static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
if (hw->gpio_cs_count > 0) {
gpio_set_value(hw->gpio_cs[spi->chip_select],
(spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
}
}
static int tiny_spi_setup(struct spi_device *spi)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
if (spi->max_speed_hz != hw->speed_hz) {
hw->speed_hz = spi->max_speed_hz;
hw->baud = tiny_spi_baud(spi, hw->speed_hz);
}
hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
return 0;
}
static int tiny_spi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
unsigned int baud = hw->baud;
if (t) {
if (t->speed_hz && t->speed_hz != hw->speed_hz)
baud = tiny_spi_baud(spi, t->speed_hz);
}
writel(baud, hw->base + TINY_SPI_BAUD);
writel(hw->mode, hw->base + TINY_SPI_CONTROL);
return 0;
}
static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
const u8 *txp = t->tx_buf;
u8 *rxp = t->rx_buf;
unsigned int i;
if (hw->irq >= 0) {
/* use interrupt driven data transfer */
hw->len = t->len;
hw->txp = t->tx_buf;
hw->rxp = t->rx_buf;
hw->txc = 0;
hw->rxc = 0;
/* send the first byte */
if (t->len > 1) {
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
} else {
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
}
wait_for_completion(&hw->done);
} else {
/* we need to tighten the transfer loop */
writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);
for (i = 1; i < t->len; i++) {
writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);
if (rxp || (i != t->len - 1))
tiny_spi_wait_txr(hw);
if (rxp)
*rxp++ = readb(hw->base + TINY_SPI_TXDATA);
}
tiny_spi_wait_txe(hw);
if (rxp)
*rxp++ = readb(hw->base + TINY_SPI_RXDATA);
}
return t->len;
}
static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
}
static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
const u8 *txp = t->tx_buf;
u8 *rxp = t->rx_buf;
unsigned int i;
if (hw->irq >= 0) {
hw->len = t->len;
hw->txp = t->tx_buf;
hw->rxp = t->rx_buf;
hw->txc = 0;
hw->rxc = 0;
if (t->len > 1) {
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
} else {
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
}
wait_for_completion(&hw->done);
} else if (txp && rxp) {
writeb(*txp++, hw->base + TINY_SPI_TXDATA);
if (t->len > 1) {
writeb(*txp++, hw->base + TINY_SPI_TXDATA);
for (i = 2; i < t->len; i++) {
u8 rx, tx = *txp++;
tiny_spi_wait_txr(hw);
rx = readb(hw->base + TINY_SPI_TXDATA);
writeb(tx, hw->base + TINY_SPI_TXDATA);
*rxp++ = rx;
}
tiny_spi_wait_txr(hw);
*rxp++ = readb(hw->base + TINY_SPI_TXDATA);
}
tiny_spi_wait_txe(hw);
*rxp++ = readb(hw->base + TINY_SPI_RXDATA);
} else if (rxp) {
writeb(0, hw->base + TINY_SPI_TXDATA);
if (t->len > 1) {
writeb(0,
hw->base + TINY_SPI_TXDATA);
for (i = 2; i < t->len; i++) {
u8 rx;
tiny_spi_wait_txr(hw);
rx = readb(hw->base + TINY_SPI_TXDATA);
writeb(0, hw->base + TINY_SPI_TXDATA);
*rxp++ = rx;
}
tiny_spi_wait_txr(hw);
*rxp++ = readb(hw->base + TINY_SPI_TXDATA);
}
tiny_spi_wait_txe(hw);
*rxp++ = readb(hw->base + TINY_SPI_RXDATA);
} else if (txp) {
writeb(*txp++, hw->base + TINY_SPI_TXDATA);
if (t->len > 1) {
writeb(*txp++, hw->base + TINY_SPI_TXDATA);
for (i = 2; i < t->len; i++) {
u8 tx = *txp++;
tiny_spi_wait_txr(hw);
writeb(tx, hw->base + TINY_SPI_TXDATA);
}
}
tiny_spi_wait_txe(hw);
} else {
writeb(0, hw->base + TINY_SPI_TXDATA);
if (t->len > 1) {
writeb(0, hw->base + TINY_SPI_TXDATA);
for (i = 2; i < t->len; i++) {
tiny_spi_wait_txr(hw);
writeb(0, hw->base + TINY_SPI_TXDATA);
}
}
tiny_spi_wait_txe(hw);
}
return t->len;
}