hwmon: WM831x PMIC hardware monitoring driver
[linux-2.6.git] / drivers / hwmon / wm831x-hwmon.c
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
28 #include <linux/mfd/wm831x/core.h>
29 #include <linux/mfd/wm831x/auxadc.h>
30
31 struct wm831x_hwmon {
32         struct wm831x *wm831x;
33         struct device *classdev;
34 };
35
36 static ssize_t show_name(struct device *dev,
37                          struct device_attribute *attr, char *buf)
38 {
39         return sprintf(buf, "wm831x\n");
40 }
41
42 static const char *input_names[] = {
43         [WM831X_AUX_SYSVDD]    = "SYSVDD",
44         [WM831X_AUX_USB]       = "USB",
45         [WM831X_AUX_BKUP_BATT] = "Backup battery",
46         [WM831X_AUX_BATT]      = "Battery",
47         [WM831X_AUX_WALL]      = "WALL",
48         [WM831X_AUX_CHIP_TEMP] = "PMIC",
49         [WM831X_AUX_BATT_TEMP] = "Battery",
50 };
51
52
53 static ssize_t show_voltage(struct device *dev,
54                             struct device_attribute *attr, char *buf)
55 {
56         struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
57         int channel = to_sensor_dev_attr(attr)->index;
58         int ret;
59
60         ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel);
61         if (ret < 0)
62                 return ret;
63
64         return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
65 }
66
67 static ssize_t show_chip_temp(struct device *dev,
68                               struct device_attribute *attr, char *buf)
69 {
70         struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
71         int channel = to_sensor_dev_attr(attr)->index;
72         int ret;
73
74         ret = wm831x_auxadc_read(hwmon->wm831x, channel);
75         if (ret < 0)
76                 return ret;
77
78         /* Degrees celsius = (512.18-ret) / 1.0983 */
79         ret = 512180 - (ret * 1000);
80         ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
81
82         return sprintf(buf, "%d\n", ret);
83 }
84
85 static ssize_t show_label(struct device *dev,
86                           struct device_attribute *attr, char *buf)
87 {
88         int channel = to_sensor_dev_attr(attr)->index;
89
90         return sprintf(buf, "%s\n", input_names[channel]);
91 }
92
93 #define WM831X_VOLTAGE(id, name) \
94         static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
95                                   NULL, name)
96
97 #define WM831X_NAMED_VOLTAGE(id, name) \
98         WM831X_VOLTAGE(id, name); \
99         static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
100                                   NULL, name)
101
102 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
103
104 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
105 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
106 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
107 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
108
109 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
110 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
111 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
112 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
113 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
114
115 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
116                           WM831X_AUX_CHIP_TEMP);
117 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
118                           WM831X_AUX_CHIP_TEMP);
119 /* Report as a voltage since conversion depends on external components
120  * and that's what the ABI wants. */
121 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
122                           WM831X_AUX_BATT_TEMP);
123 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
124                           WM831X_AUX_BATT_TEMP);
125
126 static struct attribute *wm831x_attributes[] = {
127         &dev_attr_name.attr,
128
129         &sensor_dev_attr_in0_input.dev_attr.attr,
130         &sensor_dev_attr_in1_input.dev_attr.attr,
131         &sensor_dev_attr_in2_input.dev_attr.attr,
132         &sensor_dev_attr_in3_input.dev_attr.attr,
133
134         &sensor_dev_attr_in4_input.dev_attr.attr,
135         &sensor_dev_attr_in4_label.dev_attr.attr,
136         &sensor_dev_attr_in5_input.dev_attr.attr,
137         &sensor_dev_attr_in5_label.dev_attr.attr,
138         &sensor_dev_attr_in6_input.dev_attr.attr,
139         &sensor_dev_attr_in6_label.dev_attr.attr,
140         &sensor_dev_attr_in7_input.dev_attr.attr,
141         &sensor_dev_attr_in7_label.dev_attr.attr,
142         &sensor_dev_attr_in8_input.dev_attr.attr,
143         &sensor_dev_attr_in8_label.dev_attr.attr,
144
145         &sensor_dev_attr_temp1_input.dev_attr.attr,
146         &sensor_dev_attr_temp1_label.dev_attr.attr,
147         &sensor_dev_attr_temp2_input.dev_attr.attr,
148         &sensor_dev_attr_temp2_label.dev_attr.attr,
149
150         NULL
151 };
152
153 static const struct attribute_group wm831x_attr_group = {
154         .attrs  = wm831x_attributes,
155 };
156
157 static int __devinit wm831x_hwmon_probe(struct platform_device *pdev)
158 {
159         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
160         struct wm831x_hwmon *hwmon;
161         int ret;
162
163         hwmon = kzalloc(sizeof(struct wm831x_hwmon), GFP_KERNEL);
164         if (!hwmon)
165                 return -ENOMEM;
166
167         hwmon->wm831x = wm831x;
168
169         ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group);
170         if (ret)
171                 goto err;
172
173         hwmon->classdev = hwmon_device_register(&pdev->dev);
174         if (IS_ERR(hwmon->classdev)) {
175                 ret = PTR_ERR(hwmon->classdev);
176                 goto err_sysfs;
177         }
178
179         platform_set_drvdata(pdev, hwmon);
180
181         return 0;
182
183 err_sysfs:
184         sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
185 err:
186         kfree(hwmon);
187         return ret;
188 }
189
190 static int __devexit wm831x_hwmon_remove(struct platform_device *pdev)
191 {
192         struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev);
193
194         hwmon_device_unregister(hwmon->classdev);
195         sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
196         platform_set_drvdata(pdev, NULL);
197         kfree(hwmon);
198
199         return 0;
200 }
201
202 static struct platform_driver wm831x_hwmon_driver = {
203         .probe = wm831x_hwmon_probe,
204         .remove = __devexit_p(wm831x_hwmon_remove),
205         .driver = {
206                 .name = "wm831x-hwmon",
207                 .owner = THIS_MODULE,
208         },
209 };
210
211 static int __init wm831x_hwmon_init(void)
212 {
213         return platform_driver_register(&wm831x_hwmon_driver);
214 }
215 module_init(wm831x_hwmon_init);
216
217 static void __exit wm831x_hwmon_exit(void)
218 {
219         platform_driver_unregister(&wm831x_hwmon_driver);
220 }
221 module_exit(wm831x_hwmon_exit);
222
223 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
224 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
225 MODULE_LICENSE("GPL");
226 MODULE_ALIAS("platform:wm831x-hwmon");