data->checksum_ok = (sht15_crc8(data, checksum_vals, 2) in sht15_update_status()
487 if (data->checksumming && !data->checksum_ok) { in sht15_update_status()
488 previous_config = data->val_status & 0x07; in sht15_update_status()
495 dev_err(data->dev, in sht15_update_status()
501 ret = -EAGAIN; in sht15_update_status()
505 data->val_status = status; in sht15_update_status()
506 data->status_valid = true; in sht15_update_status()
507 data->last_status = jiffies; in sht15_update_status()
511 mutex_unlock(&data->read_lock); in sht15_update_status()
516 * sht15_measurement() - get a new value from device
533 ret = gpiod_direction_input(data->data); in sht15_measurement()
536 atomic_set(&data->interrupt_handled, 0); in sht15_measurement()
538 enable_irq(gpiod_to_irq(data->data)); in sht15_measurement()
539 if (gpiod_get_value(data->data) == 0) { in sht15_measurement()
540 disable_irq_nosync(gpiod_to_irq(data->data)); in sht15_measurement()
542 if (!atomic_read(&data->interrupt_handled)) in sht15_measurement()
543 schedule_work(&data->read_work); in sht15_measurement()
545 ret = wait_event_timeout(data->wait_queue, in sht15_measurement()
546 (data->state == SHT15_READING_NOTHING), in sht15_measurement()
548 if (data->state != SHT15_READING_NOTHING) { /* I/O error occurred */ in sht15_measurement()
549 data->state = SHT15_READING_NOTHING; in sht15_measurement()
550 return -EIO; in sht15_measurement()
552 disable_irq_nosync(gpiod_to_irq(data->data)); in sht15_measurement()
556 return -ETIME; in sht15_measurement()
564 if (data->checksumming && !data->checksum_ok) { in sht15_measurement()
565 previous_config = data->val_status & 0x07; in sht15_measurement()
572 dev_err(data->dev, in sht15_measurement()
578 return -EAGAIN; in sht15_measurement()
585 * sht15_update_measurements() - get updated measures from device if too old
593 mutex_lock(&data->read_lock); in sht15_update_measurements()
594 if (time_after(jiffies, data->last_measurement + timeout) in sht15_update_measurements()
595 || !data->measurements_valid) { in sht15_update_measurements()
596 data->state = SHT15_READING_HUMID; in sht15_update_measurements()
600 data->state = SHT15_READING_TEMP; in sht15_update_measurements()
604 data->measurements_valid = true; in sht15_update_measurements()
605 data->last_measurement = jiffies; in sht15_update_measurements()
609 mutex_unlock(&data->read_lock); in sht15_update_measurements()
614 * sht15_calc_temp() - convert the raw reading to a temperature
622 int d2 = (data->val_status & SHT15_STATUS_LOW_RESOLUTION) ? 40 : 10; in sht15_calc_temp()
625 for (i = ARRAY_SIZE(temppoints) - 1; i > 0; i--) in sht15_calc_temp()
627 if (data->supply_uv > temppoints[i - 1].vdd) { in sht15_calc_temp()
628 d1 = (data->supply_uv - temppoints[i - 1].vdd) in sht15_calc_temp()
629 * (temppoints[i].d1 - temppoints[i - 1].d1) in sht15_calc_temp()
630 / (temppoints[i].vdd - temppoints[i - 1].vdd) in sht15_calc_temp()
631 + temppoints[i - 1].d1; in sht15_calc_temp()
635 return data->val_temp * d2 + d1; in sht15_calc_temp()
639 * sht15_calc_humid() - using last temperature convert raw to humid
646 * Humidity conversion coefficients are shown in table 7 of the datasheet.
654 const int c1 = -4; in sht15_calc_humid()
656 if (data->val_status & SHT15_STATUS_LOW_RESOLUTION) { in sht15_calc_humid()
657 c2 = 648000; /* x 10 ^ -6 */ in sht15_calc_humid()
658 c3 = -7200; /* x 10 ^ -7 */ in sht15_calc_humid()
661 c2 = 40500; /* x 10 ^ -6 */ in sht15_calc_humid()
662 c3 = -28; /* x 10 ^ -7 */ in sht15_calc_humid()
667 + c2 * data->val_humid / 1000 in sht15_calc_humid()
668 + (data->val_humid * data->val_humid * c3) / 10000; in sht15_calc_humid()
669 return (temp - 25000) * (10000 + t2 * data->val_humid) in sht15_calc_humid()
674 * sht15_show_status() - show status information in sysfs
689 u8 bit = to_sensor_dev_attr(attr)->index; in sht15_show_status()
693 return ret ? ret : sprintf(buf, "%d\n", !!(data->val_status & bit)); in sht15_show_status()
697 * sht15_store_heater() - change heater state via sysfs
716 return -EINVAL; in sht15_store_heater()
718 mutex_lock(&data->read_lock); in sht15_store_heater()
719 status = data->val_status & 0x07; in sht15_store_heater()
726 mutex_unlock(&data->read_lock); in sht15_store_heater()
732 * sht15_show_temp() - show temperature measurement value in sysfs
755 * sht15_show_humidity() - show humidity measurement value in sysfs
