[PATCH v2] spi: atmel: Fix CS and initialization bug

[PATCH v2] spi: atmel: Fix CS and initialization bug

[Dan Sneddon]

Commit 5fa5e6dec762 ("spi: atmel: Switch to transfer_one transfer
method") switched to using transfer_one and set_cs.  The
core doesn't call set_cs when the chip select lines are gpios.  Add the
SPI_MASTER_GPIO_SS flag to the driver to ensure the calls to set_cs
happen since the driver programs configuration registers there.

Fixes: 5fa5e6dec762 ("spi: atmel: Switch to transfer_one transfer method")

Signed-off-by: Dan Sneddon <dan.sneddon@microchip.com>
---

Changes in v2:
- Updated commit message
- Dropped unnecessary change to enable variable in set_cs

 drivers/spi/spi-atmel.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 2ef74885ffa2..788dcdf25f00 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -352,8 +352,6 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 		}
 
 		mr = spi_readl(as, MR);
-		if (spi->cs_gpiod)
-			gpiod_set_value(spi->cs_gpiod, 1);
 	} else {
 		u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
 		int i;
@@ -369,8 +367,6 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 
 		mr = spi_readl(as, MR);
 		mr = SPI_BFINS(PCS, ~(1 << chip_select), mr);
-		if (spi->cs_gpiod)
-			gpiod_set_value(spi->cs_gpiod, 1);
 		spi_writel(as, MR, mr);
 	}
 
@@ -400,8 +396,6 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
 
 	if (!spi->cs_gpiod)
 		spi_writel(as, CR, SPI_BIT(LASTXFER));
-	else
-		gpiod_set_value(spi->cs_gpiod, 0);
 }
 
 static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock)
@@ -1483,7 +1477,8 @@ static int atmel_spi_probe(struct platform_device *pdev)
 	master->bus_num = pdev->id;
 	master->num_chipselect = 4;
 	master->setup = atmel_spi_setup;
-	master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
+	master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX |
+			SPI_MASTER_GPIO_SS);
 	master->transfer_one = atmel_spi_one_transfer;
 	master->set_cs = atmel_spi_set_cs;
 	master->cleanup = atmel_spi_cleanup;
-- 
2.17.1

Re: [PATCH v2] spi: atmel: Fix CS and initialization bug

[Mark Brown]

On Tue, 29 Jun 2021 12:22:18 -0700, Dan Sneddon wrote:
> Commit 5fa5e6dec762 ("spi: atmel: Switch to transfer_one transfer
> method") switched to using transfer_one and set_cs.  The
> core doesn't call set_cs when the chip select lines are gpios.  Add the
> SPI_MASTER_GPIO_SS flag to the driver to ensure the calls to set_cs
> happen since the driver programs configuration registers there.
> 
> Fixes: 5fa5e6dec762 ("spi: atmel: Switch to transfer_one transfer method")

Applied to

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

Thanks!

[1/1] spi: atmel: Fix CS and initialization bug
      commit: 69e1818ad27bae167eeaaf6829d4a08900ef5153

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