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Subject[PATCH v2 3/4] spi: make `cs_change_delay` the first user of the `spi_delay` logic
Date
Since the logic for `spi_delay` struct + `spi_delay_exec()` has been copied
from the `cs_change_delay` logic, it's natural to make this delay, the
first user.

The `cs_change_delay` logic requires that the default remain 10 uS, in case
it is unspecified/unconfigured. So, there is some special handling needed
to do that.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
drivers/spi/spi.c | 28 +++++++---------------------
include/linux/spi/spi.h | 4 +---
2 files changed, 8 insertions(+), 24 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 1883de8ffa82..d0bf0ffca042 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1160,9 +1160,9 @@ EXPORT_SYMBOL_GPL(spi_delay_exec);
static void _spi_transfer_cs_change_delay(struct spi_message *msg,
struct spi_transfer *xfer)
{
- u32 delay = xfer->cs_change_delay;
- u32 unit = xfer->cs_change_delay_unit;
- u32 hz;
+ u32 delay = xfer->cs_change_delay.value;
+ u32 unit = xfer->cs_change_delay.unit;
+ int ret;

/* return early on "fast" mode - for everything but USECS */
if (!delay) {
@@ -1171,27 +1171,13 @@ static void _spi_transfer_cs_change_delay(struct spi_message *msg,
return;
}

- switch (unit) {
- case SPI_DELAY_UNIT_USECS:
- delay *= 1000;
- break;
- case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
- break;
- case SPI_DELAY_UNIT_SCK:
- /* if there is no effective speed know, then approximate
- * by underestimating with half the requested hz
- */
- hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
- delay *= DIV_ROUND_UP(1000000000, hz);
- break;
- default:
+ ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
+ if (ret) {
dev_err_once(&msg->spi->dev,
"Use of unsupported delay unit %i, using default of 10us\n",
- xfer->cs_change_delay_unit);
- delay = 10000;
+ unit);
+ _spi_transfer_delay_ns(10000);
}
- /* now sleep for the requested amount of time */
- _spi_transfer_delay_ns(delay);
}

/*
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index c18cfa7cda35..9ded3f44d58e 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -754,7 +754,6 @@ 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
- * @cs_change_delay_unit: unit of cs_change_delay
* @delay_usecs: microseconds to delay after this transfer before
* (optionally) changing the chipselect status, then starting
* the next transfer or completing this @spi_message.
@@ -847,8 +846,7 @@ struct spi_transfer {
u8 bits_per_word;
u8 word_delay_usecs;
u16 delay_usecs;
- u16 cs_change_delay;
- u8 cs_change_delay_unit;
+ struct spi_delay cs_change_delay;
u32 speed_hz;
u16 word_delay;

--
2.20.1
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