[U-Boot] [PATCH 20/34] spi: mpc8xxx: Re-order transfer setup

Jagan Teki
2018-11-20T12:48:00Z

From: Mario Six <mario.six@gdsys.cc>

Minize the time the adapter is disabled (via SPI_MODE_EN
clearing/setting) to just the character length setting, and only set up
the temporary data writing variable right before we need it, so there is
a more clear distinction between setting up the SPI adapter, and setting
up the data to be written.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
---
drivers/spi/mpc8xxx_spi.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/mpc8xxx_spi.c b/drivers/spi/mpc8xxx_spi.c
index 1dd5bd9799..1e7c0144c2 100644
--- a/drivers/spi/mpc8xxx_spi.c
+++ b/drivers/spi/mpc8xxx_spi.c
@@ -116,9 +116,6 @@ int spi_xfer(struct spi_slave *slave, uint bitlen, const void *dout, void *din,
u32 tmpdout = 0;
uchar xfer_bitlen = (bitlen >= 32 ? 32 : bitlen);

- /* Shift data so it's msb-justified */
- tmpdout = *(u32 *)dout >> (32 - xfer_bitlen);
-
clrbits_be32(&spi->mode, SPI_MODE_EN);

/* Set up length for this transfer */
@@ -130,14 +127,17 @@ int spi_xfer(struct spi_slave *slave, uint bitlen, const void *dout, void *din,
else /* more than 16 bits -> full 32 bit transfer */
set_char_len(spi, 0);

+ setbits_be32(&spi->mode, SPI_MODE_EN);
+
+ /* Shift data so it's msb-justified */
+ tmpdout = *(u32 *)dout >> (32 - xfer_bitlen);
+
if (bitlen > 16) {
/* Set up the next iteration if sending > 32 bits */
bitlen -= 32;
dout += 4;
}

- setbits_be32(&spi->mode, SPI_MODE_EN);
-
/* Write the data out */
out_be32(&spi->tx, tmpdout);

--
2.18.0.321.gffc6fa0e3