From: Alexandru Ardelean <alexandru.ardelean@analog.com>
To: <linux-iio@vger.kernel.org>, <linux-spi@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <jic23@kernel.org>, <broonie@kernel.org>,
Alexandru Ardelean <alexandru.ardelean@analog.com>
Subject: [PATCH v3 3/3] spi: make `cs_change_delay` the first user of the `spi_delay` logic
Date: Mon, 16 Sep 2019 10:10:24 +0300 [thread overview]
Message-ID: <20190916071024.21447-4-alexandru.ardelean@analog.com> (raw)
In-Reply-To: <20190916071024.21447-1-alexandru.ardelean@analog.com>
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.
The ADIS library is one of the few users of the new `cs_change_delay`
parameter for an spi_transfer.
The introduction of the `spi_delay` struct, requires that the users of of
`cs_change_delay` get an update. This change also updates the ADIS library.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
drivers/iio/imu/adis.c | 24 ++++++++++++------------
drivers/spi/spi.c | 28 +++++++---------------------
include/linux/spi/spi.h | 4 +---
3 files changed, 20 insertions(+), 36 deletions(-)
diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index 1631c255deab..2cd2cc2316c6 100644
--- a/drivers/iio/imu/adis.c
+++ b/drivers/iio/imu/adis.c
@@ -39,24 +39,24 @@ int adis_write_reg(struct adis *adis, unsigned int reg,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
- .cs_change_delay = adis->data->cs_change_delay,
- .cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
+ .cs_change_delay.value = adis->data->cs_change_delay,
+ .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
}, {
.tx_buf = adis->tx + 2,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
- .cs_change_delay = adis->data->cs_change_delay,
- .cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
+ .cs_change_delay.value = adis->data->cs_change_delay,
+ .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
}, {
.tx_buf = adis->tx + 4,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
- .cs_change_delay = adis->data->cs_change_delay,
- .cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
+ .cs_change_delay.value = adis->data->cs_change_delay,
+ .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
}, {
.tx_buf = adis->tx + 6,
.bits_per_word = 8,
@@ -139,16 +139,16 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
- .cs_change_delay = adis->data->cs_change_delay,
- .cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
+ .cs_change_delay.value = adis->data->cs_change_delay,
+ .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
}, {
.tx_buf = adis->tx + 2,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->read_delay,
- .cs_change_delay = adis->data->cs_change_delay,
- .cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
+ .cs_change_delay.value = adis->data->cs_change_delay,
+ .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
}, {
.tx_buf = adis->tx + 4,
.rx_buf = adis->rx,
@@ -156,8 +156,8 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->read_delay,
- .cs_change_delay = adis->data->cs_change_delay,
- .cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
+ .cs_change_delay.value = adis->data->cs_change_delay,
+ .cs_change_delay.unit = SPI_DELAY_UNIT_USECS,
}, {
.rx_buf = adis->rx + 2,
.bits_per_word = 8,
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
prev parent reply other threads:[~2019-09-16 7:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-16 7:10 [PATCH v3 0/3] spi: introduce `struct spi_delay` data-type Alexandru Ardelean
2019-09-16 7:10 ` [PATCH v3 1/3] spi: move `cs_change_delay` backwards compat logic outside switch Alexandru Ardelean
2019-09-16 7:10 ` [PATCH v3 2/3] spi: introduce spi_delay struct as "value + unit" & spi_delay_exec() Alexandru Ardelean
2019-09-16 7:10 ` Alexandru Ardelean [this message]
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