1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * lm77.c - Part of lm_sensors, Linux kernel modules for hardware
21 #include <linux/hwmon-sysfs.h>
65 #define LM77_TEMP_MIN (-55000)
83  * All registers are word-sized, except for the configuration register.
84  * The LM77 uses the high-byte first convention.
105 	struct i2c_client *client = data->client;  in lm77_update_device()
108 	mutex_lock(&data->update_lock);  in lm77_update_device()
110 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)  in lm77_update_device()
111 	    || !data->valid) {  in lm77_update_device()
112 		dev_dbg(&client->dev, "Starting lm77 update\n");  in lm77_update_device()
114 			data->temp[i] =  in lm77_update_device()
118 		data->alarms =  in lm77_update_device()
120 		data->last_updated = jiffies;  in lm77_update_device()
121 		data->valid = true;  in lm77_update_device()
124 	mutex_unlock(&data->update_lock);  in lm77_update_device()
137 	return sprintf(buf, "%d\n", data->temp[attr->index]);  in temp_show()
145 	int nr = attr->index;  in temp_hyst_show()
148 	temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] :  in temp_hyst_show()
149 			     data->temp[nr] - data->temp[t_hyst];  in temp_hyst_show()
160 	struct i2c_client *client = data->client;  in temp_store()
161 	int nr = attr->index;  in temp_store()
170 	mutex_lock(&data->update_lock);  in temp_store()
171 	data->temp[nr] = val;  in temp_store()
173 	mutex_unlock(&data->update_lock);  in temp_store()
186 	struct i2c_client *client = data->client;  in temp_hyst_store()
194 	mutex_lock(&data->update_lock);  in temp_hyst_store()
195 	val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX);  in temp_hyst_store()
196 	data->temp[t_hyst] = val;  in temp_hyst_store()
198 			 LM77_TEMP_TO_REG(data->temp[t_hyst]));  in temp_hyst_store()
199 	mutex_unlock(&data->update_lock);  in temp_hyst_store()
206 	int bitnr = to_sensor_dev_attr(attr)->index;  in alarm_show()
208 	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);  in alarm_show()
239 /* Return 0 if detection is successful, -ENODEV otherwise */
242 	struct i2c_adapter *adapter = client->adapter;  in lm77_detect()
243 	int i, cur, conf, hyst, crit, min, max;  in lm77_detect()  local
247 		return -ENODEV;  in lm77_detect()
258 	 * 4. registers cycling over 8-address boundaries  in lm77_detect()
260 	 * Word-sized registers are high-byte first.  in lm77_detect()
264 	cur = i2c_smbus_read_word_data(client, 0);  in lm77_detect()
269 	max = i2c_smbus_read_word_data(client, 5);  in lm77_detect()
275 		 || i2c_smbus_read_word_data(client, i + 5) != max)  in lm77_detect()
276 			return -ENODEV;  in lm77_detect()
280 	if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)  in lm77_detect()
284 	 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))  in lm77_detect()
285 		return -ENODEV;  in lm77_detect()
289 		return -ENODEV;  in lm77_detect()
292 	cur = i2c_smbus_read_word_data(client, 0);  in lm77_detect()
293 	if (i2c_smbus_read_word_data(client, 6) != cur  in lm77_detect()
294 	 || i2c_smbus_read_word_data(client, 7) != cur)  in lm77_detect()
295 		return -ENODEV;  in lm77_detect()
299 		return -ENODEV;  in lm77_detect()
303 		return -ENODEV;  in lm77_detect()
305 	strscpy(info->type, "lm77", I2C_NAME_SIZE);  in lm77_detect()
312 	/* Initialize the LM77 chip - turn off shutdown mode */  in lm77_init_client()
320 	struct device *dev = &client->dev;  in lm77_probe()
326 		return -ENOMEM;  in lm77_probe()
328 	data->client = client;  in lm77_probe()
329 	mutex_init(&data->update_lock);  in lm77_probe()
334 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,  in lm77_probe()