@@ -91,6 +91,7 @@ available subsections can be seen below.
phy/index
pti_intel_mid
pwm
+ pwm-sysfs
rfkill
serial/index
sm501
new file mode 100644
@@ -0,0 +1,44 @@
+Using PWMs with the sysfs interface
+-----------------------------------
+
+If CONFIG_SYSFS is enabled in your kernel configuration a simple sysfs
+interface is provided to use the PWMs from userspace. It is exposed at
+/sys/class/pwm/. Each probed PWM controller/chip will be exported as
+pwmchipN, where N is the base of the PWM chip. Inside the directory you
+will find:
+
+ npwm
+ The number of PWM channels this chip supports (read-only).
+
+ export
+ Exports a PWM channel for use with sysfs (write-only).
+
+ unexport
+ Unexports a PWM channel from sysfs (write-only).
+
+The PWM channels are numbered using a per-chip index from 0 to npwm-1.
+
+When a PWM channel is exported a pwmX directory will be created in the
+pwmchipN directory it is associated with, where X is the number of the
+channel that was exported. The following properties will then be available:
+
+ period
+ The total period of the PWM signal (read/write).
+ Value is in nanoseconds and is the sum of the active and inactive
+ time of the PWM.
+
+ duty_cycle
+ The active time of the PWM signal (read/write).
+ Value is in nanoseconds and must be less than the period.
+
+ polarity
+ Changes the polarity of the PWM signal (read/write).
+ Writes to this property only work if the PWM chip supports changing
+ the polarity. The polarity can only be changed if the PWM is not
+ enabled. Value is the string "normal" or "inversed".
+
+ enable
+ Enable/disable the PWM signal (read/write).
+
+ - 0 - disabled
+ - 1 - enabled
@@ -69,51 +69,6 @@ All consumers should really be reconfiguring the PWM upon resume as
appropriate. This is the only way to ensure that everything is resumed in
the proper order.
-Using PWMs with the sysfs interface
------------------------------------
-
-If CONFIG_SYSFS is enabled in your kernel configuration a simple sysfs
-interface is provided to use the PWMs from userspace. It is exposed at
-/sys/class/pwm/. Each probed PWM controller/chip will be exported as
-pwmchipN, where N is the base of the PWM chip. Inside the directory you
-will find:
-
- npwm
- The number of PWM channels this chip supports (read-only).
-
- export
- Exports a PWM channel for use with sysfs (write-only).
-
- unexport
- Unexports a PWM channel from sysfs (write-only).
-
-The PWM channels are numbered using a per-chip index from 0 to npwm-1.
-
-When a PWM channel is exported a pwmX directory will be created in the
-pwmchipN directory it is associated with, where X is the number of the
-channel that was exported. The following properties will then be available:
-
- period
- The total period of the PWM signal (read/write).
- Value is in nanoseconds and is the sum of the active and inactive
- time of the PWM.
-
- duty_cycle
- The active time of the PWM signal (read/write).
- Value is in nanoseconds and must be less than the period.
-
- polarity
- Changes the polarity of the PWM signal (read/write).
- Writes to this property only work if the PWM chip supports changing
- the polarity. The polarity can only be changed if the PWM is not
- enabled. Value is the string "normal" or "inversed".
-
- enable
- Enable/disable the PWM signal (read/write).
-
- - 0 - disabled
- - 1 - enabled
-
Implementing a PWM driver
-------------------------
The two are related but still disjoint enough to justify two documents. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- Documentation/driver-api/index.rst | 1 + Documentation/driver-api/pwm-sysfs.rst | 44 +++++++++++++++++++++++++ Documentation/driver-api/pwm.rst | 45 -------------------------- 3 files changed, 45 insertions(+), 45 deletions(-) create mode 100644 Documentation/driver-api/pwm-sysfs.rst