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 && sensor->name)
 60		return S_IRUGO;
 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");