This is a note to let you know that I've just added the patch titled
spi: fsl-spi: Fix CPM/QE mode Litte Endian
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spi-fsl-spi-fix-cpm-qe-mode-litte-endian.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ee5d5fc09b2a9bf2294a5b2d14277c429b447761
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date: Sat Apr 1 19:59:46 2023 +0200
spi: fsl-spi: Fix CPM/QE mode Litte Endian
[ 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>
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c
index 02b999d48ca19..ae805f91eafa5 100644
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -208,8 +208,8 @@ 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
@@ -217,9 +217,11 @@ 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,
@@ -249,7 +251,7 @@ 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);
