121 lines
2.9 KiB
C
121 lines
2.9 KiB
C
/**
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* \file
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* <!--
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* This file is part of BeRTOS.
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*
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* Bertos is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* As a special exception, you may use this file as part of a free software
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* library without restriction. Specifically, if other files instantiate
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* templates or use macros or inline functions from this file, or you compile
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* this file and link it with other files to produce an executable, this
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* file does not by itself cause the resulting executable to be covered by
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* the GNU General Public License. This exception does not however
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* invalidate any other reasons why the executable file might be covered by
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* the GNU General Public License.
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*
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* Copyright 2003, 2004, 2006 Develer S.r.l. (http://www.develer.com/)
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* Copyright 2000 Bernie Innocenti <bernie@codewiz.org>
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*
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* -->
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*
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* \brief Emulated SPI Master for DSP firmware download (impl.)
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*
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*
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* \author Francesco Sacchi <batt@develer.com>
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* \author Daniele Basile <asterix@develer.com>
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*/
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#include "spi_bitbang.h"
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#include "hw/hw_spi.h"
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#include "cfg/cfg_spi_bitbang.h"
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#include <cfg/module.h>
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#include <cpu/irq.h>
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void spi_assertSS(void)
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{
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ATOMIC(SS_ACTIVE());
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}
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void spi_deassertSS(void)
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{
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ATOMIC(SS_INACTIVE());
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}
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/**
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* Send byte \c c over MOSI line, CONFIG_SPI_DATAORDER first.
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* SS pin state is left unchanged.
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*/
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uint8_t spi_sendRecv(uint8_t c)
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{
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uint8_t data = 0;
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uint8_t shift = SPI_DATAORDER_START;
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ATOMIC(
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for (int i = 0; i < 8; i++)
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{
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/* Shift the i-th bit to MOSI */
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if (c & shift)
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MOSI_HIGH();
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else
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MOSI_LOW();
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/* Assert clock */
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SCK_ACTIVE();
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data |= IS_MISO_HIGH() ? shift : 0;
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/* De-assert clock */
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SCK_INACTIVE();
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SPI_DATAORDER_SHIFT(shift);
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}
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);
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return data;
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}
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MOD_DEFINE(spi);
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void spi_init(void)
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{
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ATOMIC(SPI_HW_INIT());
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MOD_INIT(spi);
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}
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/**
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* Read \param len from spi, and put it in \param _buff .
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*/
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void spi_read(void *_buff, size_t len)
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{
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uint8_t *buff = (uint8_t *)_buff;
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while (len--)
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/* Read byte from spi and put it in buffer. */
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*buff++ = spi_sendRecv(0);
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}
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/**
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* Write \param len to spi, and take it from \param _buff .
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*/
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void spi_write(const void *_buff, size_t len)
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{
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const uint8_t *buff = (const uint8_t *)_buff;
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while (len--)
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/* Write byte pointed at by *buff to spi */
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spi_sendRecv(*buff++);
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}
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