From bebcfd272df648542c458d28fbd6a8f9428b5310 Mon Sep 17 00:00:00 2001 From: Alexandru Ardelean Date: Thu, 26 Sep 2019 13:51:36 +0300 Subject: 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 Link: https://lore.kernel.org/r/20190926105147.7839-9-alexandru.ardelean@analog.com Signed-off-by: Mark Brown --- include/linux/spi/spi.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/spi') 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 -- cgit