u-boot/cpu/arm926ejs/at91sam9/spi.c

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/*
* Driver for ATMEL DataFlash support
* Author : Hamid Ikdoumi (Atmel)
*
* 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 <config.h>
#include <common.h>
#include <asm/hardware.h>
#ifdef CONFIG_HAS_DATAFLASH
#include <dataflash.h>
/* Max Value = 10MHz to be compliant to the Continuous Array Read function */
#define AT91C_SPI_CLK 10000000
/* AC Characteristics: DLYBS = tCSS = 250ns min and DLYBCT = tCSH = 250ns */
#define DATAFLASH_TCSS (0xFA << 16)
#define DATAFLASH_TCHS (0x8 << 24)
#define AT91C_TIMEOUT_WRDY 200000
#define AT91C_SPI_PCS0_DATAFLASH_CARD 0xE /* Chip Select 0: NPCS0%1110 */
#define AT91C_SPI_PCS3_DATAFLASH_CARD 0x7 /* Chip Select 3: NPCS3%0111 */
void AT91F_SpiInit(void)
{
/* Reset the SPI */
AT91C_BASE_SPI0->SPI_CR = AT91C_SPI_SWRST;
/* Configure SPI in Master Mode with No CS selected !!! */
AT91C_BASE_SPI0->SPI_MR =
AT91C_SPI_MSTR | AT91C_SPI_MODFDIS | AT91C_SPI_PCS;
/* Configure CS0 */
AT91C_BASE_SPI0->SPI_CSR[0] =
AT91C_SPI_CPOL |
(AT91C_SPI_DLYBS & DATAFLASH_TCSS) |
(AT91C_SPI_DLYBCT & DATAFLASH_TCHS) |
((AT91C_MASTER_CLOCK / (2*AT91C_SPI_CLK)) << 8);
}
void AT91F_SpiEnable(int cs)
{
switch (cs) {
case 0: /* Configure SPI CS0 for Serial DataFlash AT45DBxx */
AT91C_BASE_SPI0->SPI_MR &= 0xFFF0FFFF;
AT91C_BASE_SPI0->SPI_MR |=
((AT91C_SPI_PCS0_DATAFLASH_CARD<<16) & AT91C_SPI_PCS);
break;
case 3:
AT91C_BASE_SPI0->SPI_MR &= 0xFFF0FFFF;
AT91C_BASE_SPI0->SPI_MR |=
((AT91C_SPI_PCS3_DATAFLASH_CARD<<16) & AT91C_SPI_PCS);
break;
}
/* SPI_Enable */
AT91C_BASE_SPI0->SPI_CR = AT91C_SPI_SPIEN;
}
unsigned int AT91F_SpiWrite(AT91PS_DataflashDesc pDesc)
{
unsigned int timeout;
pDesc->state = BUSY;
AT91C_BASE_SPI0->SPI_PTCR = AT91C_PDC_TXTDIS + AT91C_PDC_RXTDIS;
/* Initialize the Transmit and Receive Pointer */
AT91C_BASE_SPI0->SPI_RPR = (unsigned int)pDesc->rx_cmd_pt;
AT91C_BASE_SPI0->SPI_TPR = (unsigned int)pDesc->tx_cmd_pt;
/* Intialize the Transmit and Receive Counters */
AT91C_BASE_SPI0->SPI_RCR = pDesc->rx_cmd_size;
AT91C_BASE_SPI0->SPI_TCR = pDesc->tx_cmd_size;
if (pDesc->tx_data_size != 0) {
/* Initialize the Next Transmit and Next Receive Pointer */
AT91C_BASE_SPI0->SPI_RNPR = (unsigned int)pDesc->rx_data_pt;
AT91C_BASE_SPI0->SPI_TNPR = (unsigned int)pDesc->tx_data_pt;
/* Intialize the Next Transmit and Next Receive Counters */
AT91C_BASE_SPI0->SPI_RNCR = pDesc->rx_data_size;
AT91C_BASE_SPI0->SPI_TNCR = pDesc->tx_data_size;
}
/* arm simple, non interrupt dependent timer */
reset_timer_masked();
timeout = 0;
AT91C_BASE_SPI0->SPI_PTCR = AT91C_PDC_TXTEN + AT91C_PDC_RXTEN;
while (!(AT91C_BASE_SPI0->SPI_SR & AT91C_SPI_RXBUFF) &&
((timeout = get_timer_masked()) < CFG_SPI_WRITE_TOUT));
AT91C_BASE_SPI0->SPI_PTCR = AT91C_PDC_TXTDIS + AT91C_PDC_RXTDIS;
pDesc->state = IDLE;
if (timeout >= CFG_SPI_WRITE_TOUT) {
printf("Error Timeout\n\r");
return DATAFLASH_ERROR;
}
return DATAFLASH_OK;
}
#endif