Bluetooth: Use HCI request in interleaved discovery

In order to have a better HCI error handling in interleaved discovery
functionality, we should use the HCI request framework.

This patch updates le_scan_disable_work function so it uses the
HCI request framework instead of the hci_send_cmd helper. A complete
callback is registered (le_scan_disable_work_complete function) so we
are able to trigger the inquiry procedure (if we are running the
interleaved discovery) or to stop the discovery procedure (if we are
runnning LE-only discovery).

This patch also removes the extra logic in hci_cc_le_set_scan_enable
to trigger the inquiry procedure and the mgmt_interleaved_discovery
function since they become useless.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Update stop_discovery to use HCI request

This patch modifies the stop_discovery function so it uses the HCI
request framework.

The HCI request is built according to the current discovery state
(inquiry, LE scanning or name resolving) and a complete callback is
register to handle the command complete event for the stop discovery
command. This way, we move all stop_discovery mgmt handling code
spread in hci_event.c to a single place in mgmt.c.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
WIP: Bluetooth: Fix race between stop_discovery and le_scan_disable work

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Remove stop discovery handling from hci_event.c

Since all mgmt stop discovery command complete events are now handled
in stop_discovery_complete callback in mgmt.c, we can remove this
handling from hci_event.c.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Refactor hci_cc_le_set_scan_enable

This patch does a trivial refactoring in hci_cc_le_set_scan_enable.
Since start and stop discovery command failures are now handled in
mgmt layer, the status check became empty. So, we can move it to
outside the switch statement.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Remove LE scan helpers

This patch removes the LE scan helpers hci_le_scan and hci_cancel_
le_scan and all code related to it. We now use the HCI request
framework in device discovery functionality and these helpers are
no longer needed.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Remove inquiry helpers

This patch removes hci_do_inquiry and hci_cancel_inquiry helpers. We
now use the HCI request framework in device discovery functionality
and these helpers are no longer needed.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Remove empty event handler

This patch removes the hci_cc_le_set_scan_param event handler. This
handler became empty because failures of this event are now handled
by start_discovery_complete function in mgmt.c.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Mgmt Device Found Event

We only want to send Mgmt Device Found Events if we are running the
Device Discovery procedure (started by the MGMT Start Discovery
Command). Inquiry or LE scanning triggered by HCI raw interface (e.g.
hcitool) or kernel internals should not send Mgmt Device Found Events.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>