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spi: mpc8xxx: Document LEN setting better

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Instead of having a table right before the code implementing the length
setting for documentation, have inline comments for the if branches
actually implementing the length setting described table's entries
(which is readable thanks to the set_char_len function).

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
This commit is contained in:
Mario Six 2019-04-29 01:58:49 +05:30 committed by Jagan Teki
parent 5ccfb8a995
commit 85fa265530
1 changed files with 5 additions and 11 deletions
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16
drivers/spi/mpc8xxx_spi.c
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@ -119,21 +119,15 @@ int spi_xfer(struct spi_slave *slave, uint bitlen, const void *dout, void *din,
/* Shift data so it's msb-justified */
tmpdout = *(u32 *)dout >> (32 - xfer_bitlen);
/* The LEN field of the SPMODE register is set as follows:
*
* Bit length setting
* len <= 4 3
* 4 < len <= 16 len - 1
* len > 16 0
*/
clrbits_be32(&spi->mode, SPI_MODE_EN);
if (bitlen <= 4)
/* Set up length for this transfer */
if (bitlen <= 4) /* 4 bits or less */
set_char_len(spi, 3);
else if (bitlen <= 16)
else if (bitlen <= 16) /* at most 16 bits */
set_char_len(spi, bitlen - 1);
else
else /* more than 16 bits -> full 32 bit transfer */
set_char_len(spi, 0);
if (bitlen > 16) {