1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * mcp3021.c - driver for Microchip MCP3021 and MCP3221
5  * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc.
11  * voltage unit is mV. Through the sysfs interface, lm-sensors tool
25 /* Vdd / reference voltage in millivolt */
33 #define MCP3021_OUTPUT_RES	10	/* 10-bit resolution */
37 #define MCP3221_OUTPUT_RES	12	/* 12-bit resolution */
49 	u32 vdd;        /* supply and reference voltage in millivolt */  member
66 		return -EIO;  in mcp3021_read16()
72 	 * The ten-bit output code is composed of the lower 4-bit of the  in mcp3021_read16()
73 	 * first byte and the upper 6-bit of the second byte.  in mcp3021_read16()
75 	reg = (reg >> data->sar_shift) & data->sar_mask;  in mcp3021_read16()
82 	return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);  in volts_from_reg()
109 	struct device_node *np = client->dev.of_node;  in mcp3021_probe()
111 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))  in mcp3021_probe()
112 		return -ENODEV;  in mcp3021_probe()
114 	data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data),  in mcp3021_probe()
117 		return -ENOMEM;  in mcp3021_probe()
122 		if (!of_property_read_u32(np, "reference-voltage-microvolt",  in mcp3021_probe()
123 					  &data->vdd))  in mcp3021_probe()
124 			data->vdd /= 1000;  in mcp3021_probe()
126 			data->vdd = MCP3021_VDD_REF_DEFAULT;  in mcp3021_probe()
128 		u32 *pdata = dev_get_platdata(&client->dev);  in mcp3021_probe()
131 			data->vdd = *pdata;  in mcp3021_probe()
133 			data->vdd = MCP3021_VDD_REF_DEFAULT;  in mcp3021_probe()
136 	switch (i2c_match_id(mcp3021_id, client)->driver_data) {  in mcp3021_probe()
138 		data->sar_shift = MCP3021_SAR_SHIFT;  in mcp3021_probe()
139 		data->sar_mask = MCP3021_SAR_MASK;  in mcp3021_probe()
140 		data->output_res = MCP3021_OUTPUT_RES;  in mcp3021_probe()
144 		data->sar_shift = MCP3221_SAR_SHIFT;  in mcp3021_probe()
145 		data->sar_mask = MCP3221_SAR_MASK;  in mcp3021_probe()
146 		data->output_res = MCP3221_OUTPUT_RES;  in mcp3021_probe()
150 	if (data->vdd > MCP3021_VDD_REF_MAX || data->vdd < MCP3021_VDD_REF_MIN)  in mcp3021_probe()
151 		return -EINVAL;  in mcp3021_probe()
153 	err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr);  in mcp3021_probe()
157 	data->hwmon_dev = hwmon_device_register(&client->dev);  in mcp3021_probe()
158 	if (IS_ERR(data->hwmon_dev)) {  in mcp3021_probe()
159 		err = PTR_ERR(data->hwmon_dev);  in mcp3021_probe()
166 	sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);  in mcp3021_probe()
174 	hwmon_device_unregister(data->hwmon_dev);  in mcp3021_remove()
175 	sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);  in mcp3021_remove()