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spi: fsl-spi: Re-organise transfer bits_per_word adaptation

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commit 8a5299a1278eadf1e08a598a5345c376206f171e upstream.

For different reasons, fsl-spi driver performs bits_per_word
modifications for different reasons:
- On CPU mode, to minimise amount of interrupts
- On CPM/QE mode to work around controller byte order

For CPU mode that's done in fsl_spi_prepare_message() while
for CPM mode that's done in fsl_spi_setup_transfer().

Reunify all of it in fsl_spi_prepare_message(), and catch
impossible cases early through master's bits_per_word_mask
instead of returning EINVAL later.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/0ce96fe96e8b07cba0613e4097cfd94d09b8919a.1680371809.git.christophe.leroy@csgroup.eu
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christophe Leroy 2023-04-01 19:59:47 +02:00 committed by Greg Kroah-Hartman
parent 76ce326826
commit 441fa64299
1 changed files with 21 additions and 25 deletions
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46
drivers/spi/spi-fsl-spi.c
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@ -177,26 +177,6 @@ static int mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs,
return bits_per_word;
}
static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
struct spi_device *spi,
int bits_per_word)
{
/* 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
* tfcr/rfcr is set to CPMFCR_GBL */
if (spi->mode & SPI_LSB_FIRST &&
bits_per_word > 8)
return -EINVAL;
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,
struct spi_transfer *t)
{
@ -224,9 +204,6 @@ 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
bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
bits_per_word);
if (bits_per_word < 0)
return bits_per_word;
@ -361,6 +338,19 @@ static int fsl_spi_prepare_message(struct spi_controller *ctlr,
t->bits_per_word = 32;
else if ((t->len & 1) == 0)
t->bits_per_word = 16;
} else {
/*
* 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
* tfcr/rfcr is set to CPMFCR_GBL
*/
if (m->spi->mode & SPI_LSB_FIRST && t->bits_per_word > 8)
return -EINVAL;
if (t->bits_per_word == 16 || t->bits_per_word == 32)
t->bits_per_word = 8; /* pretend its 8 bits */
}
}
return fsl_spi_setup_transfer(m->spi, first);
@ -594,8 +584,14 @@ static struct spi_master *fsl_spi_probe(struct device *dev,
if (mpc8xxx_spi->type == TYPE_GRLIB)
fsl_spi_grlib_probe(dev);
master->bits_per_word_mask =
(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32)) &
if (mpc8xxx_spi->flags & SPI_CPM_MODE)
master->bits_per_word_mask =
(SPI_BPW_RANGE_MASK(4, 8) | SPI_BPW_MASK(16) | SPI_BPW_MASK(32));
else
master->bits_per_word_mask =
(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32));
master->bits_per_word_mask &=
SPI_BPW_RANGE_MASK(1, mpc8xxx_spi->max_bits_per_word);
if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)