On Wednesday, April 01, 2015 11:13:16 AM Mika Westerberg wrote: > With ACPI 5.1 _DSD (Device Specific Data) it is now possible to name > functions just like Device Tree is doing. Make sure that the documentation > mentions _DSD as the recommended way to describe GPIOs in ACPI systems. > > Reported-by: Darren Hart <[email protected]> > Signed-off-by: Mika Westerberg <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]> > --- > v2: Corrected text according what Darren suggested > > Documentation/gpio/board.txt | 41 +++++++++++++++++++++++++++++++++++++---- > 1 file changed, 37 insertions(+), 4 deletions(-) > > diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt > index 8b35f51fe7b6..b80606de545a 100644 > --- a/Documentation/gpio/board.txt > +++ b/Documentation/gpio/board.txt > @@ -50,10 +50,43 @@ gpiod_is_active_low(power) will be true). > > ACPI > ---- > -ACPI does not support function names for GPIOs. Therefore, only the "idx" > -argument of gpiod_get_index() is useful to discriminate between GPIOs > assigned > -to a device. The "con_id" argument can still be set for debugging purposes > (it > -will appear under error messages as well as debug and sysfs nodes). > +ACPI also supports function names for GPIOs in a similar fashion to DT. > +The above DT example can be converted to an equivalent ACPI description > +with the help of _DSD (Device Specific Data), introduced in ACPI 5.1: > + > + Device (FOO) { > + Name (_CRS, ResourceTemplate () { > + GpioIo (Exclusive, ..., IoRestrictionOutputOnly, > + "\\_SB.GPI0") {15} // red > + GpioIo (Exclusive, ..., IoRestrictionOutputOnly, > + "\\_SB.GPI0") {16} // green > + GpioIo (Exclusive, ..., IoRestrictionOutputOnly, > + "\\_SB.GPI0") {17} // blue > + GpioIo (Exclusive, ..., IoRestrictionOutputOnly, > + "\\_SB.GPI0") {1} // power > + }) > + > + Name (_DSD, Package () { > + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > + Package () { > + Package () { > + "led-gpios", > + Package () { > + ^FOO, 0, 0, 1, > + ^FOO, 1, 0, 1, > + ^FOO, 2, 0, 1, > + } > + }, > + Package () { > + "power-gpios", > + Package () {^FOO, 3, 0, 0}, > + }, > + } > + }) > + } > + > +For more information about the ACPI GPIO bindings see > +Documentation/acpi/gpio-properties.txt. > > Platform Data > ------------- > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
