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-rw-r--r--arch/sandbox/include/asm/spi.h45
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/sandbox/include/asm/spi.h b/arch/sandbox/include/asm/spi.h
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+++ b/arch/sandbox/include/asm/spi.h
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+/*
+ * 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