Implement SPI modes for CPOL/CPHA in the soft-spi driver. Previously, CPOL=1 was hard-coded and CPHA was implemented inversely (defaulting to CPHA=1).

Signed-off-by: Johannes Holland joh.ho@gmx.de ---  drivers/spi/soft_spi.c | 56 ++++++++++++++++++++++++++++++++----------  1 file changed, 43 insertions(+), 13 deletions(-)

diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c index b80f810bd1..5932ce8c5c 100644 --- a/drivers/spi/soft_spi.c +++ b/drivers/spi/soft_spi.c @@ -58,10 +58,12 @@ static int soft_spi_sda(struct udevice *dev, int bit)  static int soft_spi_cs_activate(struct udevice *dev)  {      struct udevice *bus = dev_get_parent(dev); +    struct soft_spi_priv *priv = dev_get_priv(bus);      struct soft_spi_platdata *plat = dev_get_platdata(bus); +    int cidle = !!(priv->mode & SPI_CPOL);

dm_gpio_set_value(&plat->cs, 0); -    dm_gpio_set_value(&plat->sclk, 0); +    dm_gpio_set_value(&plat->sclk, cidle); /* to idle */      dm_gpio_set_value(&plat->cs, 1);

return 0; @@ -79,11 +81,14 @@ static int soft_spi_cs_deactivate(struct udevice *dev)

static int soft_spi_claim_bus(struct udevice *dev)  { +    struct udevice *bus = dev_get_parent(dev); +    struct soft_spi_priv *priv = dev_get_priv(bus); +    int cidle = !!(priv->mode & SPI_CPOL);      /*       * Make sure the SPI clock is in idle state as defined for       * this slave.       */ -    return soft_spi_scl(dev, 0); +    return soft_spi_scl(dev, cidle);  }

static int soft_spi_release_bus(struct udevice *dev) @@ -114,15 +119,18 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,      uchar        tmpdout = 0;      const u8    *txd = dout;      u8        *rxd = din; -    int        cpha = priv->mode & SPI_CPHA; +    int        cpha = !!(priv->mode & SPI_CPHA); +    int        cidle = !!(priv->mode & SPI_CPOL);      unsigned int    j;

debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n",            dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd,            bitlen);

-    if (flags & SPI_XFER_BEGIN) +    if (flags & SPI_XFER_BEGIN) {          soft_spi_cs_activate(dev); +        udelay(plat->spi_delay_us); +    }

for (j = 0; j < bitlen; j++) {          /* @@ -140,22 +148,42 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,              tmpdin  = 0;          }

-        if (!cpha) -            soft_spi_scl(dev, 0); +        /* +         * CPOL 0: idle is low (0), active is high (1) +         * CPOL 1: idle is high (1), active is low (0) +         */ + +        /* +         * drive bit +         *  CPHA 1: CLK from idle to active +         */ +        if (cpha) +            soft_spi_scl(dev, !cidle);          if ((plat->flags & SPI_MASTER_NO_TX) == 0)              soft_spi_sda(dev, !!(tmpdout & 0x80));          udelay(plat->spi_delay_us); -        if (cpha) -            soft_spi_scl(dev, 0); + +        /* +         * sample bit +         *  CPHA 0: CLK from idle to active +         *  CPHA 1: CLK from active to idle +         */ +        if (!cpha) +            soft_spi_scl(dev, !cidle);          else -            soft_spi_scl(dev, 1); +            soft_spi_scl(dev, cidle);          tmpdin    <<= 1;          if ((plat->flags & SPI_MASTER_NO_RX) == 0)              tmpdin    |= dm_gpio_get_value(&plat->miso);          tmpdout    <<= 1;          udelay(plat->spi_delay_us); -        if (cpha) -            soft_spi_scl(dev, 1); + +        /* +         * drive bit +         *  CPHA 0: CLK from active to idle +         */ +        if (!cpha) +            soft_spi_scl(dev, cidle);      }      /*       * If the number of bits isn't a multiple of 8, shift the last @@ -168,15 +196,17 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,          *rxd++ = tmpdin;      }

-    if (flags & SPI_XFER_END) +    if (flags & SPI_XFER_END) { +        udelay(plat->spi_delay_us);          soft_spi_cs_deactivate(dev); +    }

return 0;  }

static int soft_spi_set_speed(struct udevice *dev, unsigned int speed)  { -    /* Accept any speed */ +    /* Ignore any speed settings. Speed is implemented via "spi-delay-us" */      return 0;  }

-- 2.26.0