Hi Scott,
On Thu, Sep 25, 2014 at 1:57 AM, Scott James Remnant <scott@xxxxxxxxxxxx> wrote:
> This is presented as a raw property rather than a parsed "PathLoss"
> property because in the case of many devices, this specific field will
> not be present and instead the TX power will have to be parsed from
> manufacturer-specific data anyway.
>
> It's better therefore to document the Path Loss equation rather than
> hide it.
Im trying to understand your reasoning here, so TxPower is better
because is what you can get from manufacturer data? If we have RSSI
and Tx Power we could just do the math and expose as PathLoss don't
we?
> ---
> doc/device-api.txt | 12 ++++++++++++
> src/adapter.c | 6 ++++--
> src/device.c | 41 +++++++++++++++++++++++++++++++++++++++++
> src/device.h | 1 +
> 4 files changed, 58 insertions(+), 2 deletions(-)
>
> diff --git a/doc/device-api.txt b/doc/device-api.txt
> index 86d8af8..68388e9 100644
> --- a/doc/device-api.txt
> +++ b/doc/device-api.txt
> @@ -193,3 +193,15 @@ Properties string Address [readonly]
>
> Received Signal Strength Indicator of the remote
> device (inquiry or advertising).
> +
> + int16 TxPower [readonly, optional]
> +
> + Transmission power claimed by the remote device
> + (inquiry or advertising). Many devices may not make
> + this available at all, or may incorporate this data
> + into a manufacturer or service-specific field instead.
> +
> + However the remote transmission power is obtained,
> + path loss can be calculated by the equation:
> +
> + Path Loss = Tx Power - RSSI
> diff --git a/src/adapter.c b/src/adapter.c
> index 92ee1a0..1b44dc5 100644
> --- a/src/adapter.c
> +++ b/src/adapter.c
> @@ -1585,16 +1585,17 @@ static int compare_sender(gconstpointer a, gconstpointer b)
> return g_strcmp0(client->owner, sender);
> }
>
> -static void invalidate_rssi(gpointer a)
> +static void invalidate_inquiry_data(gpointer a)
> {
> struct btd_device *dev = a;
>
> device_set_rssi(dev, 0);
> + device_set_tx_power(dev, 127);
> }
>
> static void discovery_cleanup(struct btd_adapter *adapter)
> {
> - g_slist_free_full(adapter->discovery_found, invalidate_rssi);
> + g_slist_free_full(adapter->discovery_found, invalidate_inquiry_data);
> adapter->discovery_found = NULL;
> }
>
> @@ -4715,6 +4716,7 @@ static void update_found_devices(struct btd_adapter *adapter,
>
> device_set_legacy(dev, legacy);
> device_set_rssi(dev, rssi);
> + device_set_tx_power(dev, eir_data.tx_power);
>
> if (eir_data.appearance != 0)
> device_set_appearance(dev, eir_data.appearance);
> diff --git a/src/device.c b/src/device.c
> index 875a5c5..d4ebf4f 100644
> --- a/src/device.c
> +++ b/src/device.c
> @@ -219,6 +219,7 @@ struct btd_device {
>
> bool legacy;
> int8_t rssi;
> + int8_t tx_power;
>
> GIOChannel *att_io;
> guint cleanup_id;
> @@ -812,6 +813,28 @@ static gboolean dev_property_exists_rssi(const GDBusPropertyTable *property,
> return TRUE;
> }
>
> +static gboolean dev_property_get_tx_power(const GDBusPropertyTable *property,
> + DBusMessageIter *iter, void *data)
> +{
> + struct btd_device *dev = data;
> + dbus_int16_t val = dev->tx_power;
> +
> + dbus_message_iter_append_basic(iter, DBUS_TYPE_INT16, &val);
> +
> + return TRUE;
> +}
> +
> +static gboolean dev_property_exists_tx_power(const GDBusPropertyTable *property,
> + void *data)
> +{
> + struct btd_device *dev = data;
> +
> + if (dev->tx_power == 127)
> + return FALSE;
> +
> + return TRUE;
> +}
> +
> static gboolean dev_property_get_trusted(const GDBusPropertyTable *property,
> DBusMessageIter *iter, void *data)
> {
> @@ -1957,6 +1980,8 @@ static const GDBusPropertyTable device_properties[] = {
> { "Blocked", "b", dev_property_get_blocked, dev_property_set_blocked },
> { "LegacyPairing", "b", dev_property_get_legacy },
> { "RSSI", "n", dev_property_get_rssi, NULL, dev_property_exists_rssi },
> + { "TxPower", "n", dev_property_get_tx_power, NULL,
> + dev_property_exists_tx_power },
> { "Connected", "b", dev_property_get_connected },
> { "UUIDs", "as", dev_property_get_uuids },
> { "Modalias", "s", dev_property_get_modalias, NULL,
> @@ -4107,6 +4132,22 @@ void device_set_rssi(struct btd_device *device, int8_t rssi)
> DEVICE_INTERFACE, "RSSI");
> }
>
> +void device_set_tx_power(struct btd_device *device, int8_t tx_power)
> +{
> + if (!device)
> + return;
> +
> + if (device->tx_power == tx_power)
> + return;
> +
> + DBG("tx_power %d", tx_power);
> +
> + device->tx_power = tx_power;
> +
> + g_dbus_emit_property_changed(dbus_conn, device->path,
> + DEVICE_INTERFACE, "TxPower");
> +}
> +
> static gboolean start_discovery(gpointer user_data)
> {
> struct btd_device *device = user_data;
> diff --git a/src/device.h b/src/device.h
> index 2e0473e..b568593 100644
> --- a/src/device.h
> +++ b/src/device.h
> @@ -88,6 +88,7 @@ void btd_device_set_trusted(struct btd_device *device, gboolean trusted);
> void device_set_bonded(struct btd_device *device, uint8_t bdaddr_type);
> void device_set_legacy(struct btd_device *device, bool legacy);
> void device_set_rssi(struct btd_device *device, int8_t rssi);
> +void device_set_tx_power(struct btd_device *device, int8_t tx_power);
> bool btd_device_is_connected(struct btd_device *dev);
> uint8_t btd_device_get_bdaddr_type(struct btd_device *dev);
> bool device_is_retrying(struct btd_device *device);
> --
> 2.1.0.rc2.206.gedb03e5
>
> --
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--
Luiz Augusto von Dentz
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