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; }