--- /dev/null
+/*\r
+ LUFA Library\r
+ Copyright (C) Dean Camera, 2009.\r
+ \r
+ dean [at] fourwalledcubicle [dot] com\r
+ www.fourwalledcubicle.com\r
+*/\r
+\r
+/*\r
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+\r
+ Permission to use, copy, modify, and distribute this software\r
+ and its documentation for any purpose and without fee is hereby\r
+ granted, provided that the above copyright notice appear in all\r
+ copies and that both that the copyright notice and this\r
+ permission notice and warranty disclaimer appear in supporting\r
+ documentation, and that the name of the author not be used in\r
+ advertising or publicity pertaining to distribution of the\r
+ software without specific, written prior permission.\r
+\r
+ The author disclaim all warranties with regard to this\r
+ software, including all implied warranties of merchantability\r
+ and fitness. In no event shall the author be liable for any\r
+ special, indirect or consequential damages or any damages\r
+ whatsoever resulting from loss of use, data or profits, whether\r
+ in an action of contract, negligence or other tortious action,\r
+ arising out of or in connection with the use or performance of\r
+ this software.\r
+*/\r
+\r
+/** \file\r
+ *\r
+ * Hardware SPI subsystem driver for the supported USB AVRs models.\r
+ */\r
+\r
+#ifndef __SPI_H__\r
+#define __SPI_H__\r
+\r
+ /* Includes: */\r
+ #include <stdbool.h>\r
+\r
+ /* Enable C linkage for C++ Compilers: */\r
+ #if defined(__cplusplus)\r
+ extern "C" {\r
+ #endif\r
+\r
+ /* Private Interface - For use in library only: */\r
+ #if !defined(__DOXYGEN__)\r
+ /* Macros: */\r
+ #define SPI_USE_DOUBLESPEED (1 << 7)\r
+ #endif\r
+ \r
+ /* Public Interface - May be used in end-application: */\r
+ /* Macros: */\r
+ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 2. */\r
+ #define SPI_SPEED_FCPU_DIV_2 SPI_USE_DOUBLESPEED\r
+\r
+ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 4. */\r
+ #define SPI_SPEED_FCPU_DIV_4 0\r
+\r
+ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 8. */\r
+ #define SPI_SPEED_FCPU_DIV_8 (SPI_USE_DOUBLESPEED | (1 << SPR0))\r
+\r
+ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 16. */\r
+ #define SPI_SPEED_FCPU_DIV_16 (1 << SPR0)\r
+\r
+ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 32. */\r
+ #define SPI_SPEED_FCPU_DIV_32 (SPI_USE_DOUBLESPEED | (1 << SPR1))\r
+\r
+ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 64. */\r
+ #define SPI_SPEED_FCPU_DIV_64 (SPI_USE_DOUBLESPEED | (1 << SPR1) | (1 < SPR0))\r
+\r
+ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 128. */\r
+ #define SPI_SPEED_FCPU_DIV_128 ((1 << SPR1) | (1 < SPR0))\r
+\r
+ /* Inline Functions: */\r
+ /** Initializes the SPI subsystem, ready for transfers. Must be called before calling any other\r
+ * SPI routines.\r
+ *\r
+ * \param PrescalerMask Prescaler mask to set the SPI clock speed\r
+ * \param Master If true, sets the SPI system to use master mode, slave if false\r
+ */\r
+ static inline void SPI_Init(const uint8_t PrescalerMask, const bool Master)\r
+ {\r
+ DDRB |= ((1 << 1) | (1 << 2));\r
+ PORTB |= ((1 << 0) | (1 << 3));\r
+ \r
+ SPCR = ((1 << SPE) | (Master << MSTR) | (1 << CPOL) | (1 << CPHA) |\r
+ (PrescalerMask & ~SPI_USE_DOUBLESPEED));\r
+ \r
+ if (PrescalerMask & SPI_USE_DOUBLESPEED)\r
+ SPSR = (1 << SPI2X);\r
+ }\r
+ \r
+ /** Sends and receives a byte through the SPI interface, blocking until the transfer is complete.\r
+ *\r
+ * \param Byte Byte to send through the SPI interface\r
+ *\r
+ * \return Response byte from the attached SPI device\r
+ */\r
+ static inline uint8_t SPI_TransferByte(const uint8_t Byte) ATTR_ALWAYSINLINE;\r
+ static inline uint8_t SPI_TransferByte(const uint8_t Byte)\r
+ {\r
+ SPDR = Byte;\r
+ while (!(SPSR & (1 << SPIF)));\r
+ return SPDR;\r
+ }\r
+\r
+ /** Sends a byte through the SPI interface, blocking until the transfer is complete. The response\r
+ * byte sent to from the attached SPI device is ignored.\r
+ *\r
+ * \param Byte Byte to send through the SPI interface\r
+ */\r
+ static inline void SPI_SendByte(const uint8_t Byte) ATTR_ALWAYSINLINE;\r
+ static inline void SPI_SendByte(const uint8_t Byte)\r
+ {\r
+ SPDR = Byte;\r
+ while (!(SPSR & (1 << SPIF)));\r
+ }\r
+\r
+ /** Sends a dummy byte through the SPI interface, blocking until the transfer is complete. The response\r
+ * byte from the attached SPI device is returned.\r
+ *\r
+ * \return The response byte from the attached SPI device\r
+ */\r
+ static inline uint8_t SPI_ReceiveByte(void) ATTR_ALWAYSINLINE ATTR_WARN_UNUSED_RESULT;\r
+ static inline uint8_t SPI_ReceiveByte(void)\r
+ {\r
+ SPDR = 0x00;\r
+ while (!(SPSR & (1 << SPIF)));\r
+ return SPDR;\r
+ }\r
+\r
+ /* Disable C linkage for C++ Compilers: */\r
+ #if defined(__cplusplus)\r
+ }\r
+ #endif\r
+ \r
+#endif\r
projects / pub / lufa.git / blobdiff