lkml.org 
[lkml]   [2023]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v1 1/5] spi: fsl-spi: Fix CPM/QE mode Litte Endian
Date
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@csgroup.eu>
Cc: Joakim Tjernlund <Joakim.Tjernlund@infinera.com>
Fixes: 0398fb70940e ("spi/spi_mpc8xxx: Fix QE mode Litte Endian")
---
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 93152144fd2e..5602f052b2b5 100644
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -181,8 +181,8 @@ 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
@@ -190,9 +190,11 @@ 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,
@@ -222,7 +224,7 @@ 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
\
 
 \ /
  Last update: 2023-04-01 20:00    [W:0.038 / U:0.484 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site