MicroAPRS/bertos/drv/sipo.c

123 lines
3.2 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos 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 2 of the License, or
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*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
*
* Copyright 2009 Develer S.r.l. (http://www.develer.com/)
*
* -->
*
*
* \brief SIPO Module
*
* The SIPO module transforms a serial input in a parallel output. Please check hw_sipo.h
* file to customize hardware related parameters.
*
* \author Andrea Grandi <andrea@develer.com>
* \author Daniele Basile <asterix@develer.com>
*/
#include "sipo.h"
#include "hw/hw_sipo.h"
#include <cfg/compiler.h>
#include <cfg/log.h>
#include <io/kfile.h>
#include <string.h>
#define SIPO_DATAORDER_START(order) (order ? SIPO_DATAORDER_START_LSB : SIPO_DATAORDER_START_MSB)
#define SIPO_DATAORDER_SHIFT(shift, order) (order ? ((shift) <<= 1) : ((shift) >>= 1))
/**
* Write a char in sipo shift register
*/
INLINE void sipo_putchar(uint8_t c, uint8_t bit_order, uint8_t clock_pol)
{
uint8_t shift = SIPO_DATAORDER_START(bit_order);
for(int i = 0; i < 8; i++)
{
if((c & shift) == 0)
SIPO_SI_LOW();
else
SIPO_SI_HIGH();
SIPO_SI_CLOCK(clock_pol);
SIPO_DATAORDER_SHIFT(shift, bit_order);
}
}
/**
* Write a buffer into the sipo register and, when finished, give a load pulse.
*/
static size_t sipo_write(struct KFile *_fd, const void *_buf, size_t size)
{
const uint8_t *buf = (const uint8_t *)_buf;
Sipo *fd = SIPO_CAST(_fd);
size_t write_len = size;
ASSERT(buf);
SIPO_SET_SI_LEVEL();
SIPO_SET_CLK_LEVEL(fd->clock_pol);
SIPO_SET_LD_LEVEL(fd->load_device, fd->load_pol);
// Load into the shift register all the buffer bytes
while(size--)
sipo_putchar(*buf++, fd->bit_order, fd->clock_pol);
// We finsh to load bytes, so load it.
SIPO_LOAD(fd->load_device, fd->load_pol);
return write_len;
}
/**
* Initialize the SIPO
*/
void sipo_init(Sipo *fd)
{
ASSERT(fd);
memset(fd, 0, sizeof(Sipo));
//Set kfile struct type as a generic kfile structure.
DB(fd->fd._type = KFT_SIPO);
// Set up SIPO writing functions.
fd->fd.write = sipo_write;
SIPO_INIT_PIN();
/* Enable sipo output */
SIPO_ENABLE();
}