alistair23-linux/include/linux/mailbox_client.h
Thierry Reding a8803d7421 mailbox: Support blocking transfers in atomic context
The mailbox framework supports blocking transfers via completions for
clients that can sleep. In order to support blocking transfers in cases
where the transmission is not permitted to sleep, add a new ->flush()
callback that controller drivers can implement to busy loop until the
transmission has been completed. A new mbox_flush() function can be
called by mailbox consumers in atomic context to make sure a transfer
has completed.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2018-12-21 22:31:26 -06:00

53 lines
1.9 KiB
C

/*
* 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_prepare: Atomic callback to ask client to prepare the payload
* before initiating the transmission if required.
* @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_prepare)(struct mbox_client *cl, void *mssg);
void (*tx_done)(struct mbox_client *cl, void *mssg, int r);
};
struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
const char *name);
struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index);
int mbox_send_message(struct mbox_chan *chan, void *mssg);
int mbox_flush(struct mbox_chan *chan, unsigned long timeout);
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 */