1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Driver for MAX31730 3-Channel Remote Temperature Sensor
5  * Copyright (c) 2019 Guenter Roeck <linux@roeck-us.net>
41 #define MAX31730_TEMP_MIN		(-128000)
44 /* Each client has this additional data */
53 /*-----------------------------------------------------------------------*/
60 static int max31730_write_config(struct max31730_data *data, u8 set_mask,  in max31730_write_config()  argument
66 	value = data->current_conf & ~clr_mask;  in max31730_write_config()
69 	if (data->current_conf != value) {  in max31730_write_config()
72 		err = i2c_smbus_write_byte_data(data->client, MAX31730_REG_CONF,  in max31730_write_config()
76 		data->current_conf = value;  in max31730_write_config()
82 			       u8 *confdata, int channel, bool enable)  in max31730_set_enable()  argument
88 		regval |= BIT(channel);  in max31730_set_enable()
90 		regval &= ~BIT(channel);  in max31730_set_enable()
101 static int max31730_set_offset_enable(struct max31730_data *data, int channel,  in max31730_set_offset_enable()  argument
104 	return max31730_set_enable(data->client, MAX31730_REG_OFFSET_ENABLE,  in max31730_set_offset_enable()
105 				   &data->offset_enable, channel, enable);  in max31730_set_offset_enable()
108 static int max31730_set_channel_enable(struct max31730_data *data, int channel,  in max31730_set_channel_enable()  argument
111 	return max31730_set_enable(data->client, MAX31730_REG_CHANNEL_ENABLE,  in max31730_set_channel_enable()
112 				   &data->channel_enable, channel, enable);  in max31730_set_channel_enable()
116 			 u32 attr, int channel, long *val)  in max31730_read()  argument
118 	struct max31730_data *data = dev_get_drvdata(dev);  in max31730_read()  local
122 		return -EINVAL;  in max31730_read()
126 		if (!(data->channel_enable & BIT(channel)))  in max31730_read()
127 			return -ENODATA;  in max31730_read()
128 		reg = MAX31730_REG_TEMP + (channel * 2);  in max31730_read()
131 		reg = MAX31730_REG_TEMP_MAX + (channel * 2);  in max31730_read()
137 		*val = !!(data->channel_enable & BIT(channel));  in max31730_read()
140 		if (!channel)  in max31730_read()
141 			return -EINVAL;  in max31730_read()
142 		if (!(data->offset_enable & BIT(channel))) {  in max31730_read()
146 		offset = i2c_smbus_read_byte_data(data->client,  in max31730_read()
150 		*val = (offset - MAX31730_TEMP_OFFSET_BASELINE) * 125;  in max31730_read()
153 		regval = i2c_smbus_read_byte_data(data->client,  in max31730_read()
157 		*val = !!(regval & BIT(channel));  in max31730_read()
160 		regval = i2c_smbus_read_byte_data(data->client,  in max31730_read()
164 		*val = !!(regval & BIT(channel));  in max31730_read()
167 		regval = i2c_smbus_read_byte_data(data->client,  in max31730_read()
171 		*val = !!(regval & BIT(channel));  in max31730_read()
174 		return -EINVAL;  in max31730_read()
176 	regval = i2c_smbus_read_word_swapped(data->client, reg);  in max31730_read()
186 			  u32 attr, int channel, long val)  in max31730_write()  argument
188 	struct max31730_data *data = dev_get_drvdata(dev);  in max31730_write()  local
192 		return -EINVAL;  in max31730_write()
196 		reg = MAX31730_REG_TEMP_MAX + channel * 2;  in max31730_write()
203 			return -EINVAL;  in max31730_write()
204 		return max31730_set_channel_enable(data, channel, val);  in max31730_write()
206 		val = clamp_val(val, -14875, 17000) + 14875;  in max31730_write()
208 		err = max31730_set_offset_enable(data, channel,  in max31730_write()
212 		return i2c_smbus_write_byte_data(data->client,  in max31730_write()
215 		return -EINVAL;  in max31730_write()
221 	return i2c_smbus_write_word_swapped(data->client, reg, (u16)val);  in max31730_write()
224 static umode_t max31730_is_visible(const void *data,  in max31730_is_visible()  argument
226 				   u32 attr, int channel)  in max31730_is_visible()  argument
237 			return channel ? 0444 : 0644;  in max31730_is_visible()
284 static void max31730_remove(void *data)  in max31730_remove()  argument
286 	struct max31730_data *max31730 = data;  in max31730_remove()
287 	struct i2c_client *client = max31730->client;  in max31730_remove()
290 				  max31730->orig_conf);  in max31730_remove()
296 	struct device *dev = &client->dev;  in max31730_probe()
298 	struct max31730_data *data;  in max31730_probe()  local
301 	if (!i2c_check_functionality(client->adapter,  in max31730_probe()
303 		return -EIO;  in max31730_probe()
305 	data = devm_kzalloc(dev, sizeof(struct max31730_data), GFP_KERNEL);  in max31730_probe()
306 	if (!data)  in max31730_probe()
307 		return -ENOMEM;  in max31730_probe()
309 	data->client = client;  in max31730_probe()
315 	data->channel_enable = status;  in max31730_probe()
320 	data->offset_enable = status;  in max31730_probe()
325 	data->orig_conf = status;  in max31730_probe()
326 	data->current_conf = status;  in max31730_probe()
328 	err = max31730_write_config(data,  in max31730_probe()
329 				    data->channel_enable ? 0 : MAX31730_STOP,  in max31730_probe()
330 				    data->channel_enable ? MAX31730_STOP : 0);  in max31730_probe()
334 	dev_set_drvdata(dev, data);  in max31730_probe()
336 	err = devm_add_action_or_reset(dev, max31730_remove, data);  in max31730_probe()
340 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,  in max31730_probe()
341 							 data,  in max31730_probe()
370 /* Return 0 if detection is successful, -ENODEV otherwise */
374 	struct i2c_adapter *adapter = client->adapter;  in max31730_detect()
380 		return -ENODEV;  in max31730_detect()
384 		return -ENODEV;  in max31730_detect()
387 		return -ENODEV;  in max31730_detect()
391 		return -ENODEV;  in max31730_detect()
395 			return -ENODEV;  in max31730_detect()
398 			return -ENODEV;  in max31730_detect()
401 	strscpy(info->type, "max31730", I2C_NAME_SIZE);  in max31730_detect()
408 	struct max31730_data *data = dev_get_drvdata(dev);  in max31730_suspend()  local
410 	return max31730_write_config(data, MAX31730_STOP, 0);  in max31730_suspend()
415 	struct max31730_data *data = dev_get_drvdata(dev);  in max31730_resume()  local
417 	return max31730_write_config(data, 0, MAX31730_STOP);  in max31730_resume()
437 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");