+++ /dev/null
-/**
- * \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
- * (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, 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 2005 Develer S.r.l. (http://www.develer.com/)
- * -->
- *
- * \version $Id$
- *
- * \brief TC520 ADC driver (implementation)
- *
- * \version $Id$
- * \author Francesco Sacchi <batt@develer.com>
- * \author Marco Benelli <marco@develer.com>
- */
-
-#include <drv/tc520.h>
-#include <drv/timer.h>
-
-#include <hw_tc520.h>
-
-#include <cfg/macros.h>
-#include <cfg/compiler.h>
-
-#include <drv/ser.h>
-
-static Serial *spi_ser;
-
-#define TC520_CONVERSION_TIMEOUT ms_to_ticks(1000)
-#define INIT_LOAD_VALUE 0x00
-
-/**
- * Start an AD conversion and return result.
- *
- * To start a conversion first we must pull down CE pin.
- * The ADC starts a convertion and keeps the DV pin high until the end.
- * At this point, we can read the conversion value by SPI.
- * The convertion result is yield in 3 bytes.
- *
- * \verbatim
- *
- * First byte:
- * bit | Value
- * ----|-------
- * 7 | Overrange
- * 6 | Polarity
- * 5:0 | data bits 15:10
- *
- * Second byte: data 9:2
- *
- * Third byte:
- * bit | Value
- * ----|-------
- * 7 | data bit 1
- * 6 | data bit 0
- * 5:0 | '0'
- *
- * \endverbatim
- *
- * So, to get the result we must shift and recompose the bits.
- * \note Overrange bit is handled as the 17th data bit.
- */
-tc520_data_t tc520_read(void)
-{
- /* Start convertion and wait */
- CE_LOW();
- ticks_t start = timer_clock();
- do
- {
- /* timeout check */
- if (timer_clock() - start >= TC520_CONVERSION_TIMEOUT)
- {
- ASSERT(0);
- CE_HIGH();
- return TC520_MAX_VALUE;
- }
- }
- while(DV_LOW());
-
- start = timer_clock();
- do
- {
- /* timeout check */
- if (timer_clock() - start >= TC520_CONVERSION_TIMEOUT)
- {
- ASSERT(0);
- CE_HIGH();
- return TC520_MAX_VALUE;
- }
- }
- while(DV_HIGH());
-
- /* Ok, convertion finished, read result */
- CE_HIGH();
- READ_LOW();
-
- /* RX buffer could be dirty...*/
- ser_purge(spi_ser);
-
- /* I/O buffer */
- uint8_t buf[3] = "\x0\x0\x0";
-
- /* Dummy write to activate recv */
- ser_write(spi_ser, buf, sizeof(buf));
- ser_drain(spi_ser);
- READ_HIGH();
-
- /* recv */
- ASSERT(ser_read(spi_ser, buf, sizeof(buf)) == sizeof(buf));
-
- tc520_data_t res;
-
- /* Recompose data */
- res = (((tc520_data_t)(buf[0] & 0x3F)) << 10) | (((tc520_data_t)buf[1]) << 2) | (((tc520_data_t)buf[2]) >> 6);
-
- #define OVERRANGE_BIT BV(7)
- /* Handle overrange bit as 17th bit */
- if (buf[0] & OVERRANGE_BIT)
- res |= BV32(16);
-
- return res;
-}
-
-
-/**
- * Initialize tc520 A/D converter driver
- */
-void tc520_init(Serial *spi_port)
-{
- spi_ser = spi_port;
- /* init io ports */
- TC520_HW_INIT;
- /* Send initial load value */
- LOAD_LOW();
- ser_putchar(INIT_LOAD_VALUE, spi_ser);
- ser_drain(spi_ser);
- LOAD_HIGH();
-}