From: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
[ Upstream commit c20c57d9868d7f9fd1b2904c7801b07e128f6322 ]
CPM has the same problem as QE so for CPM also use the fix added
by commit 0398fb70940e ("spi/spi_mpc8xxx: Fix QE mode Litte Endian"):
CPM mode uses Little Endian so words > 8 bits are byte swapped.
Workaround this by always enforcing wordsize 8 for 16 and 32 bits
words. Unfortunately this will not work for LSB transfers
where wordsize is > 8 bits so disable these for now.
Also limit the workaround to 16 and 32 bits words because it can
only work for multiples of 8-bits.
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
Fixes: 0398fb70940e ("spi/spi_mpc8xxx: Fix QE mode Litte Endian")
Link: https://lore.kernel.org/r/1b7d3e84b1128f42c1887dd2fb9cdf390f541bc1.1680371809.git.christophe.leroy@xxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/spi/spi-fsl-spi.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c
index bdf94cc7be1af..1bad0ceac81b4 100644
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -207,8 +207,8 @@ static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
struct spi_device *spi,
int bits_per_word)
{
- /* QE uses Little Endian for words > 8
- * so transform all words > 8 into 8 bits
+ /* CPM/QE uses Little Endian for words > 8
+ * so transform 16 and 32 bits words into 8 bits
* Unfortnatly that doesn't work for LSB so
* reject these for now */
/* Note: 32 bits word, LSB works iff
@@ -216,9 +216,11 @@ static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
if (spi->mode & SPI_LSB_FIRST &&
bits_per_word > 8)
return -EINVAL;
- if (bits_per_word > 8)
+ if (bits_per_word <= 8)
+ return bits_per_word;
+ if (bits_per_word == 16 || bits_per_word == 32)
return 8; /* pretend its 8 bits */
- return bits_per_word;
+ return -EINVAL;
}
static int fsl_spi_setup_transfer(struct spi_device *spi,
@@ -248,7 +250,7 @@ static int fsl_spi_setup_transfer(struct spi_device *spi,
bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi,
mpc8xxx_spi,
bits_per_word);
- else if (mpc8xxx_spi->flags & SPI_QE)
+ else
bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
bits_per_word);
--
2.39.2
