Messages in this thread | | | Date | Tue, 10 Nov 2020 17:04:29 +0000 | From | Cristian Marussi <> | Subject | Re: [PATCH v2 4/6] firmware: arm_scmi: add SCMIv3.0 Sensors timestamped reads |
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Hi Peter
thanks for the review.
On Tue, Nov 10, 2020 at 05:01:26PM +0100, Peter Hilber wrote: > On 26.10.20 21:10, Cristian Marussi wrote: > > Add new .reading_get_timestamped() method to sensor_ops to support SCMIv3.0 > > timestamped reads. > > > > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> > > --- > > drivers/firmware/arm_scmi/sensors.c | 134 ++++++++++++++++++++++++++-- > > include/linux/scmi_protocol.h | 22 +++++ > > 2 files changed, 151 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c > > index 5a18f8c84bef..bdb0ed0df683 100644 > > --- a/drivers/firmware/arm_scmi/sensors.c > > +++ b/drivers/firmware/arm_scmi/sensors.c > > @@ -156,6 +156,27 @@ struct scmi_msg_sensor_reading_get { > > #define SENSOR_READ_ASYNC BIT(0) > > }; > > > > +struct scmi_resp_sensor_reading_get { > > + __le64 readings; > > +}; > > + > > +struct scmi_resp_sensor_reading_complete { > > + __le32 id; > > + __le64 readings; > > +}; > > In my understanding the id field is not present in the spec. The > implementation seems to have introduced it already before this patch. >
Well, it is indeed defined in 4.7.3.1 "SENSOR_READING_COMPLETE" both in SCMI V3.0 and in V2.0: it is the async delayed response and this 'id' represents the sensor_id: in fact it is used only the in the async path in the reading funcs; the sync version uses directly sensor_reading_le. (which has no id n it)
> > + > > +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[]; > > +}; > > As above, IMHO the id field is not present in the spec. >
As said above it is for the delayed_responses, in this case for V3 messages.
> > + > > struct scmi_sensor_trip_notify_payld { > > __le32 agent_id; > > __le32 sensor_id; > > @@ -576,6 +597,21 @@ 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) > > { > > @@ -593,18 +629,105 @@ static int scmi_sensor_reading_get(const struct scmi_handle *handle, > > How about changing the scmi_xfer_get_init() rx_size to 0 (in the > immediately preceding, not shown lines)? An SCMI platform might not > expect to just have room for the first reading, excluding the timestamp. >
Ah right, because this is the old v2.0 interface which I kept unchanged but now internally the same v3.0 SENSOR_READING_GET message on a v3.0 platform could return multiple per-axis timestamped values even if I just return the first u64 without timestamp. Is this that you mean ? I'll fix to 0.
> > > > 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) { > > + struct scmi_resp_sensor_reading_complete *resp; > > + > > + resp = t->rx.buf; > > + if (le32_to_cpu(resp->id) == sensor_id) > > + *value = le64_to_cpu(resp->readings); > > Maybe this le64_to_cpu() and the one a few lines below should be > replaced by get_unaligned_le64()?
I'll check. > > > + else > > + ret = -EPROTO; > > + } > > + } else { > > + sensor->flags = cpu_to_le32(0); > > + ret = scmi_do_xfer(handle, t); > > + if (!ret) { > > + struct scmi_resp_sensor_reading_get *resp; > > + > > + resp = t->rx.buf; > > + *value = le64_to_cpu(resp->readings); > > + } > > + } > > > > + scmi_xfer_put(handle, t); > > + return ret; > > +} > > + > > [...] > > + > > /** > > * scmi_range_attrs - specifies a sensor or axis values' range > > * @min_range: The minimum value which can be represented by the sensor/axis. > > @@ -387,6 +401,11 @@ 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 v2.1 spec) > > Nitpicking: v2.1 -> v3.0 >
Ok.
> > + * 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); > > @@ -396,6 +415,9 @@ 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); > > }; > > > > /** > > > > Best regards, > > Peter
Thanks
Cristian
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