1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License version 2 as
4  * published by the Free Software Foundation.
5  *
6  * This program is distributed in the hope that it will be useful,
7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9  * GNU General Public License for more details.
10  *
11  * Copyright (C) 2012 ARM Limited
12  */
13 
14 #define DRVNAME "vexpress-hwmon"
15 #define pr_fmt(fmt) DRVNAME ": " fmt
16 
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/hwmon.h>
20 #include <linux/hwmon-sysfs.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include <linux/platform_device.h>
25 #include <linux/vexpress.h>
26 
27 struct vexpress_hwmon_data {
28 	struct device *hwmon_dev;
29 	struct regmap *reg;
30 };
31 
32 static ssize_t vexpress_hwmon_label_show(struct device *dev,
33 		struct device_attribute *dev_attr, char *buffer)
34 {
35 	const char *label = of_get_property(dev->of_node, "label", NULL);
36 
37 	return snprintf(buffer, PAGE_SIZE, "%s\n", label);
38 }
39 
40 static ssize_t vexpress_hwmon_u32_show(struct device *dev,
41 		struct device_attribute *dev_attr, char *buffer)
42 {
43 	struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
44 	int err;
45 	u32 value;
46 
47 	err = regmap_read(data->reg, 0, &value);
48 	if (err)
49 		return err;
50 
51 	return snprintf(buffer, PAGE_SIZE, "%u\n", value /
52 			to_sensor_dev_attr(dev_attr)->index);
53 }
54 
55 static ssize_t vexpress_hwmon_u64_show(struct device *dev,
56 		struct device_attribute *dev_attr, char *buffer)
57 {
58 	struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
59 	int err;
60 	u32 value_hi, value_lo;
61 
62 	err = regmap_read(data->reg, 0, &value_lo);
63 	if (err)
64 		return err;
65 
66 	err = regmap_read(data->reg, 1, &value_hi);
67 	if (err)
68 		return err;
69 
70 	return snprintf(buffer, PAGE_SIZE, "%llu\n",
71 			div_u64(((u64)value_hi << 32) | value_lo,
72 			to_sensor_dev_attr(dev_attr)->index));
73 }
74 
75 static umode_t vexpress_hwmon_attr_is_visible(struct kobject *kobj,
76 		struct attribute *attr, int index)
77 {
78 	struct device *dev = kobj_to_dev(kobj);
79 	struct device_attribute *dev_attr = container_of(attr,
80 				struct device_attribute, attr);
81 
82 	if (dev_attr->show == vexpress_hwmon_label_show &&
83 			!of_get_property(dev->of_node, "label", NULL))
84 		return 0;
85 
86 	return attr->mode;
87 }
88 
89 struct vexpress_hwmon_type {
90 	const char *name;
91 	const struct attribute_group **attr_groups;
92 };
93 
94 #if !defined(CONFIG_REGULATOR_VEXPRESS)
95 static DEVICE_ATTR(in1_label, 0444, vexpress_hwmon_label_show, NULL);
96 static SENSOR_DEVICE_ATTR_RO(in1_input, vexpress_hwmon_u32, 1000);
97 static struct attribute *vexpress_hwmon_attrs_volt[] = {
98 	&dev_attr_in1_label.attr,
99 	&sensor_dev_attr_in1_input.dev_attr.attr,
100 	NULL
101 };
102 static struct attribute_group vexpress_hwmon_group_volt = {
103 	.is_visible = vexpress_hwmon_attr_is_visible,
104 	.attrs = vexpress_hwmon_attrs_volt,
105 };
106 static struct vexpress_hwmon_type vexpress_hwmon_volt = {
107 	.name = "vexpress_volt",
108 	.attr_groups = (const struct attribute_group *[]) {
109 		&vexpress_hwmon_group_volt,
110 		NULL,
111 	},
112 };
113 #endif
114 
115 static DEVICE_ATTR(curr1_label, 0444, vexpress_hwmon_label_show, NULL);
116 static SENSOR_DEVICE_ATTR_RO(curr1_input, vexpress_hwmon_u32, 1000);
117 static struct attribute *vexpress_hwmon_attrs_amp[] = {
118 	&dev_attr_curr1_label.attr,
119 	&sensor_dev_attr_curr1_input.dev_attr.attr,
120 	NULL
121 };
122 static struct attribute_group vexpress_hwmon_group_amp = {
123 	.is_visible = vexpress_hwmon_attr_is_visible,
124 	.attrs = vexpress_hwmon_attrs_amp,
125 };
126 static struct vexpress_hwmon_type vexpress_hwmon_amp = {
127 	.name = "vexpress_amp",
128 	.attr_groups = (const struct attribute_group *[]) {
129 		&vexpress_hwmon_group_amp,
130 		NULL
131 	},
132 };
133 
