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-rw-r--r--drivers/hwmon/scmi-hwmon.c374
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
new file mode 100644
index 000000000..e192f0c67
--- /dev/null
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -0,0 +1,374 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface(SCMI) based hwmon sensor driver
+ *
+ * Copyright (C) 2018-2021 ARM Ltd.
+ * Sudeep Holla <sudeep.holla@arm.com>
+ */
+
+#include <linux/hwmon.h>
+#include <linux/module.h>
+#include <linux/scmi_protocol.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+static const struct scmi_sensor_proto_ops *sensor_ops;
+
+struct scmi_sensors {
+ const struct scmi_protocol_handle *ph;
+ const struct scmi_sensor_info **info[hwmon_max];
+};
+
+struct scmi_thermal_sensor {
+ const struct scmi_protocol_handle *ph;
+ const struct scmi_sensor_info *info;
+};
+
+static inline u64 __pow10(u8 x)
+{
+ u64 r = 1;
+
+ while (x--)
+ r *= 10;
+
+ return r;
+}
+
+static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value)
+{
+ int scale = sensor->scale;
+ u64 f;
+
+ switch (sensor->type) {
+ case TEMPERATURE_C:
+ case VOLTAGE:
+ case CURRENT:
+ scale += 3;
+ break;
+ case POWER:
+ case ENERGY:
+ scale += 6;
+ break;
+ default:
+ break;
+ }
+
+ if (scale == 0)
+ return 0;
+
+ if (abs(scale) > 19)
+ return -E2BIG;
+
+ f = __pow10(abs(scale));
+ if (scale > 0)
+ *value *= f;
+ else
+ *value = div64_u64(*value, f);
+
+ return 0;
+}
+
+static int scmi_hwmon_read_scaled_value(const struct scmi_protocol_handle *ph,
+ const struct scmi_sensor_info *sensor,
+ long *val)
+{
+ int ret;
+ u64 value;
+
+ ret = sensor_ops->reading_get(ph, sensor->id, &value);
+ if (ret)
+ return ret;
+
+ ret = scmi_hwmon_scale(sensor, &value);
+ if (!ret)
+ *val = value;
+
+ return ret;
+}
+
+static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ const struct scmi_sensor_info *sensor;
+ struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);
+
+ sensor = *(scmi_sensors->info[type] + channel);
+
+ return scmi_hwmon_read_scaled_value(scmi_sensors->ph, sensor, val);
+}
+
+static int
+scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, const char **str)
+{
+ const struct scmi_sensor_info *sensor;
+ struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);
+
+ sensor = *(scmi_sensors->info[type] + channel);
+ *str = sensor->name;
+
+ return 0;
+}
+
+static umode_t
+scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ const struct scmi_sensor_info *sensor;
+ const struct scmi_sensors *scmi_sensors = drvdata;
+
+ sensor = *(scmi_sensors->info[type] + channel);
+ if (sensor)
+ return 0444;
+
+ return 0;
+}
+
+static const struct hwmon_ops scmi_hwmon_ops = {
+ .is_visible = scmi_hwmon_is_visible,
+ .read = scmi_hwmon_read,
+ .read_string = scmi_hwmon_read_string,
+};
+
+static struct hwmon_chip_info scmi_chip_info = {
+ .ops = &scmi_hwmon_ops,
+ .info = NULL,
+};
+
+static int scmi_hwmon_thermal_get_temp(struct thermal_zone_device *tz,
+ int *temp)
+{
+ int ret;
+ long value;
+ struct scmi_thermal_sensor *th_sensor = tz->devdata;
+
+ ret = scmi_hwmon_read_scaled_value(th_sensor->ph, th_sensor->info,
+ &value);
+ if (!ret)
+ *temp = value;
+
+ return ret;
+}
+
+static const struct thermal_zone_device_ops scmi_hwmon_thermal_ops = {
+ .get_temp = scmi_hwmon_thermal_get_temp,
+};
+
+static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan,
+ struct device *dev, int num,
+ enum hwmon_sensor_types type, u32 config)
+{
+ int i;
+ u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
+
+ if (!cfg)
+ return -ENOMEM;
+
+ scmi_hwmon_chan->type = type;
+ scmi_hwmon_chan->config = cfg;
+ for (i = 0; i < num; i++, cfg++)
+ *cfg = config;
+
+ return 0;
+}
+
+static enum hwmon_sensor_types scmi_types[] = {
+ [TEMPERATURE_C] = hwmon_temp,
+ [VOLTAGE] = hwmon_in,
+ [CURRENT] = hwmon_curr,
+ [POWER] = hwmon_power,
+ [ENERGY] = hwmon_energy,
+};
+
+static u32 hwmon_attributes[hwmon_max] = {
+ [hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
+ [hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
+ [hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
+ [hwmon_power] = HWMON_P_INPUT | HWMON_P_LABEL,
+ [hwmon_energy] = HWMON_E_INPUT | HWMON_E_LABEL,
+};
+
+static int scmi_thermal_sensor_register(struct device *dev,
+ const struct scmi_protocol_handle *ph,
+ const struct scmi_sensor_info *sensor)
+{
+ struct scmi_thermal_sensor *th_sensor;
+ struct thermal_zone_device *tzd;
+
+ th_sensor = devm_kzalloc(dev, sizeof(*th_sensor), GFP_KERNEL);
+ if (!th_sensor)
+ return -ENOMEM;
+
+ th_sensor->ph = ph;
+ th_sensor->info = sensor;
+
+ /*
+ * Try to register a temperature sensor with the Thermal Framework:
+ * skip sensors not defined as part of any thermal zone (-ENODEV) but
+ * report any other errors related to misconfigured zones/sensors.
