The mailbox core uses jiffy based timer to handle polling for the
transmit completion. If the client/protocol have/support notification
of the last packet transmit completion via ACK packet, then we tick the
Tx state machine immediately in the callback. However if the client
doesn't support that mechanism we might end-up waiting for atleast a
jiffy even though the remote is ready to receive the next request.
This patch switches the timer used for that polling from jiffy-based
to hrtimer-based so that we can support polling at much higher time
resolution.
Reported-and-suggested-by: Juri Lelli <Juri.Lelli@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
This patch supplies a new framework API; mbox_request_channel_byname().
It works by supplying the usual client pointer as the first argument and
a string as the second. The API will search the client's node for a
'mbox-names' property then request a channel in the normal way using the
requested string's index as the expected second 'index' argument.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mbox_request_channel() currently returns EBUSY in the event the controller
is not present or if of_xlate() fails, but in neither case is EBUSY really
appropriate. Return EPROBE_DEFER if the controller is not yet present
and change of_xlate() to return an ERR_PTR instead of NULL so that the
error can be propagated back to the caller of mbox_request_channel().
Signed-off-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Suman Anna <s-anna@ti.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Before polling we just need to see if the TXDONE_BY_POLL bit
is set in txdone_method. There may be another bit (method)
specified as well, like TXDONE_BY_ACK.
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
ACPI 5.0+ spec defines a generic mode of communication
between the OS and a platform such as the BMC. This medium
(PCC) is typically used by CPPC (ACPI CPU Performance management),
RAS (ACPI reliability protocol) and MPST (ACPI Memory power
states).
This patch adds PCC support as a Mailbox Controller. As of
ACPI v5.1 there is no provision for clients to lookup mailbox
controllers in a way that Linux expects. e.g. in DT the clients
can list the mailboxes they can associate with in the DT binding
and then provide a unique index to lookup a channel within a mailbox.
Since the ACPI spec doesn't have anything similar, we introduce a
mailbox controller specific API so that when the client calls it,
we know to lookup in the context of a specific controller. This
also helps in keeping a consistent interface across DT and ACPI
for such drivers.
This patch implements basic PCC support using the ACPI v5.1
structures. IRQ mode support will be provided as follow up patches.
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
If the mailbox controller expects the payload is in place before
initiating the transmit, then it's impossible to reuse the list
maintained by core mailbox code currently. Maintaining another list
for sending the message in the controller seems totally unnecessary
as core mailbox library already provides that feature.
This patch introduces tx_prepare callback in mbox_client which
can be used by the core mailbox library before initiating the
transaction through mbox->ops->send_data. The client driver can
implement this callback to ensure the payload is copied to the
shared memory.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
poll_txdone() will unconditionally re-arm the polling timer if there was
an active request, even if the active request completed and no other
requests were submitted. This is fixed by:
- only re-arming the timer if the controller reported that the current
transmission has not completed, and,
- moving the call to poll_txdone() into msg_submit() so that the
controller gets polled (and the timer re-armed, if necessary) whenever
a new message is submitted.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Introduce common framework for client/protocol drivers and
controller drivers of Inter-Processor-Communication (IPC).
Client driver developers should have a look at
include/linux/mailbox_client.h to understand the part of
the API exposed to client drivers.
Similarly controller driver developers should have a look
at include/linux/mailbox_controller.h
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Sudeep Holla