static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
{
unsigned gpio = (unsigned) spi->controller_data;
unsigned active = spi->mode & SPI_CS_HIGH;
u32 mr;
int i;
u32 csr;
u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
/* Make sure clock polarity is correct */
for (i = 0; i < spi->master->num_chipselect; i++) {
csr = spi_readl(as, CSR0 + 4 * i);
if ((csr ^ cpol) & SPI_BIT(CPOL))
spi_writel(as, CSR0 + 4 * i, csr ^ SPI_BIT(CPOL));
}
mr = spi_readl(as, MR);
mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
gpio, active ? " (high)" : "",
mr);
if (!(cpu_is_at91rm9200() && spi->chip_select == 0))
gpio_set_value(gpio, active);
spi_writel(as, MR, mr);
}
static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
{
struct atmel_spi_device *asd = spi->controller_state;
unsigned active = spi->mode & SPI_CS_HIGH;
u32 mr;
if (atmel_spi_is_v2(as)) {
spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr);
/* For the low SPI version, there is a issue that PDC transfer
* on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS
*/
spi_writel(as, CSR0, asd->csr);
if (as->caps.has_wdrbt) {
spi_writel(as, MR,
SPI_BF(PCS, ~(0x01 << spi->chip_select))
| SPI_BIT(WDRBT)
| SPI_BIT(MODFDIS)
| SPI_BIT(MSTR));
} else {
spi_writel(as, MR,
SPI_BF(PCS, ~(0x01 << spi->chip_select))
| SPI_BIT(MODFDIS)
| SPI_BIT(MSTR));
}
mr = spi_readl(as, MR);
if (as->use_cs_gpios)
gpio_set_value(asd->npcs_pin, active);
} else {
u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
int i;
u32 csr;
/* Make sure clock polarity is correct */
for (i = 0; i < spi->master->num_chipselect; i++) {
csr = spi_readl(as, CSR0 + 4 * i);
if ((csr ^ cpol) & SPI_BIT(CPOL))
spi_writel(as, CSR0 + 4 * i,
csr ^ SPI_BIT(CPOL));
}
mr = spi_readl(as, MR);
mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
if (as->use_cs_gpios && spi->chip_select != 0)
gpio_set_value(asd->npcs_pin, active);
spi_writel(as, MR, mr);
}
dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
asd->npcs_pin, active ? " (high)" : "",
mr);
}
static int spi_has_wdrbt(struct atmel_spi_slave *slave)
{
unsigned int ver;
ver = spi_readl(slave, VERSION);
return (ATMEL_SPI_VERSION_REV(ver) >= 0x210);
}
static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
{
struct atmel_spi_device *asd = spi->controller_state;
unsigned active = spi->mode & SPI_CS_HIGH;
u32 mr;
if (atmel_spi_is_v2()) {
/*
* Always use CSR0. This ensures that the clock
* switches to the correct idle polarity before we
* toggle the CS.
*/
spi_writel(as, CSR0, asd->csr);
spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
| SPI_BIT(MSTR));
mr = spi_readl(as, MR);
gpio_set_value(asd->npcs_pin, active);
} else {
u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
int i;
u32 csr;
/* Make sure clock polarity is correct */
for (i = 0; i < spi->master->num_chipselect; i++) {
csr = spi_readl(as, CSR0 + 4 * i);
if ((csr ^ cpol) & SPI_BIT(CPOL))
spi_writel(as, CSR0 + 4 * i,
csr ^ SPI_BIT(CPOL));
}
mr = spi_readl(as, MR);
mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
if (spi->chip_select != 0)
gpio_set_value(asd->npcs_pin, active);
spi_writel(as, MR, mr);
}
dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
asd->npcs_pin, active ? " (high)" : "",
mr);
}
static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
{
unsigned gpio = (unsigned) spi->controller_data;
unsigned active = spi->mode & SPI_CS_HIGH;
u32 mr;
mr = spi_readl(as, MR);
mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
gpio, active ? " (high)" : "",
mr);
if (!(cpu_is_at91rm9200() && spi->chip_select == 0))
gpio_set_value(gpio, active);
spi_writel(as, MR, mr);
}
static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
{
struct atmel_spi_device *asd = spi->controller_state;
unsigned active = spi->mode & SPI_CS_HIGH;
u32 mr;
/* only deactivate *this* device; sometimes transfers to
* another device may be active when this routine is called.
*/
mr = spi_readl(as, MR);
if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
mr = SPI_BFINS(PCS, 0xf, mr);
spi_writel(as, MR, mr);
}
dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
asd->npcs_pin, active ? " (low)" : "",
mr);
if (atmel_spi_is_v2() || spi->chip_select != 0)
gpio_set_value(asd->npcs_pin, !active);
}
static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
{
unsigned gpio = (unsigned) spi->controller_data;
unsigned active = spi->mode & SPI_CS_HIGH;
u32 mr;
/* only deactivate *this* device; sometimes transfers to
* another device may be active when this routine is called.
*/
mr = spi_readl(as, MR);
if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
mr = SPI_BFINS(PCS, 0xf, mr);
spi_writel(as, MR, mr);
}
dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
gpio, active ? " (low)" : "",
mr);
if (!(cpu_is_at91rm9200() && spi->chip_select == 0))
gpio_set_value(gpio, !active);
}
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;
u32 status;
const u8 *txp = dout;
u8 *rxp = din;
u8 value;
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);
/*
* sometimes the RDR is not empty when we get here,
* in theory that should not happen, but it DOES happen.
* Read it here to be on the safe side.
* That also clears the OVRES flag. Required if the
* following loop exits due to OVRES!
*/
spi_readl(as, RDR);
}
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;
spi_writel(as, TDR, value);
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_cs_deactivate(slave);
}
return 0;
}
int spi_xfer(unsigned int len, const void *dout,
void *din, unsigned long flags)
{
unsigned int len_tx;
unsigned int len_rx;
const unsigned char *txp = dout;
unsigned char *rxp = din;
unsigned int status;
unsigned char value;
if (len == 0)
goto out;
/*
* 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();
/*
* sometimes the RDR is not empty when we get here,
* in theory that should not happen, but it DOES happen.
* Read it here to be on the safe side.
* That also clears the OVRES flag. Required if the
* following loop exits due to OVRES!
*/
spi_readl(SPI_RDR);
spi_readl(SPI_SR);
}
for (len_tx = 0, len_rx = 0; len_rx < len; ) {
/* send data */
if (len_tx < len) {
do {
status = spi_readl(SPI_SR);
} while ((status & AT91C_SPI_TDRE) == 0);
if (txp)
value = *txp++;
else
value = 0;
spi_writel(SPI_TDR, value);
len_tx++;
}
/* recv data */
do {
status = spi_readl(SPI_SR);
if (status & AT91C_SPI_OVRES) {
spi_cs_deactivate();
return -1;
}
} while ((status & AT91C_SPI_RDRF) == 0);
value = spi_readl(SPI_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(SPI_SR);
} while (!(status & AT91C_SPI_TXEMPTY));
spi_cs_deactivate();
}
return 0;
}