780 return sprintf(buf, "%s\n", pdev->name); in name_show()
814 atomic_inc(&data->interrupt_handled); in sht15_interrupt_fired()
816 if (data->state != SHT15_READING_NOTHING) in sht15_interrupt_fired()
817 schedule_work(&data->read_work); in sht15_interrupt_fired()
831 if (gpiod_get_value(data->data)) { in sht15_bh_read_data()
833 * If not, then start the interrupt again - care here as could in sht15_bh_read_data()
836 atomic_set(&data->interrupt_handled, 0); in sht15_bh_read_data()
837 enable_irq(gpiod_to_irq(data->data)); in sht15_bh_read_data()
839 if (gpiod_get_value(data->data) in sht15_bh_read_data()
840 || atomic_read(&data->interrupt_handled)) in sht15_bh_read_data()
851 if (data->checksumming) { in sht15_bh_read_data()
859 checksum_vals[0] = (data->state == SHT15_READING_TEMP) ? in sht15_bh_read_data()
863 data->checksum_ok in sht15_bh_read_data()
871 switch (data->state) { in sht15_bh_read_data()
873 data->val_temp = val; in sht15_bh_read_data()
876 data->val_humid = val; in sht15_bh_read_data()
882 data->state = SHT15_READING_NOTHING; in sht15_bh_read_data()
884 wake_up(&data->wait_queue); in sht15_bh_read_data()
892 data->supply_uv = regulator_get_voltage(data->reg); in sht15_update_voltage()
896 * sht15_invalidate_voltage() - mark supply voltage invalid when notified by reg
899 * @ignored: function parameter - ignored here
911 data->supply_uv_valid = false; in sht15_invalidate_voltage()
912 schedule_work(&data->update_supply_work); in sht15_invalidate_voltage()
930 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); in sht15_probe()
932 return -ENOMEM; in sht15_probe()
934 INIT_WORK(&data->read_work, sht15_bh_read_data); in sht15_probe()
935 INIT_WORK(&data->update_supply_work, sht15_update_voltage); in sht15_probe()
937 mutex_init(&data->read_lock); in sht15_probe()
938 data->dev = &pdev->dev; in sht15_probe()
939 init_waitqueue_head(&data->wait_queue); in sht15_probe()
945 data->reg = devm_regulator_get_optional(data->dev, "vcc"); in sht15_probe()
946 if (!IS_ERR(data->reg)) { in sht15_probe()
949 voltage = regulator_get_voltage(data->reg); in sht15_probe()
951 data->supply_uv = voltage; in sht15_probe()
953 ret = regulator_enable(data->reg); in sht15_probe()
955 dev_err(&pdev->dev, in sht15_probe()
964 data->nb.notifier_call = &sht15_invalidate_voltage; in sht15_probe()
965 ret = regulator_register_notifier(data->reg, &data->nb); in sht15_probe()
967 dev_err(&pdev->dev, in sht15_probe()
969 regulator_disable(data->reg); in sht15_probe()
974 /* Try requesting the GPIOs */ in sht15_probe()
975 data->sck = devm_gpiod_get(&pdev->dev, "clk", GPIOD_OUT_LOW); in sht15_probe()
976 if (IS_ERR(data->sck)) { in sht15_probe()
977 ret = PTR_ERR(data->sck); in sht15_probe()
978 dev_err(&pdev->dev, "clock line GPIO request failed\n"); in sht15_probe()
981 data->data = devm_gpiod_get(&pdev->dev, "data", GPIOD_IN); in sht15_probe()
982 if (IS_ERR(data->data)) { in sht15_probe()
983 ret = PTR_ERR(data->data); in sht15_probe()
984 dev_err(&pdev->dev, "data line GPIO request failed\n"); in sht15_probe()
988 ret = devm_request_irq(&pdev->dev, gpiod_to_irq(data->data), in sht15_probe()
994 dev_err(&pdev->dev, "failed to get irq for data line\n"); in sht15_probe()
997 disable_irq_nosync(gpiod_to_irq(data->data)); in sht15_probe()
1005 ret = sysfs_create_group(&pdev->dev.kobj, &sht15_attr_group); in sht15_probe()
1007 dev_err(&pdev->dev, "sysfs create failed\n"); in sht15_probe()
1011 data->hwmon_dev = hwmon_device_register(data->dev); in sht15_probe()
1012 if (IS_ERR(data->hwmon_dev)) { in sht15_probe()
1013 ret = PTR_ERR(data->hwmon_dev); in sht15_probe()
1020 sysfs_remove_group(&pdev->dev.kobj, &sht15_attr_group); in sht15_probe()
1022 if (!IS_ERR(data->reg)) { in sht15_probe()
1023 regulator_unregister_notifier(data->reg, &data->nb); in sht15_probe()
1024 regulator_disable(data->reg); in sht15_probe()
1037 mutex_lock(&data->read_lock); in sht15_remove()
1039 mutex_unlock(&data->read_lock); in sht15_remove()
1040 return -EFAULT; in sht15_remove()
1042 hwmon_device_unregister(data->hwmon_dev); in sht15_remove()
1043 sysfs_remove_group(&pdev->dev.kobj, &sht15_attr_group); in sht15_remove()
1044 if (!IS_ERR(data->reg)) { in sht15_remove()
1045 regulator_unregister_notifier(data->reg, &data->nb); in sht15_remove()
1046 regulator_disable(data->reg); in sht15_remove()
1049 mutex_unlock(&data->read_lock); in sht15_remove()