sandbox: spi: Add SPI emulation bus
This adds a SPI framework for people to hook up simulated SPI clients.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/include/asm/config.h b/arch/sandbox/include/asm/config.h
index 7755a4d..ec7729e 100644
--- a/arch/sandbox/include/asm/config.h
+++ b/arch/sandbox/include/asm/config.h
@@ -9,4 +9,12 @@
#define CONFIG_SANDBOX_ARCH
+/* Used by drivers/spi/sandbox_spi.c and arch/sandbox/include/asm/state.h */
+#ifndef CONFIG_SANDBOX_SPI_MAX_BUS
+#define CONFIG_SANDBOX_SPI_MAX_BUS 1
+#endif
+#ifndef CONFIG_SANDBOX_SPI_MAX_CS
+#define CONFIG_SANDBOX_SPI_MAX_CS 10
+#endif
+
#endif
diff --git a/arch/sandbox/include/asm/spi.h b/arch/sandbox/include/asm/spi.h
new file mode 100644
index 0000000..49b4a0f
--- /dev/null
+++ b/arch/sandbox/include/asm/spi.h
@@ -0,0 +1,58 @@
+/*
+ * Simulate a SPI port and clients (see README.sandbox 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);
+};
+
+/*
+ * There are times when the data lines are allowed to tristate. What
+ * is actually sensed on the line depends on the hardware. It could
+ * always be 0xFF/0x00 (if there are pull ups/downs), or things could
+ * float and so we'd get garbage back. This func encapsulates that
+ * scenario so we can worry about the details here.
+ */
+static inline void sandbox_spi_tristate(u8 *buf, uint len)
+{
+ /* XXX: make this into a user config option ? */
+ memset(buf, 0xff, len);
+}
+
+/*
+ * 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
diff --git a/arch/sandbox/include/asm/state.h b/arch/sandbox/include/asm/state.h
index 093c81d..a38820b 100644
--- a/arch/sandbox/include/asm/state.h
+++ b/arch/sandbox/include/asm/state.h
@@ -15,6 +15,11 @@
STATE_EXIT_POWER_OFF,
};
+struct sandbox_spi_info {
+ const char *spec;
+ const struct sandbox_spi_emu_ops *ops;
+};
+
/* The complete state of the test system */
struct sandbox_state {
const char *cmd; /* Command to execute */
@@ -23,6 +28,10 @@
const char *parse_err; /* Error to report from parsing */
int argc; /* Program arguments */
char **argv;
+
+ /* Pointer to information for each SPI bus/cs */
+ struct sandbox_spi_info spi[CONFIG_SANDBOX_SPI_MAX_BUS]
+ [CONFIG_SANDBOX_SPI_MAX_CS];
};
/**