diff options
| author |   Stephen Boyd <sboyd@codeaurora.org> | 2018-03-23 09:34:49 -0700 |
|---|---|---|
| committer |   Linus Walleij <linus.walleij@linaro.org> | 2018-03-27 15:33:40 +0200 |
| commit | b9c725ed73b7cecc7c9bc4b752ab3eb975ef9330 (patch) | |
| tree | 0449d1b714e78f0374f6d39d2e4b84c0659a0116 | |
| parent | Linux 4.16-rc5 (diff) | |
| download | linux-dev-b9c725ed73b7cecc7c9bc4b752ab3eb975ef9330.tar.xz linux-dev-b9c725ed73b7cecc7c9bc4b752ab3eb975ef9330.zip | |
dt-bindings: gpio: Add a gpio-reserved-ranges property
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>
| -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 b5de08e3b1a2..a7c31de29362 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -151,9 +151,9 @@ 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. Optionally, a GPIO controller may have a "gpio-line-names" property. This is an array of strings defining the names of the GPIO lines going out of the @@ -178,6 +178,7 @@ gpio-controller@00000000 { gpio-controller; #gpio-cells = <2>; ngpios = <18>; + gpio-reserved-ranges = <0 4>, <12 2>; gpio-line-names = "MMC-CD", "MMC-WP", "VDD eth", "RST eth", "LED R", "LED G", "LED B", "Col A", "Col B", "Col C", "Col D", "Row A", "Row B", "Row C", "Row D", "NMI button", |