Merge branch 'net-renesas-rswitch-fix-a-lot-of-redundant-irq-issue'
[linux-2.6-block.git] / drivers / hwmon / scpi-hwmon.c
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23297edb 1// SPDX-License-Identifier: GPL-2.0
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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>
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7 */
8
9#include <linux/hwmon.h>
10#include <linux/module.h>
39f03438 11#include <linux/of.h>
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12#include <linux/platform_device.h>
13#include <linux/scpi_protocol.h>
14#include <linux/slab.h>
15#include <linux/sysfs.h>
68acc77a 16#include <linux/thermal.h>
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17
18struct sensor_data {
ccc9b826 19 unsigned int scale;
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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
68acc77a 27struct scpi_thermal_zone {
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28 int sensor_id;
29 struct scpi_sensors *scpi_sensors;
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30};
31
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32struct scpi_sensors {
33 struct scpi_ops *scpi_ops;
34 struct sensor_data *data;
68acc77a 35 struct list_head thermal_zones;
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36 struct attribute **attrs;
37 struct attribute_group group;
38 const struct attribute_group *groups[2];
39};
40
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41static 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
49static 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
57static 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
e5181331 65static int scpi_read_temp(struct thermal_zone_device *tz, int *temp)
68acc77a 66{
0ce637a5 67 struct scpi_thermal_zone *zone = thermal_zone_device_priv(tz);
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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];
2e874159 71 u64 value;
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72 int ret;
73
74 ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
75 if (ret)
76 return ret;
77
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78 scpi_scale_reading(&value, sensor);
79
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80 *temp = value;
81 return 0;
82}
83
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84/* hwmon callback functions */
85static ssize_t
86scpi_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;
2e874159 91 u64 value;
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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
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100 scpi_scale_reading(&value, sensor);
101
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102 /*
103 * Temperature sensor values are treated as signed values based on
104 * observation even though that is not explicitly specified, and
105 * because an unsigned u64 temperature does not really make practical
106 * sense especially when the temperature is below zero degrees Celsius.
107 */
108 if (sensor->info.class == TEMPERATURE)
109 return sprintf(buf, "%lld\n", (s64)value);
110
2e874159 111 return sprintf(buf, "%llu\n", value);
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112}
113
114static ssize_t
115scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
116{
117 struct sensor_data *sensor;
118
119 sensor = container_of(attr, struct sensor_data, dev_attr_label);
120
121 return sprintf(buf, "%s\n", sensor->info.name);
122}
123
e5181331 124static const struct thermal_zone_device_ops scpi_sensor_ops = {
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125 .get_temp = scpi_read_temp,
126};
127
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128static const struct of_device_id scpi_of_match[] = {
129 {.compatible = "arm,scpi-sensors", .data = &scpi_scale},
130 {.compatible = "amlogic,meson-gxbb-scpi-sensors", .data = &gxbb_scpi_scale},
131 {},
132};
133MODULE_DEVICE_TABLE(of, scpi_of_match);
134
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135static int scpi_hwmon_probe(struct platform_device *pdev)
136{
137 u16 nr_sensors, i;
ccc9b826 138 const u32 *scale;
ea98b29a 139 int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0;
fb3b07ef 140 int num_energy = 0;
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141 struct scpi_ops *scpi_ops;
142 struct device *hwdev, *dev = &pdev->dev;
143 struct scpi_sensors *scpi_sensors;
d7817ff2 144 int idx, ret;
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145
146 scpi_ops = get_scpi_ops();
147 if (!scpi_ops)
148 return -EPROBE_DEFER;
149
150 ret = scpi_ops->sensor_get_capability(&nr_sensors);
151 if (ret)
152 return ret;
153
154 if (!nr_sensors)
155 return -ENODEV;
156
157 scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL);
158 if (!scpi_sensors)
159 return -ENOMEM;
160
161 scpi_sensors->data = devm_kcalloc(dev, nr_sensors,
162 sizeof(*scpi_sensors->data), GFP_KERNEL);
163 if (!scpi_sensors->data)
164 return -ENOMEM;
165
166 scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1,
167 sizeof(*scpi_sensors->attrs), GFP_KERNEL);
168 if (!scpi_sensors->attrs)
169 return -ENOMEM;
170
171 scpi_sensors->scpi_ops = scpi_ops;
172
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173 scale = of_device_get_match_data(&pdev->dev);
174 if (!scale) {
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175 dev_err(&pdev->dev, "Unable to initialize scpi-hwmon data\n");
176 return -ENODEV;
177 }
ccc9b826 178
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179 for (i = 0, idx = 0; i < nr_sensors; i++) {
180 struct sensor_data *sensor = &scpi_sensors->data[idx];
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181
182 ret = scpi_ops->sensor_get_info(i, &sensor->info);
183 if (ret)
184 return ret;
185
186 switch (sensor->info.class) {
187 case TEMPERATURE:
188 snprintf(sensor->input, sizeof(sensor->input),
189 "temp%d_input", num_temp + 1);
190 snprintf(sensor->label, sizeof(sensor->input),
191 "temp%d_label", num_temp + 1);
192 num_temp++;
193 break;
194 case VOLTAGE:
195 snprintf(sensor->input, sizeof(sensor->input),
196 "in%d_input", num_volt);
197 snprintf(sensor->label, sizeof(sensor->input),
198 "in%d_label", num_volt);
199 num_volt++;
200 break;
201 case CURRENT:
202 snprintf(sensor->input, sizeof(sensor->input),
203 "curr%d_input", num_current + 1);
204 snprintf(sensor->label, sizeof(sensor->input),
205 "curr%d_label", num_current + 1);
206 num_current++;
207 break;
208 case POWER:
209 snprintf(sensor->input, sizeof(sensor->input),
210 "power%d_input", num_power + 1);
211 snprintf(sensor->label, sizeof(sensor->input),
212 "power%d_label", num_power + 1);
213 num_power++;
214 break;
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215 case ENERGY:
216 snprintf(sensor->input, sizeof(sensor->input),
217 "energy%d_input", num_energy + 1);
218 snprintf(sensor->label, sizeof(sensor->input),
219 "energy%d_label", num_energy + 1);
220 num_energy++;
221 break;
ea98b29a 222 default:
cef03d7e 223 continue;
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224 }
225
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226 sensor->scale = scale[sensor->info.class];
227
6a0785aa 228 sensor->dev_attr_input.attr.mode = 0444;
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229 sensor->dev_attr_input.show = scpi_show_sensor;
230 sensor->dev_attr_input.attr.name = sensor->input;
231
6a0785aa 232 sensor->dev_attr_label.attr.mode = 0444;
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233 sensor->dev_attr_label.show = scpi_show_label;
234 sensor->dev_attr_label.attr.name = sensor->label;
235
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236 scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr;
237 scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr;
ea98b29a 238
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239 sysfs_attr_init(scpi_sensors->attrs[idx << 1]);
240 sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]);
241 idx++;
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242 }
243
244 scpi_sensors->group.attrs = scpi_sensors->attrs;
245 scpi_sensors->groups[0] = &scpi_sensors->group;
246
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247 platform_set_drvdata(pdev, scpi_sensors);
248
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249 hwdev = devm_hwmon_device_register_with_groups(dev,
250 "scpi_sensors", scpi_sensors, scpi_sensors->groups);
251
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252 if (IS_ERR(hwdev))
253 return PTR_ERR(hwdev);
254
255 /*
256 * Register the temperature sensors with the thermal framework
257 * to allow their usage in setting up the thermal zones from
258 * device tree.
259 *
260 * NOTE: Not all temperature sensors maybe used for thermal
261 * control
262 */
263 INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
264 for (i = 0; i < nr_sensors; i++) {
265 struct sensor_data *sensor = &scpi_sensors->data[i];
d7817ff2 266 struct thermal_zone_device *z;
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267 struct scpi_thermal_zone *zone;
268
269 if (sensor->info.class != TEMPERATURE)
270 continue;
271
272 zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL);
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273 if (!zone)
274 return -ENOMEM;
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275
276 zone->sensor_id = i;
277 zone->scpi_sensors = scpi_sensors;
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278 z = devm_thermal_of_zone_register(dev,
279 sensor->info.sensor_id,
280 zone,
281 &scpi_sensor_ops);
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282 /*
283 * The call to thermal_zone_of_sensor_register returns
284 * an error for sensors that are not associated with
285 * any thermal zones or if the thermal subsystem is
286 * not configured.
287 */
3045b5d6 288 if (IS_ERR(z))
68acc77a 289 devm_kfree(dev, zone);
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290 }
291
68acc77a 292 return 0;
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293}
294
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295static struct platform_driver scpi_hwmon_platdrv = {
296 .driver = {
297 .name = "scpi-hwmon",
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298 .of_match_table = scpi_of_match,
299 },
300 .probe = scpi_hwmon_probe,
301};
302module_platform_driver(scpi_hwmon_platdrv);
303
304MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>");
305MODULE_DESCRIPTION("ARM SCPI HWMON interface driver");
306MODULE_LICENSE("GPL v2");