|
|
@@ -1,7 +1,10 @@
|
|
|
- The Common Mailbox Framework
|
|
|
- Jassi Brar <jaswinder.singh@linaro.org>
|
|
|
+============================
|
|
|
+The Common Mailbox Framework
|
|
|
+============================
|
|
|
|
|
|
- This document aims to help developers write client and controller
|
|
|
+:Author: Jassi Brar <jaswinder.singh@linaro.org>
|
|
|
+
|
|
|
+This document aims to help developers write client and controller
|
|
|
drivers for the API. But before we start, let us note that the
|
|
|
client (especially) and controller drivers are likely going to be
|
|
|
very platform specific because the remote firmware is likely to be
|
|
|
@@ -13,14 +16,17 @@ similar copies of code written for each platform. Having said that,
|
|
|
nothing prevents the remote f/w to also be Linux based and use the
|
|
|
same api there. However none of that helps us locally because we only
|
|
|
ever deal at client's protocol level.
|
|
|
- Some of the choices made during implementation are the result of this
|
|
|
+
|
|
|
+Some of the choices made during implementation are the result of this
|
|
|
peculiarity of this "common" framework.
|
|
|
|
|
|
|
|
|
|
|
|
- Part 1 - Controller Driver (See include/linux/mailbox_controller.h)
|
|
|
+Controller Driver (See include/linux/mailbox_controller.h)
|
|
|
+==========================================================
|
|
|
+
|
|
|
|
|
|
- Allocate mbox_controller and the array of mbox_chan.
|
|
|
+Allocate mbox_controller and the array of mbox_chan.
|
|
|
Populate mbox_chan_ops, except peek_data() all are mandatory.
|
|
|
The controller driver might know a message has been consumed
|
|
|
by the remote by getting an IRQ or polling some hardware flag
|
|
|
@@ -30,91 +36,94 @@ the controller driver should set via 'txdone_irq' or 'txdone_poll'
|
|
|
or neither.
|
|
|
|
|
|
|
|
|
- Part 2 - Client Driver (See include/linux/mailbox_client.h)
|
|
|
+Client Driver (See include/linux/mailbox_client.h)
|
|
|
+==================================================
|
|
|
|
|
|
- The client might want to operate in blocking mode (synchronously
|
|
|
+
|
|
|
+The client might want to operate in blocking mode (synchronously
|
|
|
send a message through before returning) or non-blocking/async mode (submit
|
|
|
a message and a callback function to the API and return immediately).
|
|
|
|
|
|
-
|
|
|
-struct demo_client {
|
|
|
- struct mbox_client cl;
|
|
|
- struct mbox_chan *mbox;
|
|
|
- struct completion c;
|
|
|
- bool async;
|
|
|
- /* ... */
|
|
|
-};
|
|
|
-
|
|
|
-/*
|
|
|
- * This is the handler for data received from remote. The behaviour is purely
|
|
|
- * dependent upon the protocol. This is just an example.
|
|
|
- */
|
|
|
-static void message_from_remote(struct mbox_client *cl, void *mssg)
|
|
|
-{
|
|
|
- struct demo_client *dc = container_of(cl, struct demo_client, cl);
|
|
|
- if (dc->async) {
|
|
|
- if (is_an_ack(mssg)) {
|
|
|
- /* An ACK to our last sample sent */
|
|
|
- return; /* Or do something else here */
|
|
|
- } else { /* A new message from remote */
|
|
|
- queue_req(mssg);
|
|
|
+::
|
|
|
+
|
|
|
+ struct demo_client {
|
|
|
+ struct mbox_client cl;
|
|
|
+ struct mbox_chan *mbox;
|
|
|
+ struct completion c;
|
|
|
+ bool async;
|
|
|
+ /* ... */
|
|
|
+ };
|
|
|
+
|
|
|
+ /*
|
|
|
+ * This is the handler for data received from remote. The behaviour is purely
|
|
|
+ * dependent upon the protocol. This is just an example.
