Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus

[linux-2.6-omap-h63xx.git] / Documentation / gpio.txt

diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt
index 36af58eba136bac198ea3b1f33f34236be9ce5df..6bc2ba215df9a3eb4b41ff6f987e5fa294e47250 100644 (file)
--- a/Documentation/gpio.txt
+++ b/Documentation/gpio.txt
@@ -75,6 +75,9 @@ using the include file:
 If you stick to this convention then it'll be easier for other developers to
 see what your code is doing, and help maintain it.
 
 If you stick to this convention then it'll be easier for other developers to
 see what your code is doing, and help maintain it.
 

+Note that these operations include I/O barriers on platforms which need to
+use them; drivers don't need to add them explicitly.
+

 
 Identifying GPIOs
 -----------------
 
 Identifying GPIOs
 -----------------


@@ -145,7 +148,7 @@ pin ... that won't always match the specified output value, because of
 issues including wire-OR and output latencies.
 
 The get/set calls have no error returns because "invalid GPIO" should have
 issues including wire-OR and output latencies.
 
 The get/set calls have no error returns because "invalid GPIO" should have

-been reported earlier in gpio_set_direction().  However, note that not all
+been reported earlier from gpio_direction_*().  However, note that not all

 platforms can read the value of output pins; those that can't should always
 return zero.  Also, using these calls for GPIOs that can't safely be accessed
 without sleeping (see below) is an error.
 platforms can read the value of output pins; those that can't should always
 return zero.  Also, using these calls for GPIOs that can't safely be accessed
 without sleeping (see below) is an error.


@@ -236,7 +239,7 @@ map between them using calls like:
 Those return either the corresponding number in the other namespace, or
 else a negative errno code if the mapping can't be done.  (For example,
 some GPIOs can't used as IRQs.)  It is an unchecked error to use a GPIO
 Those return either the corresponding number in the other namespace, or
 else a negative errno code if the mapping can't be done.  (For example,
 some GPIOs can't used as IRQs.)  It is an unchecked error to use a GPIO

-number that hasn't been marked as an input using gpio_set_direction(), or
+number that wasn't set up as an input using gpio_direction_input(), or

 to use an IRQ number that didn't originally come from gpio_to_irq().
 
 These two mapping calls are expected to cost on the order of a single
 to use an IRQ number that didn't originally come from gpio_to_irq().
 
 These two mapping calls are expected to cost on the order of a single