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authorLinus Walleij <linus.walleij@linaro.org>2015-07-21 11:36:57 +0200
committerLinus Walleij <linus.walleij@linaro.org>2015-07-21 11:39:32 +0200
commitc21cde6fe1ba08b357c96071c71af6543f2863ec (patch)
tree336a0d54dc6da3fae97b02ed79585694d8341a9e /Documentation/gpio/sysfs.txt
parentbcae888039d5f0b522e1588c54f95a7612d1723c (diff)
gpio: document interaction with other subsystems
Now I am very fed up with people reinventing kernel wheels in userspace "just because they can" (read, sysfs). Put in a angry blurb in sysfs doc and put in a new file with pointers to other subsystem drivers utilizing GPIOs. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/gpio/sysfs.txt')
-rw-r--r--Documentation/gpio/sysfs.txt9
1 files changed, 4 insertions, 5 deletions
diff --git a/Documentation/gpio/sysfs.txt b/Documentation/gpio/sysfs.txt
index 535b6a8a7a7c..0700b55637f5 100644
--- a/Documentation/gpio/sysfs.txt
+++ b/Documentation/gpio/sysfs.txt
@@ -20,11 +20,10 @@ userspace GPIO can be used to determine system configuration data that
standard kernels won't know about. And for some tasks, simple userspace
GPIO drivers could be all that the system really needs.
-Note that standard kernel drivers exist for common "LEDs and Buttons"
-GPIO tasks: "leds-gpio" and "gpio_keys", respectively. Use those
-instead of talking directly to the GPIOs; they integrate with kernel
-frameworks better than your userspace code could.
-
+DO NOT ABUSE SYFS TO CONTROL HARDWARE THAT HAS PROPER KERNEL DRIVERS.
+PLEASE READ THE DOCUMENT NAMED "drivers-on-gpio.txt" IN THIS DOCUMENTATION
+DIRECTORY TO AVOID REINVENTING KERNEL WHEELS IN USERSPACE. I MEAN IT.
+REALLY.
Paths in Sysfs
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