1// SPDX-License-Identifier: GPL-2.0
2/*
3 * System Control and Management Interface(SCMI) based hwmon sensor driver
4 *
5 * Copyright (C) 2018 ARM Ltd.
6 * Sudeep Holla <sudeep.holla@arm.com>
7 */
8
9#include <linux/hwmon.h>
10#include <linux/module.h>
11#include <linux/scmi_protocol.h>
12#include <linux/slab.h>
13#include <linux/sysfs.h>
14#include <linux/thermal.h>
15
16struct scmi_sensors {
17 const struct scmi_handle *handle;
18 const struct scmi_sensor_info **info[hwmon_max];
19};
20
21static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
22 u32 attr, int channel, long *val)
23{
24 int ret;
25 u64 value;
26 const struct scmi_sensor_info *sensor;
27 struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);
28 const struct scmi_handle *h = scmi_sensors->handle;
29
30 sensor = *(scmi_sensors->info[type] + channel);
31 ret = h->sensor_ops->reading_get(h, sensor->id, false, &value);
32 if (!ret)
33 *val = value;
34
35 return ret;
36}
37
38static int
39scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
40 u32 attr, int channel, const char **str)
41{
42 const struct scmi_sensor_info *sensor;
43 struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);
44
45 sensor = *(scmi_sensors->info[type] + channel);
46 *str = sensor->name;
47
48 return 0;
49}
50
51static umode_t
52scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
53 u32 attr, int channel)
54{
55 const struct scmi_sensor_info *sensor;
56 const struct scmi_sensors *scmi_sensors = drvdata;
57
58 sensor = *(scmi_sensors->info[type] + channel);
59 if (sensor)
60 return 0444;
61
62 return 0;
63}
64
65static const struct hwmon_ops scmi_hwmon_ops = {
66 .is_visible = scmi_hwmon_is_visible,
67 .read = scmi_hwmon_read,
68 .read_string = scmi_hwmon_read_string,
69};
70
71static struct hwmon_chip_info scmi_chip_info = {
72 .ops = &scmi_hwmon_ops,
73 .info = NULL,
74};
75
76static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan,
77 struct device *dev, int num,
78 enum hwmon_sensor_types type, u32 config)
79{
80 int i;
81 u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
82
83 if (!cfg)
84 return -ENOMEM;
85
86 scmi_hwmon_chan->type = type;
87 scmi_hwmon_chan->config = cfg;
88 for (i = 0; i < num; i++, cfg++)
89 *cfg = config;
90
91 return 0;
92}
93
94static enum hwmon_sensor_types scmi_types[] = {
95 [TEMPERATURE_C] = hwmon_temp,
96 [VOLTAGE] = hwmon_in,
97 [CURRENT] = hwmon_curr,
98 [POWER] = hwmon_power,
99 [ENERGY] = hwmon_energy,
100};
101
102static u32 hwmon_attributes[] = {
103 [hwmon_chip] = HWMON_C_REGISTER_TZ,
104 [hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
105 [hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
106 [hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
107 [hwmon_power] = HWMON_P_INPUT | HWMON_P_LABEL,
108 [hwmon_energy] = HWMON_E_INPUT | HWMON_E_LABEL,
109};
110
111static int scmi_hwmon_probe(struct scmi_device *sdev)
112{
113 int i, idx;
114 u16 nr_sensors;
115 enum hwmon_sensor_types type;
116 struct scmi_sensors *scmi_sensors;
117 const struct scmi_sensor_info *sensor;
118 int nr_count[hwmon_max] = {0}, nr_types = 0;
119 const struct hwmon_chip_info *chip_info;
120 struct device *hwdev, *dev = &sdev->dev;
121 struct hwmon_channel_info *scmi_hwmon_chan;
122 const struct hwmon_channel_info **ptr_scmi_ci;
123 const struct scmi_handle *handle = sdev->handle;
124
125 if (!handle || !handle->sensor_ops)
126 return -ENODEV;
127
128 nr_sensors = handle->sensor_ops->count_get(handle);
129 if (!nr_sensors)
130 return -EIO;
131
132 scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
133 if (!scmi_sensors)
134 return -ENOMEM;
135
136 scmi_sensors->handle = handle;
137
138 for (i = 0; i < nr_sensors; i++) {
139 sensor = handle->sensor_ops->info_get(handle, i);
140 if (!sensor)
141 return -EINVAL;
142
143 switch (sensor->type) {
144 case TEMPERATURE_C:
145 case VOLTAGE:
146 case CURRENT:
147 case POWER:
148 case ENERGY:
149 type = scmi_types[sensor->type];
150 if (!nr_count[type])
151 nr_types++;
152 nr_count[type]++;
153 break;
154 }
155 }
156
157 if (nr_count[hwmon_temp])
158 nr_count[hwmon_chip]++, nr_types++;
159
160 scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),
161 GFP_KERNEL);
162 if (!scmi_hwmon_chan)
163 return -ENOMEM;
164
165 ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),
166 GFP_KERNEL);
167 if (!ptr_scmi_ci)
168 return -ENOMEM;
169
170 scmi_chip_info.info = ptr_scmi_ci;
171 chip_info = &scmi_chip_info;
172
173 for (type = 0; type < hwmon_max; type++) {
174 if (!nr_count[type])
175 continue;
176
177 scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, nr_count[type],
178 type, hwmon_attributes[type]);
179 *ptr_scmi_ci++ = scmi_hwmon_chan++;
180
181 scmi_sensors->info[type] =
182 devm_kcalloc(dev, nr_count[type],
183 sizeof(*scmi_sensors->info), GFP_KERNEL);
184 if (!scmi_sensors->info[type])
185 return -ENOMEM;
186 }
187
188 for (i = nr_sensors - 1; i >= 0 ; i--) {
189 sensor = handle->sensor_ops->info_get(handle, i);
190 if (!sensor)
191 continue;
192
193 switch (sensor->type) {
194 case TEMPERATURE_C:
195 case VOLTAGE:
196 case CURRENT:
197 case POWER:
198 case ENERGY:
199 type = scmi_types[sensor->type];
200 idx = --nr_count[type];
201 *(scmi_sensors->info[type] + idx) = sensor;
202 break;
203 }
204 }
205
206 hwdev = devm_hwmon_device_register_with_info(dev, "scmi_sensors",
207 scmi_sensors, chip_info,
208 NULL);
209
210 return PTR_ERR_OR_ZERO(hwdev);
211}
212
213static const struct scmi_device_id scmi_id_table[] = {
214 { SCMI_PROTOCOL_SENSOR },
215 { },
216};
217MODULE_DEVICE_TABLE(scmi, scmi_id_table);
218
219static struct scmi_driver scmi_hwmon_drv = {
220 .name = "scmi-hwmon",
221 .probe = scmi_hwmon_probe,
222 .id_table = scmi_id_table,
223};
224module_scmi_driver(scmi_hwmon_drv);
225
226MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
227MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");
228MODULE_LICENSE("GPL v2");
229