xref: /openbmc/linux/drivers/hwmon/wm8350-hwmon.c (revision 1dd24dae)
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 ssize_t show_name(struct device *dev,
32 			 struct device_attribute *attr, char *buf)
33 {
34 	return sprintf(buf, "wm8350\n");
35 }
36 
37 static const char * const input_names[] = {
38 	[WM8350_AUXADC_USB]  = "USB",
39 	[WM8350_AUXADC_LINE] = "Line",
40 	[WM8350_AUXADC_BATT] = "Battery",
41 };
42 
43 
44 static ssize_t show_voltage(struct device *dev,
45 			    struct device_attribute *attr, char *buf)
46 {
47 	struct wm8350 *wm8350 = dev_get_drvdata(dev);
48 	int channel = to_sensor_dev_attr(attr)->index;
49 	int val;
50 
51 	val = wm8350_read_auxadc(wm8350, channel, 0, 0) * WM8350_AUX_COEFF;
52 	val = DIV_ROUND_CLOSEST(val, 1000);
53 
54 	return sprintf(buf, "%d\n", val);
55 }
56 
57 static ssize_t show_label(struct device *dev,
58 			  struct device_attribute *attr, char *buf)
59 {
60 	int channel = to_sensor_dev_attr(attr)->index;
61 
62 	return sprintf(buf, "%s\n", input_names[channel]);
63 }
64 
65 #define WM8350_NAMED_VOLTAGE(id, name) \
66 	static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage,\
67 				  NULL, name);		\
68 	static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,	\
69 				  NULL, name)
70 
71 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
72 
73 WM8350_NAMED_VOLTAGE(0, WM8350_AUXADC_USB);
74 WM8350_NAMED_VOLTAGE(1, WM8350_AUXADC_BATT);
75 WM8350_NAMED_VOLTAGE(2, WM8350_AUXADC_LINE);
76 
77 static struct attribute *wm8350_attributes[] = {
78 	&dev_attr_name.attr,
79 
80 	&sensor_dev_attr_in0_input.dev_attr.attr,
81 	&sensor_dev_attr_in0_label.dev_attr.attr,
82 	&sensor_dev_attr_in1_input.dev_attr.attr,
83 	&sensor_dev_attr_in1_label.dev_attr.attr,
84 	&sensor_dev_attr_in2_input.dev_attr.attr,
85 	&sensor_dev_attr_in2_label.dev_attr.attr,
86 
87 	NULL,
88 };
89 
90 static const struct attribute_group wm8350_attr_group = {
91 	.attrs	= wm8350_attributes,
92 };
93 
94 static int wm8350_hwmon_probe(struct platform_device *pdev)
95 {
96 	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
97 	int ret;
98 
99 	ret = sysfs_create_group(&pdev->dev.kobj, &wm8350_attr_group);
100 	if (ret)
101 		goto err;
102 
103 	wm8350->hwmon.classdev = hwmon_device_register(&pdev->dev);
104 	if (IS_ERR(wm8350->hwmon.classdev)) {
105 		ret = PTR_ERR(wm8350->hwmon.classdev);
106 		goto err_group;
107 	}
108 
109 	return 0;
110 
111 err_group:
112 	sysfs_remove_group(&pdev->dev.kobj, &wm8350_attr_group);
113 err:
114 	return ret;
115 }
116 
117 static int wm8350_hwmon_remove(struct platform_device *pdev)
118 {
119 	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
120 
121 	hwmon_device_unregister(wm8350->hwmon.classdev);
122 	sysfs_remove_group(&pdev->dev.kobj, &wm8350_attr_group);
123 
124 	return 0;
125 }
126 
127 static struct platform_driver wm8350_hwmon_driver = {
128 	.probe = wm8350_hwmon_probe,
129 	.remove = wm8350_hwmon_remove,
130 	.driver = {
131 		.name = "wm8350-hwmon",
132 		.owner = THIS_MODULE,
133 	},
134 };
135 
136 module_platform_driver(wm8350_hwmon_driver);
137 
138 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
139 MODULE_DESCRIPTION("WM8350 Hardware Monitoring");
140 MODULE_LICENSE("GPL");
141 MODULE_ALIAS("platform:wm8350-hwmon");
142