firmware: arm_scmi: Add SCMI v3.0 sensors timestamped reads

Add new .reading_get_timestamped() method to sensor_ops to support SCMI v3.0
timestamped reads.

Link: https://lore.kernel.org/r/20201119174906.43862-5-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index a85827f..2239af5 100644 (file)
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -155,6 +155,23 @@ struct scmi_msg_sensor_reading_get {
 #define SENSOR_READ_ASYNC      BIT(0)
 };
 
+struct scmi_resp_sensor_reading_complete {
+       __le32 id;
+       __le64 readings;
+};
+
+struct scmi_sensor_reading_le {
+       __le32 sensor_value_low;
+       __le32 sensor_value_high;
+       __le32 timestamp_low;
+       __le32 timestamp_high;
+};
+
+struct scmi_resp_sensor_reading_complete_v3 {
+       __le32 id;
+       struct scmi_sensor_reading_le readings[];
+};
+
 struct scmi_sensor_trip_notify_payld {
        __le32 agent_id;
        __le32 sensor_id;
@@ -575,6 +592,21 @@ scmi_sensor_trip_point_config(const struct scmi_handle *handle, u32 sensor_id,
        return ret;
 }
 
+/**
+ * scmi_sensor_reading_get  - Read scalar sensor value
+ * @handle: Platform handle
+ * @sensor_id: Sensor ID
+ * @value: The 64bit value sensor reading
+ *
+ * This function returns a single 64 bit reading value representing the sensor
+ * value; if the platform SCMI Protocol implementation and the sensor support
+ * multiple axis and timestamped-reads, this just returns the first axis while
+ * dropping the timestamp value.
+ * Use instead the @scmi_sensor_reading_get_timestamped to retrieve the array of
+ * timestamped multi-axis values.
+ *
+ * Return: 0 on Success
+ */
 static int scmi_sensor_reading_get(const struct scmi_handle *handle,
                                   u32 sensor_id, u64 *value)
 {
@@ -585,20 +617,24 @@ static int scmi_sensor_reading_get(const struct scmi_handle *handle,
        struct scmi_sensor_info *s = si->sensors + sensor_id;
 
        ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
-                                SCMI_PROTOCOL_SENSOR, sizeof(*sensor),
-                                sizeof(u64), &t);
+                                SCMI_PROTOCOL_SENSOR, sizeof(*sensor), 0, &t);
        if (ret)
                return ret;
 
        sensor = t->tx.buf;
        sensor->id = cpu_to_le32(sensor_id);
-
        if (s->async) {
                sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
                ret = scmi_do_xfer_with_response(handle, t);
-               if (!ret)
-                       *value = get_unaligned_le64((void *)
-                                                   ((__le32 *)t->rx.buf + 1));
+               if (!ret) {
+                       struct scmi_resp_sensor_reading_complete *resp;
+
+                       resp = t->rx.buf;
+                       if (le32_to_cpu(resp->id) == sensor_id)
+                               *value = get_unaligned_le64(&resp->readings);
+                       else
+                               ret = -EPROTO;
+               }
        } else {
                sensor->flags = cpu_to_le32(0);
                ret = scmi_do_xfer(handle, t);
@@ -610,6 +646,84 @@ static int scmi_sensor_reading_get(const struct scmi_handle *handle,
        return ret;
 }
 
