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usb: typec: altmode: Remove the notification chain

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Using the generic notification chain is not reasonable with
the alternate modes because it would require dependencies
between the drivers of the components that need the
notifications, and the typec drivers.

There are no users for the alternate mode notifications, so
removing the chain and the API for it completely.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200211112531.86510-6-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Heikki Krogerus
2020-02-11 14:25:30 +03:00
committed by Greg Kroah-Hartman
parent 684cb4b79e
commit bbe80c9a89
5 changed files with 3 additions and 107 deletions
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22
Documentation/driver-api/usb/typec_bus.rst
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@@ -53,9 +53,7 @@ in need to reconfigure the pins on the connector, the alternate mode driver
needs to notify the bus using :c:func:`typec_altmode_notify()`. The driver
passes the negotiated SVID specific pin configuration value to the function as
parameter. The bus driver will then configure the mux behind the connector using
that value as the state value for the mux, and also call blocking notification
chain to notify the external drivers about the state of the connector that need
to know it.
that value as the state value for the mux.
NOTE: The SVID specific pin configuration values must always start from
``TYPEC_STATE_MODAL``. USB Type-C specification defines two default states for
@@ -80,19 +78,6 @@ Helper macro ``TYPEC_MODAL_STATE()`` can also be used::
#define ALTMODEX_CONF_A = TYPEC_MODAL_STATE(0);
#define ALTMODEX_CONF_B = TYPEC_MODAL_STATE(1);
Notification chain
~~~~~~~~~~~~~~~~~~
The drivers for the components that the alternate modes are designed for need to
get details regarding the results of the negotiation with the partner, and the
pin configuration of the connector. In case of DisplayPort alternate mode for
example, the GPU drivers will need to know those details. In case of
Thunderbolt alternate mode, the thunderbolt drivers will need to know them, and
so on.
The notification chain is designed for this purpose. The drivers can register
notifiers with :c:func:`typec_altmode_register_notifier()`.
Cable plug alternate modes
~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -129,8 +114,3 @@ Cable Plug operations
.. kernel-doc:: drivers/usb/typec/bus.c
:functions: typec_altmode_get_plug typec_altmode_put_plug
Notifications
~~~~~~~~~~~~~
.. kernel-doc:: drivers/usb/typec/class.c
:functions: typec_altmode_register_notifier typec_altmode_unregister_notifier