1 /*
2  * Simulate a SPI port and clients (see doc/arch/sandbox.rst for details)
3  *
4  * Copyright (c) 2011-2013 The Chromium OS Authors.
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * Licensed under the GPL-2 or later.
9  */
10 
11 #ifndef __ASM_SPI_H__
12 #define __ASM_SPI_H__
13 
14 #include <linux/types.h>
15 
16 /*
17  * The interface between the SPI bus and the SPI client.  The bus will
18  * instantiate a client, and that then call into it via these entry
19  * points.  These should be enough for the client to emulate the SPI
20  * device just like the real hardware.
21  */
22 struct sandbox_spi_emu_ops {
23 	/* The bus wants to instantiate a new client, so setup everything */
24 	int (*setup)(void **priv, const char *spec);
25 	/* The bus is done with us, so break things down */
26 	void (*free)(void *priv);
27 	/* The CS has been "activated" -- we won't worry about low/high */
28 	void (*cs_activate)(void *priv);
29 	/* The CS has been "deactivated" -- we won't worry about low/high */
30 	void (*cs_deactivate)(void *priv);
31 	/* The client is rx-ing bytes from the bus, so it should tx some */
32 	int (*xfer)(void *priv, const u8 *rx, u8 *tx, uint bytes);
33 };
34 
35 #endif
36