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authorAlexandru Ardelean <alexandru.ardelean@analog.com>2019-09-26 13:51:36 +0300
committerMark Brown <broonie@kernel.org>2019-10-15 11:44:33 +0100
commitbebcfd272df648542c458d28fbd6a8f9428b5310 (patch)
treeab9e5abb9ec859a699f2a73845d461127f8aac72
parent6c613f68aabf33385c01e949204ac5ed30887161 (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>
-rw-r--r--drivers/spi/spi.c6
-rw-r--r--include/linux/spi/spi.h18
2 files changed, 21 insertions, 3 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 307e440dd92d..2e448078a117 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -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;
}
}
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