1 /* 2 * Simulate a SPI port and clients (see README.sandbox 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 /* 36 * Extract the bus/cs from the spi spec and return the start of the spi 37 * client spec. If the bus/cs are invalid for the current config, then 38 * it returns NULL. 39 * 40 * Example: arg="0:1:foo" will set bus to 0, cs to 1, and return "foo" 41 */ 42 const char *sandbox_spi_parse_spec(const char *arg, unsigned long *bus, 43 unsigned long *cs); 44 45 #endif 46
