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
32static 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
42static 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
56static 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
74static 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
91WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
92WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
93WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
94WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
95
96WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
97WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
98WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
99WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
100WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
101
102static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
103			  WM831X_AUX_CHIP_TEMP);
104static 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 */
110static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
111			  WM831X_AUX_BATT_TEMP);
112static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
113			  WM831X_AUX_BATT_TEMP);
114
115static 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
140ATTRIBUTE_GROUPS(wm831x);
141
142static 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
153static struct platform_driver wm831x_hwmon_driver = {
154	.probe = wm831x_hwmon_probe,
155	.driver = {
156		.name = "wm831x-hwmon",
157	},
158};
159
160module_platform_driver(wm831x_hwmon_driver);
161
162MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
163MODULE_DESCRIPTION("WM831x Hardware Monitoring");
164MODULE_LICENSE("GPL");
165MODULE_ALIAS("platform:wm831x-hwmon");
166