diff options
| author | Alexandru Ardelean <alexandru.ardelean@analog.com> | 2019-09-26 13:51:36 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2019-10-15 11:44:33 +0100 |
| commit | bebcfd272df648542c458d28fbd6a8f9428b5310 (patch) | |
| tree | ab9e5abb9ec859a699f2a73845d461127f8aac72 /include/linux/spi | |
| parent | 6c613f68aabf33385c01e949204ac5ed30887161 (diff) | |
spi: introduce `delay` field for `spi_transfer` + spi_transfer_delay_exec()
The change introduces the `delay` field to the `spi_transfer` struct as an
`struct spi_delay` type.
This intends to eventually replace `delay_usecs`.
But, since there are many users of `delay_usecs`, this needs some
intermediate work.
A helper called `spi_transfer_delay_exec()` is also added, which maintains
backwards compatibility with `delay_usecs`, by assigning the value to
`delay` if non-zero.
This should maintain backwards compatibility with current users of
`udelay_usecs`.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-9-alexandru.ardelean@analog.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'include/linux/spi')
| -rw-r--r-- | include/linux/spi/spi.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index ebeb272aeb0f..fe5b85df2c79 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -778,6 +778,9 @@ extern void spi_res_release(struct spi_controller *ctlr, * @cs_change: affects chipselect after this transfer completes * @cs_change_delay: delay between cs deassert and assert when * @cs_change is set and @spi_transfer is not the last in @spi_message + * @delay: delay to be introduced after this transfer before + * (optionally) changing the chipselect status, then starting + * the next transfer or completing this @spi_message. * @delay_usecs: microseconds to delay after this transfer before * (optionally) changing the chipselect status, then starting * the next transfer or completing this @spi_message. @@ -896,6 +899,7 @@ struct spi_transfer { #define SPI_NBITS_QUAD 0x04 /* 4bits transfer */ u8 bits_per_word; u16 delay_usecs; + struct spi_delay delay; struct spi_delay cs_change_delay; struct spi_delay word_delay; u32 speed_hz; @@ -1003,6 +1007,20 @@ spi_transfer_del(struct spi_transfer *t) list_del(&t->transfer_list); } +static inline int +spi_transfer_delay_exec(struct spi_transfer *t) +{ + struct spi_delay d; + + if (t->delay_usecs) { + d.value = t->delay_usecs; + d.unit = SPI_DELAY_UNIT_USECS; + return spi_delay_exec(&d, NULL); + } + + return spi_delay_exec(&t->delay, t); +} + /** * spi_message_init_with_transfers - Initialize spi_message and append transfers * @m: spi_message to be initialized |