xref: /openbmc/linux/drivers/hwmon/wm8350-hwmon.c (revision f3539c12)
1 /*
2  * drivers/hwmon/wm8350-hwmon.c - Wolfson Microelectronics WM8350 PMIC
3  *                                  hardware monitoring features.
4  *
5  * Copyright (C) 2009 Wolfson Microelectronics plc
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License v2 as published by the
9  * Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
19  */
20 
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/err.h>
24 #include <linux/platform_device.h>
25 #include <linux/hwmon.h>
26 #include <linux/hwmon-sysfs.h>
27 
28 #include <linux/mfd/wm8350/core.h>
29 #include <linux/mfd/wm8350/comparator.h>
30 
31 static const char * const input_names[] = {
32 	[WM8350_AUXADC_USB]  = "USB",
33 	[WM8350_AUXADC_LINE] = "Line",
34 	[WM8350_AUXADC_BATT] = "Battery",
35 };
36 
37 static ssize_t show_voltage(struct device *dev,
38 			    struct device_attribute *attr, char *buf)
39 {
40 	struct wm8350 *wm8350 = dev_get_drvdata(dev);
41 	int channel = to_sensor_dev_attr(attr)->index;
42 	int val;
43 
44 	val = wm8350_read_auxadc(wm8350, channel, 0, 0) * WM8350_AUX_COEFF;
45 	val = DIV_ROUND_CLOSEST(val, 1000);
46 
47 	return sprintf(buf, "%d\n", val);
48 }
49 
50 static ssize_t show_label(struct device *dev,
51 			  struct device_attribute *attr, char *buf)
52 {
53 	int channel = to_sensor_dev_attr(attr)->index;
54 
55 	return sprintf(buf, "%s\n", input_names[channel]);
56 }
57 
58 #define WM8350_NAMED_VOLTAGE(id, name) \
59 	static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage,\
60 				  NULL, name);		\
61 	static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,	\
62 				  NULL, name)
63 
64 WM8350_NAMED_VOLTAGE(0, WM8350_AUXADC_USB);
65 WM8350_NAMED_VOLTAGE(1, WM8350_AUXADC_BATT);
66 WM8350_NAMED_VOLTAGE(2, WM8350_AUXADC_LINE);
67 
68 static struct attribute *wm8350_attrs[] = {
69 	&sensor_dev_attr_in0_input.dev_attr.attr,
70 	&sensor_dev_attr_in0_label.dev_attr.attr,
71 	&sensor_dev_attr_in1_input.dev_attr.attr,
72 	&sensor_dev_attr_in1_label.dev_attr.attr,
73 	&sensor_dev_attr_in2_input.dev_attr.attr,
74 	&sensor_dev_attr_in2_label.dev_attr.attr,
75 
76 	NULL,
77 };
78 
79 ATTRIBUTE_GROUPS(wm8350);
80 
81 static int wm8350_hwmon_probe(struct platform_device *pdev)
82 {
83 	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
84 	struct device *hwmon_dev;
85 
86 	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, "wm8350",
87 							   wm8350,
88 							   wm8350_groups);
89 	return PTR_ERR_OR_ZERO(hwmon_dev);
90 }
91 
92 static struct platform_driver wm8350_hwmon_driver = {
93 	.probe = wm8350_hwmon_probe,
94 	.driver = {
95 		.name = "wm8350-hwmon",
96 	},
97 };
98 
99 module_platform_driver(wm8350_hwmon_driver);
100 
101 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
102 MODULE_DESCRIPTION("WM8350 Hardware Monitoring");
103 MODULE_LICENSE("GPL");
104 MODULE_ALIAS("platform:wm8350-hwmon");
105