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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2020-10-29 21:32:42 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-11-09 18:59:43 +0100
commit0d6c41cf801fd56b92f4359374667061d27a6472 (patch)
treee0576f1d823469ab9887da41ade463ea5571528e /Documentation/firmware-guide
parentDocumentation: firmware-guide: gpio-properties: Fix factual mistakes (diff)
downloadlinux-dev-0d6c41cf801fd56b92f4359374667061d27a6472.tar.xz
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Documentation: firmware-guide: gpio-properties: active_low only for GpioIo()
It appears that people may misinterpret active_low field in _DSD for GpioInt() resource. Add a paragraph to clarify this. Reported-by: Ricardo Ribalda <ribalda@chromium.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Ricardo Ribalda <ribalda@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/firmware-guide')
-rw-r--r--Documentation/firmware-guide/acpi/gpio-properties.rst3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/firmware-guide/acpi/gpio-properties.rst b/Documentation/firmware-guide/acpi/gpio-properties.rst
index e6e65ceb2ca1..370fe46c6af9 100644
--- a/Documentation/firmware-guide/acpi/gpio-properties.rst
+++ b/Documentation/firmware-guide/acpi/gpio-properties.rst
@@ -55,6 +55,9 @@ Since ACPI GpioIo() resource does not have a field saying whether it is
active low or high, the "active_low" argument can be used here. Setting
it to 1 marks the GPIO as active low.
+Note, active_low in _DSD does not make sense for GpioInt() resource and
+must be 0. GpioInt() resource has its own means of defining it.
+
In our Bluetooth example the "reset-gpios" refers to the second GpioIo()
resource, second pin in that resource with the GPIO number of 31.