static void altera_spi_chipsel(struct spi_device *spi, int value)
{
struct altera_spi *hw = altera_spi_to_hw(spi);
if (spi->mode & SPI_CS_HIGH) {
switch (value) {
case BITBANG_CS_INACTIVE:
writel(1 << spi->chip_select,
hw->base + ALTERA_SPI_SLAVE_SEL);
hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
break;
case BITBANG_CS_ACTIVE:
hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
break;
}
} else {
switch (value) {
case BITBANG_CS_INACTIVE:
hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
break;
case BITBANG_CS_ACTIVE:
writel(1 << spi->chip_select,
hw->base + ALTERA_SPI_SLAVE_SEL);
hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
break;
}
}
}
static int altera_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
{
struct altera_spi *hw = altera_spi_to_hw(spi);
hw->tx = t->tx_buf;
hw->rx = t->rx_buf;
hw->count = 0;
hw->bytes_per_word = (t->bits_per_word ? : spi->bits_per_word) / 8;
hw->len = t->len / hw->bytes_per_word;
if (hw->irq >= 0) {
/* enable receive interrupt */
hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
/* send the first byte */
writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);
wait_for_completion(&hw->done);
/* disable receive interrupt */
hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
} else {
/* send the first byte */
writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);
while (1) {
unsigned int rxd;
while (!(readl(hw->base + ALTERA_SPI_STATUS) &
ALTERA_SPI_STATUS_RRDY_MSK))
cpu_relax();
rxd = readl(hw->base + ALTERA_SPI_RXDATA);
if (hw->rx) {
switch (hw->bytes_per_word) {
case 1:
hw->rx[hw->count] = rxd;
break;
case 2:
hw->rx[hw->count * 2] = rxd;
hw->rx[hw->count * 2 + 1] = rxd >> 8;
break;
}
}
hw->count++;
if (hw->count < hw->len)
writel(hw_txbyte(hw, hw->count),
hw->base + ALTERA_SPI_TXDATA);
else
break;
}
}
return hw->count * hw->bytes_per_word;
}
