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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x PMIC
4  *                                hardware monitoring features.
5  *
6  * Copyright (C) 2009 Wolfson Microelectronics plc
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/err.h>
13 #include <linux/hwmon.h>
14 #include <linux/hwmon-sysfs.h>
15 #include <linux/slab.h>
16 
17 #include <linux/mfd/wm831x/core.h>
18 #include <linux/mfd/wm831x/auxadc.h>
19 
20 static const char * const input_names[] = {
21 	[WM831X_AUX_SYSVDD]    = "SYSVDD",
22 	[WM831X_AUX_USB]       = "USB",
23 	[WM831X_AUX_BKUP_BATT] = "Backup battery",
24 	[WM831X_AUX_BATT]      = "Battery",
25 	[WM831X_AUX_WALL]      = "WALL",
26 	[WM831X_AUX_CHIP_TEMP] = "PMIC",
27 	[WM831X_AUX_BATT_TEMP] = "Battery",
28 };
29 
show_voltage(struct device * dev,struct device_attribute * attr,char * buf)30 static ssize_t show_voltage(struct device *dev,
31 			    struct device_attribute *attr, char *buf)
32 {
33 	struct wm831x *wm831x = dev_get_drvdata(dev);
34 	int channel = to_sensor_dev_attr(attr)->index;
35 	int ret;
36 
37 	ret = wm831x_auxadc_read_uv(wm831x, channel);
38 	if (ret < 0)
39 		return ret;
40 
41 	return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
42 }
43 
show_chip_temp(struct device * dev,struct device_attribute * attr,char * buf)44 static ssize_t show_chip_temp(struct device *dev,
45 			      struct device_attribute *attr, char *buf)
46 {
47 	struct wm831x *wm831x = dev_get_drvdata(dev);
48 	int channel = to_sensor_dev_attr(attr)->index;
49 	int ret;
50 
51 	ret = wm831x_auxadc_read(wm831x, channel);
52 	if (ret < 0)
53 		return ret;
54 
55 	/* Degrees celsius = (512.18-ret) / 1.0983 */
56 	ret = 512180 - (ret * 1000);
57 	ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
58 
59 	return sprintf(buf, "%d\n", ret);
60 }
61 
show_label(struct device * dev,struct device_attribute * attr,char * buf)62 static ssize_t show_label(struct device *dev,
63 			  struct device_attribute *attr, char *buf)
64 {
65 	int channel = to_sensor_dev_attr(attr)->index;
66 
67 	return sprintf(buf, "%s\n", input_names[channel]);
68 }
69 
70 #define WM831X_VOLTAGE(id, name) \
71 	static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
72 				  NULL, name)
73 
74 #define WM831X_NAMED_VOLTAGE(id, name) \
75 	WM831X_VOLTAGE(id, name); \
76 	static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,	\
77 				  NULL, name)
78 
79 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
80 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
81 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
82 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
83 
84 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
85 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
86 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
87 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
88 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
89 
90 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
91 			  WM831X_AUX_CHIP_TEMP);
92 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
93 			  WM831X_AUX_CHIP_TEMP);
94 /*
95  * Report as a voltage since conversion depends on external components
96  * and that's what the ABI wants.
97  */
98 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
99 			  WM831X_AUX_BATT_TEMP);
100 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
101 			  WM831X_AUX_BATT_TEMP);
102 
103 static struct attribute *wm831x_attrs[] = {
104 	&sensor_dev_attr_in0_input.dev_attr.attr,
105 	&sensor_dev_attr_in1_input.dev_attr.attr,
106 	&sensor_dev_attr_in2_input.dev_attr.attr,
107 	&sensor_dev_attr_in3_input.dev_attr.attr,
108 
109 	&sensor_dev_attr_in4_input.dev_attr.attr,
110 	&sensor_dev_attr_in4_label.dev_attr.attr,
111 	&sensor_dev_attr_in5_input.dev_attr.attr,
112 	&sensor_dev_attr_in5_label.dev_attr.attr,
113 	&sensor_dev_attr_in6_input.dev_attr.attr,
114 	&sensor_dev_attr_in6_label.dev_attr.attr,
115 	&sensor_dev_attr_in7_input.dev_attr.attr,
116 	&sensor_dev_attr_in7_label.dev_attr.attr,
117 	&sensor_dev_attr_in8_input.dev_attr.attr,
118 	&sensor_dev_attr_in8_label.dev_attr.attr,
119 
120 	&sensor_dev_attr_temp1_input.dev_attr.attr,
121 	&sensor_dev_attr_temp1_label.dev_attr.attr,
122 	&sensor_dev_attr_temp2_input.dev_attr.attr,
123 	&sensor_dev_attr_temp2_label.dev_attr.attr,
124 
125 	NULL
126 };
127 
128 ATTRIBUTE_GROUPS(wm831x);
129 
wm831x_hwmon_probe(struct platform_device * pdev)130 static int wm831x_hwmon_probe(struct platform_device *pdev)
131 {
132 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
133 	struct device *hwmon_dev;
134 
135 	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, "wm831x",
136 							   wm831x,
137 							   wm831x_groups);
138 	return PTR_ERR_OR_ZERO(hwmon_dev);
139 }
140 
141 static struct platform_driver wm831x_hwmon_driver = {
142 	.probe = wm831x_hwmon_probe,
143 	.driver = {
144 		.name = "wm831x-hwmon",
145 	},
146 };
147 
148 module_platform_driver(wm831x_hwmon_driver);
149 
150 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
151 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
152 MODULE_LICENSE("GPL");
153 MODULE_ALIAS("platform:wm831x-hwmon");
154