From 6122813fa2cb9eef4a211bd47292322096db9fa8 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 3 Dec 2013 16:43:26 -0700 Subject: sandbox: spi: Add SPI emulation bus This adds a SPI framework for people to hook up simulated SPI clients. Signed-off-by: Mike Frysinger Signed-off-by: Simon Glass --- arch/sandbox/include/asm/config.h | 8 ++++++ arch/sandbox/include/asm/spi.h | 58 +++++++++++++++++++++++++++++++++++++++ arch/sandbox/include/asm/state.h | 9 ++++++ 3 files changed, 75 insertions(+) create mode 100644 arch/sandbox/include/asm/spi.h (limited to 'arch/sandbox/include/asm') diff --git a/arch/sandbox/include/asm/config.h b/arch/sandbox/include/asm/config.h index 7755a4deff..ec7729eb4c 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 0000000000..49b4a0f103 --- /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 + +/* + * 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 093c81d918..a38820bdee 100644 --- a/arch/sandbox/include/asm/state.h +++ b/arch/sandbox/include/asm/state.h @@ -15,6 +15,11 @@ enum exit_type_id { 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 @@ struct sandbox_state { 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]; }; /** -- cgit v1.2.1