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| -rw-r--r-- | Documentation/pwm.txt | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index 93cb97974986..0527f615b115 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt | |||
| @@ -97,6 +97,13 @@ pwm_chip as argument which provides a description of the PWM chip, the | |||
| 97 | number of PWM devices provided by the chip and the chip-specific | 97 | number of PWM devices provided by the chip and the chip-specific |
| 98 | implementation of the supported PWM operations to the framework. | 98 | implementation of the supported PWM operations to the framework. |
| 99 | 99 | ||
| 100 | When implementing polarity support in a PWM driver, make sure to respect the | ||
| 101 | signal conventions in the PWM framework. By definition, normal polarity | ||
| 102 | characterizes a signal starts high for the duration of the duty cycle and | ||
| 103 | goes low for the remainder of the period. Conversely, a signal with inversed | ||
| 104 | polarity starts low for the duration of the duty cycle and goes high for the | ||
| 105 | remainder of the period. | ||
| 106 | |||
| 100 | Locking | 107 | Locking |
| 101 | ------- | 108 | ------- |
| 102 | 109 | ||