diff options
| author | Stephen Boyd <sboyd@codeaurora.org> | 2019-05-16 10:39:35 +0100 |
|---|---|---|
| committer | Pavel <pavel@ucw.cz> | 2019-06-23 12:16:57 +0200 |
| commit | e1843cd25eee8a830cbbdd6c8c9f9225a8c8f2e6 (patch) | |
| tree | 38d803e5361654532c0c1d51ac90205294f16b49 | |
| parent | 3aa2e9de3b4fccb43bcf109c14772d93edc4d225 (diff) | |
| download | linux-cip-e1843cd25eee8a830cbbdd6c8c9f9225a8c8f2e6.tar.gz | |
dt-bindings: gpio: Add a gpio-reserved-ranges property
commit b9c725ed73b7cecc7c9bc4b752ab3eb975ef9330 upstream.
Some qcom platforms make some GPIOs or pins unavailable for use
by non-secure operating systems, and thus reading or writing the
registers for those pins will cause access control issues.
Introduce a DT property to describe the set of GPIOs that are
available for use so that higher level OSes are able to know what
pins to avoid reading/writing.
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio.txt | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index 069cdf6f9dace2..6550775f5dafef 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -141,9 +141,9 @@ in a lot of designs, some using all 32 bits, some using 18 and some using first 18 GPIOs, at local offset 0 .. 17, are in use. If these GPIOs do not happen to be the first N GPIOs at offset 0...N-1, an -additional bitmask is needed to specify which GPIOs are actually in use, -and which are dummies. The bindings for this case has not yet been -specified, but should be specified if/when such hardware appears. +additional set of tuples is needed to specify which GPIOs are unusable, with +the gpio-reserved-ranges binding. This property indicates the start and size +of the GPIOs that can't be used. Example: @@ -153,6 +153,7 @@ gpio-controller@00000000 { gpio-controller; #gpio-cells = <2>; ngpios = <18>; + gpio-reserved-ranges = <0 4>, <12 2>; } The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism |