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Commit 170e2232 authored by Christophe Leroy's avatar Christophe Leroy Committed by Greg Kroah-Hartman
Browse files

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 0398fb70 ("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: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joakim Tjernlund <Joakim.Tjernlund@infinera.com>
Fixes: 0398fb70 ("spi/spi_mpc8xxx: Fix QE mode Litte Endian")
Link: https://lore.kernel.org/r/1b7d3e84b1128f42c1887dd2fb9cdf390f541bc1.1680371809.git.christophe.leroy@csgroup.eu


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 86323843

drivers/spi/spi-fsl-spi.c

+7 −5
Original line number Diff line number Diff line
@@ -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)

		return 8; /* pretend its 8 bits */

	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 -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);