|
|
|
+ */
|
|
|
+ static void message_from_remote(struct mbox_client *cl, void *mssg)
|
|
|
+ {
|
|
|
+ struct demo_client *dc = container_of(cl, struct demo_client, cl);
|
|
|
+ if (dc->async) {
|
|
|
+ if (is_an_ack(mssg)) {
|
|
|
+ /* An ACK to our last sample sent */
|
|
|
+ return; /* Or do something else here */
|
|
|
+ } else { /* A new message from remote */
|
|
|
+ queue_req(mssg);
|
|
|
+ }
|
|
|
+ } else {
|
|
|
+ /* Remote f/w sends only ACK packets on this channel */
|
|
|
+ return;
|
|
|
}
|
|
|
- } else {
|
|
|
- /* Remote f/w sends only ACK packets on this channel */
|
|
|
- return;
|
|
|
}
|
|
|
-}
|
|
|
-
|
|
|
-static void sample_sent(struct mbox_client *cl, void *mssg, int r)
|
|
|
-{
|
|
|
- struct demo_client *dc = container_of(cl, struct demo_client, cl);
|
|
|
- complete(&dc->c);
|
|
|
-}
|
|
|
-
|
|
|
-static void client_demo(struct platform_device *pdev)
|
|
|
-{
|
|
|
- struct demo_client *dc_sync, *dc_async;
|
|
|
- /* The controller already knows async_pkt and sync_pkt */
|
|
|
- struct async_pkt ap;
|
|
|
- struct sync_pkt sp;
|
|
|
-
|
|
|
- dc_sync = kzalloc(sizeof(*dc_sync), GFP_KERNEL);
|
|
|
- dc_async = kzalloc(sizeof(*dc_async), GFP_KERNEL);
|
|
|
-
|
|
|
- /* Populate non-blocking mode client */
|
|
|
- dc_async->cl.dev = &pdev->dev;
|
|
|
- dc_async->cl.rx_callback = message_from_remote;
|
|
|
- dc_async->cl.tx_done = sample_sent;
|
|
|
- dc_async->cl.tx_block = false;
|
|
|
- dc_async->cl.tx_tout = 0; /* doesn't matter here */
|
|
|
- dc_async->cl.knows_txdone = false; /* depending upon protocol */
|
|
|
- dc_async->async = true;
|
|
|
- init_completion(&dc_async->c);
|
|
|
-
|
|
|
- /* Populate blocking mode client */
|
|
|
- dc_sync->cl.dev = &pdev->dev;
|
|
|
- dc_sync->cl.rx_callback = message_from_remote;
|
|
|
- dc_sync->cl.tx_done = NULL; /* operate in blocking mode */
|
|
|
- dc_sync->cl.tx_block = true;
|
|
|
- dc_sync->cl.tx_tout = 500; /* by half a second */
|
|
|
- dc_sync->cl.knows_txdone = false; /* depending upon protocol */
|
|
|
- dc_sync->async = false;
|
|
|
-
|
|
|
- /* ASync mailbox is listed second in 'mboxes' property */
|
|
|
- dc_async->mbox = mbox_request_channel(&dc_async->cl, 1);
|
|
|
- /* Populate data packet */
|
|
|
- /* ap.xxx = 123; etc */
|
|
|
- /* Send async message to remote */
|
|
|
- mbox_send_message(dc_async->mbox, &ap);
|
|
|
-
|
|
|
- /* Sync mailbox is listed first in 'mboxes' property */
|
|
|
- dc_sync->mbox = mbox_request_channel(&dc_sync->cl, 0);
|
|
|
- /* Populate data packet */
|
|
|
- /* sp.abc = 123; etc */
|
|
|
- /* Send message to remote in blocking mode */
|
|
|
- mbox_send_message(dc_sync->mbox, &sp);
|
|
|
- /* At this point 'sp' has been sent */
|
|
|
-
|
|
|
- /* Now wait for async chan to be done */
|
|
|
- wait_for_completion(&dc_async->c);
|
|
|
-}
|
|
|
+
|
|
|
+ static void sample_sent(struct mbox_client *cl, void *mssg, int r)
|
|
|
+ {
|
|
|
+ struct demo_client *dc = container_of(cl, struct demo_client, cl);
|
|
|
+ complete(&dc->c);
|
|
|
+ }
|
|
|
+
|
|
|
+ static void client_demo(struct platform_device *pdev)
|
|
|
+ {
|
|
|
+ struct demo_client *dc_sync, *dc_async;
|
|
|
+ /* The controller already knows async_pkt and sync_pkt */
|
|
|
+ struct async_pkt ap;
|
|
|
+ struct sync_pkt sp;
|
|
|
+
|
|
|
+ dc_sync = kzalloc(sizeof(*dc_sync), GFP_KERNEL);
|
|
|
+ dc_async = kzalloc(sizeof(*dc_async), GFP_KERNEL);
|
|
|
+
|
|
|
+ /* Populate non-blocking mode client */
|
|
|
+ dc_async->cl.dev = &pdev->dev;
|
|
|
+ dc_async->cl.rx_callback = message_from_remote;
|
|
|
+ dc_async->cl.tx_done = sample_sent;
|
|
|
+ dc_async->cl.tx_block = false;
|
|
|
+ dc_async->cl.tx_tout = 0; /* doesn't matter here */
|
|
|
+ dc_async->cl.knows_txdone = false; /* depending upon protocol */
|
|
|
+ dc_async->async = true;
|
|
|
+ init_completion(&dc_async->c);
|
|
|
+
|
|
|
+ /* Populate blocking mode client */
|
|
|
+ dc_sync->cl.dev = &pdev->dev;
|
|
|
+ dc_sync->cl.rx_callback = message_from_remote;
|
|
|
+ dc_sync->cl.tx_done = NULL; /* operate in blocking mode */
|
|
|
+ dc_sync->cl.tx_block = true;
|
|
|
+ dc_sync->cl.tx_tout = 500; /* by half a second */
|
|
|
+ dc_sync->cl.knows_txdone = false; /* depending upon protocol */
|
|
|
+ dc_sync->async = false;
|
|
|
+
|
|
|
+ /* ASync mailbox is listed second in 'mboxes' property */
|
|
|
+ dc_async->mbox = mbox_request_channel(&dc_async->cl, 1);
|
|
|
+ /* Populate data packet */
|
|
|
+ /* ap.xxx = 123; etc */
|
|
|
+ /* Send async message to remote */
|
|
|
+ mbox_send_message(dc_async->mbox, &ap);
|
|
|
+
|
|
|
+ /* Sync mailbox is listed first in 'mboxes' property */
|
|
|
+ dc_sync->mbox = mbox_request_channel(&dc_sync->cl, 0);
|
|
|
+ /* Populate data packet */
|
|
|
+ /* sp.abc = 123; etc */
|
|
|
+ /* Send message to remote in blocking mode */
|
|
|
+ mbox_send_message(dc_sync->mbox, &sp);
|
|
|
+ /* At this point 'sp' has been sent */
|
|
|
+
|
|
|
+ /* Now wait for async chan to be done */
|
|
|
+ wait_for_completion(&dc_async->c);
|
|
|
+ }
|