Merge tag 'for-5.13-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...
[linux-2.6-microblaze.git] / drivers / hwmon / scpi-hwmon.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * System Control and Power Interface(SCPI) based hwmon sensor driver
4  *
5  * Copyright (C) 2015 ARM Ltd.
6  * Punit Agrawal <punit.agrawal@arm.com>
7  */
8
9 #include <linux/hwmon.h>
10 #include <linux/module.h>
11 #include <linux/of_device.h>
12 #include <linux/platform_device.h>
13 #include <linux/scpi_protocol.h>
14 #include <linux/slab.h>
15 #include <linux/sysfs.h>
16 #include <linux/thermal.h>
17
18 struct sensor_data {
19         unsigned int scale;
20         struct scpi_sensor_info info;
21         struct device_attribute dev_attr_input;
22         struct device_attribute dev_attr_label;
23         char input[20];
24         char label[20];
25 };
26
27 struct scpi_thermal_zone {
28         int sensor_id;
29         struct scpi_sensors *scpi_sensors;
30 };
31
32 struct scpi_sensors {
33         struct scpi_ops *scpi_ops;
34         struct sensor_data *data;
35         struct list_head thermal_zones;
36         struct attribute **attrs;
37         struct attribute_group group;
38         const struct attribute_group *groups[2];
39 };
40
41 static const u32 gxbb_scpi_scale[] = {
42         [TEMPERATURE]   = 1,            /* (celsius)            */
43         [VOLTAGE]       = 1000,         /* (millivolts)         */
44         [CURRENT]       = 1000,         /* (milliamperes)       */
45         [POWER]         = 1000000,      /* (microwatts)         */
46         [ENERGY]        = 1000000,      /* (microjoules)        */
47 };
48
49 static const u32 scpi_scale[] = {
50         [TEMPERATURE]   = 1000,         /* (millicelsius)       */
51         [VOLTAGE]       = 1000,         /* (millivolts)         */
52         [CURRENT]       = 1000,         /* (milliamperes)       */
53         [POWER]         = 1000000,      /* (microwatts)         */
54         [ENERGY]        = 1000000,      /* (microjoules)        */
55 };
56
57 static void scpi_scale_reading(u64 *value, struct sensor_data *sensor)
58 {
59         if (scpi_scale[sensor->info.class] != sensor->scale) {
60                 *value *= scpi_scale[sensor->info.class];
61                 do_div(*value, sensor->scale);
62         }
63 }
64
65 static int scpi_read_temp(void *dev, int *temp)
66 {
67         struct scpi_thermal_zone *zone = dev;
68         struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
69         struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
70         struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
71         u64 value;
72         int ret;
73
74         ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
75         if (ret)
76                 return ret;
77
78         scpi_scale_reading(&value, sensor);
79
80         *temp = value;
81         return 0;
82 }
83
84 /* hwmon callback functions */
85 static ssize_t
86 scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)
87 {
88         struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev);
89         struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
90         struct sensor_data *sensor;
91         u64 value;
92         int ret;
93
94         sensor = container_of(attr, struct sensor_data, dev_attr_input);
95
96         ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
97         if (ret)
98                 return ret;
99
100         scpi_scale_reading(&value, sensor);
101
102         return sprintf(buf, "%llu\n", value);
103 }
104
105 static ssize_t
106 scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
107 {
108         struct sensor_data *sensor;
109
110         sensor = container_of(attr, struct sensor_data, dev_attr_label);
111
112         return sprintf(buf, "%s\n", sensor->info.name);
113 }
114
115 static const struct thermal_zone_of_device_ops scpi_sensor_ops = {
116         .get_temp = scpi_read_temp,
117 };
118
119 static const struct of_device_id scpi_of_match[] = {
120         {.compatible = "arm,scpi-sensors", .data = &scpi_scale},
121         {.compatible = "amlogic,meson-gxbb-scpi-sensors", .data = &gxbb_scpi_scale},
122         {},
123 };
124 MODULE_DEVICE_TABLE(of, scpi_of_match);
125
126 static int scpi_hwmon_probe(struct platform_device *pdev)
127 {
128         u16 nr_sensors, i;
129         const u32 *scale;
130         int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
131         int num_energy = 0;
132         struct scpi_ops *scpi_ops;
133         struct device *hwdev, *dev = &pdev->dev;
134         struct scpi_sensors *scpi_sensors;
135         const struct of_device_id *of_id;
136         int idx, ret;
137
138         scpi_ops = get_scpi_ops();
139         if (!scpi_ops)
140                 return -EPROBE_DEFER;
141
142         ret = scpi_ops->sensor_get_capability(&nr_sensors);
143         if (ret)
144                 return ret;
145
146         if (!nr_sensors)
147                 return -ENODEV;
148
149         scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL);
150         if (!scpi_sensors)
151                 return -ENOMEM;
152
153         scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
154                                    sizeof(*scpi_sensors->data), GFP_KERNEL);
155         if (!scpi_sensors->data)
156                 return -ENOMEM;
157
158         scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
159                                    sizeof(*scpi_sensors->attrs), GFP_KERNEL);
160         if (!scpi_sensors->attrs)
161                 return -ENOMEM;
162
163         scpi_sensors->scpi_ops = scpi_ops;
164
165         of_id = of_match_device(scpi_of_match, &pdev->dev);
166         if (!of_id) {
167                 dev_err(&pdev->dev, "Unable to initialize scpi-hwmon data\n");
168                 return -ENODEV;
