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Diffstat (limited to 'arch/sandbox/include/asm/spi.h')
-rw-r--r-- | arch/sandbox/include/asm/spi.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/sandbox/include/asm/spi.h b/arch/sandbox/include/asm/spi.h new file mode 100644 index 0000000..98e1826 --- /dev/null +++ b/arch/sandbox/include/asm/spi.h @@ -0,0 +1,45 @@ +/* + * Simulate a SPI port and clients (see doc/arch/sandbox.rst for details) + * + * Copyright (c) 2011-2013 The Chromium OS Authors. + * See file CREDITS for list of people who contributed to this + * project. + * + * Licensed under the GPL-2 or later. + */ + +#ifndef __ASM_SPI_H__ +#define __ASM_SPI_H__ + +#include <linux/types.h> + +/* + * The interface between the SPI bus and the SPI client. The bus will + * instantiate a client, and that then call into it via these entry + * points. These should be enough for the client to emulate the SPI + * device just like the real hardware. + */ +struct sandbox_spi_emu_ops { + /* The bus wants to instantiate a new client, so setup everything */ + int (*setup)(void **priv, const char *spec); + /* The bus is done with us, so break things down */ + void (*free)(void *priv); + /* The CS has been "activated" -- we won't worry about low/high */ + void (*cs_activate)(void *priv); + /* The CS has been "deactivated" -- we won't worry about low/high */ + void (*cs_deactivate)(void *priv); + /* The client is rx-ing bytes from the bus, so it should tx some */ + int (*xfer)(void *priv, const u8 *rx, u8 *tx, uint bytes); +}; + +/* + * Extract the bus/cs from the spi spec and return the start of the spi + * client spec. If the bus/cs are invalid for the current config, then + * it returns NULL. + * + * Example: arg="0:1:foo" will set bus to 0, cs to 1, and return "foo" + */ +const char *sandbox_spi_parse_spec(const char *arg, unsigned long *bus, + unsigned long *cs); + +#endif |