From mboxrd@z Thu Jan  1 00:00:00 1970
From: sunr2007 <ravilinux4u@gmail.com>
Date: Wed, 21 Oct 2009 12:16:05 -0700 (PDT)
Subject: [U-Boot] My SPI driver not working in u-boot.
Message-ID: <25998508.post@talk.nabble.com>
List-Id: <u-boot.lists.denx.de>
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To: u-boot@lists.denx.de


Dear All

Im tryin to write a SPI Driver in u-boot-1.3.4 with SPI BUS 1 support for my
processor AT91SAM9261 . I have defined the base macro for SPI bus 1
AT91SAM9261_BASE_SPI1 in /asm/arch/hardware.h and i av passed the bus id and
chip select id . but im not getting any data or clock value on the pins .
can any body let me what stupid mistake im committing? below is my source 
if this is not correct way to post plz let me  know right way!


#include <common.h>
#include <spi.h>
#include <malloc.h>

#include <asm/io.h>

#include <asm/arch/hardware.h
#include <asm/arch/at91_spi.h>
#include "atmel_spi.h"


void spi_init()
{
/* do some initialization of SPI bus pins*/
at91_set_A_periph(AT91_PIN_PA25, 0); /* SPI0_NPCS01 */
at91_set_A_periph(AT91_PIN_PB30, 0); /* SPI0_MISO */
at91_set_A_periph(AT91_PIN_PB31, 0); /* SPI0_MOSI */
at91_set_A_periph(AT91_PIN_PB29, 0); /* SPI0_SPCK */

/* Enable clock */
at91_sys_write(AT91_PMC_PCER, 1 << AT91SAM9261_ID_SPI1);


/* Reset the SPI */
//spi_writel(ATMEL_SPI_SWRST, ATMEL_SPI_CR,1);

}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct atmel_spi_slave *as;
unsigned int scbr;
u32 csrx;
void *regs;
max_hz=15000000;/* modified for AMOLED*/
mode=ATMEL_SPI_MR_MSTR;
mode =0;/* falling edge of clock spi XFER*/
bus=AT91SAM9261_ID_SPI1;
cs=AT91_PIN_PA25;/* chip select of the slave connected to . */
if (cs > 3 || !spi_cs_is_valid(bus, cs))
return NULL;
regs = (void *)AT91SAM9261_BASE_SPI1; /* spi bus 1 ID of the */
/* Reset the SPI */
spi_writel(as,ATMEL_SPI_CR,ATMEL_SPI_SWRST);
scbr = (AT91_MASTER_CLOCK/max_hz)<<8; /* configure serial clock baud rate*/
if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
/* Too low max SCK rate */
return NULL;
if (scbr < 1)
scbr = 1;

csrx = ATMEL_SPI_CSRx_SCBR(scbr);
csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
if (!(mode & SPI_CPHA))
csrx |= ATMEL_SPI_CSRx_NCPHA;
if (mode & SPI_CPOL)
csrx |= ATMEL_SPI_CSRx_CPOL;

as = malloc(sizeof(struct atmel_spi_slave));
if (!as)
return NULL;

as->slave.bus = bus;
as->slave.cs = cs;
as->regs = regs;
as->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS
| ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf);
as->mr = ATMEL_SPI_CSRx_NCPHA | ATMEL_SPI_CSR(2) | ATMEL_SPI_MR_MSTR ;/*
configure chipselect*/
spi_writel(as, CSR(cs), csrx);

return &as->slave;
}

void spi_free_slave(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);

free(as);
}

int spi_claim_bus(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);

/* Enable the SPI hardware */
spi_writel(as, CR, ATMEL_SPI_CR_SPIEN);

/*
* Select the slave. This should set SCK to the correct
* initial state, etc.
*/
spi_writel(as, MR, as->mr);

return 0;
}

void spi_release_bus(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);

/* Disable the SPI hardware */
spi_writel(as, CR, ATMEL_SPI_CR_SPIDIS);
}

int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
unsigned int len_tx;
unsigned int len_rx;
unsigned int len;
int ret;
u32 status;
unsigned short mask ;
const u8 *txp = dout;
u8 *rxp = din;
u8 value;
unsigned int pol;
bitlen=8;

ret = 0;
if (bitlen == 0)
/* Finish any previously submitted transfers */
goto out;

/*
* TODO: The controller can do non-multiple-of-8 bit
* transfers, but this driver currently doesn't support it.
*
* It's also not clear how such transfers are supposed to be
* represented as a stream of bytes...this is a limitation of
* the current SPI interface.
*/
if (bitlen % 8) {
/* Errors always terminate an ongoing transfer */
flags |= SPI_XFER_END;
goto out;
}

len = bitlen / 8;

/*
* The controller can do automatic CS control, but it is
* somewhat quirky, and it doesn't really buy us much anyway
* in the context of U-Boot.
*/
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);

for (len_tx = 0, len_rx = 0; len_rx < len; ) {
status = spi_readl(as, SR);

if (status & ATMEL_SPI_SR_OVRES)
return -1;

if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
if (txp)
value = *txp++;
else
value = 0;
udelay(500000);
pol=spi_claim_bus(slave);
spi_writel(as, TDR, value); /*write data into device */
spi_release_bus(slave)
len_tx++;


if (status & ATMEL_SPI_SR_RDRF) {


value = spi_readl(as, RDR);

if (rxp)
*rxp++ = value;
len_rx++;
}
}

out:
if (flags & SPI_XFER_END) {
/*
* Wait until the transfer is completely done before
* we deactivate CS.
*/
do {
status = spi_readl(as, SR);
} while (!(status & ATMEL_SPI_SR_TXEMPTY));
//spi_writel(as,ATMEL_SPI_CSRx_CSAAT, value);
spi_cs_deactivate(slave);
}

return 0;
}
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