openpcd/firmware/src/picc/poti.c

75 lines
2.4 KiB
C

/* SPI Potentiometer AD 7367 Driver for OpenPICC
* (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
*
* 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 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sys/types.h>
#include <lib_AT91SAM7.h>
#include "../openpcd.h"
static const AT91PS_SPI spi = AT91C_BASE_SPI;
void poti_comp_carr(uint8_t position)
{
volatile int i;
while (!(spi->SPI_SR & AT91C_SPI_TDRE)) { }
AT91F_PIO_ClearOutput(AT91C_BASE_PIOA, OPENPICC_PIO_SS2_DT_THRESH);
/* shift one left, since it is a seven-bit value written as 8 bit xfer */
spi->SPI_TDR = position & 0x7f;
while (!(spi->SPI_SR & AT91C_SPI_TDRE)) { }
for (i = 0; i < 0xff; i++) { }
AT91F_PIO_SetOutput(AT91C_BASE_PIOA, OPENPICC_PIO_SS2_DT_THRESH);
}
void poti_reset(void)
{
volatile int i;
AT91F_PIO_ClearOutput(AT91C_BASE_PIOA, OPENPICC_PIO_nSLAVE_RESET);
for (i = 0; i < 0xff; i++) { }
AT91F_PIO_SetOutput(AT91C_BASE_PIOA, OPENPICC_PIO_nSLAVE_RESET);
}
void poti_init(void)
{
AT91F_SPI_CfgPMC();
AT91F_PIO_CfgPeriph(AT91C_BASE_PIOA,
AT91C_PA13_MOSI | AT91C_PA14_SPCK, 0);
AT91F_PIO_CfgOutput(AT91C_BASE_PIOA, OPENPICC_PIO_SS2_DT_THRESH);
AT91F_PIO_SetOutput(AT91C_BASE_PIOA, OPENPICC_PIO_SS2_DT_THRESH);
AT91F_PIO_CfgOutput(AT91C_BASE_PIOA, OPENPICC_PIO_nSLAVE_RESET);
poti_reset();
#if 0
AT91F_AIC_ConfigureIt(AT91C_BASE_AIC, AT91C_ID_SPI,
OPENPCD_IRQ_PRIO_SPI,
AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, &spi_irq);
AT91G_AIC_EnableIt(AT9C_BASE_AIC, AT91C_ID_SPI);
#endif
AT91F_SPI_CfgMode(spi, AT91C_SPI_MSTR |
AT91C_SPI_PS_FIXED | AT91C_SPI_MODFDIS);
/* CPOL = 0, NCPHA = 1, CSAAT = 0, BITS = 0000, SCBR = 13 (3.69MHz),
* DLYBS = 6 (125nS), DLYBCT = 0 */
AT91F_SPI_CfgCs(spi, 0, AT91C_SPI_BITS_8 | AT91C_SPI_NCPHA |
(13 << 8) | (6 << 16));
AT91F_SPI_Enable(spi);
}