mailbox: Introduce framework for mailbox

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>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/linux/mailbox_client.h b/include/linux/mailbox_client.h
new file mode 100644
index 000000000000..307d9cab2026
--- /dev/null
+++ b/include/linux/mailbox_client.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2013-2014 Linaro Ltd.
+ * Author: Jassi Brar <jassisinghbrar@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __MAILBOX_CLIENT_H
+#define __MAILBOX_CLIENT_H
+
+#include <linux/of.h>
+#include <linux/device.h>
+
+struct mbox_chan;
+
+/**
+ * struct mbox_client - User of a mailbox
+ * @dev:                The client device
+ * @tx_block:           If the mbox_send_message should block until data is
+ *                      transmitted.
+ * @tx_tout:            Max block period in ms before TX is assumed failure
+ * @knows_txdone:       If the client could run the TX state machine. Usually
+ *                      if the client receives some ACK packet for transmission.
+ *                      Unused if the controller already has TX_Done/RTR IRQ.
+ * @rx_callback:        Atomic callback to provide client the data received
+ * @tx_done:            Atomic callback to tell client of data transmission
+ */
+struct mbox_client {
+        struct device *dev;
+        bool tx_block;
+        unsigned long tx_tout;
+        bool knows_txdone;
+
+        void (*rx_callback)(struct mbox_client *cl, void *mssg);
+        void (*tx_done)(struct mbox_client *cl, void *mssg, int r);
+};
+
+struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index);
+int mbox_send_message(struct mbox_chan *chan, void *mssg);
+void mbox_client_txdone(struct mbox_chan *chan, int r); /* atomic */
+bool mbox_client_peek_data(struct mbox_chan *chan); /* atomic */
+void mbox_free_channel(struct mbox_chan *chan); /* may sleep */
+
+#endif /* __MAILBOX_CLIENT_H */