1 // SPDX-License-Identifier: GPL-2.0-only
4  * aht10.c - Linux hwmon driver for AHT10 Temperature and Humidity sensor
17  * Poll intervals (in milliseconds)
48  *   struct aht10_data - All the data required to operate an AHT10 chip
52  *   @min_poll_interval: the minimum poll interval
53  *                   While the poll rate limit is not 100% necessary,
81  * aht10_init() - Initialize an AHT10 chip
92 	struct i2c_client *client = data->client;  in aht10_init()
103 		return -ENODATA;  in aht10_init()
106 		return -EBUSY;  in aht10_init()
112  * aht10_polltime_expired() - check if the minimum poll interval has
115  * Return: 1 if the minimum poll interval has expired, 0 if not
120 	ktime_t difference = ktime_sub(current_time, data->previous_poll_time);  in aht10_polltime_expired()
122 	return ktime_after(difference, data->min_poll_interval);  in aht10_polltime_expired()
126  * aht10_read_values() - read and parse the raw data from the AHT10
136 	struct i2c_client *client = data->client;  in aht10_read_values()
138 	mutex_lock(&data->lock);  in aht10_read_values()
142 			mutex_unlock(&data->lock);  in aht10_read_values()
151 			mutex_unlock(&data->lock);  in aht10_read_values()
153 				return -ENODATA;  in aht10_read_values()
169 		data->temperature = (int)temp - 50000;  in aht10_read_values()
170 		data->humidity = hum;  in aht10_read_values()
171 		data->previous_poll_time = ktime_get_boottime();  in aht10_read_values()
173 	mutex_unlock(&data->lock);  in aht10_read_values()
178  * aht10_interval_write() - store the given minimum poll interval.
179  * Return: 0 on success, -EINVAL if a value lower than the
185 	data->min_poll_interval = ms_to_ktime(clamp_val(val, 2000, LONG_MAX));  in aht10_interval_write()
190  * aht10_interval_read() - read the minimum poll interval
196 	*val = ktime_to_ms(data->min_poll_interval);  in aht10_interval_read()
201  * aht10_temperature1_read() - read the temperature in millidegrees
211 	*val = data->temperature;  in aht10_temperature1_read()
216  * aht10_humidity1_read() - read the relative humidity in millipercent
226 	*val = data->humidity;  in aht10_humidity1_read()
257 		return -EOPNOTSUPP;  in aht10_hwmon_read()
270 		return -EOPNOTSUPP;  in aht10_hwmon_write()
295 	struct device *device = &client->dev;  in aht10_probe()
300 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))  in aht10_probe()
301 		return -ENOENT;  in aht10_probe()
305 		return -ENOMEM;  in aht10_probe()
307 	data->min_poll_interval = ms_to_ktime(AHT10_DEFAULT_MIN_POLL_INTERVAL);  in aht10_probe()
308 	data->client = client;  in aht10_probe()
310 	mutex_init(&data->lock);  in aht10_probe()
321 							 client->name,  in aht10_probe()