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, S_IRUGO, vexpress_hwmon_label_show, NULL);
96 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
97 		NULL, 1000);
98 static struct attribute *vexpress_hwmon_attrs_volt[] = {
99 	&dev_attr_in1_label.attr,
100 	&sensor_dev_attr_in1_input.dev_attr.attr,
101 	NULL
102 };
103 static struct attribute_group vexpress_hwmon_group_volt = {
104 	.is_visible = vexpress_hwmon_attr_is_visible,
105 	.attrs = vexpress_hwmon_attrs_volt,
106 };
107 static struct vexpress_hwmon_type vexpress_hwmon_volt = {
108 	.name = "vexpress_volt",
109 	.attr_groups = (const struct attribute_group *[]) {
110 		&vexpress_hwmon_group_volt,
111 		NULL,
112 	},
113 };
114 #endif
115 
116 static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
117 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
118 		NULL, 1000);
119 static struct attribute *vexpress_hwmon_attrs_amp[] = {
120 	&dev_attr_curr1_label.attr,
121 	&sensor_dev_attr_curr1_input.dev_attr.attr,
122 	NULL
123 };
124 static struct attribute_group vexpress_hwmon_group_amp = {
125 	.is_visible = vexpress_hwmon_attr_is_visible,
126 	.attrs = vexpress_hwmon_attrs_amp,
127 };
128 static struct vexpress_hwmon_type vexpress_hwmon_amp = {
129 	.name = "vexpress_amp",
130 	.attr_groups = (const struct attribute_group *[]) {
131 		&vexpress_hwmon_group_amp,
132 		NULL
133 	},
134 };
135 
136 static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
137 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
138 		NULL, 1000);
139 static struct attribute *vexpress_hwmon_attrs_temp[] = {
140 	&dev_attr_temp1_label.attr,
141 	&sensor_dev_attr_temp1_input.dev_attr.attr,
142 	NULL
143 };
144 static struct attribute_group vexpress_hwmon_group_temp = {
145 	.is_visible = vexpress_hwmon_attr_is_visible,
146 	.attrs = vexpress_hwmon_attrs_temp,
147 };
148 static struct vexpress_hwmon_type vexpress_hwmon_temp = {
149 	.name = "vexpress_temp",
150 	.attr_groups = (const struct attribute_group *[]) {
151 		&vexpress_hwmon_group_temp,
152 		NULL
153 	},
154 };
155 
156 static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
157 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
158 		NULL, 1);
159 static struct attribute *vexpress_hwmon_attrs_power[] = {
160 	&dev_attr_power1_label.attr,
161 	&sensor_dev_attr_power1_input.dev_attr.attr,
162 	NULL
163 };
164 static struct attribute_group vexpress_hwmon_group_power = {
165 	.is_visible = vexpress_hwmon_attr_is_visible,
166 	.attrs = vexpress_hwmon_attrs_power,
167 };
168 static struct vexpress_hwmon_type vexpress_hwmon_power = {
169 	.name = "vexpress_power",
170 	.attr_groups = (const struct attribute_group *[]) {
171 		&vexpress_hwmon_group_power,
172 		NULL
173 	},
174 };
175 
176 static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
177 static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
178 		NULL, 1);
179 static struct attribute *vexpress_hwmon_attrs_energy[] = {
180 	&dev_attr_energy1_label.attr,
181 	&sensor_dev_attr_energy1_input.dev_attr.attr,
182 	NULL
183 };
184 static struct attribute_group vexpress_hwmon_group_energy = {
185 	.is_visible = vexpress_hwmon_attr_is_visible,
186 	.attrs = vexpress_hwmon_attrs_energy,
187 };
188 static struct vexpress_hwmon_type vexpress_hwmon_energy = {
189 	.name = "vexpress_energy",
190 	.attr_groups = (const struct attribute_group *[]) {
191 		&vexpress_hwmon_group_energy,
192 		NULL
193 	},
194 };
195 
196 static const struct of_device_id vexpress_hwmon_of_match[] = {
197 #if !defined(CONFIG_REGULATOR_VEXPRESS)
198 	{
199 		.compatible = "arm,vexpress-volt",
200 		.data = &vexpress_hwmon_volt,
201 	},
202 #endif
203 	{
204 		.compatible = "arm,vexpress-amp",
205 		.data = &vexpress_hwmon_amp,
206 	}, {
207 		.compatible = "arm,vexpress-temp",
208 		.data = &vexpress_hwmon_temp,
209 	}, {
210 		.compatible = "arm,vexpress-power",
211 		.data = &vexpress_hwmon_power,
212 	}, {
213 		.compatible = "arm,vexpress-energy",
214 		.data = &vexpress_hwmon_energy,
215 	},
216 	{}
217 };
218 MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
219 
220 static int vexpress_hwmon_probe(struct platform_device *pdev)
221 {
222 	const struct of_device_id *match;
223 	struct vexpress_hwmon_data *data;
224 	const struct vexpress_hwmon_type *type;
225 
226 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
227 	if (!data)
228 		return -ENOMEM;
229 	platform_set_drvdata(pdev, data);
230 
231 	match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
232 	if (!match)
233 		return -ENODEV;
234 	type = match->data;
235 
236 	data->reg = devm_regmap_init_vexpress_config(&pdev->dev);
237 	if (IS_ERR(data->reg))
238 		return PTR_ERR(data->reg);
239 
240 	data->hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
241 			type->name, data, type->attr_groups);
242 
243 	return PTR_ERR_OR_ZERO(data->hwmon_dev);
244 }
245 
246 static struct platform_driver vexpress_hwmon_driver = {
247 	.probe = vexpress_hwmon_probe,
248 	.driver	= {
249 		.name = DRVNAME,
250 		.of_match_table = vexpress_hwmon_of_match,
251 	},
252 };
253 
254 module_platform_driver(vexpress_hwmon_driver);
255 
256 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
257 MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
258 MODULE_LICENSE("GPL");
259 MODULE_ALIAS("platform:vexpress-hwmon");
260