134 static DEVICE_ATTR(temp1_label, 0444, vexpress_hwmon_label_show, NULL);
135 static SENSOR_DEVICE_ATTR_RO(temp1_input, vexpress_hwmon_u32, 1000);
136 static struct attribute *vexpress_hwmon_attrs_temp[] = {
137 	&dev_attr_temp1_label.attr,
138 	&sensor_dev_attr_temp1_input.dev_attr.attr,
139 	NULL
140 };
141 static struct attribute_group vexpress_hwmon_group_temp = {
142 	.is_visible = vexpress_hwmon_attr_is_visible,
143 	.attrs = vexpress_hwmon_attrs_temp,
144 };
145 static struct vexpress_hwmon_type vexpress_hwmon_temp = {
146 	.name = "vexpress_temp",
147 	.attr_groups = (const struct attribute_group *[]) {
148 		&vexpress_hwmon_group_temp,
149 		NULL
150 	},
151 };
152 
153 static DEVICE_ATTR(power1_label, 0444, vexpress_hwmon_label_show, NULL);
154 static SENSOR_DEVICE_ATTR_RO(power1_input, vexpress_hwmon_u32, 1);
155 static struct attribute *vexpress_hwmon_attrs_power[] = {
156 	&dev_attr_power1_label.attr,
157 	&sensor_dev_attr_power1_input.dev_attr.attr,
158 	NULL
159 };
160 static struct attribute_group vexpress_hwmon_group_power = {
161 	.is_visible = vexpress_hwmon_attr_is_visible,
162 	.attrs = vexpress_hwmon_attrs_power,
163 };
164 static struct vexpress_hwmon_type vexpress_hwmon_power = {
165 	.name = "vexpress_power",
166 	.attr_groups = (const struct attribute_group *[]) {
167 		&vexpress_hwmon_group_power,
168 		NULL
169 	},
170 };
171 
172 static DEVICE_ATTR(energy1_label, 0444, vexpress_hwmon_label_show, NULL);
173 static SENSOR_DEVICE_ATTR_RO(energy1_input, vexpress_hwmon_u64, 1);
174 static struct attribute *vexpress_hwmon_attrs_energy[] = {
175 	&dev_attr_energy1_label.attr,
176 	&sensor_dev_attr_energy1_input.dev_attr.attr,
177 	NULL
178 };
179 static struct attribute_group vexpress_hwmon_group_energy = {
180 	.is_visible = vexpress_hwmon_attr_is_visible,
181 	.attrs = vexpress_hwmon_attrs_energy,
182 };
183 static struct vexpress_hwmon_type vexpress_hwmon_energy = {
184 	.name = "vexpress_energy",
185 	.attr_groups = (const struct attribute_group *[]) {
186 		&vexpress_hwmon_group_energy,
187 		NULL
188 	},
189 };
190 
191 static const struct of_device_id vexpress_hwmon_of_match[] = {
192 #if !defined(CONFIG_REGULATOR_VEXPRESS)
193 	{
194 		.compatible = "arm,vexpress-volt",
195 		.data = &vexpress_hwmon_volt,
196 	},
197 #endif
198 	{
199 		.compatible = "arm,vexpress-amp",
200 		.data = &vexpress_hwmon_amp,
201 	}, {
202 		.compatible = "arm,vexpress-temp",
203 		.data = &vexpress_hwmon_temp,
204 	}, {
205 		.compatible = "arm,vexpress-power",
206 		.data = &vexpress_hwmon_power,
207 	}, {
208 		.compatible = "arm,vexpress-energy",
209 		.data = &vexpress_hwmon_energy,
210 	},
211 	{}
212 };
213 MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
214 
215 static int vexpress_hwmon_probe(struct platform_device *pdev)
216 {
217 	const struct of_device_id *match;
218 	struct vexpress_hwmon_data *data;
219 	const struct vexpress_hwmon_type *type;
220 
221 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
222 	if (!data)
223 		return -ENOMEM;
224 	platform_set_drvdata(pdev, data);
225 
226 	match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
227 	if (!match)
228 		return -ENODEV;
229 	type = match->data;
230 
231 	data->reg = devm_regmap_init_vexpress_config(&pdev->dev);
232 	if (IS_ERR(data->reg))
233 		return PTR_ERR(data->reg);
234 
235 	data->hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
236 			type->name, data, type->attr_groups);
237 
238 	return PTR_ERR_OR_ZERO(data->hwmon_dev);
239 }
240 
241 static struct platform_driver vexpress_hwmon_driver = {
242 	.probe = vexpress_hwmon_probe,
243 	.driver	= {
244 		.name = DRVNAME,
245 		.of_match_table = vexpress_hwmon_of_match,
246 	},
247 };
248 
249 module_platform_driver(vexpress_hwmon_driver);
250 
251 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
252 MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
253 MODULE_LICENSE("GPL");
254 MODULE_ALIAS("platform:vexpress-hwmon");
255