Unverified Commit bebcfd27 authored by Alexandru Ardelean's avatar Alexandru Ardelean Committed by Mark Brown
Browse files

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: default avatarAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20190926105147.7839-9-alexandru.ardelean@analog.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 6c613f68

drivers/spi/spi.c

+3 −3
Original line number Diff line number Diff line
@@ -1248,8 +1248,7 @@ static int spi_transfer_one_message(struct spi_controller *ctlr, 
		if (msg->status != -EINPROGRESS)

			goto out;



		if (xfer->delay_usecs)

			_spi_transfer_delay_ns(xfer->delay_usecs * 1000);

		spi_transfer_delay_exec(xfer);



		if (xfer->cs_change) {

			if (list_is_last(&xfer->transfer_list,
@@ -3026,10 +3025,11 @@ struct spi_replaced_transfers *spi_replace_transfers( 
		/* add to list */

		list_add(&xfer->transfer_list, rxfer->replaced_after);



		/* clear cs_change and delay_usecs for all but the last */

		/* clear cs_change and delay for all but the last */

		if (i) {

			xfer->cs_change = false;

			xfer->delay_usecs = 0;

			xfer->delay.value = 0;

		}

	}

include/linux/spi/spi.h

+18 −0
Original line number Diff line number Diff line
@@ -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

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