+ */
+ tzd = devm_thermal_of_zone_register(dev, th_sensor->info->id, th_sensor,
+ &scmi_hwmon_thermal_ops);
+ if (IS_ERR(tzd)) {
+ devm_kfree(dev, th_sensor);
+
+ if (PTR_ERR(tzd) != -ENODEV)
+ return PTR_ERR(tzd);
+
+ dev_dbg(dev, "Sensor '%s' not attached to any thermal zone.\n",
+ sensor->name);
+ } else {
+ dev_dbg(dev, "Sensor '%s' attached to thermal zone ID:%d\n",
+ sensor->name, tzd->id);
+ }
+
+ return 0;
+}
+
+static int scmi_hwmon_probe(struct scmi_device *sdev)
+{
+ int i, idx;
+ u16 nr_sensors;
+ enum hwmon_sensor_types type;
+ struct scmi_sensors *scmi_sensors;
+ const struct scmi_sensor_info *sensor;
+ int nr_count[hwmon_max] = {0}, nr_types = 0, nr_count_temp = 0;
+ const struct hwmon_chip_info *chip_info;
+ struct device *hwdev, *dev = &sdev->dev;
+ struct hwmon_channel_info *scmi_hwmon_chan;
+ const struct hwmon_channel_info **ptr_scmi_ci;
+ const struct scmi_handle *handle = sdev->handle;
+ struct scmi_protocol_handle *ph;
+
+ if (!handle)
+ return -ENODEV;
+
+ sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
+ if (IS_ERR(sensor_ops))
+ return PTR_ERR(sensor_ops);
+
+ nr_sensors = sensor_ops->count_get(ph);
+ if (!nr_sensors)
+ return -EIO;
+
+ scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);
+ if (!scmi_sensors)
+ return -ENOMEM;
+
+ scmi_sensors->ph = ph;
+
+ for (i = 0; i < nr_sensors; i++) {
+ sensor = sensor_ops->info_get(ph, i);
+ if (!sensor)
+ return -EINVAL;
+
+ switch (sensor->type) {
+ case TEMPERATURE_C:
+ case VOLTAGE:
+ case CURRENT:
+ case POWER:
+ case ENERGY:
+ type = scmi_types[sensor->type];
+ if (!nr_count[type])
+ nr_types++;
+ nr_count[type]++;
+ break;
+ }
+ }
+
+ if (nr_count[hwmon_temp])
+ nr_count_temp = nr_count[hwmon_temp];
+
+ scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),
+ GFP_KERNEL);
+ if (!scmi_hwmon_chan)
+ return -ENOMEM;
+
+ ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),
+ GFP_KERNEL);
+ if (!ptr_scmi_ci)
+ return -ENOMEM;
+
+ scmi_chip_info.info = ptr_scmi_ci;
+ chip_info = &scmi_chip_info;
+
+ for (type = 0; type < hwmon_max; type++) {
+ if (!nr_count[type])
+ continue;
+
+ scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, nr_count[type],
+ type, hwmon_attributes[type]);
+ *ptr_scmi_ci++ = scmi_hwmon_chan++;
+
+ scmi_sensors->info[type] =
+ devm_kcalloc(dev, nr_count[type],
+ sizeof(*scmi_sensors->info), GFP_KERNEL);
+ if (!scmi_sensors->info[type])
+ return -ENOMEM;
+ }
+
+ for (i = nr_sensors - 1; i >= 0 ; i--) {
+ sensor = sensor_ops->info_get(ph, i);
+ if (!sensor)
+ continue;
+
+ switch (sensor->type) {
+ case TEMPERATURE_C:
+ case VOLTAGE:
+ case CURRENT:
+ case POWER:
+ case ENERGY:
+ type = scmi_types[sensor->type];
+ idx = --nr_count[type];
+ *(scmi_sensors->info[type] + idx) = sensor;
+ break;
+ }
+ }
+
+ hwdev = devm_hwmon_device_register_with_info(dev, "scmi_sensors",
+ scmi_sensors, chip_info,
+ NULL);
+ if (IS_ERR(hwdev))
+ return PTR_ERR(hwdev);
+
+ for (i = 0; i < nr_count_temp; i++) {
+ int ret;
+
+ sensor = *(scmi_sensors->info[hwmon_temp] + i);
+ if (!sensor)
+ continue;
+
+ /*
+ * Warn on any misconfiguration related to thermal zones but
+ * bail out of probing only on memory errors.
+ */
+ ret = scmi_thermal_sensor_register(dev, ph, sensor);
+ if (ret) {
+ if (ret == -ENOMEM)
+ return ret;
+ dev_warn(dev,
+ "Thermal zone misconfigured for %s. err=%d\n",
+ sensor->name, ret);
+ }
+ }
+
+ return 0;
+}
+
+static const struct scmi_device_id scmi_id_table[] = {
+ { SCMI_PROTOCOL_SENSOR, "hwmon" },
+ { },
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_hwmon_drv = {
+ .name = "scmi-hwmon",
+ .probe = scmi_hwmon_probe,
+ .id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_hwmon_drv);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");
+MODULE_LICENSE("GPL v2");