When 3-wire mode is claimed on the bus, use the MOSI (output) pin to receive data. In this mode, since the transfer can only be either TX or RX, return -EINVAL if both are required at the same time.
Signed-off-by: Hironori KIKUCHI kikuchan98@gmail.com --- drivers/spi/soft_spi.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c index a8ec2f4f7b..ae444dad8a 100644 --- a/drivers/spi/soft_spi.c +++ b/drivers/spi/soft_spi.c @@ -124,8 +124,19 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen, u8 *rxd = din; int cpha = !!(priv->mode & SPI_CPHA); int cidle = !!(priv->mode & SPI_CPOL); + int txrx = plat->flags; unsigned int j;
+ if (priv->mode & SPI_3WIRE) { + if (txd && rxd) + return -EINVAL; + + txrx = txd ? SPI_MASTER_NO_RX : SPI_MASTER_NO_TX; + dm_gpio_set_dir_flags(&plat->mosi, + txd ? GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE : + GPIOD_IS_IN); + } + debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n", dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd, bitlen); @@ -160,7 +171,7 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen, */ if (cpha) soft_spi_scl(dev, !cidle); - if ((plat->flags & SPI_MASTER_NO_TX) == 0) + if ((txrx & SPI_MASTER_NO_TX) == 0) soft_spi_sda(dev, !!(tmpdout & 0x80)); udelay(plat->spi_delay_us);
@@ -174,8 +185,10 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen, else soft_spi_scl(dev, cidle); tmpdin <<= 1; - if ((plat->flags & SPI_MASTER_NO_RX) == 0) - tmpdin |= dm_gpio_get_value(&plat->miso); + if ((txrx & SPI_MASTER_NO_RX) == 0) + tmpdin |= dm_gpio_get_value((priv->mode & SPI_3WIRE) ? + &plat->mosi : + &plat->miso); tmpdout <<= 1; udelay(plat->spi_delay_us);