diff options
| author | Hironori KIKUCHI <kikuchan98@gmail.com> | 2025-01-31 10:38:41 +0900 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2025-02-14 17:12:49 -0600 |
| commit | 064556910e61044f1295162ceaad600582b66cda (patch) | |
| tree | 4aed4e024002e949bd33a043c57e7d30898329c0 | |
| parent | 8fe2c68c3267b6c5885c320141d2af52d0681025 (diff) | |
spi: soft_spi: Add support for SPI_3WIRE
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>
| -rw-r--r-- | drivers/spi/soft_spi.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c index a8ec2f4f7b4..50bd7be5640 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 | GPIOD_PULL_UP); + } + 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); |