diff options
Diffstat (limited to 'Documentation/gpio.txt')
| -rw-r--r-- | Documentation/gpio.txt | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 18022e249c5..8a7c45956d2 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -264,7 +264,7 @@ map between them using calls like: /* map GPIO numbers to IRQ numbers */ int gpio_to_irq(unsigned gpio); - /* map IRQ numbers to GPIO numbers */ + /* map IRQ numbers to GPIO numbers (avoid using this) */ int irq_to_gpio(unsigned irq); Those return either the corresponding number in the other namespace, or @@ -284,7 +284,8 @@ system wakeup capabilities. Non-error values returned from irq_to_gpio() would most commonly be used with gpio_get_value(), for example to initialize or update driver state -when the IRQ is edge-triggered. +when the IRQ is edge-triggered. Note that some platforms don't support +this reverse mapping, so you should avoid using it. Emulating Open Drain Signals |