Hi Mika,
On 01/12/2015 14:03, Mika Westerberg wrote:
[...]
Now for the same kind of i2c driver using acpi description, the GpioInt
polarity/type is at the moment never kept in the irq property.
It is possible to check that following about the same path...
i2c_device_probe (drivers/i2c/i2c-core.c), retrieves irq property from
acpi_dev_gpio_irq_get but does not save the irq_type.
This would allow not to have to use an additional gpio field and all
the configuration step to configure the gpio interrupt correctly in a
device driver and taking a real benefit of the GpioInt acpi keyword
compare to GpioIo keyword.
Most the of the drivers based on acpi description retrieve gpio number
to assign an interrupt and a fix polarity. I believe my patchset
proposal would improve this and allow to
be much closer with devicetree.
Do you see any issue with this ?
No, but I wonder if it would be better to do this in acpi_dev_gpio_irq_get()
instead of acpi_find_gpio() which gets called everytime a GPIO is looked up?
I believe, setting the irq type requires triggering and polarity data
stored into a struct acpi_resource_gpio.
acpi_dev_gpio_irq_get call acpi_get_gpiod_by_index which run acpi_find_gpio.
Actually acpi_dev_gpio_irq_get is called everytime an i2c device slave
is probed, acpi_find_gpio will get called to "register" gpios.
If done correctly, i think this will be done only once...
The only improvement i may see would be to add an extra field in the
acpi_gpio_info structure in drivers/gpio/gpiolib.h (for example int
irq_type).
And call irq_set_irq_type in acpi_dev_gpio_irq_get if the gpio is an
interrupt.
I guess the current proposal and this one are equivalent...
What do you think ?
Best Regards
Christophe
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