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spi: spi-fsl-dspi: Simplify bytes_per_word gymnastics

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Reduce the if-then-else-if-then-else sequence to:
 - a simple division in the case of bytes_per_word calculation
 - a memcpy command with a variable size. The semantics of larger-than-8
   xfer->bits_per_word is that those words are to be interpreted and
   transmitted in CPU native endianness.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20200304220044.11193-2-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Vladimir Oltean 2020-03-05 00:00:33 +02:00 committed by Mark Brown
parent cb71d8efd7
commit 53fadb4d90
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 3 additions and 18 deletions
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21
drivers/spi/spi-fsl-dspi.c
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@ -252,12 +252,7 @@ static u32 dspi_pop_tx(struct fsl_dspi *dspi)
u32 txdata = 0;
if (dspi->tx) {
if (dspi->bytes_per_word == 1)
txdata = *(u8 *)dspi->tx;
else if (dspi->bytes_per_word == 2)
txdata = *(u16 *)dspi->tx;
else /* dspi->bytes_per_word == 4 */
txdata = *(u32 *)dspi->tx;
memcpy(&txdata, dspi->tx, dspi->bytes_per_word);
dspi->tx += dspi->bytes_per_word;
}
dspi->len -= dspi->bytes_per_word;
@ -284,12 +279,7 @@ static void dspi_push_rx(struct fsl_dspi *dspi, u32 rxdata)
/* Mask off undefined bits */
rxdata &= (1 << dspi->bits_per_word) - 1;
if (dspi->bytes_per_word == 1)
*(u8 *)dspi->rx = rxdata;
else if (dspi->bytes_per_word == 2)
*(u16 *)dspi->rx = rxdata;
else /* dspi->bytes_per_word == 4 */
*(u32 *)dspi->rx = rxdata;
memcpy(dspi->rx, &rxdata, dspi->bytes_per_word);
dspi->rx += dspi->bytes_per_word;
}
@ -814,12 +804,7 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr,
dspi->progress = 0;
/* Validated transfer specific frame size (defaults applied) */
dspi->bits_per_word = transfer->bits_per_word;
if (transfer->bits_per_word <= 8)
dspi->bytes_per_word = 1;
else if (transfer->bits_per_word <= 16)
dspi->bytes_per_word = 2;
else
dspi->bytes_per_word = 4;
dspi->bytes_per_word = DIV_ROUND_UP(dspi->bits_per_word, 8);
regmap_update_bits(dspi->regmap, SPI_MCR,
SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,