+static inline void
+scmi_parse_sensor_readings(struct scmi_sensor_reading *out,
+                          const struct scmi_sensor_reading_le *in)
+{
+       out->value = get_unaligned_le64((void *)&in->sensor_value_low);
+       out->timestamp = get_unaligned_le64((void *)&in->timestamp_low);
+}
+
+/**
+ * scmi_sensor_reading_get_timestamped  - Read multiple-axis timestamped values
+ * @handle: Platform handle
+ * @sensor_id: Sensor ID
+ * @count: The length of the provided @readings array
+ * @readings: An array of elements each representing a timestamped per-axis
+ *           reading of type @struct scmi_sensor_reading.
+ *           Returned readings are ordered as the @axis descriptors array
+ *           included in @struct scmi_sensor_info and the max number of
+ *           returned elements is min(@count, @num_axis); ideally the provided
+ *           array should be of length @count equal to @num_axis.
+ *
+ * Return: 0 on Success
+ */
+static int
+scmi_sensor_reading_get_timestamped(const struct scmi_handle *handle,
+                                   u32 sensor_id, u8 count,
+                                   struct scmi_sensor_reading *readings)
+{
+       int ret;
+       struct scmi_xfer *t;
+       struct scmi_msg_sensor_reading_get *sensor;
+       struct sensors_info *si = handle->sensor_priv;
+       struct scmi_sensor_info *s = si->sensors + sensor_id;
+
+       if (!count || !readings ||
+           (!s->num_axis && count > 1) || (s->num_axis && count > s->num_axis))
+               return -EINVAL;
+
+       ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
+                                SCMI_PROTOCOL_SENSOR, sizeof(*sensor), 0, &t);
+       if (ret)
+               return ret;
+
+       sensor = t->tx.buf;
+       sensor->id = cpu_to_le32(sensor_id);
+       if (s->async) {
+               sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
+               ret = scmi_do_xfer_with_response(handle, t);
+               if (!ret) {
+                       int i;
+                       struct scmi_resp_sensor_reading_complete_v3 *resp;
+
+                       resp = t->rx.buf;
+                       /* Retrieve only the number of requested axis anyway */
+                       if (le32_to_cpu(resp->id) == sensor_id)
+                               for (i = 0; i < count; i++)
+                                       scmi_parse_sensor_readings(&readings[i],
+                                                                  &resp->readings[i]);
+                       else
+                               ret = -EPROTO;
+               }
+       } else {
+               sensor->flags = cpu_to_le32(0);
+               ret = scmi_do_xfer(handle, t);
+               if (!ret) {
+                       int i;
+                       struct scmi_sensor_reading_le *resp_readings;
+
+                       resp_readings = t->rx.buf;
+                       for (i = 0; i < count; i++)
+                               scmi_parse_sensor_readings(&readings[i],
+                                                          &resp_readings[i]);
+               }
+       }
+
+       scmi_xfer_put(handle, t);
+       return ret;
+}
+
 static const struct scmi_sensor_info *
 scmi_sensor_info_get(const struct scmi_handle *handle, u32 sensor_id)
 {
@@ -630,6 +744,7 @@ static const struct scmi_sensor_ops sensor_ops = {
        .info_get = scmi_sensor_info_get,
        .trip_point_config = scmi_sensor_trip_point_config,
        .reading_get = scmi_sensor_reading_get,
+       .reading_get_timestamped = scmi_sensor_reading_get_timestamped,
 };
 
 static int scmi_sensor_set_notify_enabled(const struct scmi_handle *handle,

diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 0792b0b..0c52bf0 100644 (file)
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -149,6 +149,20 @@ struct scmi_power_ops {
                         u32 *state);
 };
 
+/**
+ * scmi_sensor_reading  - represent a timestamped read
+ *
+ * Used by @reading_get_timestamped method.
+ *
+ * @value: The signed value sensor read.
+ * @timestamp: An unsigned timestamp for the sensor read, as provided by
+ *            SCMI platform. Set to zero when not available.
+ */
+struct scmi_sensor_reading {
+       long long value;
+       unsigned long long timestamp;
+};
+
 /**
  * scmi_range_attrs  - specifies a sensor or axis values' range
  * @min_range: The minimum value which can be represented by the sensor/axis.
@@ -390,6 +404,11 @@ enum scmi_sensor_class {
  * @info_get: get the information of the specified sensor
  * @trip_point_config: selects and configures a trip-point of interest
  * @reading_get: gets the current value of the sensor
+ * @reading_get_timestamped: gets the current value and timestamp, when
+ *                          available, of the sensor. (as of v3.0 spec)
+ *                          Supports multi-axis sensors for sensors which
+ *                          supports it and if the @reading array size of
+ *                          @count entry equals the sensor num_axis
  */
 struct scmi_sensor_ops {
        int (*count_get)(const struct scmi_handle *handle);
@@ -399,6 +418,9 @@ struct scmi_sensor_ops {
                                 u32 sensor_id, u8 trip_id, u64 trip_value);
        int (*reading_get)(const struct scmi_handle *handle, u32 sensor_id,
                           u64 *value);
+       int (*reading_get_timestamped)(const struct scmi_handle *handle,
+                                      u32 sensor_id, u8 count,
+                                      struct scmi_sensor_reading *readings);
 };
 
 /**