169         }
170         scale = of_id->data;
171
172         for (i = 0, idx = 0; i < nr_sensors; i++) {
173                 struct sensor_data *sensor = &scpi_sensors->data[idx];
174
175                 ret = scpi_ops->sensor_get_info(i, &sensor->info);
176                 if (ret)
177                         return ret;
178
179                 switch (sensor->info.class) {
180                 case TEMPERATURE:
181                         snprintf(sensor->input, sizeof(sensor->input),
182                                  "temp%d_input", num_temp + 1);
183                         snprintf(sensor->label, sizeof(sensor->input),
184                                  "temp%d_label", num_temp + 1);
185                         num_temp++;
186                         break;
187                 case VOLTAGE:
188                         snprintf(sensor->input, sizeof(sensor->input),
189                                  "in%d_input", num_volt);
190                         snprintf(sensor->label, sizeof(sensor->input),
191                                  "in%d_label", num_volt);
192                         num_volt++;
193                         break;
194                 case CURRENT:
195                         snprintf(sensor->input, sizeof(sensor->input),
196                                  "curr%d_input", num_current + 1);
197                         snprintf(sensor->label, sizeof(sensor->input),
198                                  "curr%d_label", num_current + 1);
199                         num_current++;
200                         break;
201                 case POWER:
202                         snprintf(sensor->input, sizeof(sensor->input),
203                                  "power%d_input", num_power + 1);
204                         snprintf(sensor->label, sizeof(sensor->input),
205                                  "power%d_label", num_power + 1);
206                         num_power++;
207                         break;
208                 case ENERGY:
209                         snprintf(sensor->input, sizeof(sensor->input),
210                                  "energy%d_input", num_energy + 1);
211                         snprintf(sensor->label, sizeof(sensor->input),
212                                  "energy%d_label", num_energy + 1);
213                         num_energy++;
214                         break;
215                 default:
216                         continue;
217                 }
218
219                 sensor->scale = scale[sensor->info.class];
220
221                 sensor->dev_attr_input.attr.mode = 0444;
222                 sensor->dev_attr_input.show = scpi_show_sensor;
223                 sensor->dev_attr_input.attr.name = sensor->input;
224
225                 sensor->dev_attr_label.attr.mode = 0444;
226                 sensor->dev_attr_label.show = scpi_show_label;
227                 sensor->dev_attr_label.attr.name = sensor->label;
228
229                 scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr;
230                 scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr;
231
232                 sysfs_attr_init(scpi_sensors->attrs[idx << 1]);
233                 sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]);
234                 idx++;
235         }
236
237         scpi_sensors->group.attrs = scpi_sensors->attrs;
238         scpi_sensors->groups[0] = &scpi_sensors->group;
239
240         platform_set_drvdata(pdev, scpi_sensors);
241
242         hwdev = devm_hwmon_device_register_with_groups(dev,
243                         "scpi_sensors", scpi_sensors, scpi_sensors->groups);
244
245         if (IS_ERR(hwdev))
246                 return PTR_ERR(hwdev);
247
248         /*
249          * Register the temperature sensors with the thermal framework
250          * to allow their usage in setting up the thermal zones from
251          * device tree.
252          *
253          * NOTE: Not all temperature sensors maybe used for thermal
254          * control
255          */
256         INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
257         for (i = 0; i < nr_sensors; i++) {
258                 struct sensor_data *sensor = &scpi_sensors->data[i];
259                 struct thermal_zone_device *z;
260                 struct scpi_thermal_zone *zone;
261
262                 if (sensor->info.class != TEMPERATURE)
263                         continue;
264
265                 zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
266                 if (!zone)
267                         return -ENOMEM;
268
269                 zone->sensor_id = i;
270                 zone->scpi_sensors = scpi_sensors;
271                 z = devm_thermal_zone_of_sensor_register(dev,
272                                                          sensor->info.sensor_id,
273                                                          zone,
274                                                          &scpi_sensor_ops);
275                 /*
276                  * The call to thermal_zone_of_sensor_register returns
277                  * an error for sensors that are not associated with
278                  * any thermal zones or if the thermal subsystem is
279                  * not configured.
280                  */
281                 if (IS_ERR(z))
282                         devm_kfree(dev, zone);
283         }
284
285         return 0;
286 }
287
288 static struct platform_driver scpi_hwmon_platdrv = {
289         .driver = {
290                 .name   = "scpi-hwmon",
291                 .of_match_table = scpi_of_match,
292         },
293         .probe          = scpi_hwmon_probe,
294 };
295 module_platform_driver(scpi_hwmon_platdrv);
296
297 MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
298 MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
299 MODULE_LICENSE("GPL v2");