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spi: fsl-spi: Fix CPM/QE mode Litte Endian

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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")
Link: https://lore.kernel.org/r/1b7d3e84b1128f42c1887dd2fb9cdf390f541bc1.1680371809.git.christophe.leroy@csgroup.eu
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Christophe Leroy 2023-04-01 19:59:46 +02:00 committed by Mark Brown
parent 43bac5158b
commit c20c57d986
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 7 additions and 5 deletions
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12
drivers/spi/spi-fsl-spi.c
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@ -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);