Unverified Commit 53fadb4d authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Mark Brown
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spi: spi-fsl-dspi: Simplify bytes_per_word gymnastics 



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: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20200304220044.11193-2-olteanv@gmail.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent cb71d8ef

drivers/spi/spi-fsl-dspi.c

+3 −18
Original line number Diff line number Diff line
@@ -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,

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