acpi_gpiobus: IoRestriction is only for type IO

[cperciva]

Summary

The IoRestriction field of ACPI_RESOURCE_GPIO is only meaningful
for resources of type ACPI_RESOURCE_GPIO_TYPE_IO.

Reported by: jrtc27

[andrew]

Don't we need to set GPIO_PIN_INPUT for interrupts?

[jrtc27]

Technically should have a blank line between the ifs, though that was true before.

c.f. https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/06_Device_Configuration/Device_Configuration.html#gpio-connection-descriptor

[jrtc27]

In D47331#1079365, @andrew wrote:

Don't we need to set GPIO_PIN_INPUT for interrupts?

Depends what our framework is expecting I guess, but that would seem sensible to me.

[cperciva]

Hmm, I don't actually see anything in the ACPI spec saying that IoRestriction only applies for ACPI_RESOURCE_GPIO_TYPE_IO. So I think we have three options here:

1. Go ahead with this patch, on the basis of "this is what Linux does",
2. Force GPIO_PIN_INPUT for ACPI_RESOURCE_GPIO_TYPE_INT on the basis of "if we're generating interrupts obviously it's an input", or
3. Just parse the values we're given and hope they make sense.

@andrew, @jrtc27, any preference?

[jrtc27]

In D47331#1079374, @cperciva wrote:

Hmm, I don't actually see anything in the ACPI spec saying that IoRestriction only applies for ACPI_RESOURCE_GPIO_TYPE_IO. So I think we have three options here:

1. Go ahead with this patch, on the basis of "this is what Linux does",
2. Force GPIO_PIN_INPUT for ACPI_RESOURCE_GPIO_TYPE_INT on the basis of "if we're generating interrupts obviously it's an input", or
3. Just parse the values we're given and hope they make sense.

@andrew, @jrtc27, any preference?

This table in the link I posted above:

[jrtc27]

In D47331#1079376, @jrtc27 wrote:

In D47331#1079374, @cperciva wrote:

Hmm, I don't actually see anything in the ACPI spec saying that IoRestriction only applies for ACPI_RESOURCE_GPIO_TYPE_IO. So I think we have three options here:

1. Go ahead with this patch, on the basis of "this is what Linux does",
2. Force GPIO_PIN_INPUT for ACPI_RESOURCE_GPIO_TYPE_INT on the basis of "if we're generating interrupts obviously it's an input", or
3. Just parse the values we're given and hope they make sense.

@andrew, @jrtc27, any preference?

This table in the link I posted above:

(Note that interrupts have a separate definition for byte 7, with some common fields, but the I/O Restriction bits are replaced by the Interrupt Mode and half the Interrupt Polarity)

[cperciva]

In D47331#1079376, @jrtc27 wrote:

This table in the link I posted above:

Aha, I didn't notice the text "for IO Connections" .