| Message ID | 1427875996-216926-1-git-send-email-mika.westerberg@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
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 <dvhart@linux.intel.com> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > 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 > ------------- >
On 4/1/15, 1:13 AM, "Mika Westerberg" <mika.westerberg@linux.intel.com> 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 <dvhart@linux.intel.com> >Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> >--- >v2: Corrected text according what Darren suggested Thanks Mika, Reviewed-by: Darren Hart <dvhart@linux.intel.com>
On Wed, 1 Apr 2015 11:13:16 +0300 Mika Westerberg <mika.westerberg@linux.intel.com> 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. OK, I've applied this to the docs tree, thanks. jon -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Apr 4, 2015 at 11:27 AM, Jonathan Corbet <corbet@lwn.net> wrote: > On Wed, 1 Apr 2015 11:13:16 +0300 > Mika Westerberg <mika.westerberg@linux.intel.com> 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. > > OK, I've applied this to the docs tree, thanks. Aha Jon takes it, thx, Acked-by. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 -------------
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 <dvhart@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> --- v2: Corrected text according what Darren suggested Documentation/gpio/board.txt | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-)