[PATCH] tpm_tis_spi: Pass the SPI IRQ down to the driver

[PATCH] tpm_tis_spi: Pass the SPI IRQ down to the driver

[Linus Walleij]

An SPI TPM device managed directly on an embedded board using
the SPI bus and some GPIO or similar line as IRQ handler will
pass the IRQn from the TPM device associated with the SPI
device. This is already handled by the SPI core, so make sure
to pass this down to the core as well.

(The TPM core habit of using -1 to signal no IRQ is dubious
(as IRQ 0 is NO_IRQ) but I do not want to mess with that
semantic in this patch.)

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/char/tpm/tpm_tis_spi.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index 424ff2fde1f2..9914f6973463 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -199,6 +199,7 @@ static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
 static int tpm_tis_spi_probe(struct spi_device *dev)
 {
 	struct tpm_tis_spi_phy *phy;
+	int irq;
 
 	phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
 			   GFP_KERNEL);
@@ -211,7 +212,13 @@ static int tpm_tis_spi_probe(struct spi_device *dev)
 	if (!phy->iobuf)
 		return -ENOMEM;
 
-	return tpm_tis_core_init(&dev->dev, &phy->priv, -1, &tpm_spi_phy_ops,
+	/* If the SPI device has an IRQ then use that */
+	if (dev->irq > 0)
+		irq = dev->irq;
+	else
+		irq = -1;
+
+	return tpm_tis_core_init(&dev->dev, &phy->priv, irq, &tpm_spi_phy_ops,
 				 NULL);
 }
 
-- 
2.17.0

Re: [PATCH] tpm_tis_spi: Pass the SPI IRQ down to the driver

[Jarkko Sakkinen]

On Fri, Jun 08, 2018 at 09:09:07AM +0200, Linus Walleij wrote:
> An SPI TPM device managed directly on an embedded board using
> the SPI bus and some GPIO or similar line as IRQ handler will
> pass the IRQn from the TPM device associated with the SPI
> device. This is already handled by the SPI core, so make sure
> to pass this down to the core as well.
> 
> (The TPM core habit of using -1 to signal no IRQ is dubious
> (as IRQ 0 is NO_IRQ) but I do not want to mess with that
> semantic in this patch.)
> 
> Cc: Mark Brown <broonie@kernel.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

/Jarkko

[PATCH] tpm_tis_spi: Pass the SPI IRQ down to the driver

[Linus Walleij]

An SPI TPM device managed directly on an embedded board using
the SPI bus and some GPIO or similar line as IRQ handler will
pass the IRQn from the TPM device associated with the SPI
device. This is already handled by the SPI core, so make sure
to pass this down to the core as well.

(The TPM core habit of using -1 to signal no IRQ is dubious
(as IRQ 0 is NO_IRQ) but I do not want to mess with that
semantic in this patch.)

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/char/tpm/tpm_tis_spi.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index 424ff2fde1f2..9914f6973463 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -199,6 +199,7 @@ static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
 static int tpm_tis_spi_probe(struct spi_device *dev)
 {
 	struct tpm_tis_spi_phy *phy;
+	int irq;
 
 	phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
 			   GFP_KERNEL);
@@ -211,7 +212,13 @@ static int tpm_tis_spi_probe(struct spi_device *dev)
 	if (!phy->iobuf)
 		return -ENOMEM;
 
-	return tpm_tis_core_init(&dev->dev, &phy->priv, -1, &tpm_spi_phy_ops,
+	/* If the SPI device has an IRQ then use that */
+	if (dev->irq > 0)
+		irq = dev->irq;
+	else
+		irq = -1;
+
+	return tpm_tis_core_init(&dev->dev, &phy->priv, irq, &tpm_spi_phy_ops,
 				 NULL);
 }
 
-- 
2.17.0

Re: [PATCH] tpm_tis_spi: Pass the SPI IRQ down to the driver

[Jason Gunthorpe]

On Fri, Jun 08, 2018 at 09:02:09AM +0200, Linus Walleij wrote:
> An SPI TPM device managed directly on an embedded board using
> the SPI bus and some GPIO or similar line as IRQ handler will
> pass the IRQn from the TPM device associated with the SPI
> device. This is already handled by the SPI core, so make sure
> to pass this down to the core as well.
> 
> (The TPM core habit of using -1 to signal no IRQ is dubious
> (as IRQ 0 is NO_IRQ) but I do not want to mess with that
> semantic in this patch.)

Unless something has changed, there is no cross-arch constant called
NO_IRQ, and the few arches that do define it, tend to use -1..

Jason

Re: [PATCH] tpm_tis_spi: Pass the SPI IRQ down to the driver

[Linus Walleij]

On Fri, Jun 8, 2018 at 5:50 PM, Jason Gunthorpe <jgg@ziepe.ca> wrote:
> On Fri, Jun 08, 2018 at 09:02:09AM +0200, Linus Walleij wrote:
>> An SPI TPM device managed directly on an embedded board using
>> the SPI bus and some GPIO or similar line as IRQ handler will
>> pass the IRQn from the TPM device associated with the SPI
>> device. This is already handled by the SPI core, so make sure
>> to pass this down to the core as well.
>>
>> (The TPM core habit of using -1 to signal no IRQ is dubious
>> (as IRQ 0 is NO_IRQ) but I do not want to mess with that
>> semantic in this patch.)
>
> Unless something has changed, there is no cross-arch constant called
> NO_IRQ, and the few arches that do define it, tend to use -1..

AFAIU the idea is that for archs that don't define it, it is implicitly
0.

I just refer to this, albeit it's been 7 years:
https://lwn.net/Articles/470820/

Yours,
Linus Walleij