[PATCH 0/2] spi: bcm2835/bcm2835aux: support effective_speed_hz

[PATCH 0/2] spi: bcm2835/bcm2835aux: support effective_speed_hz

[Marc Kleine-Budde]

Hello,

I've picked up and forward ported Martin Sperl's patches which add support for
effective_speed_hz to the SPI controllers found on all raspberry pi models.

See the following patch, which adds this feature to the SPI core, for more
information:

    5d7e2b5ed585 spi: core: allow reporting the effectivly used speed_hz for a transfer

regards,
Marc

[PATCH 1/2] spi: bcm2835: support effective_speed_hz

[Marc Kleine-Budde]

From: Martin Sperl <kernel@martin.sperl.org>

Setting spi_transfer->effective_speed_hz in transfer_one so that
it can get used in cs_change_delay configured with delay as a muliple
of SPI clock cycles.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-bcm2835.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index 237bd306c268..86b6510a2e32 100644
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -1084,7 +1084,7 @@ static int bcm2835_spi_transfer_one(struct spi_controller *ctlr,
 				    struct spi_transfer *tfr)
 {
 	struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
-	unsigned long spi_hz, clk_hz, cdiv, spi_used_hz;
+	unsigned long spi_hz, clk_hz, cdiv;
 	unsigned long hz_per_byte, byte_limit;
 	u32 cs = bs->prepare_cs[spi->chip_select];
 
@@ -1104,7 +1104,7 @@ static int bcm2835_spi_transfer_one(struct spi_controller *ctlr,
 	} else {
 		cdiv = 0; /* 0 is the slowest we can go */
 	}
-	spi_used_hz = cdiv ? (clk_hz / cdiv) : (clk_hz / 65536);
+	tfr->effective_speed_hz = cdiv ? (clk_hz / cdiv) : (clk_hz / 65536);
 	bcm2835_wr(bs, BCM2835_SPI_CLK, cdiv);
 
 	/* handle all the 3-wire mode */
@@ -1124,7 +1124,7 @@ static int bcm2835_spi_transfer_one(struct spi_controller *ctlr,
 	 * per 300,000 Hz of bus clock.
 	 */
 	hz_per_byte = polling_limit_us ? (9 * 1000000) / polling_limit_us : 0;
-	byte_limit = hz_per_byte ? spi_used_hz / hz_per_byte : 1;
+	byte_limit = hz_per_byte ? tfr->effective_speed_hz / hz_per_byte : 1;
 
 	/* run in polling mode for short transfers */
 	if (tfr->len < byte_limit)
-- 
2.27.0

[PATCH 2/2] spi: bcm2835aux: support effective_speed_hz

[Marc Kleine-Budde]

From: Martin Sperl <kernel@martin.sperl.org>

Setting spi_transfer->effective_speed_hz in transfer_one so that
it can get used in cs_change_delay configured with delay as a muliple
of SPI clock cycles.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/spi/spi-bcm2835aux.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index c331efd6e86b..2f717812c766 100644
--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -345,7 +345,7 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master,
 				       struct spi_transfer *tfr)
 {
 	struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
-	unsigned long spi_hz, clk_hz, speed, spi_used_hz;
+	unsigned long spi_hz, clk_hz, speed;
 	unsigned long hz_per_byte, byte_limit;
 
 	/* calculate the registers to handle
@@ -374,7 +374,7 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master,
 	/* set the new speed */
 	bs->cntl[0] |= speed << BCM2835_AUX_SPI_CNTL0_SPEED_SHIFT;
 
-	spi_used_hz = clk_hz / (2 * (speed + 1));
+	tfr->effective_speed_hz = clk_hz / (2 * (speed + 1));
 
 	/* set transmit buffers and length */
 	bs->tx_buf = tfr->tx_buf;
@@ -391,7 +391,7 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master,
 	 * 30 µs per 300,000 Hz of bus clock.
 	 */
 	hz_per_byte = polling_limit_us ? (9 * 1000000) / polling_limit_us : 0;
-	byte_limit = hz_per_byte ? spi_used_hz / hz_per_byte : 1;
+	byte_limit = hz_per_byte ? tfr->effective_speed_hz / hz_per_byte : 1;
 
 	/* run in polling mode for short transfers */
 	if (tfr->len < byte_limit)
-- 
2.27.0

Re: [PATCH 0/2] spi: bcm2835/bcm2835aux: support effective_speed_hz

[Mark Brown]

On Thu, 9 Jul 2020 09:41:18 +0200, Marc Kleine-Budde wrote:
> I've picked up and forward ported Martin Sperl's patches which add support for
> effective_speed_hz to the SPI controllers found on all raspberry pi models.
> 
> See the following patch, which adds this feature to the SPI core, for more
> information:
> 
>     5d7e2b5ed585 spi: core: allow reporting the effectivly used speed_hz for a transfer
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/2] spi: bcm2835: support effective_speed_hz
      commit: 9df2003df79a0f763dbf76891fcc7d4a5141861d
[2/2] spi: bcm2835aux: support effective_speed_hz
      commit: 5e94c3cdaa29e28f6739c91a74d9ddd96f4ba6b6

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark