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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>
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8fe2c68c32
commit
064556910e
1 changed files with 16 additions and 3 deletions
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@ -124,8 +124,19 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
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u8 *rxd = din;
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int cpha = !!(priv->mode & SPI_CPHA);
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int cidle = !!(priv->mode & SPI_CPOL);
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int txrx = plat->flags;
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unsigned int j;
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if (priv->mode & SPI_3WIRE) {
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if (txd && rxd)
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return -EINVAL;
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txrx = txd ? SPI_MASTER_NO_RX : SPI_MASTER_NO_TX;
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dm_gpio_set_dir_flags(&plat->mosi,
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txd ? GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE :
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GPIOD_IS_IN | GPIOD_PULL_UP);
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}
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debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n",
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dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd,
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bitlen);
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@ -160,7 +171,7 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
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*/
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if (cpha)
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soft_spi_scl(dev, !cidle);
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if ((plat->flags & SPI_MASTER_NO_TX) == 0)
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if ((txrx & SPI_MASTER_NO_TX) == 0)
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soft_spi_sda(dev, !!(tmpdout & 0x80));
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udelay(plat->spi_delay_us);
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@ -174,8 +185,10 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
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else
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soft_spi_scl(dev, cidle);
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tmpdin <<= 1;
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if ((plat->flags & SPI_MASTER_NO_RX) == 0)
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tmpdin |= dm_gpio_get_value(&plat->miso);
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if ((txrx & SPI_MASTER_NO_RX) == 0)
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tmpdin |= dm_gpio_get_value((priv->mode & SPI_3WIRE) ?
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&plat->mosi :
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&plat->miso);
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tmpdout <<= 1;
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udelay(plat->spi_delay_us);
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