1 /*
2 * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x 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/platform_device.h>
24 #include <linux/err.h>
25 #include <linux/hwmon.h>
26 #include <linux/hwmon-sysfs.h>
27 #include <linux/slab.h>
28
29 #include <linux/mfd/wm831x/core.h>
30 #include <linux/mfd/wm831x/auxadc.h>
31
32 static const char * const input_names[] = {
33 [WM831X_AUX_SYSVDD] = "SYSVDD",
34 [WM831X_AUX_USB] = "USB",
35 [WM831X_AUX_BKUP_BATT] = "Backup battery",
36 [WM831X_AUX_BATT] = "Battery",
37 [WM831X_AUX_WALL] = "WALL",
38 [WM831X_AUX_CHIP_TEMP] = "PMIC",
39 [WM831X_AUX_BATT_TEMP] = "Battery",
40 };
41
show_voltage(struct device * dev,struct device_attribute * attr,char * buf)42 static ssize_t show_voltage(struct device *dev,
43 struct device_attribute *attr, char *buf)
44 {
45 struct wm831x *wm831x = dev_get_drvdata(dev);
46 int channel = to_sensor_dev_attr(attr)->index;
47 int ret;
48
49 ret = wm831x_auxadc_read_uv(wm831x, channel);
50 if (ret < 0)
51 return ret;
52
53 return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
54 }
55
show_chip_temp(struct device * dev,struct device_attribute * attr,char * buf)56 static ssize_t show_chip_temp(struct device *dev,
57 struct device_attribute *attr, char *buf)
58 {
59 struct wm831x *wm831x = dev_get_drvdata(dev);
60 int channel = to_sensor_dev_attr(attr)->index;
61 int ret;
62
63 ret = wm831x_auxadc_read(wm831x, channel);
64 if (ret < 0)
65 return ret;
66
67 /* Degrees celsius = (512.18-ret) / 1.0983 */
68 ret = 512180 - (ret * 1000);
69 ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
70
71 return sprintf(buf, "%d\n", ret);
72 }
73
show_label(struct device * dev,struct device_attribute * attr,char * buf)74 static ssize_t show_label(struct device *dev,
75 struct device_attribute *attr, char *buf)
76 {
77 int channel = to_sensor_dev_attr(attr)->index;
78
79 return sprintf(buf, "%s\n", input_names[channel]);
80 }
81
82 #define WM831X_VOLTAGE(id, name) \
83 static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
84 NULL, name)
85
86 #define WM831X_NAMED_VOLTAGE(id, name) \
87 WM831X_VOLTAGE(id, name); \
88 static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label, \
89 NULL, name)
90
91 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
92 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
93 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
94 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
95
96 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
97 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
98 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
99 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
100 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
101
102 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
103 WM831X_AUX_CHIP_TEMP);
104 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
105 WM831X_AUX_CHIP_TEMP);
106 /*
107 * Report as a voltage since conversion depends on external components
108 * and that's what the ABI wants.
109 */
110 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
111 WM831X_AUX_BATT_TEMP);
112 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
113 WM831X_AUX_BATT_TEMP);
114
115 static struct attribute *wm831x_attrs[] = {
116 &sensor_dev_attr_in0_input.dev_attr.attr,
117 &sensor_dev_attr_in1_input.dev_attr.attr,
118 &sensor_dev_attr_in2_input.dev_attr.attr,
119 &sensor_dev_attr_in3_input.dev_attr.attr,
120
121 &sensor_dev_attr_in4_input.dev_attr.attr,
122 &sensor_dev_attr_in4_label.dev_attr.attr,
123 &sensor_dev_attr_in5_input.dev_attr.attr,
124 &sensor_dev_attr_in5_label.dev_attr.attr,
125 &sensor_dev_attr_in6_input.dev_attr.attr,
126 &sensor_dev_attr_in6_label.dev_attr.attr,
127 &sensor_dev_attr_in7_input.dev_attr.attr,
128 &sensor_dev_attr_in7_label.dev_attr.attr,
129 &sensor_dev_attr_in8_input.dev_attr.attr,
130 &sensor_dev_attr_in8_label.dev_attr.attr,
131
132 &sensor_dev_attr_temp1_input.dev_attr.attr,
133 &sensor_dev_attr_temp1_label.dev_attr.attr,
134 &sensor_dev_attr_temp2_input.dev_attr.attr,
135 &sensor_dev_attr_temp2_label.dev_attr.attr,
136
137 NULL
138 };
139
140 ATTRIBUTE_GROUPS(wm831x);
141
wm831x_hwmon_probe(struct platform_device * pdev)142 static int wm831x_hwmon_probe(struct platform_device *pdev)
143 {
144 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
145 struct device *hwmon_dev;
146
147 hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, "wm831x",
148 wm831x,
149 wm831x_groups);
150 return PTR_ERR_OR_ZERO(hwmon_dev);
151 }
152
153 static struct platform_driver wm831x_hwmon_driver = {
154 .probe = wm831x_hwmon_probe,
155 .driver = {
156 .name = "wm831x-hwmon",
157 },
158 };
159
160 module_platform_driver(wm831x_hwmon_driver);
161
162 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
163 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
164 MODULE_LICENSE("GPL");
165 MODULE_ALIAS("platform:wm831x-hwmon");
166
