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Diffstat (limited to 'libmaple/spi.h')
| -rw-r--r-- | libmaple/spi.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/libmaple/spi.h b/libmaple/spi.h new file mode 100644 index 0000000..cde3b42 --- /dev/null +++ b/libmaple/spi.h @@ -0,0 +1,115 @@ +/* ***************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Perry Hung. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + * ****************************************************************************/ + +/** + * @brief libmaple serial peripheral interface (SPI) prototypes and declarations + */ + +#ifndef _SPI_H_ +#define _SPI_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +/* peripheral addresses */ +#define SPI1_BASE 0x40013000 +#define SPI2_BASE 0x40003800 + +/* baud rate prescaler bits */ +#define CR1_BR 0x00000038 +#define CR1_BR_PRESCALE_2 0x00000000 +#define CR1_BR_PRESCALE_4 0x00000008 +#define CR1_BR_PRESCALE_8 0x00000010 +#define CR1_BR_PRESCALE_16 0x00000018 +#define CR1_BR_PRESCALE_32 0x00000020 +#define CR1_BR_PRESCALE_64 0x00000028 +#define CR1_BR_PRESCALE_128 0x00000030 +#define CR1_BR_PRESCALE_256 0x00000038 + +#define CR1_LSBFIRST BIT(7) // data frame format +#define CR1_MSTR BIT(2) // master selection +#define CR1_SSM BIT(9) // software slave management +#define CR1_SSI BIT(8) // internal slave select +#define CR1_SPE BIT(6) // peripheral enable + +/* Status register bits */ +#define SR_RXNE BIT(0) // rx buffer not empty +#define SR_TXE BIT(1) // transmit buffer empty +#define SR_BSY BIT(7) // busy flag + +typedef struct SPI { + __io uint16 CR1; + uint16 pad0; + __io uint8 CR2; + uint8 pad1[3]; + __io uint8 SR; + uint8 pad2[3]; + __io uint16 DR; + uint16 pad3; + __io uint16 CRCPR; + uint16 pad4; + __io uint16 RXCRCR; + uint16 pad5; + __io uint16 TXCRCR; + uint16 pad6; +} SPI; + +enum { + SPI_MSBFIRST = 0, + SPI_LSBFIRST = BIT(7), +}; + +enum { + SPI_PRESCALE_2 = (0x0 << 3), + SPI_PRESCALE_4 = (0x1 << 3), + SPI_PRESCALE_8 = (0x2 << 3), + SPI_PRESCALE_16 = (0x3 << 3), + SPI_PRESCALE_32 = (0x4 << 3), + SPI_PRESCALE_64 = (0x5 << 3), + SPI_PRESCALE_128 = (0x6 << 3), + SPI_PRESCALE_256 = (0x7 << 3) +}; + +void spi_init(uint32 spi_num, + uint32 prescale, + uint32 endian, + uint32 mode); +void spi_tx(uint32 spi_num, uint8 data); + +static inline uint8 spi_rx(uint32 spi_num) { + SPI *spi; + + ASSERT(spi_num == 1 || spi_num == 2); + spi = (spi_num == 1) ? (SPI*)SPI1_BASE : (SPI*)SPI2_BASE; + + return spi->DR; +} + +#ifdef __cplusplus +} +#endif + +#endif + |