/* * This file is part of the libopenstm32 project. * * Copyright (C) 2009 Uwe Hermann * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include /* * SPI and I2S code. * * Examples: * spi_init_master(SPI1, 1000000, SPI_CR1_CPOL_CLK_TO_0_WHEN_IDLE, * SPI_CR1_CPHA_CLK_TRANSITION_1, SPI_CR1_DFF_8BIT, * SPI_CR1_LSBFIRST); * spi_write(SPI1, 0x55); // 8-bit write * spi_write(SPI1, 0xaa88); // 16-bit write * reg8 = spi_read(SPI1); // 8-bit read * reg16 = spi_read(SPI1); // 16-bit read */ int spi_init_master(u32 spi, u32 br, u32 cpol, u32 cpha, u32 dff, u32 lsbfirst) { u32 reg32 = 0; reg32 |= SPI_CR1_MSTR; /* Configure SPI as master. */ reg32 |= br; /* Set BAUD rate bits. */ reg32 |= cpol; /* Set CPOL value. */ reg32 |= cpha; /* Set CPHA value. */ reg32 |= dff; /* Set data format (8 or 16 bits). */ reg32 |= lsbfirst; /* Set frame format (LSB- or MSB-first). */ /* TODO: NSS pin handling. */ SPI_CR1(spi) = reg32; return 0; /* TODO */ } /* TODO: Error handling? */ void spi_enable(u32 spi) { u32 reg32; reg32 = SPI_CR1(spi); reg32 |= SPI_CR1_SPE; /* Enable SPI. */ SPI_CR1(spi) = reg32; } /* TODO: Error handling? */ void spi_disable(u32 spi) { u32 reg32; /* TODO: Follow procedure from section 23.3.8 in the techref manual. */ reg32 = SPI_CR1(spi); reg32 &= ~(SPI_CR1_SPE); /* Disable SPI. */ SPI_CR1(spi) = reg32; } void spi_write(u32 spi, u16 data) { /* Write data (8 or 16 bits, depending on DFF) into DR. */ SPI_DR(spi) = data; } u16 spi_read(u32 spi) { /* Read the data (8 or 16 bits, depending on DFF bit) from DR. */ return SPI_DR(spi); }